AIO battery storage with no solar panels

I was wondering if anyone was in the same position as myself? I have just fitted 2 x 13.5kWh AIO batteries along with a Giv Gateway. I have no solar panels or any other means of generation.

Currently I'm on the standard Octopus Go tariff (not intelligent) and am charging my batteries using the cheap 8.5p/kWh rate between 00:30 and 05:30. This easily takes the batteries to 100% in this period. I'm not using any export tariffs right now but am seeing a great saving already with my set up. It's costing me approximately 45-50% less per day.

We are in a fully electric, 4 bedroom house with a heat pump. My question is could I make even more savings by going on to another smart tariff such as Octopus Flux? Does anyone have any experience with this? I went to register my batteries with Octopus but a pop up informed me that I would be agreeing to give full control of the batteries to Octopus. I got scared and backed out.

Thank you in advance for your advice and ideas.

Kevo1 All of the Octopus intelligent tariffs need you to give control of the battery to them and that may mean that you don't get optimum usage of your system. People have seen charging and discharging at odd times in the day. It is likely that Octopus, on the intelligent tariffs, adjust the charge/discharge times to suit when they have surplus/dearth of energy rather than to minimise your costs.

If you can store enough energy in your batteries to cover the rest of the day then all your energy will be billed at the off peak rate. But with a Heat Pump you probably can't do that so it might be Octopus Cosy that is better than Flux as you get three charging periods. However the energy costs on Cosy is more than Octopus Go. Depends how much goes in the car too.

Have a look at some of the other forum threads. There has been a lot of discussion between Agile, Cosy and Go tariffs with some real data buried there. Many of us do have panels but the solar over the winter is so low that it doesn't actually make too much difference to the comparisons between November and February.

Kevo1 We are in a fully electric, 4 bedroom house with a heat pump. My question is could I make even more savings by going on to another smart tariff such as Octopus Flux?

Probably not Flux, but maybe Cosy. Depends a bit on HP usage. Do you also have an EV? (Go requires one, but since they don't seem to check, some people just apply anyway.)

If your 27kWh of battery gets you through the whole day, Go is probably best bet. If you still have to import at day rate, then being able to charge twice a day might work better. There's some discussion at the moment I the Making the most of Agile thread.

I'm on IOG with HP, but only 9.5kWh of storage, which usually runs out long before the end of the day. For Jan, average import price was about 14p/kWh, so I perhaps should have switched to Cosy. But Dec was about 11p, and I'm hoping Feb might be similar, in which case IOG wins.

My contribution to that thread is here

https://community.givenergy.cloud/d/3678-making-the-most-of-octopus-agile/682

I have compared the five non-intelligent Octopus tariffs and Go comes out best if you can get it. But only if you can avoid grid power during the non-peak times.

In the summer time, when you don't need the heat pump and the car is charged, you can charge up your batteries in the cheap period and discharge them for profit later in the day.

Kevo1 I'm not using any export tariffs right now

Did you get an MCS certificate for your AIO install? Most electricity suppliers require one as well as the DNO G99/G100 approval before they will give you an export MPAN and enable export.
There are ways around this but they can be more expensive, eg. Octopus charge I think £300 for a non-MCS export.

In terms of tariff, there is a big difference between Octopus Intelligent Flux and Octopus Flux. Intelligent Flux, Octopus take control of your battery and in return they give you the same rate for export as they do for import. Its really aimed at people with lots of solar and since you don't have any, I doubt it would be worth it.

All of the different tariffs: Flux, Go, Cosy, Economy 7, Agile have different costs and benefits, all depends on how much you import each day, your battery storage capacity and your daily consumption. There isn't a single best answer, and the answer for winter is very likely to be different for summer!

In terms of the cheaper rates I would discount Flux as its a paired import/export tariff and without any generation you probably won't find its best for you. As @Windy Miller says have a look at the "making best use of agile" thread, there's an active conversation considering the options

Windy Miller thank you for the reply. I'm very new to the system so I think you may be right that Go is the right one for the moment. I can't quite get a full day with the batteries after charging but I am getting up till about 7pm. The remainder of the day doesn't draw a whole load. I might get a lot closer to the full day in the summer when I'm not using the heat pump for the central heating. That's the hope anyway.

