5 Reasons To Get A (Bigger) Home Battery

[@JBoy340a]

I am the West of the US and found your explanations very useful. I was amazed by the massive price changes you have. We never get to the point where they pay us to use electricity. I wish we did because we have solar and 28 kWh of batteries. We have largely eliminated our electric bill which reduced our home costs about 400 USD per month. We also got paid about 300 USD for spare energy we exported to the grid during a 4 day power emergency. All and all solar plus batteries was one of the best home improvement we ever made.

[@GaryDoesSolar]

Thanks. Yeah, the price rises in the UK last couple of years have been scary, especially for those already struggling to make ends meet. Great to hear your solar/battery installation is paying off handsomely! :-)

[@josephunden6108]

Where in the west do you live? What batteries did you get?

[@kadmow]

To benefit the most, one has to invest in the range of 20-30kGBP in solar plus big battery - to ensure self consumption is covered, then have enough to "play the market" - via the algos... Enough "playing the game" - the transients will go away and the memory of "the age of stupid pricing" will be a distant memory.

[@robertsprigge5535]

Does your State. have a free market as England has? I chose Octopus as they have a variety of tariffs. I'm currently on Octopus Agiie, which has 48 different prices each day, with a price list issued at 4pm the previous day.. Occasionally it's free or pays us. I get paid at 15p per kWh for any electricity I export.

[@JBoy340a]

not that many options where I am. Primary our terrible main utility. Think BP. But, since we don't buy much power the price is a minimal factor

[@michaelp998]

Our self sufficiency is running around 86% with solar and battery👍👍

[@GaryDoesSolar]

That is pretty cool, Michael - it's a little too early to tell with my own installation, but if I can get anywhere near that, I'll be well happy :-)

[@andyxox4168]

Serious question, how do you overcome the more than 10:1 output of solar panels on sunny summer vs. Cloudy winter days? Are you actually saying you take from the grid and give back in which case you’re actually exacerbating the problem of load in the grid and adding to the instability caused by renewables on the grid?

[@michaelp998]

Goes into extra storage batteries that have yet to be maxed out.

[@greg_takacs]

I'm really happy to see your channel and site grow and get better and better. While I'd consider myself a solar/battery expert I'm still watching every video of yours as they're possibly the best illustrated and explain very complex concepts very easily for all to understand. Anyone who's a beginner and interested in solar I recommend to watch all your videos, they're truly the best on KZbin and far better than my engineer brain can explain!

[@GaryDoesSolar]

Wow - thanks, Greg! I'm highly flattered. Really appreciate you taking the time to write this :-)

[@PazLeBon]

I dont think experts ever call themselves experts, i dont think just bad etiqueette I think it is actually a given title generally lol

[@greg_takacs]

​@@PazLeBon I have plenty imposter syndrome at work... in my hobby I'm definitely more of an expert than some "professionals" I've dealt with. ;-)

[@paulbradford8240]

Great video, well explained. I have subscribed. Our neighbour here in France has just had a virtual solar system installed. I didn't fully understand his explanation of how it works, so you have cleared that up! We have a 4kWh solar pv system installed since September 2011. We have a contract with EDF to purchase our excess energy for 20 years at 43 cents per kwh. We have received a cheque from them each year for roughly the same production, gaining between €1350-1450. The system paid for itself in less than 9 years. As we are under contract with them, we can't change anything, but when the contract is up, I'll buy a battery. The best investment we had was installing our own solar hot water system. 20 evacuated tubes bought in the UK and transported over. Including travelling, hotels, ferries and installation course, the total price was less than £1500. The savings were immediate. 500 litres of fuel oil saved per year. It paid for itself in less than four years. I installed it in 2008 and it's still working fine. Two new circulation pumps, an expansion vessel and one cheap fuse in that time. I also upgraded the tank to a 500 litre purpose built solar tank about six years ago.

[@GaryDoesSolar]

Wow - that's such great results! Well done - many would have shied away from such an endeavour to get your hot water solution, but you made it work! :-)

[@johnkeepin7527]

You are right about your solar hot water investment. I did the same in southern England in 2006 (well before solar PV looked sensible financially), and it’s had a replacement water pump over the years, and part of the control unit a year or so ago, after a failure, along with anti-freeze fluid replacement every couple of years, and it is topped up by a night rate electric tariff. No fuel burning boiler at my place. Ten years ago, I added a solar PV system under the “feed in tariff” deal, and in effect, the solar thermal kit normally runs on the solar PV, so not much need to import day rate electricity from the grid. Alright, it’s less flexible than a battery, but 190l of water that can creep up to 90°C stores a fair bit! The firm that did all the work was Greenshopsolar, based in Gloucestershire.

[@kadmow]

@@johnkeepin7527 - hot water is by far the cheapest installed energy storage readily available, for a 60 degree swing there is 7kWh per 100L of water stored - 7kWh in Lithium takes up 50-70kg (depending on chemistry - ball park). Fantastic if you have the use for it.

[@wemorgan]

Another great video. When battery prices fall 30% I can see them being the default choice for all home solar buyers. For now the financials are quite marginal, for me at least.

[@GaryDoesSolar]

Thanks :-) Yeah, I tend to agree. And I think we might even see that kind of price drop soon... :-)

[@SteveLoughran]

Waiting to see what Tesla do in the UK as the products they sell here lags the US market. An LFP model would be lovely for those of us who don't care about density -And I do think the Tesla software is way ahead of the competitors.

[@JohnR31415]

The price is much less marginal if you can get a time of day tariff.

[@codprawn]

Why not use a forklift battery? Far cheaper and easy to recycle.

[@PazLeBon]

not close to being marginal , not really

[@SinbadSailing]

One of the best non-fiction videos I have watched for years.

[@GaryDoesSolar]

Thank you 😀🙏

[@arpadvarga3475]

Excellent video! I have upgraded my storage from 3kw to 6kw as it wasn't enough throughout the night.

[@GaryDoesSolar]

Thanks, and great to hear you decided to increase your battery size. Is it sufficient now, or do you think you'll need to upgrade even more?

[@cyumadbrosummit3534]

All grid operators throughout the world reserve the right to change the field goal post whenever they want. Don’t play their games go completely battery and solar and shut your main breaker off. Much money saved and far less confusion in last three years since being off grid totally. Once I hit 66 kWh of batteries storage I had no reason to stay connected to the grid as my house would run for 3 to 4 days on battery alone.

[@GaryDoesSolar]

That's pretty good you've been able to stay off-grid a large percentage of the time! :-)

[@tonymac7706]

Everything explained thoroughly and simplified for the novice such as myself...the way you presented your findings and graphs are second to none, i had no difficulty understanding,by far the best presentation ive seen to date..Thank you.

[@GaryDoesSolar]

Wow - thanks for this comment, Tony :-) I'm humbled...

[@ianbeck5897]

A very informative and useful video Gary, as always. Just over a month ago we had a 15KWh battery system installed (to go with our legacy inverter/PV/FIT system) and have experienced many of the things that you have highlighted in your video already: It's a bit of a roller coaster as this was a retrofit AC invert/battery to an existing PV array with 3KWp output to the house/grid. I didn't turn on any charging of the batteries from the grid as I wanted to monitor how things went over the summer/autumn with just PV and decide after that. In the first two weeks the sun shone beautifully and the batteries were singing on full charge each day - life was great! Then the sun went away, the batteries discharged and the modest PV generated barely covered the base load of the house, let alone charging the batteries. Batteries barely above 20% charge at any time - four letter words! Suddenly, was getting batteries such a good idea after all? I decided that I couldn't wait until the autumn to gather enough data to select a smart tariff - I had to do it sooner. We dont have a heat pump (our old house isn't a natural partner to them). We don't have and don't plan to have a EV - so bang goes a few Octopus tariff options. We have a semi decent FIT based upon generation and deemed export and, this early on I don't want to meddle with the FIT at all - bang goes Flux (as far as I can tell). So this left us with Agile - the risky one .... Octopus moved us over at the start of this week - it took less than 24 hours (as we were already with them and had a SMETS2). So ... We've kept the FIT as it was. I've set the charging up so that we stuff about 9KWh into the batteries in the middle of the night and I add another 6KWh in early in the afternoon - but only up to a 75% fill of the battery. My theory is that the PV can do the rest, if the sun ever shines again. I'm not governed by one cheap rate - it's relative, across the whole day - just pick a reasonably reliable cheapish window or windows and fill my boots! The load shifting is working and buying electricity at 8 or 9p or even 12 or 13p per KWh (compared to 30p as it was) is a revelation and makes us feel that the batteries are starting to earn their keep. Today we experienced plunge pricing for the first time - it's happening again tomorrow. To be able to fill our batteries and run heavy loads and be paid to do so seems like madness - but we will "take it for the team". In the back of our minds is the concern that we may get stuffed at a high rate based upon wholesale pricing at some stage - but if that happens we can revert to the standard tariff or take it on the chin for as long as it lasts. Now, it is VERY early days and my data is very limited but, so far, it feels like we are on to a winner again. If this is the future of electricity pricing, I'm in!

