Is Intelligent Go now the best all year Octopus tariff? - Rule of thumb update - July 2024

[@stevegame3000]

Thanks for a great update. Happy that I am on Intelligent Go and can forget about switching (until the tariff rates change). Now all we need is some sun 😀

[@TimAndKatsGreenWalk]

Yes, indeed, July has been rubbish so far! Looks like we've got a few sunny days on the way but I doubt it'll make up for the poor start to the month.

[@elslopez]

@@TimAndKatsGreenWalk Well maybe all this rain will clean off the panels somewhat? My natural solar panels (The Lawn) is happy!

[@TimAndKatsGreenWalk]

@@elslopez a day of rain every now and then is certainly not unwelcome.

[@devjon123]

@@elslopez I got really indignant the first time i spotted bird poo on the panels. We have the occasional visit from a flock of seagulls as well as the usual pigeons. Fortunately the regular rain is very effective at cleaning of the poo 🤔

[@elslopez]

@@devjon123 Still, I bet they are not as clean as you would like eh? 😉

[@mark82421]

Very detailed video (love it!) and OIG is the best rate, I have been on many and found OIG is the best having PV, 20kW batteries, ASHP and EV. Gone from approx 3500 pounds to 600 pounds energy cost per year.

[@TimAndKatsGreenWalk]

That's a great result!

[@TonetheBone]

This is excellent. Using ratios for the tariffs is the most useful as it lets everyone see their circumstance. I had done some modelling for my specific set up but only for 2 tarifs to see when it makes sense to change (my set up I would describe as large solar generation, low consumption (no EV or elec heating)) So that puts me more to the right hand side of your graph and i will aee how it compares with my sums. But in closing, excellent info - thank you very much!

[@TimAndKatsGreenWalk]

No problem, and thank you for the kind words. I've realised that if export rates drop below off-peak import rates (which could happen) a different strategy and rule of thumb will be required, so I'll be looking into that at some point, but for now at least I think this is a decent way to do the calculation.

[@devjon123]

A really interesting video, thanks for putting in all this work for the community. We don't have a car, or a heat pump though that is on the horizon. What has surprised me is our ratio of consumption to export, it's not at all what my gut feeling told me. System went " live " in December of last year and looking at the figures so far using the excellent " Inverter "app I see that we have generated 3264kWh and consumed 1736kWh so far. We switched to the " Agile " tariff several months ago coming from Flux, combined with the fixed 15p export, and think we will stick with that until the first year is up and take a look at the figures again then.

[@TimAndKatsGreenWalk]

That's pretty good going for just over six months of generation. We generated 5300 kWh in our first 12 months.

[@Lawrence7of9]

Great video, thanks for doing the data work for us. This all aligns really well with my own experience/research so good to see a sound confirmation. Cheers

[@TimAndKatsGreenWalk]

Good to hear.

[@johnd3309]

Got octopus here at this moment installing my ohme pro charger. I was making money from IOF but not happy with them exporting in the off peak period as I’ve paid for the conversion from filling from the grid and the conversion exporting to the grid. IOF exports from 4:30 till 9pm every night. So I’m going to switch to IOG as I can export most of my 19kwh battery before the off peak period and then charge my battery to 95% leaving space for excess solar if needed. Glad you produced this vid Tim convinced me I was doing the right thing.

[@davidcoates6768]

Awesome video (and spreadsheet) again! Hopefully Octopus can approve the givenergy charger for you before autumn.

[@TimAndKatsGreenWalk]

Thank you! Yes, I sure do hope the GE charger will be added to IOG soon. I'm gonna chase Octopus to see where they're at with it.

[@dalecard9158]

Hi Tim, Thanks for sharing. I had come to a similar answer to you but through "feels" rather than hard logic. Thanks for doing the work. In my case, during the sunny seasons, the fact I have a DC coupled battery means I can discharge early morning about 2.5kwh, export everything during the day and top up with what would otherwise be clipped energy which tips them marginal 3 months of summer well away from flux into IO territory. Thanks again.

[@TimAndKatsGreenWalk]

No problem. Avoiding clipping is a really tricky thing to get right so good job managing that.

[@redshift3]

Interesting, thanks. I agree with your conclusion. I have a large PV array (10.2kWp) and a moderate EV mileage (500kWh/month). I calculate (using my own method) that Intelligent Go is best for me all year. Considering your methodology, in June my Generation (1429kWh) / Consumption (815kWh) = 1.75 which suggests that for this sunniest month Intelligent Go is marginally not quite the best, but it is the best for the 11 less sunny months e.g. May 1191 / 760 = 1.56.

