Octopus Energy, Tesla Powerall, and no Solar panels

14
Posted 30th Jun
Rough Napkin math

£6000 installation on a battery

Electric Bill £100 per Month on avergage

Cost of the peak time 4-7PM usage on ours bills is roughly 30-50% of the amount we pay therefore, charging powerwall on cheap times and using at peak could netus a big chunk, lets say 40% in my example.

6000/40£ would take 150 Months/ 12.5 years.
To earn the money back for the powerwall.

This is looking at savings of 4-7, but from usage this peak time can be used for little bit after to save even more (depends on battery size and how much we typically use at the 4-10pm time for example)

Are my calculations roughly precise?
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14 Comments
I think you're missing the install costs from your math. Last time I checked they were between £500 to £1000 depending on a number of factor. I'm guessing that the cost to you would at the lower end as it doesn't need to be connected to panels.
Total cost should be closer to £7,000
Also, I think all your prices are ex vat, so you might need to add another 20% to your bottom line.
Edited by: "steve1221" 30th Jun
steve122130/06/2020 16:48

I think you're missing the install costs from your math. Last time I …I think you're missing the install costs from your math. Last time I checked they were between £500 to £1000 depending on a number of factor. I'm guessing that the cost to you would at the lower end as it doesn't need to be connected to panels.Total cost should be closer to £7,000Also, I think all your prices are ex vat, so you might need to add another 20% to your bottom line.


Fair enough tbh I have no intention of doing what I suggested I'm more just visualizing if this will be a thing in the future

If the cost of install and powerwall was to come down to something like circa 4000£ I can see this becoming a no brainer

But then I would have questionmarks of agile being adopted by other suppliers and the chance of getting 10pkw or less off peak will shrink as more people move out of using peak times

(I'd imagine this would be long time before you get money back on investment
Gumbon30/06/2020 16:51

Fair enough tbh I have no intention of doing what I suggested I'm more …Fair enough tbh I have no intention of doing what I suggested I'm more just visualizing if this will be a thing in the future If the cost of install and powerwall was to come down to something like circa 4000£ I can see this becoming a no brainerBut then I would have questionmarks of agile being adopted by other suppliers and the chance of getting 10pkw or less off peak will shrink as more people move out of using peak times (I'd imagine this would be long time before you get money back on investment



At 4 grand I agree. I've just checked a site I used to price a system a while back they're quoting around £9,000 for a Powerwall 2 install!!! Link below, info at bottom of page.

spiritenergy.co.uk/tes…lar
I know someone who lives in a rural area of UK and gets regular power outages of up to 5 hours. Mainly concerned about fridge/freeze and CH that need continuous power. A Powerwall combined with the right tariff might make sense.

And a friend on the edge of a town in NJ in the U.S. gets regular outages in winter - they have leccy arriving on poles. Problem is that with melting snow their bilge pump then fails and the huge basement floor gets waterlogged, particularly annoying when they are travelling. A standard UPS won't power the pump for long enough. Another good use-case.
Edited by: "harrythefish" 30th Jun
Also need to consider how long these batteries need changing.

If you are to cycle it daily then the batteries are not likely to last 10 years.
Van197330/06/2020 18:22

Also need to consider how long these batteries need changing.If you are to …Also need to consider how long these batteries need changing.If you are to cycle it daily then the batteries are not likely to last 10 years.


I looked into this a couple of years ago. I think you'll find Tesla put a lifetime infinite guarantee / replacement of batteries if they fail, which is great if true...
steve122130/06/2020 16:53

At 4 grand I agree. I've just checked a site I used to price a system a …At 4 grand I agree. I've just checked a site I used to price a system a while back they're quoting around £9,000 for a Powerwall 2 install!!! Link below, info at bottom of page.https://www.spiritenergy.co.uk/tesla-battery-solar


Yep, this is what put me off. I have a 4kW Solar system which I gambled on and was lucky to install in 2011 before the FIT payments died a death. I looked at the outlay of fitting a Tesla Powerwall, and basically it's too expensive at the mo for the recouped energy saving.
philajones30/06/2020 21:46

Yep, this is what put me off. I have a 4kW Solar system which I gambled on …Yep, this is what put me off. I have a 4kW Solar system which I gambled on and was lucky to install in 2011 before the FIT payments died a death. I looked at the outlay of fitting a Tesla Powerwall, and basically it's too expensive at the mo for the recouped energy saving.


