Is A2A to be included in the BUS grant spring 2025 ?

[Mart]

Gas is about 6p/kWh and Peak electric is about 25p/kWh. A gas boiler is possibly 80% efficient whereas a HP is about 350% efficient.

That makes gas heating cost 7.5p/kWh of heat output and a HP cost about 7.1p/kWh of heat output (at peak prices). So a HP is financially viable even on peak electric. However if you're running your HP on timeshifted ToU electric then the heat is as good as free!

I think this argument can be carried through to the emissions side too, even if assume all of the HP leccy comes from marginal/additional gas generation.

So using your numbers, 1kWh of gas will produce 0.8kWh(t) of heat.

But that same 1kWh of gas, burnt at a CCGT powerstation will produce 0.5 to 0.6 kWh of leccy. Assuming 6% grid losses, the heat pump in the house will recieve 0.47kWh to 0.56kWh of leccy. Which will produce 1.65kWh(t) to 1.97kWh(t) of heat, for the same amount of gas burnt / emissions.

Using my 'best case for gas' numbers, we get 0.9kWh(t) from the boiler v's 1.29kWh(t) from the HP, or 1.5kWh(t) at a SCOP of 2.9.


But just to stress, that's not the real/average emissions from leccy, that's a comparison of gas boiler, to HP running on gas generated leccy, effectively a worst case scenario.

[Stinsy]

Gas is about 6p/kWh and Peak electric is about 25p/kWh. A gas boiler is possibly 80% efficient whereas a HP is about 350% efficient.

That makes gas heating cost 7.5p/kWh of heat output and a HP cost about 7.1p/kWh of heat output (at peak prices). So a HP is financially viable even on peak electric. However if you're running your HP on timeshifted ToU electric then the heat is as good as free!

I think this argument can be carried through to the emissions side too, even if assume all of the HP leccy comes from marginal/additional gas generation.

So using your numbers, 1kWh of gas will produce 0.8kWh(t) of heat.

But that same 1kWh of gas, burnt at a CCGT powerstation will produce 0.5 to 0.6 kWh of leccy. Assuming 6% grid losses, the heat pump in the house will recieve 0.47kWh to 0.56kWh of leccy. Which will produce 1.65kWh(t) to 1.97kWh(t) of heat, for the same amount of gas burnt / emissions.

Using my 'best case for gas' numbers, we get 0.9kWh(t) from the boiler v's 1.29kWh(t) from the HP, or 1.5kWh(t) at a SCOP of 2.9.


But just to stress, that's not the real/average emissions from leccy, that's a comparison of gas boiler, to HP running on gas generated leccy, effectively a worst case scenario.

Yes. I've seen that point made by people who know what they're talking about: burning gas in a power plant, sending the electric to your house, converting it to heat in a HP is way more efficient than sending the gas to your house and burning it in a boiler. And the HP can also use electric from a nuke or wind turbine whereas your gas boiler is gas-only.

[Ken]

Hi all,

I have a quick question on this - playing devils advocate.

I admire a lot of the installs you all have and I am working towards them too. But a key element is time of use tariffs (with or without batteries). If time of use tariffs disappeared so that there was just the simple day rate electricity all the time - how would everyone's costs stack up then?

I just have a concern that as things like heat pumps (A2A or A2W) become mainstream and the country starts getting more and more large scale energy storage solutions to soak up the cheap/over production of electricity at night that there are less benefits to offering cheap electricity slots for people.

If the figures all stack up without using cheap electricity slots then that would be great - and I apologise if this is covered somewhere else - I have not seen it discussed.

I do not have batteries nor a smart meter nor TOU tariffs but i do have PV and as far as i am concerned PV is the best thing since sliced bread.
The costs of PV have come down so much it does stack up however you want to cut it. Batteries and TOU tariffs only serve to put icing on the cake.
Once you have got PV then all the other things start to fall in to place including EV.

You are right to have reservations about HPs as these cost just as much as mains gas to run and can be a problem to retrofit.

Cheap leccy at night will always be an intergral part of our new net zero CO2 world. It will be economically bad to build enough storage to store night excesses and will not happen. This is a whole subject in itself i do not have the time now.

PS dont mind devils advocate but i do detest the lies and inaccuracies of the media to sell their ware. For me and many others the Daily Mail is the worst.

Ken

[Stinsy]

I do not have batteries nor a smart meter nor TOU tariffs but i do have PV and as far as i am concerned PV is the best thing since sliced bread.
The costs of PV have come down so much it does stack up however you want to cut it. Batteries and TOU tariffs only serve to put icing on the cake.
Once you have got PV then all the other things start to fall in to place including EV.

You are right to have reservations about HPs as these cost just as much as mains gas to run and can be a problem to retrofit.

Cheap leccy at night will always be an intergral part of our new net zero CO2 world. It will be economically bad to build enough storage to store night excesses and will not happen. This is a whole subject in itself i do not have the time now.

PS dont mind devils advocate but i do detest the lies and inaccuracies of the media to sell their ware. For me and many others the Daily Mail is the worst.