[@TimAndKatsGreenWalk]

It certainly makes life easier not having to switch. It'll be interesting to see if this remains the case for the foreseeable future or not.

[@warrentaylor405]

This approach really does bring a level of science and objectivity to tariff selection. I like the assumptions/caveats set out in the earlier video. Congratulations. May I ask how I can download the spreadsheet please?

[@TimAndKatsGreenWalk]

Take a look in the video description, you should find the link there. Grab your own copy by following the instructions on the first tab. Enjoy!

[@warrentaylor405]

@@TimAndKatsGreenWalk Thanks. Warren

[@terrymackenzie6784]

That's good news as I've been on it for the last ten months so simple as you don't need to keep fiddling with it. I force discharge some days when it's sunny but that's not that often this year and it only makes me about 70 pence a day after you buy it back I do it more to cycle the battery

[@ians3328]

Right there with you. It is so simple to stay on IOG for the full year. I could get some more exporting the whole battery each night too but happy not to bother for the 60p it would get. I only force export once a week to keep the battery SOC sensible. Now if they have some "help the grid" prices then that is different.

[@TimAndKatsGreenWalk]

It certainly makes life easier, not having to worry about switching.

[@redshift3]

I force discharge and recharge every night. I bought the battery to put it to work.

[@FFVoyager]

@@redshift3 that was my thoughts too - even if I export and then buy back just 5kWh every day for a year that's still a not inconsiderable additional £150. (Earning me an extra 25% and shortening my return by a year!) Octopus paying more to do that during saving sessions would be even better!

[@olninyo]

Mega useful

[@kevinoconnor2051]

Excellent work, clear and concise. I'm not using Octopus yet as I've just started the journey into PV and battery storage. I'm wondering if the daily standing charge changes between these tariffs and if so how much it affects a single months value? Or is it already included in your calculations? I've noticed with other suppliers that if you select a better rate you are also given a higher standing charge so you need to look closely if a lower tariff is actually better.

[@TimAndKatsGreenWalk]

Thanks! From what I can tell the standing charges are the same for all these tariffs, so it wouldn't change the rank ordering. If that ever changes though it would make the calculation somewhat more complicated, so I'm hoping they stay the same regardless of the tariff!

[@TimAndKatsGreenWalk]

Your question made me paranoid so I just double checked all five tariffs and they do all indeed have the same standing charge. Phew!

[@radiotowers1159]

Nice one Tim, I changed to Intelligent Go at the start of June and have just (12 July) got the smart meter to finally work as it should. Changing tariff should be simple but smart meters dont always play the way they should and a few emails need to be sent. I will download the file to the PC and see how it compares as I only have one 6.5 growatt battery so it about 4 kwh short for daily consumption in winter.

[@TimAndKatsGreenWalk]

No problem. Having a smaller battery than your typical daily usage will change things slightly, for sure, but I don't expect you'd go far wrong with IOG in either case.

[@DaveB-r7u]

Hi Tim, thank you for the video. Very interesting thought process and spreadsheet, thank you also for sharing. I am currently on Agile and fixed 15p export. However since 1st June, I am trying a different idea (summer only June-August) At the moment I do not charge or discharge my battery to the grid (at any time as no need, flux tariff only) I just top up with Solar. (The battery goes down to about 60% over night and is now at 100% by about 10 ish. I am then exporting at 15p till about 20:30. In September I will set the battery to charge if the rate is below 10p for any 30 min slot (night or day). I can do this for free on Wonder Watt. So here are my costs via Octopus app (I use about 14 kWh a day) June - cost £3.67 - export £114.24 July (so far) - cost £0.80 - export £50.05

[@TimAndKatsGreenWalk]

Agile is very difficult to compare to the other tariffs because it changes so much. But if you're getting good results from it then that's the main thing.

[@devjon123]

@@TimAndKatsGreenWalk Hi again Tim, I have just visited the " Octoprice Compare " and fed my details in. If I had been on the IOF tariff I would have earned an extra £374 in export income but paid £406 more on import so there's not a great deal in it. I'm sure the figures are skewed somewhat as on several occasions I have forced export to drain the battery so I could charge at a very good, sometimes negative rate.

