Solar stats update - February 2024 - zero peak import?

Here's the monthly stats update for our solar, battery, and A2A heat pump system for February 2024.
Our home system summary:
6.8 kWp solar array split E/W
5 kW Gen 2 GivEnergy hybrid inverter
14.7 kWh GivEnergy batteries
A2A heat pump heating/cooling system
Myenergi eddi hot water diverter
Fiat 500e EV
00:00 Introduction
00:02 GivEnergy monthly report
02:33 Generation
02:54 Consumption
04:24 Heating
04:48 Met Office summary
05:28 Half-hourly totals
07:20 Bill and Savings
09:25 Closing remarks
Please note that Tim is not a professional consultant, just an enthusiastic amateur, so cannot reply to requests for advice or opinions on specific systems or green investment opportunities. Thank you for your understanding.
Support the channel and get £50 of credit by switching to Octopus Energy using my referral code:
share.octopus.energy/cute-qua...
Or buy us a coffee:
www.buymeacoffee.com/timandkat

[@keithw32123]

Hello. I live near Seattle, Washington State, USA. Great visual presentation of your data showing amazing performance of your system. Great job electrifying your house and transportation. Very detailed tracking. Also, on some days 50 percent of the electricity you import into your home is from WIND TURBINES with another 5 percent from nuclear. Your country has done a really good job decarbonizing the UK grid. Five Gold Stars should be awarded.

[@TimAndKatsGreenWalk]

Thank you. The UK is doing pretty well, for sure. The grid carbon intensity is coming down every year so I like to think we're on the right track. Plenty more still to do, of course.

[@Jaw0lf]

Great stats and amazing how cheap you can run your home. I have the same ASHP, 8kWh Solar PV but split over E/W roof and a Tesla Powerwall. My home uses about 27kWh 3 adults and mostly at home all day. We have a detched 5 bed house and used 238.89kWh in February for the ASHP, Solar provided 198.6kWh and we also had some days where we only used 7.5p electricity and solar all day. This is a wonderful feeling! We used 1330kWh for the month approx 70% of which was cheap rate. We also used 343.03kWh for the EV to complete 1164 miles at a cost of £27.05

[@TimAndKatsGreenWalk]

Our array is also split E/W, which works great in the Summer for spreading the generation out over the day. Not so great in Winter, however! I'm hoping to add some South facing panels at some point though, as we've got a small amount of space left on the roof. More on that in a future video!

[@Jaw0lf]

Yes that is what I have found E/W split gives a good use for a longer period of the day. I looked at getting some more panels added to the south facing gable end but unfortunately the DNO say no and want me to update to 3 phase electricity supply. I hope you have better luck!

[@olninyo]

Impressed you can last the whole peak period without running out of battery. Our 6 panels and 5kw battery run out very very quickly in the winter months.

[@TimAndKatsGreenWalk]

We have a pretty big battery capacity of 14.5 kWh, and 18 panels, so that helps a lot. Even so, we run out of battery when it gets super cold and have to run the heating lots.

[@b5bobby]

Many thanks for all your videos in general, I’m looking forward to March figure and seeing what the whole year energy bill come out as as you are closest person I’ve found to the system I’m planning myself, although I’m likely to be a year and a half behind your solar installation, I’ll hopefully only be a month or so behind on the mixergy hot water tank installation, (looking forward to those vids too). You and Gary does solar (who I know you’ve met) are my favourite KZbinrs and I’ve grown in confidence that I’m planning the right system to have a £1 standing order to Octopus and probably still end up with a year on year increasing positive account balance, the surplus might even pay the deposit on cruise with luck. 🍀

[@TimAndKatsGreenWalk]

Fantastic, I'm so pleased you've been finding the videos helpful. Gary is an absolute legend and we've become good friends so I'm sure he'd be pleased to hear you've enjoyed his videos too. Best of luck with your install I bet you can't wait!

[@jchidley]

Thanks for all of your videos and, especially spreadsheets and insights. I have been looking to move to greener technologies for several years and getting ready - by adjusting my plumbing and insulation - to install an optimal system, at a reasonable price, for my situation. My house in London is probably a similar size to yours but constructed in the 1930s with brick, tile and suspended floors. Interestingly my heating needs (using gas at the moment) are between 4 and 5 times yours (lower in the colder months and higher in the warmer months). I think that this is a reflection of the poorer heat loss and, possibly, higher heat capacity (and the fact that I'd expect a COP of around 4 in my final solution) of my home. Michael de Podesta and John Cantor do similarly in-depth and insightful videos (and websites). Have you looked at them?