[@BikeNutt1970]

Enjoyable read. Thanks for posting.

[@PazLeBon]

so you go offgrid to end up at the mercy of the energy company pricing?

[@GaryDoesSolar]

Thanks for the kind words, Ian. And thanks also for your experiences - I hope that Agile works out well for you - I really do see these price plunges happening more and more. The world we're living in seems to be getting more chaotic, not less...

[@sugarloafoutdoors7601]

@@PazLeBon With Octopus agile, you are using electricity from the grid at wholesale rates not energy company rates like you do on standard rates where you pretty much pay a flat fee or fixed rate per kWh. You get these wholesale rates 24 hours in advance at half hourly rate. Obviously these rates go up and down over the 24 hour period, with highest pricing in the high usage periods of the day (Generally 4 - 7pm). As Ian mentioned you can get plunge pricing where too much electricity has been generated so the price goes in to the negative, so you get paid to use it, or charge your battery. You can though run the risk of high prices (capped at £1 per kWh). I expect in the winter time I may change to Octopus Flux and then back to Agile in the spring. I have also considered getting another battery. It is also not really offgrid as you are still paying standing charge, my last few months I have paid more in standing charge than electricity from the grid. The whole system just makes you more aware of what you are using but also you have a lot of flexibility on how much it is costing you. You get a bit obsessed with checking wholesale prices 😁

[@chrismalloy7688]

That was interesting read. I installed (all myself in late 2021) 4kWh of PV power combined with a hybrid 5kWh inverter and batteries with a 11kWh capacity. Total cost @£2750 +@£250 for incidentals. The inverter will draw grid power but we don’t export. I clicked on this link as the heading was ‘reasons to get a bigger battery’, I tried a few different battery types (small scale) but ended up with 8x Trojan (used) T105 = 6v / 225ah for my 48v system. I also have 8x spare set too. I was going to add the spare batt’s to double the capacity. Now everything works great during the summer months but with the nights drawing in - it’s not so good. Now I find that there is insufficient daylight to charge the batteries as it stands without trying to double the capacity up. We do not use grid to charge the batteries and we do not have company smart meter. We have our own smart meter or one we can trust. At first when i plumbed everything in, we were getting up to elec usage of 6kWh from midnight to 06:00. That was the inverter drawing grid to recharge the batteries. That link was isolated and now we see less than 1kWh for the same time slot (summer usage) due to the batteries having sufficient capacity to run the large fridge/freezer during the night which is the biggest hit. Now with November in a few days, we see that the kWh usage is nudging 1.5kWh for the same period and expect it to top out at 2kWh+ over winter. Trouble with using lead batteries is their output and you need to keep an eye out on the 48v draw supply. Sometimes we isolate the batteries before they get too low to prevent damage. With that in mind my original costing is now probably going to double in price as I will probably go with a shot of replacing the T105 with a bank of Lithium’s. Hopefully that expense will be recovered within a few years and they have a 10y life span and they will charge quicker and discharge for longer. Let’s see if I do find that they are an upgrade vs price. Trouble is once you get the bug, you just go for it.

[@bryanwhitton1784]

BTW, I subscribed to your channel after watching this video. Additionally I forwarded a link to a family member who is looking at solar so that she can visualize what I have been explaining . This is by far the best video for explaining how it all works that I have seen. I have retired from the solar industry but try to stay on top of it all. Yours is an extremely good presentation.

[@GaryDoesSolar]

Wow - that's high praise indeed - thank you, Bryan! I'll keep the videos coming... :-)

[@glockieme]

Great content. I’m getting solar shortly but not batteries. Think your video has changed my mind.

[@GaryDoesSolar]

Thanks Dave, and great that I've given you food for thought. All the best in whatever you decide! :-)

[@SmithyMC]

Yep I have a 4kw Solar Array and 14.4kw Battery Bank after adding an extra 4.8kw Battery in May! With Agile Octopus Energy this is almost perfect for our 20kw Average daily usage! Bills Gone down and I am regularly feeding into grid. On hot sunny days we also use portable air conditioner! Government should be supporting home Solar/Battery arrays way more to stop burning fossil fuels!

[@GaryDoesSolar]

This is just brilliant, and a perfect example of why home batteries are so useful. Thanks for sharing :-)

[@boblatkey7160]

The power rating of your solar is expressed in kilowatts the energy storage rating of a battery bank is expressed in kilowatt hours. That keeps everything straight so people are talking the same language.

[@leet3707]

Absolutely 100% spot on. Gary, you've put into 15-20mins the exact conversation I have with others that don't have or have been sold tiny, overpriced Pylontech and other brands at 2kwh or 3kwh. Having installed our first 15kwh battery of two in April for £2995 each. I have bought in less than 20kwh per month and even though its a cloudy July- still managing to scrape the 9kwh to 12kwh hours needed for a days consumption that otherwise would have been lost as not enough input to avoid Grid. On cloudy days like today, we just let the battery soak up everything and run appliances at night from the battery. (everything counts in small amounts) I have 15kwh, soon to be 30kwh to protect from the dreaded Blackouts or power failure or continue over prolonged low Solar input. In Winter, we'll fill our boots with cheap overnight to add to Solar the day after. I am so glad you mentioned Air Conditioners, although you briefly suggested for Cooling. There's more to Air Conditioners in that I installed here for Autumn, Spring and some Winter Heating which as they are technically 'Heat Pumps'- give all the benefits of efficient heating without the inherent high costs and disruption of a Heat Pump installation and very cost effective, with the benefits of Cooling. We run ours for over 180days per year and only 30days during summer for Cooling. Although, we don't get cheap Hot Water in Summer, our Gas consumption annually is a quarter of what it used to be at 3,600kwh per year. We use the boiler in Winter to 'Top-up' the already Air Conditioner/ Electric Oil Heater pre-heated house. We are moving the boiler to LPG as Standing Charges we pay annually would nearly cover the the cost of 2x of the 5x needed 47kg Propane bottles. Well done and thanks.

[@Plan3tBob]

Can I ask where you got your 15kWh battery for £3k ? I've had solar for a week and - even in our grey climate - find that I wish I had a bigger battery already... (I have 10kWh)

[@GaryDoesSolar]

Cheers Lee, and on the heat pump topic, you might be interested in my friend's KZbin channel, where he covers his own heat pump installation, which as been so successful, he's recently had his gas supply disconnected: kzbin.info

[@leet3707]

@@GaryDoesSolar thanks for your message. Regarding a Heat Pump- I'm more than happy to enjoy all the heating and cooling benefits of Air 2 Air as Air Conditioning and wished many more saw these benefits too. There are a number of reasons I will not remove the Gas Boiler and actually having a new one installed while converting to LPG later in the year, these being: 1) UK Energy Security is precarious, especially at high demand times such as Summer with others running their 'unsupported' Air Conditioners and Winter when demand is high - the Demand Response evenings of glorious CashBack schemes. Its a lot easier to heat a house with a Gas Boiler running from a battery than try to use the battery to run a Heat Pump to heat it, 100watts against 3kwh-5kwh. 2) Heat Pumps are being sold as 'Greener', not strictly true as there is not enough renewables available on the Grid during times of low Wind output. For over three weeks of June and many times over Winter the UK was not only burning a lot of Gas, but also dirty high CO2 emitting Coal to run those Heat Pumps. So, I am not convinced right now that spending £1,000s on one at this time has much environmental impact compared to driving an EV charged by the Sun since March and aiming for Grid charging on Windy days when there is high renewables in the mix. Then the house apart from 3600Kwh of annual gas, I think I contribute more than enough to Climate Change. It's a long calculation with COP and power station efficiency but on par- little CO2 savings to just burning the gas here when needed. I've met many with Heat Pumps who consumed a ridiculous amount of expensive electricity over Winter for cold houses compared to Gas. Controversial, I know but getting millions of more homes fitted with Solar should be higher priority than lucrative Grants for Heat Pumps for biggest bang for our buck on Climate. Have you seen the latest E-On advert - the world is falling apart. Quickest way to switch anyone off. Do thet truly believe scare tactics will make people rush to install Solar, move to EV and Heat Pumps to save the planet we've known is collapsing for donkeys years? Maybe they should advertise the hard cash Solar would save and earn- the Climate benefits by default. Link to it here: www.thedrum.com/news/2023/06/20/eon-starts-the-countdown-climate-change-latest-sustainable-ad Just convinced my neighbour to install Solar- not to 'save the planet' but the fact he'll make £1200 profit on Export and enjoy saving £1300 per year on electricity. Here's another one - "smart meters can help reduce our reliance on foreign gas". How? You have no idea where the electricity is coming from via a Smart meter and the only ones that would have a clue is those on Agile who notice the Import price rate rocket. I help reduce our reliance on foreign gas by quickly checking a website that takes one minute to decide if out of conscience, that I should charge the car or run the washer or wait until tomorrow. All without looking at a Smart meter screen. If, during Winter I can run the washer at a better time to avoid 250g/CO2 then I will. I am raising a complaint with the ASA and likely is will be upheld due to mis-selling.