[@edwyncorteen1527]

Thanks for another interesting Video, after your first one confirmed my thoughts to just stick to Intelligent Go which I did I am happy to see this was the correct idea! I have a heat pump and this regularly emptied our Powerwall over the winter so I took the opportunity of no VAT and Tesla selling off the remaining stocks of V2 Powerwalls to add a second, I have set these up so they charge overnight, the Powerwalls supply all house use during the day and all Solar is exported, this seems to be working very nicely and is not putting too much strain on the batteries, I was a bit worried last winter that with the single Powerwall being fully charged and discharged every day it may be affecting its long term capacity.

[@TimAndKatsGreenWalk]

Very nice. I was also finding our batteries were getting depleted over the Winter by the heat pump, so I started pre-warming the house by boosting the heat pump during the cheap overnight period. That way we needed slightly less heating during the day and it meant we were more often able to get through without using any peak power. As long as you're able to exclude your bedroom from the overnight heating then it works pretty well. Adding more battery capacity is the other solution, of course!

[@elslopez]

You nailed the recomendation 👍

[@TimAndKatsGreenWalk]

I do my best!

[@pmac6584]

Very useful thanks. Something to note, I am on intelligent Go without a compatible car/charger. I have a BMW i3 and a dumb charger but octopus said as long as I am able to put up with the bugs between their system and my car then I can go on the tariff. It has been 95% ok but I have had a few failed overnight charges over the past year. The savings are worth it though for me.

[@TimAndKatsGreenWalk]

Interesting. So they're not attempting to schedule via your car then? Are you just setting up a manual schedule? I shall have to contact them to see if we can do the same until such time that the GivEnergy charger is compatible.

[@dougbamford]

Very useful. Don't suppose you have any intel on when the Givenergy EVSE will be available with Octopus? Currently only Zappi and a few others are compatible.

[@TimAndKatsGreenWalk]

No, I don't, I'm afraid. I've been meaning to get in touch with Octopus to see how far along they are with that. If I find out anything useful I'll post a video.

[@David-bl1bt]

I have a GivEnergy charger. I have just used Octopus checker and it states that my system Tesla, GivEnergy AIO and GivEnergy charger IS compatible with IOG

[@dougbamford]

@@David-bl1bt I guess that is because the car is? I have an MG and they don't communicate with Octopus.

[@David-bl1bt]

Yes, the car needs to be compatible, too. I was just responding to your query relating to the GivEnergy charger compatability.

[@TimAndKatsGreenWalk]

@@David-bl1bt one or other of EV or charger needs to be compatible, it doesn't need to be both. The Tesla is compatible with IOG but the GE charger isn't yet.

[@UK-Cycling]

Top video. Thanks Tim and Kat. Have you any update from your friends at GivEnergy when we will be able to install and run together their all in one and Gateway with their legacy batteries? Best regards Martin

[@TimAndKatsGreenWalk]

My reply keeps getting deleted for some reason, it's a bit weird. Hopefully this (third!) time will work. No news yet but if I hear anything I'll spread the word.

[@UK-Cycling]

@@TimAndKatsGreenWalk thanks 👍💪

[@DavidThorneycroft]

hi Tim had giveenergy AIO system installed May this year with tot 10KWp (7KWp on SW roof and 3KWp on NE roof) and signed up for Octopus intelligent flux. Seems to be working out quite well but we have a 4 bed house with just the 2 of us pensioners and our total ground floor is underfloor electric heating. Elec was cheaper when we had it installed. We also have a hybrid with small 9.8KWh battery with giveenergy charger. Iam thinking we may need to change our tarriff to possibly Go but we do not have any historic data to make an informed decision. I then came across your channel with your rule of thumb stuff and thought thats what I need, however iam unable to find your spreadsheet downloads so I can plug in what data I have etc to try to getsome kind of answer. Can you point me in the right direction for download etc. For info my solar gen to usage ratios for May thro Aug are 2.23, 3.13, 2.74 and 2.63. Many thks for your channel and all the good info.

[@TimAndKatsGreenWalk]

No problem. Take a look in the video description, you should find a link there. Follow the instructions in the yellow box on the first tab and you should be good to go!

[@petegale9598]

Cheers for the spreadsheet. Used it to compare Flux vs IOF (no EV here). Looks like IOF wins over Flux for 8 months of the year. Interestingly IOF wins over IOG too for Apr-Jun (and when I have stats maybe Jul/Aug) as my ratio was circa 2.3, 2.7 and 3.0

[@TimAndKatsGreenWalk]

Wow, you must have a decent sized array to be getting that level of generation. I'm envious.