[@TimAndKatsGreenWalk]

No problem, I'm glad you've found the videos helpful. I've not seen those other channels, I'll go check them out, thanks for the tip.

[@ryannowell3802]

North East Scotland; 12.3pkw solar array, 7kw ASHP and 10kwh of battery. Produced 467kwh and consumed 648kwh all at lower rate on Octopus Cosy tarriff

[@TimAndKatsGreenWalk]

Wow, great going. Nice big array, that, I'm very jealous.

[@geoffreycoan]

Good update Tim. Shows you have a good well sized battery for your house and heating demand. Good result. We’ve just had a replacement 9.5 battery fitted after running all winter on just the 80% DoD 5.2 which was enough to get us through most of the evening peak but nowhere near enough to run the house and ASHP all day. The 9.5 is already making a difference of being able to run much more of the day on cheaper agile rates. Our overall bill (excluding DFS) is similar, £91 on Agile, but 1250kWh imported and 260kWh exported - much more active battery management, force exporting when the import rates are lower than the export.

[@TimAndKatsGreenWalk]

That's great to hear, I'm glad the new battery is working well for you. I've not been brave enough to try Agile, but maybe one day. I'm amazed how well we sized our battery system in the end. It was based on some pretty dodgy modelling I did well before we had any proper data so I like to think I did something right and it wasn't just a complete fluke!

[@geoffreycoan]

@@TimAndKatsGreenWalk Agile has worked out for me but my ASHP consumption is way higher than my battery storage so it was a question of how to fund the kWh as cheaply as possible. Apart from the cold period in December when peak rates reached 65p/kWh, the rates are usually around 15p with peak 30-40p/kWh so as long as I can avoid drawing in the peak, its been cheaper than any other tariff. Does need some mechanism to manage the battery activity though, I wouldn’t want to do it manually

[@John-FourteenSix]

Excellent report Tim. NW UK. 3.2kW (due south facing) array, 6kW ASHP. 19kWh Batteries. Our February figures are: Imported 918kWh Exported 45 kWh Generated 105 kWh (Max day 11kWh) Home, Hot water and EV = £93 Total 7-10 degrees ‘C’ seems to be the switch-over in energy usage. It’s only going to get better from here!!! Net zero cost would be amazing.

[@TimAndKatsGreenWalk]

I think I'll be a little short of net zero for the first year, but I'm hoping to address that with some potential extra generation at some point, so I fully intend to reach that goal sooner or later! I guess it will greatly depend on the level of the export tariffs this summer.

[@John-FourteenSix]

My roof is already full, but I’ve spotted a RidgeBlade roof mounted wind generation system (on the web). However, there doesn’t appear to be any installers in the UK yet. This could potentially trickle in, relative to solar, a constant in 2kW.

[@TimAndKatsGreenWalk]

@@John-FourteenSix I've considered that system too, but ultimately decided a few extra panels would work out better for us overall. Although I wouldn't say no to both!

[@ianjones6849]

Excellent detail. So my first ever monthly figs(well almost 2nd to 29th Feb) 🙂 N E Wales, SW facing, no EV are: Imported 154kWh; Exported 59kWh and Generated 143 kWh. I'm on the Octopus Outgoing Fixed Lite 8pkWh rate (gas is on a tracker tariff) was told lite was the best rate for the Octopus Go tariff with no EV. Will prob switch to Intelligent Flux in April. Not sure if my monthly figs are good as I am a solar/battery virgin and still getting to grips with the detail. Your videos are very informative for me. 🖕

[@TimAndKatsGreenWalk]

Oh, don't worry, you'll soon be a data expert in no time! You'll get a good feel for your system over the coming months and I'm sure you'll get a lot out of it, both in terms of generation but also as a new hobby! It can be quite compelling watching the data each day.

[@colingoode3702]

Good stats Tim. 155.03kWh generation for Feb for me from a ESE 10 panel roof. Highest day 12th Feb at 14.5kWh. I'm having 5 extra panels on a NW roof & an extra 9.5kWh battery installed next week to boost afternoon generation & storage capacity. Extra battery capacity will also give us more export options. Currently we are on Octopus Intelligent Go & our EV gets topped up most nights.

[@TimAndKatsGreenWalk]

Very nice. I'm also considering some extra panels but I'll cover that in a future video 😉

[@colingoode3702]

@@TimAndKatsGreenWalk The 5 new 420w all black panels will be half the price I paid for my 415w panels last March. The battery price has also dropped but not by the same % as the panels.