I don't generally charge my car at home at all since I get free charging at work. It's only if I've been using it for long periods over the weekend.

DD thanks for the reply. Octopus actually recommend Cosy with a fixed export when I fill in their questionnaire but I can't help but think that would benefit them more than me.

27kWh won't get me through the whole day at the moment but I'm hopeful for summer. With us being a completely electric house, we use about 12,000kWh a year. Maybe I should just get another AIO!! Actually, my installer told me that it's likely GivEnergy will update the AIO towards the end of the year so the existing stock of the model I have will probably be available with a decent discount.

geoffreycoan thank you for the reply. I've not got my MCS cert yet but my installer is MCS registered so I don't think it will be far away. It's very unusual for people in my area to be approved for G99 but somehow he managed to get it through. Makes life an awful lot easier when trying to do things in the short cheap periods.

I think I will definitely have to look at different tariffs throughout the year. Will keep an eye on Octoprice to keep me right.

I am considering solar actually but I live in the north of Scotland and nobody would entertain the idea of climbing on to my roof at this time of year. It all depends on the savings I see from the batteries alone and what the quote for the panels comes in at. I've not got a great aspect for fitting the panels with a NW facing house unfortunately. I'd have to double up on both sides of the roof to get any kind of return. However, that might make it less financially beneficial.

Kevo1 Have a look at the ‘upside down fork’ channel on YouTube. He has North facing panels and gets about 60% of the generation of his other panels. The North ones are outperforming the prediction.

Once you’ve got over the cost of the scaffolding that most installers want nowadays, panels are comparatively cheap and you should put as many up as you can do. Its a largely passive income for 20+ years.

We don’t have an EV but have a heat pump and no gas so are all electric like you. Our annual consumption is similar, 14,473kWh in 2023 and 11,326 in 2024 (principally reduced by optimising the heat pump setup), but yet our annual import - export bill for 2024 was £10 (and with the DFS saving session income was actually -£70). The solar panels generation in the summer pays for the winter import.

geoffreycoan I have seen a couple of the Upside down fork videos while searching for info. The other good person I’ve seen is Gary Does Solar. There just didn’t seem to be anyone with my particular setup. Hence the reason I came on here.

I think solar might be a worthy investment. My installer did actually mention that scaffold could be costly. He said if I’d lived in a bungalow they could have likely gotten away with a self constructed platform but it wouldn’t be right on my two story house. HSE have eyes everywhere apparently.

Mind you. I can’t complain too much. I was averaging £12-13 a day before I got the batteries installed. Now I’m getting £6-7. It’s a really decent saving over the year and will come down a lot more in summer.

geoffreycoan I'd also be interested in what you said about adjusting the settings in your heat pump to save about 2000kWh a year. I’ve not touched the settings since it was installed 6 years ago and just rely on the company who do the annual service to set it up right for me.

Kevo1

Im not in same boat totally as you but I also only run battery with no solar I dont have a heat pump

It all depends I guess on how much electric you take out of the batteries in the day

I went with Tomato in the end for my setup which is 5p for 6 hours 00:00 to 06:00 with two 14p slots 9:30 to 11:30 and 22:00 to 00:00 with rest of the time at 24.3p

My AIO when not playing up pretty much covers my use for the day and my cost per kWh over a month is about 5.5p

So it might work if 14p is considered cheap to have the mid morning boost in your setup - what it does for me is if the battery ends the day early its usually after 22:00 so its less of an impact

Windy Miller All of the Octopus intelligent tariffs need you to give control of the battery to them and that may mean that you don't get optimum usage of your system.

News to me.
I've been on Intelligent Octopus for years and have not given control of the house batteries to Octopus.

DreadorUK hey there. Thanks for the reply. That sounds like an excellent tariff you're on with Tomato. I haven't even looked at them if I'm honest. I think that if we did have a boost to the batteries later in the day at a reduced rate, we could manage to be on batteries for the whole of the standard rate. Definitely think I'll look in to other providers if they can offer something a bit more suited.