[@petegale9598]

@@TimAndKatsGreenWalk it's more that my electric consumption is very low. Gas CH though.

[@TimAndKatsGreenWalk]

@@petegale9598 in either case generating more electricity than you consume is always a good place to be. And if you do end up electrifying your heating at some point then you're already well set up for it.

[@bill_heywood]

Really useful thank you. I’m on Intelligent Go but I realise that I could be force exporting a lot more from my batteries. They are LFP batteries, is there any reason not to discharge and charge them daily?

[@TimAndKatsGreenWalk]

Opinions differ on this, some say it's not worth it due to reducing the lifetime of the batteries, whereas others think you should make the best use of your batteries while you have them. I fall into the second category, the batteries are there to be used to their fullest. They all tend to have unlimited cycle warranties nowadays anyway, so the manufacturers are expecting you to cycle them every day.

[@manzourahmed3383]

What about agile? Is it too uncertain to model?

[@TimAndKatsGreenWalk]

Yeah, it's too volatile really. It'd take more effort than I'm willing to expend to include it!

[@FFVoyager]

We've had our system going for all of 3 weeks - pleased to see that our consumption ratio of our 1970's 3 bed semi is 1.76. Currently we are giving away our generation while waiting for the export MPAN but I'd guessed that we would go onto IOG when it came through and I'd look again next spring. Perhaps not. Currently charging the car from the sun for nothing which is a nice feeling - I've just got convince myself that charging the car and getting paid 8p/kWh is better! 😄

[@redshift3]

On Octopus Intelligent Go you can charge your car for 7p/kWh and sell your export for 15p/kWh.

[@TimAndKatsGreenWalk]

Yeah, it's amazing how much the export rates have increased over the last year or so. We've gone from self consumption as the goal to exporting as much as you can! Takes some getting used to.

[@FFVoyager]

@@TimAndKatsGreenWalk I wonder if you would add a column to your spreadsheet - a 'what it would have cost without solar and a battery'. Using whatever tariff (Flexible Octopus is currently 22.10p/kWh) just to keep in mind how astonishingly good even one of the less beneficial tariffs are! I'm looking at not spending around £1200 over the next 12 months and 'getting' £550. (A net benefit of £1750 and a payback time of 8 years)

[@elslopez]

@@TimAndKatsGreenWalk Had a chat with a guy about 18 months ago now, who was peak smug with his solar setup, in the fact that had avoided a smart meter and managed to keep one of those old rotating disk meters... ...and proud of the fact he could make it spin backwards... probably not so now... But even in the USA it is considered "lucky" to get NET metering... and here we are with BETTER than 2:1 currently ;-)

[@TimAndKatsGreenWalk]

@FFVoyager that's a good idea, I'll have a think about how best to include that. Should be simple enough.

[@paulinblack9036]

So, for someone just getting a new Enphase system installed (and no EV), I assume that it would be best to start on Flux, gather data and then hope that Intelligent options become available beyond GivEnergy batteries?

[@TimAndKatsGreenWalk]

You don't need to gather data, you should have an estimated monthly generation profile from your installer, or else use the PVGIS tool to do that yourself. You should also already know your typical monthly consumption from your electricity bills. You have everything you need to know to put into the rule of thumb before you get your system.

[@pmac6584]

I let them attempt to set up the schedule and it works with the car most of the time. If I notice that it hasn’t started then I set it manually in the car. If I absolutely need to charge then I set it to 11:30 in the car after the octopus app has finished doing the schedule on their side. This has been ok so far.

[@TimAndKatsGreenWalk]

Ok, good to know, thanks.

[@Jaw0lf]

The big point is you must have an EV if you want to be Intelligent Octopus. I have been on the intelligent Octopus Go for a long time as I am a high use electric wise. Glad to see I have been right!

[@TimAndKatsGreenWalk]

Yup, I mentioned that near the end. A good reason to get an EV!

[@cingramuk]

Are Octopus checking you have an EV still when you sign up? As technically, you could have a Zappi and enrol and it doesn't do a test charge any more, so potentially you could sign up without an EV. And the T&C's just state you need to have a device connected, which you would, the Zappi. I appreciate installing a Zappi with no car seems mad, but in the right house (all electric w/ battery), it could pay for itself pretty quickly 😉

[@TimAndKatsGreenWalk]

@@cingramuk they require you to do a charge every now and then, or else they might move you off of IOG, I believe.