Ken

Lots of people have been doing the sums and finding that solar doesn't add up but batteries do. While the cost of panels is so low as to be effectively free, the cost of installation can be prohibitive.

I think that solar/batteries/ToU is a "magic trifecta" that all work together elegantly...

[Ken]

Lots of people have been doing the sums and finding that solar doesn't add up but batteries do. While the cost of panels is so low as to be effectively free, the cost of installation can be prohibitive.

I think that solar/batteries/ToU is a "magic trifecta" that all work together elegantly...

I agree with the last sentence but solar?

5kwp system producing 5kwh/yr costing £4K and substituting 23p/kwh mains leccy is £1150/yr ie a return of 28%/yr . Please please please tell me where you can get a better return than that.

I am sure that it is possible to have a zero leccy bill ( not standing charge) by

PV size kwp the same as your annual usage of leccy.
c 8kwh batt
export 90% of PV at 15p/kwh
The hp,batt, EV all used at TOU night rate.

[Joeboy]

Lots of people have been doing the sums and finding that solar doesn't add up but batteries do. While the cost of panels is so low as to be effectively free, the cost of installation can be prohibitive.

I think that solar/batteries/ToU is a "magic trifecta" that all work together elegantly...

I agree with the last sentence but solar?

5kwp system producing 5kwh/yr costing £4K and substituting 23p/kwh mains leccy is £1150/yr ie a return of 28%/yr . Please please please tell me where you can get a better return than that.

I am sure that it is possible to have a zero leccy bill ( not standing charge) by

PV size kwp the same as your annual usage of leccy.
c 8kwh batt
export 90% of PV at 15p/kwh
The hp,batt, EV all used at TOU night rate.

Are you paying 23p per kWh? I think you mean MWh for annual generation on the pv system? I pay 7p per kWh and my 5kW PV system generates 3.6MWh pa.

That's only worth £252 (6.3% roi) to me. If I export it all it's worth £540 (13.5% roi). I then have maintenance and component failure to allow for before seeing a 100% roi. These figures are closer to my reality.

[Stinsy]

Lots of people have been doing the sums and finding that solar doesn't add up but batteries do. While the cost of panels is so low as to be effectively free, the cost of installation can be prohibitive.

I think that solar/batteries/ToU is a "magic trifecta" that all work together elegantly...

I agree with the last sentence but solar?

5kwp system producing 5kwh/yr costing £4K and substituting 23p/kwh mains leccy is £1150/yr ie a return of 28%/yr . Please please please tell me where you can get a better return than that.

I am sure that it is possible to have a zero leccy bill ( not standing charge) by

PV size kwp the same as your annual usage of leccy.
c 8kwh batt
export 90% of PV at 15p/kwh
The hp,batt, EV all used at TOU night rate.

Sure by those maths! But people couldn't get anywhere close to £1/Wp installed a few years ago. I've seen quotes of £7500 or more for a 5kWp install!

https://www.greenmatch.co.uk/solar-ener ... nel-system

[Mart]

I think that solar/batteries/ToU is a "magic trifecta" that all work together elegantly...

Hope this doesn't seem pedantic, as I totally agree, but I think BEV's are a big plus to the group too, as they can make* TOU cheap rate viable, opening the door to battery charging in low PV generation periods. Not saying everyone has to get a BEV, just that each addition PV, batts, cheap rate, BEV's and HP's, all get better and easier, as we get more. A perfect example of the whole being greater than the sum of the parts.

*As I got to that point I realised I may have misunderstood, as TOU is not exactly the same as cheap rate. But what the hell, I'll throw the comment in anyways.

[Stinsy]

I think that solar/batteries/ToU is a "magic trifecta" that all work together elegantly...

Hope this doesn't seem pedantic, as I totally agree, but I think BEV's are a big plus to the group too, as they can make* TOU cheap rate viable, opening the door to battery charging in low PV generation periods. Not saying everyone has to get a BEV, just that each addition PV, batts, cheap rate, BEV's and HP's, all get better and easier, as we get more. A perfect example of the whole being greater than the sum of the parts.

*As I got to that point I realised I may have misunderstood, as TOU is not exactly the same as cheap rate. But what the hell, I'll throw the comment in anyways.

Sure. I have 2x EVs (a BEV and a PHEV). Certainly to get the Cephalopod's cheap rate you need to at least pretend to have an EV. And to get their very cheapest cheap rate with the possibility to "game" additional slots you need either a listed EV or a listed charging point.

[Joeboy]

My personal ultimate bang for buck would be 4kWp on a groundmount and running back onto 2 separate socket circuits and each on a 2kW hoymiles. Southfacing of course and 3 doors down from Nowtys town.

Something like
£640 for 8 of 535W panels
£400 for 2 of 2kW Hoymiles
£150 for cables, mc4's, switches
£300 for groundmount

Thats £1,490 for a working good sized (4,280W) pv system. All diy possible. Damn, I want to build that. It's a no brainer.