Our quest for Net Zero one year on

michaels

https://forums.moneysavingexpert.com/discussion/comment/82065359#Comment_82065359

Sadly the CFD price is not the whole story, if we have a CFD price of 7p per kWh and end up spilling but still paying for half the output (curtailment then the price per unit used is double the CFD.

NedS

Today is the one year anniversary of our Powerwall/upgraded solar installation, so I now have a full year's data (11/07/25 - 10/07/26):

Generation: 7356kWh

Consumption: 6478kWh

Very happy with that, generating roughly 13% more than we consume, and gives us a little scope to have the heating up higher in winter or for when we eventually add an EV into the mix.

silverwhistle

To truly benefit from heat pump specific tariffs one needs a very well
insulated house so that the time of delivery of heat does not impact
significantly on comfort levels.

True, but I'd also add, as I swelter in the heat, retaining coolness might also apply! I'm on Agile which by and large suits me although at the moment, with PV covering my day energy the bill is low but average unit cost is high . I hope to get a multi-split A2A (2 internal) and if it were already installed tomorrow I'd be turning down the temperature during the afternoon negative period, probably to find my solar covered it anyway!

My back up won't be a boiler but a wood burning stove with self processed wood, but for next summer I'd also like to improve my passive cooling, which is going to be increasingly important. Temporarily I've some unsightly celotex on the outside of my worst window, and was showing a friend the dramatic difference it makes on the inside compared with unprotected glass. I value comfort and indeed safety but maybe by next year I can introduce a bit of style too!

Alnat1

I thought I'd stick my little story here as it's the 2nd part of our zero energy cost journey. We're at zero with solar/battery/heat pump and now stage 2 is things that will keep life more comfortable in retirement.

We used to have French doors on the small bay in our living room, very draughty in winter, the curtains closed across the main wall and the bay behind the thermal lined curtains could be 8C colder than the room in front. In summer, even with curtains closed, the SW facing room suffered with the heat.

We decided last year to get the (useless waste of space) bay removed and have 3 panel bi-folds instead. Paid extra to have the glass fitted with integral blinds. Now in summer, we open them first thing in the morning, cools the whole house down until the living room hits around 22C. Closed they keep the heat out until the sun creeps up to the windows around 12. Then lower the blinds but angled so we can still see out until around 1pm. We close them as the sun shines directly into the room but plenty of light still gets in. Only on days 33C plus have we had to close the curtains as well because the room hit 25C.

Last winter the new doors kept the living room much warmer, no longer a cosy end and a draughty end. Although the room is officially smaller, we had the chimney breast removed as part of the renovations and it actually feels bigger and brighter.

Now planning multi-split AC, as upstairs is too hot in summer and a downstairs unit will mean we don't need to close curtains in the day as we get more and more 33C+ days in future. That's a job for next winter, once all the fuss has died down (and hopefully the price of the quotes) Our 12 year old border collie is delaying the EV purchase, hubby says he wants all the fur and mud in this car and not in a new one which I can understand.

As someone will always ask, our energy efficiency journey has cost us £19K so far, more loft insulation, solar/battery, ASHP (replaced a 14 year old gas boiler), bit more battery, bi-folds, new side door (draughty cat flap no longer required) and chimney breast removal. I've not included £1K for new induction range as we needed a new cooker anyway. I think it's money well spent.

Good luck to everyone on their free energy journey, I can confirm it feels good in lots of ways but especially ditching the gas. Also big thanks to all the regular users of this forum who have directly helped shape my plans or made me think and go away to find more information.

NedS

https://forums.moneysavingexpert.com/discussion/comment/82067564#Comment_82067564

Thanks for sharing, that's a great story and sounds like a great outcome for you.

If you don't mind me asking, for reference how much were you spending on gas/electricity before you started on this journey?

pensionpawn

https://forums.moneysavingexpert.com/discussion/comment/82058804#Comment_82058804

North Wiltshire with 4 kWs facing due east, and 3.1 kWs facing due west, no battery or EV. Paid for install after 7 years and we're now 3 years into profit. We generate 6.3 Mwhrs on average and with electric UFH across the majority of the ground floor and air conditioning for the two double bedrooms and the lounge, our annual bill is around £200. Happy with that. We'll buy our first EV when V2X is available to power the house, timeshift energy.

EricMears

https://forums.moneysavingexpert.com/discussion/comment/82067781#Comment_82067781

Some EVs can already support a 230V supply. Although limited to 3kW and not necessarily in phase with Grid my Hyundai comes in very useful in event of power cuts and could in principle run a HP & CH system all day if those circuits could be isolated from grid supply.

Alnat1

https://forums.moneysavingexpert.com/discussion/comment/82067598#Comment_82067598

Been trying to look back but Scottish Power won't show my details from 2022 and 4K posts on here are too many to scroll through, can't see a way to check earliest ones quickly to see if I posted usage here.

I seem to remember around 3,800 kWh electric and 13,000kWh gas annually previous couple of years before I moved to Octopus in April 22.

TBF, some of the things listed in the £19K might have been done anyway, loft top up, new door and bi-folds, chimney removal and if not ASHP we'd have needed a new boiler by now.

NedS

https://forums.moneysavingexpert.com/discussion/comment/82067990#Comment_82067990

Right, so your annual bills would be around £2,000 at today's prices, with payback in 9.5 years even if you included absolutely everything. And as you say, a lot of the improvements you would have done anyway so in reality far less.

JKenH

So far we have spent around £24,000 on green improvements. As with most incremental projects the biggest returns came from the first investment. Although I don’t have a spreadsheet I am happy that the initial £7,000 we spent on solar panels in 2018 has been returned and the first two A2A heat pumps (cost £2000) have displaced a substantial amount of oil. I earn around £250 in FiT and our export from our original panels exceeds our electricity import. As oil is not metered and top ups don’t follow a set pattern, I can’t be sure but may have saved 800-1000litres a year, say £600.

The additional 5kW of panels plus Tesla Powerwall at £11k together with extending the A2As at a cost of approximately £4,000 to cover upstairs won’t produce anything like the same return and as we are in our seventies we probably won’t see the capital return of this second round of expenditure. We might save another few £100s on oil and earn about £500 more in export but it’s going to be a 15-20 years payback period minimum. Financially, it would have been better to stick £15,000 in a cash ISA and earn £600 pa interest but I don’t have any regrets - it’s just another hobby. I could have blown £3-4k a year leasing a new car or fitted a new kitchen then I would be even worse off. One consolation is that it’s all money that HMRC won’t get their hands on when we move on so I try and look at it as getting tax relief on what we’ve spent.