[@cingramuk]

@@TimAndKatsGreenWalk they removed that clause some time back, before Zappi was made official. Now you just have to have a 'registered device' with no break of more than 30 days, no requirement for charging every 30 days any more. So technically you could sign up with just a Zappi and no car. But I think I read they started wanting V5's or evidence of a car before allowing you on IOG some time back, not sure its the same. I went from Agile > Go > IOG all in the app and never got asked but it was a while ago.

[@ungrim97]

Yeah this matched my observations. Especially with the decidedly poor solar gain these few months

[@TimAndKatsGreenWalk]

It's not been the best, that's for sure.

[@katebux1329]

This is a silly question but we do have a Zappi charger but no EV yet, do you know if we can be on the Intelligent Go tariff. Thank you

[@TimAndKatsGreenWalk]

You need to do a test charge to sign up for IOG, so if you can borrow an EV briefly then you should be able to. However, you may need to do periodic charges in order to stay on it longer term.

[@matthewbruce1040]

I have an GivEnergy All In One battery. Can you point me to how I can find out my monthly figures to use in your rule of thumb calculations? I can see daily figures in the app and website but is there a quick way to get the monthly figures?

[@TimAndKatsGreenWalk]

Yup, just select monthly in the drop-down in the top right corner when viewing the energy chart.

[@mentality-monster]

Can you be on Intelligent Go and Agile Export at the same time...?

[@TimAndKatsGreenWalk]

Yes, it seems you can: octopus.energy/help-and-faqs/articles/which-export-tariff-can-i-combine-with-my-import-tariff/

[@malcolmbennett4325]

Helpful research Tim. Although I have everything GivEnergy I can’t have intelligent Go as my EV is the Zoe r135 ze50 doesn’t qualify but I do have the new smart EV charger from GivEnergy which might partly qualify me. I only do about 5000 miles per year, so I’m curious to know how such low mileage is of any use to Octopus Energy. I wonder if I had a qualifying EV but had even lower annual mileage would Octopus still give me intelligent Go? Perhaps one day I will be allowed to have intelligent Go for my Zoe. I will email them.

[@TimAndKatsGreenWalk]

I think you only need to do one or two charges per month on IOG for them to let you stay on it. We're in a similar situation, hoping the GE charger will be added to IOG before the Winter.

[@malcolmbennett4325]

Octopus Energy have come back to me to say, although I have an EV that doesn’t qualify for iGo I would with a qualifying EV even if I did very low mileage. Which occurs with your reply.

[@IanHarrison-q7e]

Hi there, just enjoyed your videos on this. I am a blind owner of a Powerwall 2 and am trying to get it to allow me to export back to the grid manually My DNO allows me to export up to 6kwh but I am supposed to get Tesla to switch on this capability. I've tried my installer and the internet without success and may be forced to go to Intelligent Flux once integrated with Tesla. Can you help me in any way? Regards Ian

[@TimAndKatsGreenWalk]

I'm afraid I don't know much about how the Powerwall works. I'd have thought there would be controls in the app somewhere, but failing that you may have to ask Tesla. I'm sorry I can't help more.

[@johnh9449]

In the case of maximum self consumption (no overnight AC charge and generally no import in summer) Flux gives a better export rate. For Flux or Intelligent Go in summer if AC charge is enabled something subtle happens. If the battery reaches 100% full then you'll export sooner and longer next day and generally make up the cost of import in export, less conversion loss. If your battery becomes 100% full before the overnight import period ends - it idles doing nothing whilst your house imports at cheap rate which you may pay for or may get back from early and extended export. If you did have AC overnight charge enabled it could therefore help to limit the charging hours so 100% isn't reached overnight - more like maximum self consumption.

[@TimAndKatsGreenWalk]

But it doesn't matter if your house imports from the grid during the off-peak time, that's just the same as if you were charging your battery to use later anyway.

[@TimAndKatsGreenWalk]

Use this to help you try out different charging strategies to see how it affects things on different tariffs: garydoessolar.com/utilities/dailymodellingutility/

[@kpnuts6746]

Hi Tim & Kat. Could you give some advice please. I have a solar array which feeds two 8 kWh Givenergy batteries and drive a Kia Niro and use an Ohme home pro to charge it. So as you can see I have the kit to run Intelligent Go but at the moment I am on intelligent Flux. As I live by myself and only charge my car once a month what would you recommend. Do you think I would have a problem as I only charge the car rarely, and would i have to have your car plugged in all the time to get the cheep 6 hour rates? thanks Keith

[@TimAndKatsGreenWalk]

With IOG you don't need to leave the car plugged in all the time. You only need to do occasional charges and you're all good (although to be absolutely sure it wouldn't hurt to check with Octopus by dropping them an email). The 6 hours will be off-peak every night regardless of whether or not the car is plugged in, so you'd be able to charge your batteries super cheap every night over Winter.