[@Plan3tBob]

@@VinoVeritas_ Now that is a shame.. sounded like a great price, perhaps too good.

[@andrewnowson8766]

Please tell us about your 15kwh battery configuration, brand and supplier!

[@Ben-gm9lo]

Gary, you continue to produce amazing videos, so thanks! I love how thorough you are, how precise your delivery is, both factually and your speech. You are one of the few presenters on KZbin who actually pronounces all 3 syllabus in battery. It grates my pedantic mind when so many call it a batry. Your webtool is amazing and I can't help think that it must have massive value for so many trying to process the difficult cost/benefit issues for their circumstances. We are going the whole hog, 2 x EVs already with 7kW solar and 20kW battery coming in September. Your advice and tools have really helped me tune what to get for our needs. Massive thanks.

[@aldozilli1293]

1. His videos are great, only sometimes could be a bit snappier with quicker speech then again it can be sped up. 2. Btw you're wasting money if you have 2 EVs you shouldn't need a huge battery. I'm getting a single house battery installed and a V2L enabled car and having this linked up so I can plug in and it will act as additional battery storage or discharge. This is possible now and V2G enabled EVs are also another option with install of a V2G charger/inverter.

[@Ben-gm9lo]

@@aldozilli1293 Very true about V2G, unfortunately neither my Tesla nor my wife's Mini support this.

[@GaryDoesSolar]

Thanks Ben - high praise indeed and I'm very grateful for the feedback. Really great to hear about your situation and plans. I have a 19kWh battery, but no EV yet.. One day (sigh)... :-)

[@peeps124]

Excellent. Glad to see my thinking about batteries just prior to a solar system purchase echoed, with realistic scenarios. Your videos are great, down to earth and informative. Many thanks

[@GaryDoesSolar]

That's such great feedback to receive - thank you! And all the best with your system when it's installed :-)

[@ryanguest738]

Thanks Gary, really intresting. I did try your tool and found that actually upgrading the invereter had a much bigger impact on my retrun (80% increase in annual return changing inverter size and export limitation from 2.5kW inverter output to 5kW) on my PV system than increasing the battery capacity as my inverter limits backup supply to house and grid and hence the import and export of energy. When both are upgraded in my case it did have a 20% overall increase in annual so really good to model.

[@GaryDoesSolar]

Great to hear, Ryan! Thanks for letting me know 👍🏻

[@donferguson]

I have an Enphase 7KWdc - 6KWac system with 13.3KWH storage and your tool maps my actual performance almost perfectly. I can also run off grid continuously with the storage set to a minimum of 30%. I normally use the storage to offset peak use price, and keep 50% for backup. I really enjoy your videos. Thanks.

[@GaryDoesSolar]

Hi Don, thanks for the kind words, and great to hear the utility is mirroring what you're seeing with your setup :-) Your strategy sounds good.

[@grahamreader9141]

Hello Gary, I was introduced to your channel by a friend just as I was thinking of getting solar, which will be installed in two weeks time, cannot wait to see how much I can save using solar and yes, I am also having a battery system. Thanks for the time yo take in producing these videos.

[@GaryDoesSolar]

The pleasure is all mine, Graham - it's certainly a lot of work making these videos, but comments like this make my day. Thanks for taking the time to let me know - it means a great deal to me that my videos are helping people :-)

[@SchoolforHackers]

Graham, you are going to be so pleased long-term (as long as you’ve actually purchased your system). We broke even on our system before 7 years. We chose good parts and panels, and at 12 years they’re still producing well over 90%. So after 5 years of free energy, we’ve saved some $6000. Solar rocks.

[@mosfet500]

Thanks Gary, nice explanation. Because PV is so cheap in the US now I'm buying so much that I can can charge my 15kWh battery bank on overcast days. I just bought 370 watt, double side panels that can charge at 461 watts. This is particularly handy on snowy days when the sun reflects on the back of the panel too. In fact I'm going to experiment with turning two of my mounts 20 degrees off center east and west to extend the day because my PV is greater than my inverters can handle. I'll be limiting the charging current because on sunny days I have more charging than I need so with the off center mounts I'll do better on overcast days and still get all my charging on sunny days. It sounds more complex than it is. We live in the a rainy area that is very overcast in the winter months often for days.

[@GaryDoesSolar]

You’re very welcome and it sounds great what you’re planning! I’d be very interested to hear how it all goes 👍🏻

[@Sami-Nasr]

Gary, I watched this video before installing solar about 2 weeks ago, this video helped me to make my mind about a battery, glad I did, otherwise the solar would be useless in winter and only partially useful in summer

[@GaryDoesSolar]

Thanks for letting me know. Great to hear my videos have been useful to you :-)

[@ElectricalInnovations]

Great video Gary. I have a 20KWH battery at home and it’s transformed our energy usage.

[@GaryDoesSolar]

Cheers for the feedback! :-) Same for me too, my battery a similar size!

[@radiotowers1159]

Nice presentation Garry, Ive had my Solar installation for about 2 weeks now, It comprises of a 5.1PkW solar pv array and a 6.5 kWh battery. Most days so far there is enough solar energy for normal domestic use and to charge the battery and have enough to last over night, but I end up exporting a few kW excess through the late afternoon. Today we had a price plunge on Octopus Agile tariff( 15 June ) ,about 2 hours where is was around -2 p so I forced charged the battery, and charged my EV and had most kitchen appliances on at the same time (normally spaced out to maximise the solar without import). Tomorrow ( 16 June) we have about 10 hours below zero and peaking at about -9p a unit mid afternoon so having a smart export of say 15p I could continuously charge (at -x pence) and discharge the battery ( at 15p) if I wished to make some money but that is at odds with the price plunge ideology. Now Ive had the system for a very short while would I change anything ? , well I will wait a while but I suspect I may get another identical 6.5kWh battery to take advantage of both cheap overnight and decent export rates in the winter.

[@occamraiser]

what's the deep cycle lifespan of your battery?

[@radiotowers1159]

@@occamraiser they state 6,000 cycles which should be about 16 yrs

[@GaryDoesSolar]

Cheers, and sounds like you're doing all the right things, but yeah, doubling your battery capacity could work well for you - all the best! :-)

[@elslopez]

Excellent video Gary, some parts are like you have read my mind... They thought I was mad in the UK to go for 60Kwh of battery storage... but I have enough solar that one good day can crank the storage all the way up to 100% so even with a string of cloudy rainy days the grid draw remains at virtually zero for days on end. So the stats are in and since go live grid import has been a mere 3% of what it was... and I mainly feel that most of that was the inertia of how the system/inverter/battery deal with the grid connection. I did also opt for 10Kw inverter capacity so that multiple high load devices running at once CAN actually use the stored power. I am not on any fancy tariffs yet but look forward to what the future holds.

[@GaryDoesSolar]

Wow, that’s some battery, and I guess with a 100% charge you could go maybe 2 or 3 rainy days without drawing from the grid…?

[@elslopez]

@@GaryDoesSolar It smooths out all the peaks and troughs, two or three day with trash solar output easy! In fact its been so effective it has even eliminated the need to reorganise when appliances are used, thus making it for the most part invisible day to day. I was aware that 90% effectiveness can be achieved with less, but what you said in the video is absolutly on point for bigger batteries!

[@ste4bz]

I have an East Array, South Array and West Array... which really does draw out the power curve into the morning and evening when I'm at home before work. Not as intense noon but if you work that's no issue, and if your discharge rate on your battery also isn't enough for your usage at 6 o,clock etc, the West Array just tops it over.

[@GaryDoesSolar]

Sounds great! And for a peak export period, a West array must be ideal :-)

[@Plan3tBob]

FYI: I have Sounth and North arrays (identical on the garage roof) and in our greyer british weather they perform almost identically! I cant comment to when the sun is lower in autumn or winter as I expect they will be more impacted then. I'm suprised though how well the north panels perform.

[@NathanJones-cq1dz]

I am in the process of chosing my solar and battery package and it is a mindfield to try estimate benefits vs outlay. Your video has made it so easy to understand and how to benefit from grid fluctuation.

[@GaryDoesSolar]

Cheers Nathan - happy to have been of some help to you! :-)

[@jonbee56]

.. just discovered Gary...so glad there is someone who explains solar issues simply without those screaming and shouting presentations, in a well spoken educated, non-demeaning manner. Keep up the good work. .. is there any way to send links for downloading the excel sheets for those who aren't capable of producing them?

[@GaryDoesSolar]

Thanks for your very kind words, John :-) Here's a link to the spreadsheets I have: garydoessolar.com/utilities/fluxcalculator/ and: garydoessolar.com/utilities/solarcalculator/ Hope they're useful to you!

