4 ms·

The CO2 in the production, transport and installation of solar panels leads to an equivalent CO2 output of 50g per kWh. This compares to 975g per kWh for coal.

• ars 7y ago
  > leads to an equivalent CO2 output of 50g per kWh Like I said, it's not so simple, nuclear is 66 g/kWh, and does not have intermittency issues. > that will make the house a net-zero energy consumer (everything is electric, no fossil fuels). Are you heating with electricity as well? Because that's really bad for the environment, even with PV. (Because if you heated with natural gas, you could send your PV electricity to another grid consumer and avoid more hydrocarbon fuel being burned.) If yes, are you at least using a ground-source heat pump? (Although even there natural gas is better - install a "gas absorption heat pump" if you really want to minimize your emissions.) > If it makes sense here, it can make sense almost anywhere. In small quantities yes, but if everyone did that you need something to generate electricity at night. To me nuclear wins easily.
  • fyfy18 7y ago
    Oops I somehow read your comment as advocating for continued fossil fuel for electricity generation. Yes if the choice is between solar or nuclear, then yes nuclear is definately the better option. We are going for an air source heat pump. A ground source heat pump will need bore holes to be drilled as there isn't enough space for ground loops, and the extra cost of that doesn't offset the decreased efficiency of the air source heat pump over the life of the system. The heat pump will primarily run when PV is generating more power than the rest of the house is consuming, and store heated water in a tank for consumption at night. We are building to Passive House standards. Space heating from the heat pump will use a maximum 1000kWh of electriciy per year (worst case assuming we get a long stretch of cold days below the operating temperature of the heat pump, and it has to fall back to resistance heating), while the PV should output around 9000kWh. We'll also have a wood stove as backup, but that will generate too much heat for primary heating. Net-zero isn't perfect as you say, but for the few winter months when we probably won't generate enough electricity to cover heating consumption I don't think it's that bad. Electricity generation in my country has an average of 300g CO2/kWh. I'd prefer not to use gas as our country imports gas from Russia, and I'd rather not depend on them. Plus gas leakage has a massive impact on ghg. We are in the late planning stages, so if you have any suggestions of further reading material please let me know :-)
    • ars 7y ago
      Only suggestions I have is reconsider not running a natural gas line. Cooking on electricity is not great, and wood is really bad for pollution. I understand the Russia situation, but geopolitics changes all the time, and the house is likely to stand for a long time. Since you seem to be in Europe, and you want an air source heat pump, I would suggest this product for your heating: Lochinvar LCGHPi-40HT. Then instead of using your electricity to (inefficiently) run a heat pump, send the electricity back out on the grid, while using more efficient natural gas. And then you help CO2 emissions in a more globally way, rather than just by your house. CO2 acts globally after all. Even with the gas leakage, natural gas is still worth it over heating with electricity. I think you have something like 1/5 the emissions of electricity (and remember your PV going back on the grid reduces fuel consumption elsewhere).
• opo 7y ago
  >...I plan to install a solar PV system that will make the house a net-zero energy consumer (everything is electric, no fossil fuels). Few people are able to afford that because the battery backup needed for daily/seasonal solar variations is just too expensive. You are able to remove yourself from the grid with an estimated 10 year payback?