[unknown] I haven't even looked at them if I'm honest.

Last time I looked, tomato don't yet offer export rates, though that doesn't currently affect you.

DD And TBH there is a question of how long Tomato will survive as an energy provider, but at the moment they are providing great rates

https://www.elexon.co.uk/article/public-notification-of-tomato-energy-limiteds-lack-of-progress-against-its-efr-milestones/

https://www.reddit.com/r/OctopusEnergy/comments/1i871ga/public_notification_of_tomato_energy_limiteds/?rdt=34411

And a bit older, an Ofgem investigation is still underway https://www.ofgem.gov.uk/press-release/ofgem-opens-investigation-tomato-energy

geoffreycoan interesting reading. Octopus does feel safer for now. They only fitted my smart meter in October so I'm not desperate to move. Definitely worth keeping one eye on the market though.

Anyway, I'm not using the battery at all just now because one of them had a red fault light on this morning. From looking through the forums, this is quite common. However, my installer is going to take a look to see if he can sort it. To be fair, once he gets it up and running, it'll just mean the battery will last me later in to today. Don't think I'll end up paying any more for the day.

Zakalwe Are you sure? The two intelligent tariffs - Intelligent Go and Intelligent Flux - now require them to control your charge/discharge cycles. Maybe when you joined that wasn't a requirement.

[unknown] There just didn’t seem to be anyone with my particular setup.

Did you find Tim and Kats Green Walk videos on Youtube? They have an East/West array due to the orientation of their house and they did a video considering adding panels to the north facing roof they also have.

Kevo1 There just didn’t seem to be anyone with my particular setup.

Did you find Tim and Kat's Green Walk videos on YouTube? They have an East/West array due to the orientation of their house and made a video considering adding panels to their north facing roof. They're in Gloucestershire so considerably further south than you.

Duplicate!

I have 10 440w NW facing panels and 10 440w SE facing panels, and the NW ones produce around 60% of the SE panels (and contribute just over 1/3rd of the total output) so I think they are well worth looking at for the Northerly orientations.

Windy Miller I'm certainly going to look in to the benefits of solar over the next couple of months. It'll be at least that till I could potentially get some panels fitted anyway. I have see a couple of Tim and Kat's videos I think but I've watched so many lately, I forget which is which.

Gloucestershire is definitely a bit further south! I'm in Orkney so not a lot of comparison. However, one of the benefits I'd maybe get from solar is that in the height of summer, I get about 20 hours of daylight.

CW that's interesting. I've not had a proper solar assessment done yet but my battery installer did a roof survey while he was fitting the batteries and told me he was going to make me up a quote and a generation estimate. It will be interesting to see what he suggests for panel placement.

Kevo1 Is Orkney cabled to the mainland? Or is it all local generation?

Windy Miller There's interconnectors from the mainland to all the major Scottish isles.

Yes. I've just looked it up and there's a project for a new cable very soon to augment the existing cables.

Windy Miller we're cabled to the mainland but are actually a net exporter of renewables. Not sure what the percentage is but it's fairly significant what we export. Last I looked I think we exported about 130% of our energy demands. That may have changed though. Unfortunately, they then see fit to charge us more for importing it back in as we're so much further from civilisation! Hahaha.

Windy Miller Yes, there's a huge major project being undertaken by SSE on behalf of the government. I'm not sure how much that will benefit us though. I think we're going to be more of a hub to the mainland from further afield. The construction phase will bring in a lot to the community though.

Kevo1 Thank-you for that energy. Some of it may even find its way to me in Bedfordshire.

Windy Miller Hahaha, you're welcome. I actually just looked up the project online. It looks as though it's going to allow us to produce and export even more energy (up to 220MW). I won't hold my breath for my own bills to come down as a result though. I'll just keep looking in to the solar panels!

Kevo1 If you like getting into the weeds with this stuff, there are free solar design sites available where you can plan your own array etc (which will also calculate expected generation)

The one I used quite a bit is Easy PV - it can keep you "entertained" for many, many, hours!