[@bazcurtis178]

Another fantastic video. I have 2x 3.2kWh batteries and have been thinking about adding another one. I am using Home Assistant to “balance” the battery charging. It looks at my Solcast forecast and sets the battery charge level so I don’t over charge from the grid at night when the sun will charge it. This is more for the winter when otherwise the battery wouldn’t charge fully. In the summer the battery will last 90% of the day, I would say. Home Assistant also sets when the battery will kick in after midnight. On good days, it will be 1am. That means it has enough charge left around 6am to cover the house as the sun gets better. I only made £8 on the saving session as the battery covers the peak time so my historic saving was tough as historically most days, I don’t use the grid 😀. Lastly, plunge pricing is good again tomorrow. I will charge the battery from 10am. Hopefully it won’t be too sunny prior to that or the battery won’t need much 😀

[@TheBadoctopus]

Sounds great - I have an almost identical setup (Octopus Flux, 2x Pylontech us3000c and Home Assistant). And I have my own code managing just enough charge to cover the until the sun can take over, plus export what's spare from X minutes before 7pm, based on calculated spare and discharge rate. Next I'm going to make it look a couple of days ahead to avoid export when we need it for the day after... It's super satisfying. Looking to add a new battery or two in the autumn, 12.8 kWh usable takes us though 90% of days.

[@GaryDoesSolar]

Thanks Michael. I'll be looking at SolCast myself, as I want find a way in the utility to calculate the solar profile across multiple array orientations. And one of these days, I'll get into HA - everyone seems to be having a good experience with it :-)

[@TheBadoctopus]

@@GaryDoesSolar Solcast (and its home assistant integration) already supports multiple arrays at different angles. You can run HA on your laptop to start, just to kick the tyres and check it out. You'll be amazed what it can find on your network to integrate, monitor and control. Then before you know it you'll be installing it on a little server and building new automations and dashboards to do cool stuff without writing any code. Beware: it will become something of an obsession 😅

[@leslieburrows5293]

Hello Gary I just want to say thank for yet another great and very informative programme I have been looking for lots of answers to lots of questions for a long time about batteries and what I could add to my 13 year old 3.84kw PV array and I think you have just about covered everything I needed to know in this one so thank you very much. I don’t know if there is such a thing but if there is an award for the best and most informative presenter videos for a lay man like myself well Gary you most certainly deserve it. Well Done. Les

[@GaryDoesSolar]

Hi Les, wow - that's quite a complement - thank you! I'll keep the videos coming :-)

[@jakealmaguenther4366]

Good presentation, battery storage gets better and better, I have an off grid system with 28 kw battery. Ontario hydro has implemented an optional ultra low rate of 2.4 cents per kw between 11 pm and 7 am. My first move was installing an 80 gallon electric water heater with a timer switch, my second move was installing 2 inverter heat pumps and adding 20 kw battery storage. I calculate that even on the coldest winter day the batteries will carry the entire load from 7 am to 11 pm. A big bonus for us is emergency backup when the grid goes down.

[@PazLeBon]

but surely a 28kw battery is tens of thousands??? and if power is only 2.4c youd need like 56 years to make that investment back

[@GaryDoesSolar]

28kWh battery - sounds great!

[@mykolapliashechnykov8701]

@@PazLeBon 28 kW is essentially 32 280Ah LFP cells that go for about $100-110/pc + $700 for BMS, cables, cabinets and shipping. So about 4-5 grand if you go full DIY.

[@Tony-Stockport]

Great video. I've had solar & battery for just a couple of months now so found your video very interesting. I maxed out with 6.48kWp array and 20.8kWh of battery and have Agile and Outgoing Fixed at 15p. It was madness on that Sunday of plunge pricing, I had everything charging or switched on that we could make use of! A factor that you haven't mentioned is battery longevity. Throughout June the battery was topping out by midday so solar was going straight to grid and getting a decent rate. I prefer this to forced discharge at a higher speed just to make a little extra now while not knowing if this will shorted the life of the batteries. The biggest factor of having a battery for me is no thinking about load shifting.

[@GaryDoesSolar]

Thanks Tony. Yeah, longevity is certainly a consideration - and I note that my inverter (GivEnergy) gets super hot when force discharging for a couple of hours - so it's not only the battery that is affected... I have a 10-year warranty on both, and maybe technology will be a lot cheaper/better then anyway?

[@rjmacf0015]

Batteries are about winter? Summer is easy no matter where you are or your direction/angles/array size. Bigger batteries mean you will get through the diurnal high rate energy company charging in winter without too much difficulty. Also this is about hedging against future price rises (or gouging as its labelled in Australia). The current drop is long overdue and only because the cap they can charge (in the UK) has been artificially lowered. Its still grossly elevated compared to European pricing. No doubt the UK distributors will be lobbying furiously for it to be lifted come October regardless of the excuses (war pandemic cost of living) for their profiteering.

[@PazLeBon]

@@rjmacf0015 you reap what you sew for sure and youve been sewing tories there for decades :(

[@rjmacf0015]

@@PazLeBon greed has nothing to do with political parties. Read Simon Montessori's biography of Stalin?

[@Cptnbond]

What an excellent episode, Gary. One comment: the EV battery will not become part of the grid. Discharging and fast charging will ruin the car battery and also reduce the resale value of the EV. The car seller will not give any guarantees for that kind of usage. That must already be an issue when you buy any second-hand EV car, i.e., how much has the battery been mistreated by 'fast charging,' which will shorten the battery life - and thus the vehicle itself-just my 2c. Cheers.

[@GaryDoesSolar]

Thanks for your very kind words. I was hoping this video would be a good one, and so far the feedback has been very positive. Really good points, and of course, EVs are not always connected to the house as well - they kind of need to be around when the profit opportunities arrive. Perhaps in 5-10 years' time, home battery technology will allow for 50-100kWh capacities... actually, as I write that, I'm quite scared but he thought too! Lol

[@SteveLoughran]

The Tronity app I subscribe to to give Home Assistant and ABRP a view of my car state produces nice charts of the AC:DC ratio. so far I'm on 86% AC -I have yet to do any exciting cross country trips though. When buying a used EV you'd really want that number. And while I don't know about other manufacturers-I can see that BMW don't explicitly report it.

[@jameswestgate416]

Another high quality professional and informative video. Good work.

[@GaryDoesSolar]

That's really kind of you to say, James - thank you! :-)

[@jeanh9641]

Another great presentation. I have learned so much from your brilliant programmes.

[@GaryDoesSolar]

Thanks Jean - that’s really great to hear 😀

[@cherylschneider3294]

Amazing information I never heard anywhere else. I will definitely change my high energy tasks to daytime!

[@GaryDoesSolar]

Thanks Cheryl - that's fantastic feedback! :-)

[@kadmow]

- are you on a time variable tariff?? - check your bill... ?? Solar ?? (with monitoring)

[@cherylschneider3294]

@@kadmow I don’t know for sure.

[@penrithomas115]

I've been thinking about this it's great to have the information in such a clear format thanks

[@GaryDoesSolar]

Great to hear this feedback - thank you, and all the best with whatever you decide to do!

[@benlynch7249]

Really appreciate your vid dude, it's something that I've been thinking about for a long time now and your the only person I've witnessed so far talking about it, to me this is masive and I don't think I'm alone in that, lots of respect dude, for me, you went right for the jugular and your vid I felt was very informative, because of this, I'm now a subscriber to you, please keep doing your thing, I'm all ears, thank you very much. 👍

[@GaryDoesSolar]

Such great feedback to receive, Ben - thank you! :-)

[@mauroattilionosenzo]

Very good video Since I have installed the battery 14kwh I m totaly off grid..greeting from Italy

[@GaryDoesSolar]

Thanks for the great feedback. And just to say my wife and I LOVE Italy. I worked in Umbria for a couple years when I was younger. An amazing country! :-)

[@Humphrey181]

That video is a great resource for those considering the move. That said, I’ve yet to take the plunge. My usage is only 9kWh per day and here is Australia the feed tariffs are horrible at maybe 5c/kWh versus maybe 30c/kWh from the grid. There’s even talk of charging people to feed in due to the over supply of solar. I did some calcs and the solar alone would be about a 7 year payback and if I added a battery it was 13/14 years. That’s without factoring in pulling the up front costs from the mortgage to pay for it all. Don’t get me wrong I’m very pro this tech, but for me, and my usage, the numbers don’t stack up. If you are a bit user I’d be jumping on this technology.

[@GaryDoesSolar]

Thanks for your kind words, and hopefully soon, with continued price falls, the numbers will soon stack up!

[@wajopek2679]

As always great presentation but a Part 2 is needed that focuses on the cost versus ROI and space. Large scale storage appears to make greater sense in terms of safety, best in class technology and relaibility. No software updates and headaches to consider. Its just done as part of the National Grid Energy Plan.

[@GaryDoesSolar]

Thanks :-) And agreed, as the video was getting a little long - I'm planning a follow up video to cover off those points and a few other things...