I agree. I've the original FIT tariff here and would love to add batteries in to this mix. Unfortunately due to the configuration of my house and parking I'll never be able to get an electric car, but, this would massively help I think in reducing bills.

There are some companies starting up that use your batteries as a mini national grid and sell the electricity back to them when the power on the grid drops and charges back up during cheap periods. In theory it sounds great, but, I couldnt get past the fancy sales promo stuff they had to get the maths to add up.
markmc99930/06/2020 21:58

I agree. I've the original FIT tariff here and would love to add batteries …I agree. I've the original FIT tariff here and would love to add batteries in to this mix. Unfortunately due to the configuration of my house and parking I'll never be able to get an electric car, but, this would massively help I think in reducing bills. There are some companies starting up that use your batteries as a mini national grid and sell the electricity back to them when the power on the grid drops and charges back up during cheap periods. In theory it sounds great, but, I couldnt get past the fancy sales promo stuff they had to get the maths to add up.


I'm the same, thought of buying electric car and use surplus energy to charge (I have the space). However, electric cars are too expensive at the mo and insufficient range plus batteries die (and I don't want a battery lease agreement which a lot of car manufactures are offering). My own opinion is that electric cars are not feasible until future when range and battery technology improves. I actually never removed my old immersion tank, so have had a Solar Iboost heating excess waste electric for hot water when sun is up!
philajones30/06/2020 22:19

I'm the same, thought of buying electric car and use surplus energy to …I'm the same, thought of buying electric car and use surplus energy to charge (I have the space). However, electric cars are too expensive at the mo and insufficient range plus batteries die (and I don't want a battery lease agreement which a lot of car manufactures are offering). My own opinion is that electric cars are not feasible until future when range and battery technology improves. I actually never removed my old immersion tank, so have had a Solar Iboost heating excess waste electric for hot water when sun is up!


If your a person who would go out and spend 20,000k petrol car then maybe 30,000 electric car might be worth while IF you drive at least X amount a year

But lot of people are in the position of would go buy a second hand car for 5-10k, and the jump to a 'good range electric, at 30,000 is too much and would take too long to save money (unless rack up miles)

For me, I literally drive weekends and to up £50 2-3 months, it's literally pointless me going electric

Maybe a second hand leaf would make while but then I have the annoying 60-80 mile limit on the low end battery
Gumbon30/06/2020 22:47

If your a person who would go out and spend 20,000k petrol car then maybe …If your a person who would go out and spend 20,000k petrol car then maybe 30,000 electric car might be worth while IF you drive at least X amount a yearBut lot of people are in the position of would go buy a second hand car for 5-10k, and the jump to a 'good range electric, at 30,000 is too much and would take too long to save money (unless rack up miles)For me, I literally drive weekends and to up £50 2-3 months, it's literally pointless me going electric Maybe a second hand leaf would make while but then I have the annoying 60-80 mile limit on the low end battery


So true
£100 a month electricity. Are you growing weed
MonkeysUncle01/07/2020 00:59

£100 a month electricity. Are you growing weed


Nope. family have so many appliances, 3 freezers, 2 fridges, 1 large pond.
harrythefish30/06/2020 18:18

I know someone who lives in a rural area of UK and gets regular power …I know someone who lives in a rural area of UK and gets regular power outages of up to 5 hours. Mainly concerned about fridge/freeze and CH that need continuous power. A Powerwall combined with the right tariff might make sense.And a friend on the edge of a town in NJ in the U.S. gets regular outages in winter - they have leccy arriving on poles. Problem is that with melting snow their bilge pump then fails and the huge basement floor gets waterlogged, particularly annoying when they are travelling. A standard UPS won't power the pump for long enough. Another good use-case.


In the UK G99 fast track application (3.68kW of solar & 3.68kW battery) doesn't allow islanding (your power outage scenario). A full G99 application costs money - DNO, installer & possible Tesla charges to unlock the peak from 3.68kW to 5kW which should be Tesla password protected. Just some info on possible extra costs
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