Windy Miller I've just realised that Intelligent Octopus Go requires control of the Car Charger not the Inverter as I said so I apologise for mis-posting.

CW thanks for that. I'll definitely give that a look. Keeping an eye on my batteries through the cloud has already distracted me greatly from work so I think I might as well write the day off now if I get in to that! Hahaha.

Windy Miller I've just realised that Intelligent Octopus Go requires control of the Car Charger not the Inverter as I said so I apologise for mis-posting.

Yes, I thought that was the case. Neither my EV or my charger are compatible anyway. I considered upgrading my charger to allow me to use IOG since the cheap rate was cheaper and longer. The additional charging slots might help in topping up the battery too. However, I see a lot of people are having issues with their batteries discharging to their car when plugged in and I want to avoid that. The one way to stop it is to get a GivEnergy car charger but at the moment, that one doesn't play nicely with IOG. I'm going to keep an eye on this though.

[unknown] I've not had a proper solar assessment done yet but my battery installer did a roof survey while he was fitting the batteries and told me he was going to make me up a quote and a generation estimate

If you look at pvgis it should predict your solar generation based on different roof panels.

[unknown] I'd also be interested in what you said about adjusting the settings in your heat pump to save about 2000kWh a year. I’ve not touched the settings since it was installed 6 years ago and just rely on the company who do the annual service to set it up right for me.

I’ve been on a journey with our heat pump, we’ve just gone over the 3rd anniversary of having it fitted and whilst there is probably more tweaking I can see in the consumption the benefits of what I have changed. I have two LG Therma V 9kW heat pumps and LG must make the worst control panels and instruction manuals in the world, so working out what to change has not been easy, and getting data out is equally difficult (there’s no way of finding out what the current SCOP is for example).

Our system was designed with a flow rate temperature of 55 degrees and a SCOP of 2.85. I now know the consequences of this on my electricity bill.

The things I changed, in no particular order:

• turned on AI mode (weather compensation) so flow temperature is dependent upon temperature and is not fixed (and not fixed at a high value)
• progressively turned down the flow temperature for the AI mode to get to the lowest flow temperatures that would keep the house warm. Mine is now 52 degrees at -2 and 30 degrees at 14
• measurement of water temperature to be leaving water temperature rather than incoming water temperature
• hysteresis from -2/+2 to -4/+4, this reduces the cycling as the flow temperature can cool down more before restarting and overshoot more before stopping heating
• pump run time increased from on 2 off 1 to on 10 off 1, runs the pump longer so gets more water round the system
• changed hot water priority from Main+Boost to Boost only and heating tank heater from Use/Cycle/Delay 30 to Not use - this basically changes the hot water to only being heated by the ASHP rather than being heated by a combination of the ASHP and the immersion heater
• turned the anti-legionella cycle off (heat geek blog post and video on this, make your own assessment about what risk you think there is from legionella)
• turned hot water tank temperature down 60 to 48
• changed hot water heating to being just a single heating cycle once a day in the overnight cheaper rate. The tank stays sufficiently hot for the rest of the day for showers and baths
• programme the heating to be on with a target house temperature of 19 degrees from 10:30 to 23:30, and setback to 17 degrees overnight. As long as its not particularly cold outside the house will retain heat through the night without the heating coming on

The MCS survey predicted an annual heating demand of 22,768kWh that would be met by 7,989kWh of electricity

My annual ASHP consumption figures (taken from the meters connected to the heat pumps and the immersion heater):

• 2022-3 5,311kWh
• 2023-4 5,936kWh
• 2024-5 4,330kWh

Kevo1 I've not had a proper solar assessment done yet but my battery installer did a roof survey while he was fitting the batteries and told me he was going to make me up a quote and a generation estimate

If you look at pvgis it should predict your solar generation based on different roof panels.

Kevo1 I'd also be interested in what you said about adjusting the settings in your heat pump to save about 2000kWh a year. I’ve not touched the settings since it was installed 6 years ago and just rely on the company who do the annual service to set it up right for me.