[@stuartburns8657]

With my soon to be 1yr old GE system (gen1 5k inverter / 6k PV and 8.2k battery) ive considered an additional battery. However, apparently whist you can add more batteries, it will only use one at a time. Max discharge is 2.6kwh. So the best option (other than adding another inverter) is a newer 9.2 GE battery, which can output at 3.6kwh max, then when empty, fall back to the smaller one. Like you, Ive been getting paid well over £100 for the last few months. Inclined to wait until / if we consider a heatpump and or aircon. Good video as ever Gary.

[@GaryDoesSolar]

Thanks for the kind words, Stuart. I have the Gen 2 GE batteries, and yeah - even 3.6kW charge/discharge rate is a bit low for today's typical appliance usages. I'm always jealous of people with 2 x Tesla Powerwalls - essentially 27kWh and a 10kW charge/discharge rate! Golly! Great to hear you're earning some monies from export too! :-)

[@startingfromabsolute]

Great video. Greetings from the Netherlands. As I see it from your video…. The time of use tariffs. (We call them dynamic tariffs) are an excellent addition to a solar power and home battery setup.

[@GaryDoesSolar]

Thanks for the great feedback, and I totally agree - these kinds of tariffs can make a huge different to the returns (financial and environmental)! :-)

[@peterstrous2092]

You are an amazing teacher Gary! Very well done.

[@GaryDoesSolar]

Hi Peter - your comment has made my day - thank you! :-)

[@tomcoryell]

My wife and I are new to solar here in the US and none of the vendors here supply info on their products that even come close to what I have learned from you. Thank you Gary for easing my frustration and building my confidence that I have made some good choices so far.

[@GaryDoesSolar]

Wow - that’s praise indeed, Tom - thank you! 🙏 😀😀😀 and all the best with your solar journey!

[@GC987]

Great content. Illuminating. I've liked & subscribed. Thanks.

[@GaryDoesSolar]

Thank you for the kind words! 😀👍🏻

[@oliverpower7155]

I loved this. Clear and concise.

[@GaryDoesSolar]

Thanks Oliver :-)

[@johndoyle4723]

Thanks, a well produced video and good information for those new to or just embarking on their solar journey. I only have a 7.5Kwh battery, but for about 8 months of the year it is more than enough and I mop up surplus generation with my EV, I do not have an export agreement but do give away about 300Kwh per year, about £12 on SEG. For the Winter months, there are days when I cannot fill the battery and have to import, I do load shift and charge the battery at night, I did consider adding more battery, but it just does not make financial sense for me.More battery will work for other users, each case is different.

[@mb-3faze]

You're quite right. You *could* add another 7.5kWhrs and what that will do is expand that 8 months by, maybe, a couple of weeks(?). You've no doubt already have worked out that it's more or less impossible to have enough batteries and enough panels to be self-sufficient over the winter months. Don't know what batteries you have but right now the capital cost of batteries, and their longevity, means that they cost about 10p per kWhr every time you use the battery (this is just capital cost). I'm looking forward to the new battery tech (iron-air and flow batteries for example) where the capital cost per kWhr moves down to, hopefully, 2p per kWhr. Have you considered a 'solar diverter' to heat your water? They are a good way of using the excess solar.

[@GaryDoesSolar]

Thanks John - yeah, having an EV complicates matters slightly - I reckon your battery size is just right 👍🏻

[@johndoyle4723]

@@GaryDoesSolar Thanks for your confirmation. As I said above, you do a good job.

[@GaryDoesSolar]

@@johndoyle4723 That's so great to hear. I'll keep the videos coming 🙂

[@brianmcclure8012]

First time I have come across your videos Gary. Very professional & informative. Thank you!!

[@GaryDoesSolar]

Thanks for the great feedback, Brian :-) Next video coming soon!

[@SusannaSaunders]

Thanks Gary for your channel! It's Most helpful! I had a look in the comments to see if this question was answered but I haven't seen it... Most Lithium Ion batteries (e.g. EV car battery) operate with reduced cycle wear when charged to 85% and discharged to no less than 15%. This equates to around a 0.2 cycle wear compared to a full 100 to 0% cycle. With this 15%> 85%>15% approach only 0.2 cycle wear occurs (for our EV battery) compared to the nominal 0.7 cycle (70%) discharge cycle equivalent to 100% cycling. Thereby improving the battery longevity by over 250%. My question is whether its possible/preferable to oversize the battery in a solar-battery setup to do this by setting limiters so that it doesn't charge more than 85% and doesn't discharge to less than 15% of total charge capacity? What is the impact upon the battery life expectancy? This matters for ROI calcs as its a whole different ball game replacing the battery after 10 years compared to 15+. Thanks in advance of any guidance you can offer here. I get that this is NOT your approach (for using a battery) but I would like to know my options around this please. Am I better (cost wise over the lifetime of the battery) getting a larger battery and then limiting the cycling to 15-85% to extend its expected lifetime (e.g. beyond the warrantee period) or fitting a nominal battery size and doing full battery cycling (basically hands off approach) and not caring about the cycle wear of the battery? My gut instinct tells me that if I can more than doubling the life expectancy of the battery by limited 15-85% cycling, this has to be a better ROI equation than 100% battery cycling.

[@GaryDoesSolar]

Thanks Susanna. I’ve answered your email 👍🏻

[@Electric_Man]

I'm proud owner of a 56 kWh battery pack and earned £5 within these two cheap hours on July 2nd charging the ESS and the Tesla.

[@GaryDoesSolar]

That's great - and long way that conitinue! :-)

[@vindeballs1]

Fabulous video... Good luck in persuading the masses... I've cashed in my pension pot for solar, batteries and electric car and get so much enjoyment from generating our own energy. It works extremely well 👍 Ps. Go for as much batteries as you can afford... im glad I did with 15kwh worth.

[@GaryDoesSolar]

Thanks Vincent - I love this comment, and I agree - having a solar/battery/EV setup brings a lot of satisfaction, way more than just financial considerations :-)

[@veronicathecow]

Excellent explanations, many thanks.

[@GaryDoesSolar]

You're most welcome - thanks for the great feedback :-)

[@BlackBuck777]

Interesting. It helps being a geek - I have kept good records of electricity use since before installing Solar and then a Battery. Good historical data is a very useful tool. I have a Powerwall and since the start of June to date (17/7) I've used 6 units of electricity by managing load manually. (Would have been 0 but I messed up on a couple of days!) I'm adding sensors all the time to automate some of the users so hopefully less input from me. My base load overnight (summer) is 200 w/hr and that's for running two fridge freezers. I'm already on Octopus - since the demise of Bulb, and when that wonderful day that I feel comfortable with smart meters arrive, I might go onto their cheap tariff.

[@GaryDoesSolar]

This is great to hear - thanks for sharing! I'm not quite as into the automation as you are. I think automations are great (I mean, that is what computers should be doing for us all the time - worrying about these things so we don't have to) but I wonder if the hardware/software you're using to create all this is reliable and dependable? I'm guessing the answer is heading towards "yes'" but of course, you're on hand to investigate/diagnose/fix. But what about the average non-technical person - they would not know what to do at all. Interested in your thoughts around this conundrum given your first hand experience. And maybe it could be the subject of a future video. What technology do you mainly use? HA?

[@realdougsmart]

Excellent job, Gary. Very well explained. I'm writing from Perth, Western Australia, where we have a lot of sunshine and rooftop solar, so our export rates are getting near zero cents. Even with these structural differences to your UK situation, I've found your modelling tool (Pro Version) very helpful. We're far behind you in terms of flexible retailer behaviour and VPP development, but I found your Step 4 and Step 5 very helpful in showing where we're most certainly headed. I'm about to install an 11.62 kW PV array, a 13.8 kWh battery and a 7 kW EV charger on a new home I'm building.

[@GaryDoesSolar]

Hi Doug, thanks for the great feedback. And yes, much of the world is jealous of the amount of sunshine you are getting! :-) Really great to hear my utility has been useful to you as you plan your solar installation - and it looks to be quite a large setup too! Good luck with everything and I'd love to hear how it all goes! I think we'll see a lot in the way of steps 4 and 5 over the next year. It seems the world is waking up to solar and battery :-)

[@Roozbeh72]

Great video Gary. But having learned the maximum export limit in one of your early videos, I thought people should know that having a 12kWh battery may not always be beneficial if they want to export it to the grid within a short period of time, as they may be restricted to exporting above 3.68 or 5 kW default limit.

[@GaryDoesSolar]

Thanks, and you're right - these export restrictions can really get in the way of a profitable installation :-/

[@Just-SomeGuy]

Just about the most concise, but also comprehensive video I’ve seen on solar. I have solar panels, a Tesla battery and am also on the Flux tariff. I’ve only just switched to the tariff though so I’ve yet to see the benefits. Thanks for a great informative video that helps more people take the leap into solar 👍🏻

[@GaryDoesSolar]

That's high praise indeed - thank you! :-)

[@jimstack3694]

You should mention up front if we add batteries we also need to change the inverter to one that csn handle battery storage. That adds to the cost.

