We’ve just signed up to a 100% green(renewable) energy electricity tariff.
Miss OTS asked if we should still get Solar PV panels and a battery.
My current thinking is that it would actually be better if we didn’t have personal panels and batteries due to the footprint of their cost and installation versus just using the existing supply.
Obvs there may be financial cost savings, but from a CO2 generation perspective is this logic sound or am I missing something?

Not sure of the environmental impact of a lithium ion battery but have you considered a heat battery, sunamp or a behind the meter immersion heater. Must be a better option than a domestic lithium ion battery

Probably marginally worse even if it’s just that the installer has to drive to your house to install the ~8 panel’s rather than doing hundreds in a field somewhere.

OTOH. No grid losses, no Greenfield sites used up.

Batteries, would be interested if anyone has any real data as while they have a carbon footprint, that’s offset against making the grid more efficient over their lifetime.

Both are window dressing if you are still connected to and use mains gas.

I’d love our village to have a panels + Gravitricity combination…

Both are window dressing if you are still connected to and use mains gas.

Why would I use mains gas when I can use a CO2 free fuel for cooking?

Both are window dressing if you are still connected to and use mains gas.

I thought that statment was a bit blunt so wanted to know if I should educate myeselfand came across these figures (source https://www.carbonindependent.org/15.html) The c source contains further references and figures for losses and inefficiencies.

Electricity: 0.309 kg / kWh (kg CO2/kWh)
Natural Gas: 0.203 kg / kWh

So I’d have to disagree with your assertion there Edukator. Yes, would be better to use renewable electricity instead of natural gas, but to scrap a perfectly good boiler (and rads?) and cooking appliances to use electricity instead is going to have a large carbon cost.

Why would I use mains gas when I can use a CO2 free fuel for cooking?

Because even if you don’t use it for cooking you’re likely to use gas for domestic hot water and heating. If (note I used “if” in my original post) you don’t then great, but if you do still use gas then how you source your electricity matters little compared with cutting off the gas and insulating your home to the point it no longer needs heating. How you prouduce your domestic hot water is also far more important than where your elctricity comes from. A solar thermal system and or a heat pump hot water tank will better than halve the energy used to heat hot water.

Some people have never heard of heat pump hence the post above this one which is misleading because a heat pump with a COP of 3 and the current British electricty generating energy mix makes gas an obsulutely filthy fuel in terms of CO2 compared with electricty.

Edit: because on this thread so far I haven’t been insulted today so “misleading” is better.

Thank you Edukator for explaining why my points are invalid and my information incorrect.

FWIW
Seasonal averaged coefficient of performance is more like 2.5
https://www.evergreenenergy.co.uk/heat-pumps/how-efficient-are-heat-pumps/

Are heat pumps cost effective?

although it’s not clear whether this is averaged per unit time or per unit energy used.

Who the **** wrote that article, I know you didn’t so you aren’t to blame, jon, but that is one properly misleading article which looks suspiciously like gas industry propaganda. I quote:

Heat pumps are not generally a good idea for homes using mains gas. If LPG is being used, there may be cost savings, but there are unlikely to be carbon savings.

No carbon savings compared with LPG. FFS, and this is in an article about heat pumps. Badly wriiten at best, or deliberatley misleading.

I have no argument with you 2.5 COP for heat pumps, some are, some worse some better (4.5 for a low temperature ground-sourcedunit a mate has). Because a properly sized and installed heat pump betters gas in CO2 terms.

Sure it might cost a tad more than gas to run but even with a COP of 2.5 and electrity at 32% renewable it doesn’t take long to calculate that an electrictiy driven heat pump better than halves CO2 (which was what I originally claimed). And if someone is considering investing the sums needed for a power wall battery then much greater savings in CO2 can be made with insulation, heat pumps, solar thermal… .

Oh I agree that they are the ideal for a new build, but just disagree with ripping out existing gas burning infrastructure and installing new electricity consuming infrastructure (as manufacturing stuff = CO2 emissions).

Changing to a renewable tariff requires no immediate manufacturing on an individual level, only an incremental contribution towards another wind turbine or hydro dam 🙂

I wouldn’t bother with the battery right now but using something like an immersun to heat your hot water (and/or other stuff that needs heating) is something of a no-brainer.

We have a holiday house in a village with no mains gas so everything is electrically heated. From April to mid October the PV supplies 90% of the total power that we need and pretty much 100% of the hot water all from self-generated power.

I ripped out gas central heating and the only electricity consuming appliance I added was a 50l hot water tank which is used after the solar thermal system when the tank isn’t hot enough. I have no idea what the embedded energy/CO2 in that is but it can’t take long to repay having saved hundreds of m3 of gas per year.

A car burns about 8 tonnes of fuel in its life. A typical UK home uses similar amounts of fuel for the home and transport so it can take long to repay the embedded energy in a heat pump which isn’t especially big or heavy. I’ve seen payback periods in energy terms of about 5 years so there’s no real reason not to do it now even if your gas central heating is new – from a CO2 point of view anyhow, financially it’s no doubt another matter. Gas needs to be taxed to the point people change for financial reasons as wel as just giving their kids a better planet to live on.

Some interesting debate, but back to my main points.
1. It looks as though there should be lower CO2 emissions using a 100% renewable tariff than me installing panels and batteries.
2. For cooking alone, electricity from a 100% renewable tariff will be lower carbon than using gas.