Can you expand on the aggregate CO2 vs marginal CO2 part ?
I’m looking into installing a ground heat pump in a new house (coupled with solar panels) mostly for environmental reasons and all the critics I’ve read so far were about the costs.
If you turn on a light and use some extra electricity, some power station somewhere will need to increase power output to provide for you.
It's the CO2 production of that extra generation, known as marginal generation, you should care about, not the nationwide average.
Most of the time, in most of the world, that extra generation is combined cycle gas turbines at ~50% efficiency.
For most people, the only time a new use of electricity is eco-friendly is when all the energy in a country is already supplied by wind/solar/hydro, and therefore a newly switched on thing also gets supplied by wind/solar/hydro.
Obviously the decision to installation a heat pump depends on the marginal generation in 15 years when you are still using that heat pump. That's very hard to predict.
I’m looking into installing a ground heat pump in a new house (coupled with solar panels) mostly for environmental reasons and all the critics I’ve read so far were about the costs.