[@GaryDoesSolar]

True. This video was all about why you want want a larger battery, not the barriers and complications that might arise when getting one. My aim is to cover those in a planned follow-up video.

[@DanEVSolar7]

Great work Gary. The future looks bright for solar and home battery users. 👍

[@GaryDoesSolar]

Thanks Dan - I totally agree! And so I think you and I will have plenty to talk about in our videos for some time to come yet :-)

[@AaronBarry-f1e]

I'm really happy to see your channel

[@GaryDoesSolar]

Thank you Aaron 😀👍🏻

[@etchedpixels]

Estimator app was most useful. Gives me a good idea on sizing battery. Was going to move to Octopus energy anyway so used your referral.

[@GaryDoesSolar]

That's really kind of you to think of me with the referral code, and great to hear my work is helping you make informed decisions! :-)

[@video99couk]

We have a 5kW inverter (6.4kW solar) and a Tesla Powerwall 2. But we use up the entire capacity of the powerwall virtually every day before cheap rate charging overnight. I got a quote for a second powerwall but it was almost as much as the entire solar and powerwall system cost two years ago. Alas that's just not affordable. I wish we had specified two powerwalls from the outset, but we couldn't have known how the system would behave in enough detail at the time.

[@GaryDoesSolar]

Yeah, still scary prices on Powerwalls, but now with several Tesla clones appearing on the market, I'm thinking that Powerwall prices will reduce to stay competitive. Mind you, Tesla products will always attract some level of premium! Hope you get your 2nd unit before too long :-)

[@phil_nicholls]

Interesting video. We have a 9Kw East/West solar system and a couple of Tesla Powerwalls. Being somewhat high users of electricity, we’re saving around £3k a year - not to mention how much diesel we’re saving running 2 EV’s. My only wish would be to have some South facing panels set at a steep angle for the low sun in Winter, as production in the winter months with an East/West system is woeful. We still save by charging on cheap rate though. This is definitely the way forward - I just wish it weren’t so expensive to get into, so those with constrained budgets could benefit as we do.

[@simonm9923]

That’s bizarre, sounds like you are in exactly the same position as us. I also considered wall mounted south facing ‘winter sun’ panels but struggled to find anyone prepared to install them. We ended up investing in Ripple (co-operative wind farm) which has the advantage of decoupling generation from consumption entirely. Maybe worth considering?

[@GaryDoesSolar]

Thanks, and I agree with you on the expense - it'll take a little more time yet before prices drop within a wider range of budgets, but the great thing about technology is that it generally only ever gets cheaper... :-)

[@davidpartington4617]

Great video Gary - I’ve had 5kw solar and 5kwh battery for only a couple of months, and loving it, just wish I lived in a sunnier country 😂. Indra V2H charger is coming soon that will take my battery capacity much higher utilising an old 24kwh Leaf…can’t wait…

[@GaryDoesSolar]

Cheers David :-) And that all sounds great! Be careful what you wish for re. sunnier countries - the way things are going, we might have to move to the North Pole! Good luck with the new charger. I'd love to hear your experience with it...

[@mslcreative]

Hi Gary. An excellent analysis using solar and battery to support the home usage of power, the best I have seen to date. The only thing you didn't cover was the difference in sunlight across the UK. We have a 4kWh Solis solar system with 12 panels(about 4yrs). In Nov 22 had a 10kWh battery box installed from PureDrive. We are still working on the exact benefits but they are definitely being be achieved as our costs have reduced over the summer period dramatically. The winter period produces far less solar and consequently less power for the battery. There was still a benefit as being in the south east we seem to get more sunlight than other parts of the UK. I think one of the biggest misconceptions of installing solar is that it does not relate to the daily usage of power for the average household as you have highlighted in your video. The graph showing solar production does not match the household usage as you have explained and this is where battery power can help to match the production with usage with demand. We are also connected to the FIT tariff which has produced very little return for the energy we export. This was not a good idea for the government to roll out although I believe some installations do produce a reasonable return, we do not! We are currently looking at future options. Do we increase our solar panels to 8kWh as the daily range of energy production would increase particularly on cloudy days when there are fewer or intermittent periods of solar production. Or more battery power and increase to 15kWh or even 20kWh to hold onto as much energy as possible for use in the areas outside solar production times. I did like the Octopus options and will look at them again as the last time I made contact with Octopus they suggested we stay with our current supplier SO Energy. We are interested in further optimizing our setup and would like to move away from the FIT tariff although not sure of the best way to move away, maybe Octopus would have the answer. I do record our usage monthly so if you are interested I am willing to share this information. It does get complicated as to how much energy is going from point to point as the APPs we use are limited on what they display (PureDrive APPs). An example of this is that we do not how much charge went into the battery on a particular day all we can discover is the battery state of charge on a day/week/month/year. Interesting times. Really appreciate your video thank you.

[@GaryDoesSolar]

Thanks for your detailed comment. I can’t provide advice (for liability reasons) but I can give my views. If I was on the FiT scheme and it wasn’t working out for me, and if my panels were installed say 5-10 years ago, I’d perform a cost analysis of replacing them with much higher efficiency panels, coming out of the FiT scheme and moving to one of the Octopus Tariffs - particularly one which offers a high export rate (Flux for example). We’re moving into winter and a tariff like Flux is really for the summer, so depending on when my new panels were installed, I’d either move to Flux immediately or go on a tariff like Agile in the meantime. I have made videos on both these tariffs so you can get an idea of the pros and cons of each. All the best with whatever you decide! 😀

[@mslcreative]

@@GaryDoesSolar Thank you for your reply Gary, I will investigate the octopus options and look at your tariff videos, appreciate your comments.

[@KevinFoulds]

These are great videos. However it would be good to see the price of a solar setup today and what you could expect to get back in places like Scotland where you see very little sunlight in winter, and the extra costs associated with better quality solar panels that actually work with more diodes in winter. That way we can see what time scale you will be looking at to actually get a return on your investment. It always sounds good when people say you are making money etc, but the initial outlay can mean 25 years before you actually see a single penny and thousands spent trying this out. Plus in later years something else will come along and replace the expensive solar panels like the ridgeblade.

[@GaryDoesSolar]

Thanks Kevin - there are actually quite a few videos out there where people share their ROI calculations on their solar setups. I’d recommend you watch Anthony Dyer’s channel, for example - his setup is near Aberdeen.

[@ChrisChurchill-by7ek]

Your talks are uniformly insightful on a subject that is becoming ever more complex in parallel with the increasing opportunities. You have generously created a great spreadsheet/web app but surely the calculation is missing a significant cost - that of putting a kWh through the battery. With my panels and EV I have a 6kW (usable) Growatt battery. It is advertised for 6000 cycles (which I take to be charge and discharge from/to 10%) = 32.4MWh. At around £2750 installed this is 8.5p per kWh. In the context of the rates being discussed, that is a BIG number not to include.

[@GaryDoesSolar]

Thanks for the kind words, Chris, You'll be pleased to hear I'm covering costs and ROI in a follow-up video to this one that I'm working on now...

[@ChrisChurchill-by7ek]

Apologies, my comment was too short to be clear. It was intended to be about tariff selection rather than ROI. The lifetime of other solar hardware is expressed in years so battery is the only variable cost. If I charge at, say 7.5p per kWh, have 5 % round turn loss and using the battery (as above) costs 8.5p then I need 16.1p per kWh to make it financially viable. Fair enough if I am replacing 21p import (though by much less than it seemed) but no good at all if I thought a 15p export rate looked good. Not having this variable cost in the modelling utility could lead to the wrong tariff being chosen.

[@GaryDoesSolar]

@@ChrisChurchill-by7ek Thanks for the extra detail - I understand your point now 👍 Ok, I most definitely started a debate with the utility by using the term "profit" in the calculations - and of course, it can only ever be profit once all the expenditure is taken into account, including the battery. I'm thinking the best way to handle matters is to remove the sense of profit from the utility and instead just consider expenditure and income wrt the utility bill. Then, in a separate utility, I can look at ROI factors, including the battery cost/kWh factor you mentioned. So much work still to do on all this and limited time,... but I'll get there (slowly) 🙂

[@adddude7524]

Well structured, consice video! I'd still be hesitant to go all out on an oversized battery system today as there may be one with the same capacity for half the price in a couple of years. Better buy what makes sense today and then add/upgrade when it makes sense again.

[@GaryDoesSolar]

Thanks for the great feedback :-) Yes, this is the perennial question with any kind of technology, really... with technology continually get better and better and prices consistently falling, when is the best time to take the jump? The way I look at it is that whatever you do, the following year, the technology you bought will likely be better and cheaper. So, as long as you're happy with your decision at the time (on what ever criteria you use, e.g. financial) then it's all good. For home batteries, because of the likely effect that CATL will have in the market in a few months' time - see my video here: kzbin.info/www/bejne/g2OWhGCoipKdiZosi=hDDDPTKHCpSeUuqV - it's worth waiting a short while, as there might be a notable financial benefit.