[@TimAndKatsGreenWalk]

@@colingoode3702 that's amazing.

[@John-FourteenSix]

420w panels sounds good.

[@colingoode3702]

@@John-FourteenSix Correction. I just double checked & they are 425w Perlight Model PLM-425OM10A-44B Power 425 watts Dimensions 1096 x 1812mm

[@Pressure_23]

Apologies if this is a question you’ve answered before but: doesn’t your heat pump work more effectively with “little and often” heating throughout the day? That’s the way our ASHP / high mass house system operates best, so hard for us to run just during off peak. Is your battery big enough to power the heat pump all day?

[@TimAndKatsGreenWalk]

So yes, we do still run the heat pump during the day, trickling heat in slowly as you suggest. Heating overnight during off-peak helps prevent the house cooling down too much so that less heating is needed during the day and our batteries can last a bit longer. We've been lucky with the mild temperatures during Feb (and some input from the solar) meaning our batteries have just about lasted the whole day even with the heating running (it's come pretty close to running out on a few days though!).

[@twelvebears1971]

I don’t know about you Tim but March was particularly rubbish for us. Jan and Feb were pretty close to the PV-GIS but March was terrible!

[@TimAndKatsGreenWalk]

We were surprisingly close to PVGIS in March, as it happens. Full stats incoming shortly! Plus first full year summary.

[@davidcoates6768]

You did well to get so much in the off peak window, would be good to see the full year off peak percentage in the next one. If intelligent becomes an option, do you think that would be cheaper than flux?

[@TimAndKatsGreenWalk]

Intelligent vs Flux is a really good question. Especially now that the export rate for Intelligent is higher than it used to be. I don't know off the top of my head, I'll have to do some modeling to be sure, but my hunch is that Flux will still win out during the sunniest months (May, June, July, August) because the export rate is so good, but during the shoulder months and Winter Intelligent may well be better. It all depends on how much export you expect relative to your consumption. Probably needs a nice complicated spreadsheet!

[@JohnR31415]

My peak import last year was 365kWh - for the whole year. And that includes half the year on Go, not Intelligent, and most of the year without decent export rate. If yo can do similarly then that super cheap rate is just unbeatable.

[@MrKlawUK]

have you changed anything on your setup? Even running off battery (which you’ll still need as the daylight hours are still quite short) I get approx 1kwh a day peak due to slow response of the inverter to changes in demand etc.

[@TimAndKatsGreenWalk]

The only thing I've changed recently is to run the heating overnight during the off-peak times so that we need less heating during the day. That helps the battery last a bit longer, and combined with the milder weather has meant we only got close to running out on a few of the days in Feb. Our inverter seems pretty good at balancing the load changes so very little seems to get pulled from the grid during the day. We have a Gen 2 hybrid inverter, do you have a Gen 1 by any chance? I wonder if that's the difference?

[@MrKlawUK]

@@TimAndKatsGreenWalk its an AC3.0 so possibly

[@TimAndKatsGreenWalk]

@@MrKlawUK yes, maybe. I know they've improved the responsiveness with each iteration and the AC3.0 was one of the earliest inverters they did so that does sound plausible.

[@SolarJourneyWithMatt]

February was pretty poor for me. Only 155kWh against an average of 220kWh. Only had 4 days above 10kWh compared to 10 for Jan. Hoping for a much better March. Will you be swapping back to Flux? I'm just trying to run the numbers now to see if it's worth it yet or wait till April

[@TimAndKatsGreenWalk]

I think April will be the time to switch to Flux, for sure. I'll be keeping an eye on how much we export and switch once that starts getting decent.

[@terrymackenzie6784]

I'm surprised you're not on Intelligent Octopus Go the 2 extra hours and higher export rate makes a big difference to me especially if you need full charge in the car. It's also set and forget tariff e.g. I don't bother to change anything when I know the sun is shining the next day

[@TimAndKatsGreenWalk]

Sadly neither our car nor charger are yet compatible with Intelligent Go, that's the only reason we're not on it yet. Hopefully we'll be able to get it next Winter.

[@KenH-63]

Luckily the Zappi is (now) compatible....and it's proving good over winter. Not sure what to do for summer - as I can get the 15p export rate this is better than the "Lite" you currently get Tim. BUT is it better than the Flux export rates (taking into account the much less cheap off peak import tariff) ....struggling to model the numbers (not quite knowing what my powerwall would do re import/export either!) It managed flux well with solar surplus. Would Intelligent Go alter your view? I do wish Octopus would come up with an all weather tariff that would avoid switching - I have made this point to them!