I’ve been on a journey with our heat pump, we’ve just gone over the 3rd anniversary of having it fitted and whilst there is probably more tweaking I can see in the consumption the benefits of what I have changed. I have two LG Therma V 9kW heat pumps and LG must make the worst control panels and instruction manuals in the world, so working out what to change has not been easy, and getting data out is equally difficult (there’s no way of finding out what the current SCOP is for example).

Our system was designed with a flow rate temperature of 55 degrees and a SCOP of 2.85. I now know the consequences of this on my electricity bill.

The things I changed, in no particular order:

• turned on AI mode (weather compensation) so flow temperature is dependent upon temperature and is not fixed (and not fixed at a high value)
• progressively turned down the flow temperature for the AI mode to get to the lowest flow temperatures that would keep the house warm. Mine is now 52 degrees at -2 and 30 degrees at 14
• measurement of water temperature to be leaving water temperature rather than incoming water temperature
• hysteresis from -2/+2 to -4/+4, this reduces the cycling as the flow temperature can cool down more before restarting and overshoot more before stopping heating
• pump run time increased from on 2 off 1 to on 10 off 1, runs the pump longer so gets more water round the system
• changed hot water priority from Main+Boost to Boost only and heating tank heater from Use/Cycle/Delay 30 to Not use - this basically changes the hot water to only being heated by the ASHP rather than being heated by a combination of the ASHP and the immersion heater
• turned the anti-legionella cycle off (heat geek blog post and video on this, make your own assessment about what risk you think there is from legionella)
• turned hot water tank temperature down 60 to 48
• changed hot water heating to being just a single heating cycle once a day in the overnight cheaper rate. The tank stays sufficiently hot for the rest of the day for showers and baths
• programme the heating to be on with a target house temperature of 19 degrees from 10:30 to 23:30, and setback to 17 degrees overnight. As long as its not particularly cold outside the house will retain heat through the night without the heating coming on

The MCS survey predicted an annual heating demand of 22,768kWh that would be met by 7,989kWh of electricity

My annual ASHP consumption figures (taken from the meters connected to the heat pumps and the immersion heater):

• 2022-3 5,311kWh
• 2023-4 5,936kWh
• 2024-5 4,330kWh

Grr, bloody duplicates

geoffreycoan That's a great load of information. I operate a single 11.5kW Panasonic heat pump so I'm not entirely sure which of the settings you have outlined I will be able to change. There are definitely a few that I know I can fiddle around with though.

I know for instance that we do have the weekly anti-legionella cycle on. I'm not sure about turning it off. I will look in to it. However, it might be that I can change it to only operating within the cheap overnight tariff as a starter.

I don't think our SCOP is nearly as good as yours. Especially not at this time of year but I'll give it a check.

Also, I have the heat pump on constantly. This is the second heat pump we've had installed as the first one was a disaster (Grant Aerona). When the old one was in, we were initially on Economy 10 with the heat pump only kicking in for the cheaper periods. However, what we found was that it wasn't enough to heat the house and that the pump was running flat out every time it came on without the desired effect. We've had it on constantly since then. Except, we do have the heating side of things off from about April to October each year as the house is super insulated and the house just ends up getting too warm.

I'm definitely going to check the rest of the settings later on today when I get home to see if I can make some tweaks.

On a side note, now that I've got the bit in my teeth, I think I'm going to drive my poor wife mad with this!

[unknown] However, I see a lot of people are having issues with their batteries discharging to their car when plugged in and I want to avoid that. The one way to stop it is to get a GivEnergy car charger but at the moment, that one doesn't play nicely with IOG.

Relatively easy to avoid that with careful placement of the CT clamps, so that inverter is completely unaware of the chargepoint.

DD Thanks for the info. I'll admit it's not something I've looked in to at any great length since I generally don't charge my EV at home with it being free at work. I've not tried it at all since I had the AIO's fitted so I'm not sure how it will go.

Windy Miller

Yes, I am positive. There's no requirement to grant control of home batteries on Intelligent Go.

Zakalwe Sorry. My mispost. It was the handing over of control of the batteries to Octopus that I was trying to convey but that only applies to Intelligent Flux.

[unknown]

If they go belly up Ill just move but at the moment Im happy to be paying nearly 30% less