[@garyrooksby]

Really useful info, Gary. Fabulous. I'm currently looking into a home battery. This week I had a survey from Octopus re. heat pump but was told that my house wasn't suitable (economically, anyway) so I'm looking for a battery to match my 3kw solar array.

[@GaryDoesSolar]

Same here, Gary. Our house not suitable either :-/ Thanks for super thanks! 😀👍🏻

[@rayopeongo]

Just a small comment. In your "Time of Use Tariffs" examples, you force the battery to charge to 100% at the beginning of the reduced rate period and then immediately take over the house load until fully discharged. Shouldn't the house load be handled by the grid until the end of the 4 hour reduced rate period, at which time the battery takes over? This will make the battery last longer during the day. Granted, the amount of drain on the battery isn't that much overnight, but still, every minute you can use the battery rather than the grid during times when the grid price is up is more money in your pocket. So, use the grid to charge the battery and run the house during the four hour reduced rate period, and then automatically switch to powering the house with the battery when the reduced rate period ends. I am not sure if your app allows you to set up that sort of schedule.

[@GaryDoesSolar]

Hi Ray, you raise a great point! And I believe that many battery management systems allow for that kind of behaviour. I didn't want to get into too much detail on that in this particular video. I'll need to check my app again, just to make sure it behaves in a similar way...

[@suezysue3064]

Great video, many thanks! Only problem for me is I DIY installed my 10kWh of ground mounted solar so no MCS certificate, which prevents me getting paid for any export! The MCS certificate is an OFGEM requirement that Octopus (and all other energy suppliers) insist on before paying for export. This is a ridiculous requirement when the DNO is happy for me to export onto the grid under the G99 certification. OFGEM need to reconsider this MCS certification position as my system has been approved by the DNO

[@GaryDoesSolar]

Thanks for the great feedback. And sorry to hear about your situation. I'm that soon, there will be the ability to get respective MCS (or equivalent) certification - that's surely a market opportunity for companies...

[@71brp84]

Finally got my solar and battery installation at the end of this month, after 6 month wait. Exciting times ahead.

[@GaryDoesSolar]

Great news! Hope the installation goes well - and you're still in time for a ton of sun :-) All the best!

[@russ623]

Have you considered producing a teaching pack to use in schools? This is exactly the type of resources we need in education because our students have very little knowledge and understanding of the way the energy is used and generated especially with the push on green energy. The Department of Education might be worth considering as long as the resources are suitable for each key stage.

[@GaryDoesSolar]

I honestly wish I could spend more time working on solar/related topics 👍🏻 I’ve got a full time (and taxing) day job. I totally agree though - the next generation would be able to push adoption and innovation a hundred times further if they’re exposed to the challenges at an early age. Let’s see what happens…

[@zjzozn]

Brilliant ….. the best video so far ….. thank you 👍

[@GaryDoesSolar]

Thanks - and I feel the same about the video as well. And so far, it seems to be resonating with KZbin viewers - lots of new subscriptions - very happy about that :-) I'll try to keep the content quality up!

[@zjzozn]

@@GaryDoesSolar Every year this subject will evolve and become main stream. Will have a play with the Solar Utility… was looking for something a few weeks ago. This really make me feel like becoming a Patreon 👍

[@GaryDoesSolar]

@@zjzozn Yeah, let me know your experiences with the utility - hope you like it, and I'd be honoured to have you sign up as a patron would you decide 🙂

[@jacbisgood2221]

This is incredible info, well explained and easy to understand. Thanks Gary

[@GaryDoesSolar]

Wow - that’s for the kind words 😀

[@richardfisher3961]

What a very helpful video. Thank you Gary.

[@GaryDoesSolar]

You're most welcome, Richard - very happy to hear you'e getting something from it. I'm working on a follow-up battery video shortly...

[@nicflanagan6662]

Another fantastic presentation ... engage, inform, inspire. Incredibly well researched programme bringing a new dimension of vision to the subject. Thanks very much Gary 🙏🏼

[@GaryDoesSolar]

You’re far too kind with these words, but thank you! 😀😀😀

[@nicflanagan6662]

I spent +25 years in Export Sales, doing trading courses at dealer conferences around the world. OHP, slides & flip charts 🤣🤣🤣🤣

[@GaryDoesSolar]

@@nicflanagan6662 Well, you've given me high praise indeed - thanks again!

[@625Joe]

Great video. Very informative and helpful. Many thanks.

[@GaryDoesSolar]

You’re most welcome - thanks for taking the time to let me know! 🙏

[@binaryboyo9674]

Great Solar Vids. Gary! 🙂 However using Pounds is quite challenging for your friends in the Antipodes! 😱 We moved on to that new fangled $ in the swinging '60's which you might remember! 😉 Will your new Solarazma Calc. offer such crazy foreign currencies for us here in the Sunny 'Lucky Country'?.... 😃

[@GaryDoesSolar]

Your comment made me smile 😊 Yes, Solarazma Suite supports a range of currencies now 👍🏻

[@binaryboyo9674]

​@@GaryDoesSolar I'm Glad you Got a Giggle Gary! I love a little alliteration in the morning (ref: Apocalypse Now)! 😄 Guess I'm In! I'll now go on a challenging expedition down the back of the lounge couches for some Coin to Join! 😉 Afterwards, I believe I might be your newest, best and farthest away Patron? 🥳

[@GaryDoesSolar]

@@binaryboyo9674 I think you may well be all three! 😃 I read our message exchange to my wife and she's smiling as well! You're brightening our day! ❤

[@CrownRider]

Great video, thanks. When prices for electricity go negative on a sunny day, I want the solar panels to stop feeding the grid but keep feeding the batteries from the grid. At this moment I'm forced to turn off the solar inverter manually. So I'm looking for an automatic switch that looks at the spot market for electricity and switches off the solar inverter when prices go negative.

[@GaryDoesSolar]

Cheers for the nice feedback! Yeah, I think inverter/battery manufacturers are waking up to the need for more intelligent control. I think Home Assistant (HA) could be worth you looking into... it seems to have integrations for many suppliers' products...

[@Sekir80]

What a great overview of solar, batteries and grid cooperation! I'll share this video to my friends, especially those who are skeptical of things like this.

[@GaryDoesSolar]

Thanks very much for the great feedback, and thank you for sharing it with your friends - hope it's useful to them as well :-)

[@GrahamF]

Thank you for this video, very informative and helpful, as I'm currently scoping a solar system & selecting equipment and supplier. One thing that's popped up is the new EDF tariff "Empower" which is limited to customers who purchase equipment via their subsidiary - Contact Solar. There isn't a standing charge & rates looks much better than Octopus.

[@574rz460v3]

Great video Gary ! Once I’ve completed my first full year of solar generation I will have a better understanding as to if I need to add extra battery storage. I have a 7.2 kWh battery at the moment and a 4.8kw solar array split south and west. The battery is full most of the time so I’m cashing in with octopus flux.£££. Keep up the good work 👍🏻

[@GaryDoesSolar]

Thanks for your kind words :-) And great idea amassing lots of data, which will absolutely help you make the best decisions going forward. Data is sooo powerful these days, and we now have the computing tools to assess it extremely well... All the best with you decisions!

[@aldozilli1293]

Out of interest as I'm getting a battery, you say it's mostly full but is that not because we've had plenty of sunny days recently? What's it like in winter? You sound like you may also not have high demand at your property, at my place everything is electric including sewage pump, ASHP for water and heat and an MVHR system, plus an EV to charge.

[@t.d.5804]

Had a 45kWh (net usable) battery 10 years ago, that was a used lead acid, replaced it 3 years ago with a 50kWh (net usable) Li from used BEV cells. That size means no big load on the battery, so it lasts longer, no cooling needed. We are all electric for 10 years now, house, heatpump, BEVs. Works well, 75% off all power comes from our own roof and that in a country which is at 52°N. PV is easy, clean, cheaper.

[@GaryDoesSolar]

Wow - love it! :-)

[@PeterBache]

So the one big thing not mentioned.... What you need to take full advantage of flexible rates is for a control system to look ahead at predicting weather / yeild . For this we need an industry standard external control protocol for all inverters , heat pumps ,Aircon units , ev chargers . Similar to opentherm on boilers

[@GaryDoesSolar]

I'll try to cover topics like this in my planned follow-up video. There are services like solcast.com which many inverter manufacturers tap into.

[@edc1569]

Try and reduce consumption first, makes a huge difference to what you get out of a battery, I used automatic switches to turn off stuff when I’m not at home or am sleeping.

[@GaryDoesSolar]

Absolutely 👍🏻

[@AddyGoose]

VPP’s are a global trend we’ll see roll out in the coming decade. Dedicating a % of your home and car battery to this purpose. The micro manageability of personal battery storage and the ability to sell at peak times will be beneficial to society and individuals.