[@terrymackenzie6784]

@@KenH-63 I have a Zappi too and think I will stick with IO Go in the summer and keep changing the home battery over night I don't think it does LFP any harm keeping it fully charged all the time that's why I have an LFP EV

[@Ryanhothersall]

For me here in Adelaide South Australia, February is the last month of summer. Generated 1.08 mwh from the north facing 6.3kw House system and 1.07 mwh from the east/west shed system for a total of 2.15 mwh. March is the beginning of autumn, so days will start to get shorter. I do a similar thing to you Tim, in that my electricity plan has a super off peak rate of AU$0.8c from 12 am to 6 am, so that's when the EV and house battery recharge off the grid ready for the peak price of AU$0.50c comes in at 6 AM.

[@TimAndKatsGreenWalk]

I bet you'll still be generating more than me as you enter Winter and we enter Summer! It's all good though.

[@Ryanhothersall]

@@TimAndKatsGreenWalk yes I probably will be. Our worst month, June, I generated a combined 636 kwh from both systems last June. Will be interesting to see what happens this winter.

[@bearders22]

Can you tell me what your highest daily generation has been in the last 12 months. My system has only been live since October so I’m curious what is achievable

[@TimAndKatsGreenWalk]

Just about 40 kWh. Obviously it depends a lot on the installed system and the orientation etc. so take a look in the video description to see the basics of my system for comparison. Also, take a look at the PVGIS tool online where you can set up your system to see how much you're likely to get per month. It's pretty handy and seems quite accurate for me so far.

[@bearders22]

Thank you. I have 12 south facing panels (4.98kw) non shaded. I achieved 22kw earlier this month@@TimAndKatsGreenWalk

[@TimAndKatsGreenWalk]

@@bearders22 oh yeah, you'll definitely hit 40+ on a sunny day in June.

[@bearders22]

Thanks - just found the PVGIS tool. Projecting a 680 month in May @@TimAndKatsGreenWalk

[@TimAndKatsGreenWalk]

PVGIS predicts 721 for May for our E/W spilt array, so not too dissimilar. 748 for June. Last year we had crazy values well North of 800 for both May and June, but that seemed to be pretty exceptional and I'm not expecting that every year!

[@geoffreycoan]

The Axel/GivBack DFS sessions don’t sound to have been as profitable as they could have been. Just for simplicity I stuck with Octopus and we’ve had the 2 live sessions last year and (including today, yesterday and the day before), 12 test sessions. Axel and Octopus’s bids got rejected yesterday and today but Octopus have still funded both sessions. Only 30 minutes but every little helps !

[@TimAndKatsGreenWalk]

Yes, I heard about that, very interesting indeed. Looks like Octopus was making a point to the ESO. It's been an interesting experiment trying out the Axel system this Winter but as you say not as profitable as I was hoping. I hear next year the whole system will be completely different so we'll see what happens.

[@DumfriesDik]

I am interested in what you are doing. Can't help but notice you don't mention the cost/depreciation/replacement in you information which skews things. How long before you have to maintain or replace any hardware? My February bill will be about what you predict yours would have been. I don't have solar, but would consider a battery to help reduce the peak usage. I am just not sure how viable it would be without solar. Interesting video, thank you.

[@TimAndKatsGreenWalk]

I've covered the cost in other videos ( kzbin.info/www/bejne/o2LQep-gjtl5mtUsi=L0EArko2dw6YqMqM ). Batteries last 10+ years, solar 25+. The payback will be about 7 years. Batteries are great on their own as long as you can get a good time of use tariff like Octopus Go. Look at your typical daily usage then multiply by the difference in tariff between the peak and off-peak rates to see how much you could save per day.

[@DumfriesDik]

@@TimAndKatsGreenWalk Thanks for that info Kat or Tim! I need to get some quotes I think, seems scary putting so much money into something I don't know much about!

[@TimAndKatsGreenWalk]

@@DumfriesDik no problem. Battery prices are coming down pretty quickly at the moment so you might be pleasantly surprised. Also, check the time of use tariff terms because some require an EV, for example. You don't want to get a battery and then find you can't charge it using cheap power!

[@TimAndKatsGreenWalk]

@@DumfriesDik oh, and check out the channel Gary Does Solar. He's got lots of great videos about solar and batteries that might help.

[@DumfriesDik]

@@TimAndKatsGreenWalk I have a BEV already.