[@rugbygirlsdadg]

That's a lot of battery for one person. Is your house all electric? There're two adults in our house and I put about 20 kWhs into my car roughly weekly. My daily average usage is less than 10kWh and that's using my immersion heater rather than gas to provide hot water. (I have gas central heating)

[@Lawrence7of9]

Your air to air heating/power consumes 20-30% more than our property with a heat pump/radiator. 6.3KW solar (SE) & 10KW battery, just struck me as distinct divergence between us. Hope useful!

[@TimAndKatsGreenWalk]

There is really no point comparing different houses and lifestyles when it comes to energy consumption. There are far too many variables.

[@adammiles526]

Despite having a 12kw array, i stayed on Octopus Intelligent. Flux or IF could, in theory, be better - but only on high PV and low consumption days. Otherwise it's very similar or vastly worse and i didn't want to take the risk. I also have my automations sorted and liked the idea of being lazy this year. The amazing off peak rate means you can have a battery cycle of profit, and that really eats away at thr benefits of Flux/IF. IF was also a risk as management is not in your control, and it turns out from reports that it's not very well optimised.. I'm glad I took the lazy option and stayed on Intelligent his year! :)

[@TimAndKatsGreenWalk]

IOF is pretty well optimised from my experience. A lot of people don't understand IOF but it's worked entirely how I'd expect it to so far for me this Summer. My latest stats video certainly bears that out too. But IOG is definitely looking more attractive now after these recent tariff rate changes.

[@David-bl1bt]

Im not clear as to what the export rate is that you are using for these calcs. Im confused... Am I correct in my thinking that there is no export rate for IOG and that the outgoing lite tariff at a flat rate of 8p is the rate you are using?

[@TimAndKatsGreenWalk]

The rates are in the spreadsheet if you want to check it out. 15p/kWh for IOG and Cosy (Outgoing Fixed), 8 for regular Go (Outgoing Lite), and the Flux tariffs have their own export rates. These are the best export rates that you can get for each of those tariffs. See 1:43 in the video.

[@TimAndKatsGreenWalk]

See this for details: octopus.energy/help-and-faqs/articles/which-export-tariff-can-i-combine-with-my-import-tariff/

[@David-bl1bt]

Hi Tim, thanks for your prompt response with this info. I have solar, battery (giv AIO), EV. I dont have a heatpump as yet but planning one before winter. My thoughts are Cosy as it gives 3 off peak sessions, so would give me the opportunity to charge my AIO and car if necessary 3 periods per day, added to the fixed export of 15p for excess solar produced during the day. Assuming of course I can have the cosy tariff without a heatpump (currently)?...or do you need to prove that you have one to sign-up to the cosy tariff? And, also assuming that I can attach the fixed outgoing tariff to cosy? Is this possible/feasible? What are your thoughts?

[@TimAndKatsGreenWalk]

@@David-bl1bt yes, you can get outgoing fixed with Cosy (see the link I posted). Personally I would stick with IOG because the off-peak rate is so much better than Cosy. You can't get Cosy without a heat pump as you need the MCS certificate to sign up. The AIO is a big battery so you will probably find that it's sufficient to run a heat pump for a good fraction of the Winter without the need to charge it more than once per day.

[@TimAndKatsGreenWalk]

@@David-bl1bt you can see some of my own experience with a similar amount of battery to you in this video: kzbin.info/www/bejne/laLcpKiio8ponZIsi=EOvVxTfRzWMlpm6L

[@cingramuk]

Just digging into the spreadsheet, and two things I'd not noticed before which is having quite a big impact. (1) Standing charges need to be taken into account. The spreadsheet shows I should be a few hundred up over the year but its cancelled out by SC. The other, is we are assuming with batteries all load during the day is taken by the batteries, but in my case, house load when there is solar, will be satisfied by solar. So my export is maybe only 70% in June compared to what's expected by the spreadsheet. Ideally we should take both of these into account. I have a similar spreadsheet for tracking and only noticed I have the same issues in mine too.