[@GaryDoesSolar]

I completely agree-in my opinion, this is by far the most efficient way for consumers to capitalise on an increasingly dynamic supply and demand landscape.

[@zucan100]

nice if you can get those sort of import rates. Australia is down to 0.08c and now the government is putting the electricity companies to include a charge to all solar customers who import electricity back to the grid due to their own storage costs and infrastructure costs to facilitate feed-in.

[@GaryDoesSolar]

I’m actually creating a video on the future of export right now… 👍🏻

[@SkipMichael]

Good video, there is only one problem here in Sunny California. Our solar use system are tiered programs which benefit the power companies and not the consumer.

[@GaryDoesSolar]

Thanks, and I hope that the powers that be (no pun intended) see the light (oh, crikey - no pun intended there either!) Domestic solar and battery has the potential to solve the energy issues in just about any region - especially sunny CA! :-)

[@buddywheels]

Outstanding Gary, many thanks 👍

[@GaryDoesSolar]

Really great to get such positive feedback - thank you! :-)

[@tonyfeasby1437]

Great content. Considering an ev + givenergy AIO install (no solar) with IO. All electric @ 7.5p seems super tempting and saves the solar outlay. Just need to dodge the vat!

[@GaryDoesSolar]

Thanks Tony, and I wish the AIO was available when I had to make decisions only 6 months ago! Oh well, at least you'll benefit from what looks to be a great battery. And agreed, the government should remove VAT from home battery-only installs as well... We can but hope!

[@BikeNutt1970]

Brilliant video and fantastic modeller. 👏

[@GaryDoesSolar]

Such great feedback to hear - thank you 🙏

[@pau1phi11ips]

Amazing work Gary!

[@GaryDoesSolar]

Many thanks! It's been a while since I released a video (whole family was ill for a while) but good to be back!

[@andrewvillavicencio8496]

Great and informative video, thank you! I love the modeling utility tool, I just have to convert to US :-) Subscribed

[@GaryDoesSolar]

Thanks for your kind words, Andrew. If you wish to join my Patreon, the utilities there allow different currencies: garydoessolar.com/solarazma_pro_intro/

[@pepermintpilot1694]

Thanks Gary very much enjoyed this presentation. I, personally, run a 90kWh battery system (self built) and 10kWh of PV. One thing I think should be born in mind is being cautious of the battery discharge rate. Even though I have a relitively large pack I do think discharge should be regulated to between 0.2C to 0.3C of battery capacity. This will extend the longevity of the "pack". This I feel is even more important on smaller pack sizes such as the 3kWh pack you eluded too.

[@GaryDoesSolar]

Thanks for the kind words. The video is getting a great deal of traction - I'm very happy with it :-) Ok, that's a huge battery and I'm immediately jealous! Good point on discharge rates - thanks

[@sailrockpaperscissors8261]

great video , what batteries do you refer to ? how many disscharge cycles will they do and what is there cost . great content

[@GaryDoesSolar]

Thanks for your kind words about the content. In that video I don’t talk about particular batteries, but in this follow-up video I do: kzbin.info/www/bejne/rmmWpWSfeLKLrtksi=m9TDThS-oR6bBzKV

[@drerebus1]

Great video Gary excellent work....in US my particular electrical rates are much lower, however plugging in my values into your tool work well. You have put a lot of work into this and it's appreciated. Very nicely done videos, clear concise and and to the point. Keep up the great work and Cheers from the US.

[@GaryDoesSolar]

That's really great to hear this feedback - thank you! :-)

[@neillangridge862]

Thanks for a very interesting video. I too am on Octopus and found your description of their other tarrifs interesting. I will now try to find out more. I have had a 4kwh solar system now for 12 years and receive export payments of arround 55p per unit index linked with the assumption that 50% of our generation is exported. The agerrment has another 13 years to run. I need to find out if buying a battery will invalidate this profitable agreement. Thanks for your help.

[@GaryDoesSolar]

Hi Neil, you're certainly onto a good thing, and you probably don't want to void that. The good news is that you can add an AC Coupled battery which will not affect what's already there. See in this video: kzbin.info/www/bejne/rmmWpWSfeLKLrtk

[@handyman-at-home]

Excellent video as always Gary. Good to see how the utility has developed. 👍

[@GaryDoesSolar]

Thanks Chris - and yeah, the utility seems to be getting more and more popular. I'm being asked for lots of new features all the time (which is great, but I just wish I had more time). Hope all is well with you!

[@l.rod2827]

This was a really good video and your calculation model is quite accurate. I really like the Excel utility model you created to simplify these calculations, I wish I had something like that when I was figuring out my situation. One thing missing from these calculations is the cost of purchasing a battery system and in my case upgrading my current 5.7KW solar system was very costly and based on my calculation would take me about 12 to 15 years to pay it off. I was really aiming for a at the very max and 8 year return on investment. The one thing I really liked was in the event of a grid outage (blackout) you would still be ok depending on the battery current condition.

[@PazLeBon]

50k to save 2.4c electricity costs . its clearly gone wrong somewhere right?

[@PazLeBon]

if your ower goes out, you cut back and really prob only need a day or two of power. folk on here saying they have 30kw batteries are not people like you m8

[@GaryDoesSolar]

Cheers for the kind words - and great to see that you're getting good use out of it! Yeah, ROI is a tricky one - it's almost always better to buy the system you eventually end up with (after all the upgrades) right at the start, but hindsight is a wonderful thing. I'm hoping that videos like the one I just made, get people thinking ahead (budget notwithstanding) :-) My next video will be about choosing the right battery and calculating ROI etc.

[@Jaw0lf]

I have E/W solar as well as Tesla Powerwall with 13.5kWh Battery. It works very well during the Summer months covering my power draw from early morning to later in the evening. Out of interest I looked at your modelling utility and you have done a great job, however adding East and West as addable options will open this up to more people.

[@GaryDoesSolar]

Thanks for the great feedback on the utility. As it happens, I've been working on a new version of the Pro Edition of the utility (available to my Patreon members) that will handle up to 3 solar arrays on different orientations. I hope to release this in the next few days :-)

[@3Swillems]

Tesla uses li ion batteries in their cars. Their powerwall is li ion as well? If so; don’t put in a house or building where people sleep at night. It is not a safe enough battery technology…

[@GaryDoesSolar]

@@3Swillems I tend to agree. The new Powerwall 3 is expected to use LFP technology - much safer inside the home.

[@Jaw0lf]

@@3Swillems May I ask if you are a battery expert? Tesla uses li ion battery technology but not in all cars. LFP is now in Model 3, mostly standard range. The li ion batteries you are thinking of are the cheap batteries used in the powered skateboards. Dr Ewan McTurk is a battery scientist and has stated how safe EV batteries are now . They have far more safety systems and monitoring and do not self combust. If you are using the internet for research ensure that the figures do not include scooters, bikes or skateboards. It is many of these that have had problems with overheating and catching fire.

[@bigsteve777able]

we live in ireland and our first year of solar, we have 22 solar panels and just fitted second bank of batteries with total storage capacity of just under 20kw last few months have been bills free, still waiting for smart meter so not getting any back from electric provider, just waiting to see how close we get this winter to be able to leave national grid completely, thats the main aim we may need bit of wind as well will know after the winter has passed. yes batteries are a must if you want big savings for certain, but of course quite a big outlay.

[@GaryDoesSolar]

Thanks for sharing this Steve - hopefully not too much longer before you get your smart meter!

[@bryanlewens2068]

Thanks for the clear thinking on this. We put in 9 strings of 16* 250watt systems supplying our house and converted barns between 10-12 years ago under the FIT scheme. No smart meters were installed until 2 years ago so we didn’t know how much power was being used- only how much was being generated. The value of the FITs took our eyes off the value of the power itself. Of course the last year or so has changed that. In my own home we have an EV and a 1200litre thermal store and now use around 75% of what we generate annually. The other properties vary between

[@kevxsi16v]

36Kw that’s a nice big system. Well done for that

[@GaryDoesSolar]

Thanks for taking the time to comment and also your kind words, Bryan - Good insight in what you say - and something for me to think about for future videos...

[@bryanlewens2068]

@@kevxsi16v I was in my 60s when I put them in. I was lucky in that I knew an electrical engineer who had run power stations in the CEGB era. I thought the FIT scheme was incredibly generous and asked him if I was missing something. He told me that I wasn’t but it wouldn’t last (wise words) I wanted to put in all the systems in at the same time. That was where my education started- I made the mistake of applying for all of them at the same time which enabled the local DNO to restrict me to 3 slightly reduced systems because the local grid couldn’t cope. We discovered that the local system was operating at a voltage close to the legal limit and in summer when the sun came out, they cut out as our generation pushed the voltage over the upper limit Eventually the rules for connection to the grid changed and we could install the rest of the systems. Of course the FIT rates had been reduced as had the capital cost of the installation The cynic in me does wonder how much power we could save in this country if we operated at the bottom end of the voltage spectrum rather than the top end - or am I missing something?