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Electricity price predictions

MattEngineer · 2021-12-03T18:39:26Z

When the energy cap comes up for renewal I think it will rise to 26.5p per unit, any thoughts of the collective?

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Electricity, Tariffs, Monitoring, Electrics & Providers

Last Post by ChandyKris 10 minutes ago

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ChandyKris

(@chandykris)

Reputable Member Member

Joined: 2 years ago

Posts: 172

28/04/2026 5:16 pm

The only way to convince my Mrs is to highlight the cost savings. I go fully equipped with numbers like I would go to a CFO with RoIC stats and a DCF model, without which it won't be approved at my home.

I don't mind my home being a power station, as long as it's not using coal or gas!

Posted by: @kevh

↑

As my wife reminds me, this is my home and not a power station.

16 * 435 watts PV
13 kWh Growatt battery
1 EV - Mercedes EQB
6 kW Aira Heat Pump
Bosch Induction Hob
Pod Point Solo 3 charger

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JamesPa

(@jamespa)

Illustrious Member Moderator

Joined: 3 years ago

Posts: 4750

28/04/2026 6:02 pm

Posted by: @colinc

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@jamespa I don't believe I have said anything other than attempt to make some light of this.

I am not going to take any lecture, or warning, from anyone about how I cast my vote.

I note that your intention was to 'make light' and apologise that I thought that some might interpret your comment as serious even if that was not how you intended it. My comments were intend for those who might interpret it as serious, not for those who like did not intend or do not take your post seriously. I accept I should have made that clearer

Posted by: @colinc

↑

Best for everyone if you would stick to where your contribution is valued, viz. imparting your scientific knowledge to a Renewable Heating Hub forum

You are as entitled to an opinion as I am, and vice versa.

If the facts (as best we can ascertain them) are at variance with my opinion, then I will revise my opinion. I will not knowingly seek to obscure the facts.

I will make no apology for 'wordsmithing' contributions even if you personally find that objectionable.

This post was modified 42 minutes ago by JamesPa

This post was modified 41 minutes ago by JamesPa

4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.

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JamesPa

(@jamespa)

Illustrious Member Moderator

Joined: 3 years ago

Posts: 4750

28/04/2026 6:11 pm

Posted by: @kevh

↑

Posted by: @jamespa

↑

Posted by: @kevh

↑

As an example, my teeny 5kWh battery saw us through winter at an average cost of around 14-15p /kWh, easily outpacing what we would have spent on gas (calculated by direct comparison to last winter and also comparing the Cosy9 output to current gas prices at a SCOP of 3.66).

Thats impressive, I averaged about 20. I have been assuming I need a largeish battery (10-15kWh) but maybe I should re-evaluate the Cosy option with a smaller one!

Bear in mind that my maximum daily draw over winter was a tad under 50kWh, typically it was around the 30kWh mark, which the battery took the sting out of.

If you have an EV I am sure your daily draw will be much higher, hence maybe a larger capacity battery might suit your circumstances better.

Personally I doubt that in my circumstances I would be any better served by a larger capacity battery at present, although that doesn't stop me eyeing them up when I read of the huge solar exports that some achieve. As my wife reminds me, this is my home and not a power station. 🤣

Thanks that's helpful.

Mentally I discount the EV because it can be charged in cheap periods without recourse to a secondary battery. However sweating the battery asset using cosy and doing 3 cycles a day is something I have not yet built into my modelling. So the fact you find this beneficial is a useful spur to some more modelling.

4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.

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ChandyKris

(@chandykris)

Reputable Member Member

Joined: 2 years ago

Posts: 172

28/04/2026 7:19 pm

@jamespa I definitely made full use of the Cosy tariff and cycled thrice a day. But, I was a bit concerned, as unlike Tesla batteries Growatt doesn't offer unlimited cycles warranty. So, decided to double the battery capacity and switch to Go. This winter we just cycled once a day but still cost similar to last year on Cosy. If cycling is a concern, you can also model a scenario where you don't charge the battery during the 10 pm to 12 am period, but just pump up the heat and setback during the 12 am.to 4 am period. But the 1 pm to 4 pm slot can be used to charge the batteries and avoid touching the grid after 4pm.

Posted by: @jamespa

↑

However sweating the battery asset using cosy and doing 3 cycles a day is something I have not yet built into my modelling.

16 * 435 watts PV
13 kWh Growatt battery
1 EV - Mercedes EQB
6 kW Aira Heat Pump
Bosch Induction Hob
Pod Point Solo 3 charger

ReplyQuote

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