[@TimAndKatsGreenWalk]

Standing charges are the same regardless of the tariff, so the relative costs are the same, i.e. the rank ordering will not change so the choice of cheapest tariff is still the same. I mentioned in the video that this rule of thumb assumes you force export from your battery an amount equal to how much you have used from solar during the day, so that all your solar is effectively exported. If you can force export more than that from your battery then you can do slightly better (I mentioned this in the video too). This rule of thumb was designed so that you only needed two numbers, to make it as simple as possible to use (it is a rule of thumb after all). Adding more stuff might get you a slightly better answer for any particular system but that was not the aim with this particular piece of work. By all means add anything extra that you like, but I won't be changing anything in the version I've made available.

[@cingramuk]

@@TimAndKatsGreenWalk fair points, I missed that in the video and forgot its relative pricing. A very good tool for comparison which is the main objective, thanks for putting it together.

[@TimAndKatsGreenWalk]

@@cingramuk no problem. You can definitely do a better job if you are able to add more information about your system and usage patterns. But not everyone wants to do that or has the skills/patience to do so, hence this tool! I'm hoping it'll help a wide range of people get a "good enough" answer, rather than a small number of people getting the best possible answer.

[@shirleydanby4123]

Ps our June electric bill with 2 panels missing ( due to eaiting for rendering to be done) with standing charges was £40. And the weather here was just fair, not optimal for a month in summer.

[@TimAndKatsGreenWalk]

Good stuff.

[@JurassicJungle]

Very useful, I will play with the spreadhseet. I am on Go but don't cyrrently get paid for export (long story). I find it difficult to work out how much I am actually saving with Go when it charges outsdide teh standard off peak times. Also I currently have a granny charger so Go charges my car but takes it from my battery at times, I am not sure how go works outside the off peak time, I assume they must credit me the difference between peak rate and off peak to true up the cost. I have a modest 4.8kW array and a Give AIO. I will have my GE charger online soon which will help as all charging should then be in the off peak time. Thankfully GO works with my car not the charger so hoping that all still works OK.

[@TimAndKatsGreenWalk]

I assume you mean you're on Intelligent Go, rather than regular Go, if you're getting off-peak periods outside of the usual off-peak time. I don't know how that works either I just assume you get charged the lower rate for those periods for anything you import at those times. Hopefully I'll be able to try out myself at some point soon, assuming the GE charger gets added to the IOG system.

[@JurassicJungle]

@@TimAndKatsGreenWalk Sorry, yes intelligent Go. My understanding is you only get what the car uses at the low rate so it can't use smart meter data for that as it can't differentiate. My setup works with the car (Tesla). I am not sure what will happen when I fit my GE charger, I am hoping that for the moment Octopus can still control via the car rather than GE.

[@cingramuk]

I'm surprised by Intelligent Flux the graph, seems there is very little point in it, unless you have a massive array? Is the calc missing out export you may be getting from the battery that would push the line down? Weird that standard Flux will beat Intelligent Flux in nearly all cases.

[@TimAndKatsGreenWalk]

There is a parameter for how much you think you can export during the peak period (see the original video). You can get more out of IOF if you can push more export into that peak period, but there's only so much you can do that. In my experience I can export about 40-50% in that peak period.

[@cingramuk]

@@TimAndKatsGreenWalk ah ok, that makes sense now.

[@gopikrishnayogarajah]

Tim , you are right but one comment , if you are a non EV heat pump user and non new build .. The new cosy with three dips maybe better .

[@Lawrence7of9]

You can’t get Intelligent Go unless compatible EV/charger st home.

[@TimAndKatsGreenWalk]

Well, like I said, if you can't get certain tariffs then pick from the ones you can get. But otherwise I stand by the rule of thumb calculation. I put a lot of thought into it. Cosy may be better if you only have a very small battery, though, as you can charge it multiple times.

[@FredMalakoff]

Definition of "Home Consumption" :: I'm not sure that I have an accurate "Battery to Home Consumption" figure available. Without it, I plan on using (SolarPV Gen) + (Grid Import) Minus (Grid Export) . . . . which seems like the same thing ??

[@TimAndKatsGreenWalk]

Yes, I think that's more or less the same thing (they are slightly different due to conversion losses but they'll be close enough for the purposes of this rule of thumb).

[@serraios1989]

At current IOF rates I would take a loss of 2p/kwh as my 8.2 GivEnergy has efficiency of about 70%. Factor this in and my potential summer savings on IOF would be in the region £50. That’s why I’ve stayed with IOG all year

[@TimAndKatsGreenWalk]

I'd be surprised if the efficiency of your battery is much less than 88% round trip (6% loss AC-DC then 6% loss DC-AC). Mine is certainly way better than 70% (about 92% according to my June values). You'd have those same losses regardless of tariff, of course.

[@serraios1989]

@@TimAndKatsGreenWalk Since June 2022 when we had the pv system installed, the efficiency (battery discharge/battery charge) is 94%, according to the data from the GE app. My experiments however showed efficiency 70%, using data from the smart meter itself. Battery needs 10kwh to fully charge from empty at max rate and delivers 7kwh at forced discharge.

[@scottwills4698]

I have a heat pump and solar / battery. I’m on Intelligent Go now but plan to go onto Cosy in the winter because I can charge my battery 3 times and run my house off my battery at 10p per kWh. My Powerwall will not run my house for the day in the winter so I felt Intelligent go would be no good as I will end up spending on a lot of peak rate electric (maybe 1/2). We have 2 EV’s so charging them maybe problematic. I need to work it out, I haven’t bothered yet as the rates will probably change before winter. I’m not sure what the export rate is on Cosy.

[@TimAndKatsGreenWalk]

With Cosy you can get the fixed export rate of 15 p/kWh. Obviously that's pretty irrelevant during Winter though.

[@scottwills4698]

@@TimAndKatsGreenWalk Do you not think Cosy would be a great option? You must run your battery out with your A2A heat pumps during the winter? Cosy would mean you could keep topping your battery back up.

[@TimAndKatsGreenWalk]

@@scottwills4698 I used very little peak power over the Winter. Our battery was sufficient to cover almost all of the heating, and at a lower price than the off-peak Cosy rate. Overall Go/IOG works out better for us. I can see Cosy being a good option if you have a small battery though.

[@TimAndKatsGreenWalk]

@@scottwills4698 I cover some of that in this video: kzbin.info/www/bejne/laLcpKiio8ponZIsi=4qKsCBhLMnUIvp47

[@scottwills4698]

@@TimAndKatsGreenWalk I have a Powerwall. It’s 13.5kwh my heat pump can draw 30kwh’s on a cold day. How much do your A2A heat pumps draw? I thought you had Givenergy battery’s? They can only output 3kw right? How are you managing to not draw from the grid?

[@Joe-lb8qn]

Having just spent 30 minutes messing around trying to get my charger and IGo talking to each other again when they stopped chatting forr no obvious reason, thats another reason not to switch away from IGo once it is working. TBF the cause was, i think, a new version of my charger App , or perhaps the charger software changing or maybe the charger just felt cranky, but even so Id have handed over a crisp £20 note to not have that happen again (it is working now I think wont know until 1am though). And ithats probably the sort of money you are looking at for that 3 month switch? I can certainly forsee that disconnecr and hassle every time i switch from one tariff to another. SO I wont be doing that. There is possibly another factor in your graph which is the % of electric used by an EV. If its very high then its going to be hard to beat that 7p rate whatever better export you might get on another tariff. FWIW and I'm only 3 months in, my ratio is about 1.5x export over usage, and about half my usage is my EV. Of course in summer export will be much higher so that ratio will likely drop, but at present my off peak use is around 99% or better. Really my peak usage is just due to inverter lag other than the very rare instance i might have kettle, microwave and oven on at once..

[@TimAndKatsGreenWalk]

The EV use is part of the total consumption, so high EV use will shift that ratio towards the left of the chart. You've got to add up everything you use for the consumption value.

[@colinbrammeld2038]

Only works when octopus get their finger out and supply working smart meters. Software doesn’t work right, polling doesn’t work right, smart meters don’t work right, customer services doesn’t work right. If the basics are not fixed soon, I can see octopus going the same way as the other failed energy suppliers.

[@TimAndKatsGreenWalk]

They have consistently topped the ratings for best energy supplier so if you've had a bad experience you're in the minority. I'm sorry to hear you've had trouble but that doesn't mean that's the norm for most people.

[@colinbrammeld2038]

@@TimAndKatsGreenWalk I deal with all suppliers in my job as a letting agent, Octopus is just as bad as Scottish Power at customer services. They can’t even get dates right for new tenants. The mark of a good company is how satisfactory they solve problems eg how quickly and get it right first time. Octopus fail consistently at this. 15 months with meter not working correctly, engineers to attend sometime in the future or no appointment available. I could write a book on the numerous and consistent failings of Octopus. While Octopus work for some people, they are a disaster for others. Don’t believe the hype on Octopus winning awards.