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As a Norwegian looking into solar for my garage, all the products available now produce power when it's cloudy, snowy, rainy etc. First Google result: https://

by sigg3 4y ago

As a Norwegian looking into solar for my garage, all the products available now produce power when it's cloudy, snowy, rainy etc. First Google result: https://www.energy.gov/eere/solar/articles/busted-common-solar-myths-and-misconceptions https://www.energy.gov/eere/solar/articles/busted-common-sol...

8fingerlouie 4y ago
I’m not saying it wouldn’t produce energy, and it would probably also contribute most of the year, but the time where I need the most energy (heating and light) is also the time where it is least likely to produce any. We have an annual power consumption of 6-8k kWh, with about half during winter (heat pump, yay). More energy is required during night time due to dropping temperatures and it being dark, so realistically, I could probably save about half. At normal energy prices of €0.3/kWh, that means I would save €1200/year, and that’s without taking into account reduced electricity taxes for electric heating. Taking those into account, all electricity used beyond 4000 kWh/year would be around €0.12/kWh. Taking that into account, I could save €480/year, still assuming I could save 4000 kWh/year out of 8000 total. A solar panel installation _without_ batteries is about €13500, and saving €480/year means it would take 28 years to get back the investment. I’m aware batteries can change that equation somewhat in my favor, but it’s ever harder to calculate anything usable with those as it depends if the battery can get charged during the day. In any case, a solar panel installation with batteries is around €20000.
- sigg3 4y ago
  Yes, the ROI takes years to achieve but the alternative is to keep throwing money at the power company (and some of that energy will likely be from coal nowadays). Since I bought an electric car I've been drooling over the idea of having the car powered by the sun. I go into the office only on occasion so I don't need to charge fast either. But you need an available roof and an okay topography. But in Scandinavia, I bet most energy goes to heating so improving insulation and adding ground thermal will probably be more efficient. The idea of a sun powered car is just so enticing, however. It's kinda sci-fi.
  - 8fingerlouie 4y ago
    > but the alternative is to keep throwing money at the power company (and some of that energy will likely be from coal nowadays). This is Denmark, where a large part of our power grid is based on renewables, and backup power is based on natural gas. There is no coal involved. When we import power it's from Norway/Sweden or Germany, so either renewables or nuclear. We're not at Norwegian CO2 levels (yet), but it's getting better :) You can check for yourself here : https://app.electricitymap.org/map https://app.electricitymap.org/map > Since I bought an electric car I've been drooling over the idea of having the car powered by the sun. Denmark has outlawed sales of new ICE cars from 2030, so at that point solar will make MUCH more sense, as i can charge my car for "free", and the time to ROI will be much shorter. > But in Scandinavia, I bet most energy goes to heating so improving insulation and adding ground thermal will probably be more efficient. I thought so to, but currently, in no small part due to the Ukraine situation, lots of people are replacing oil and natural gas heaters with heat pumps or central heating, and the central heating providers are installing large heat pumps as well. As part as getting a heat pump, my house (built 1970's and renovated 2010's) has a total heat demand of roughly 13000 kWh. Assuming a heat pump with a SCOP of 3.5, that means i will need about 3700 kWh of electricity to heat it, which means that our total electricity consumption ends up around 7500 kWh, so about half the energy (in my case) being used for heating.

by sigg3 4y ago

8fingerlouie 4y ago

I’m not saying it wouldn’t produce energy, and it would probably also contribute most of the year, but the time where I need the most energy (heating and light) is also the time where it is least likely to produce any. We have an annual power consumption of 6-8k kWh, with about half during winter (heat pump, yay). More energy is required during night time due to dropping temperatures and it being dark, so realistically, I could probably save about half. At normal energy prices of €0.3/kWh, that means I would save €1200/year, and that’s without taking into account reduced electricity taxes for electric heating. Taking those into account, all electricity used beyond 4000 kWh/year would be around €0.12/kWh. Taking that into account, I could save €480/year, still assuming I could save 4000 kWh/year out of 8000 total. A solar panel installation _without_ batteries is about €13500, and saving €480/year means it would take 28 years to get back the investment. I’m aware batteries can change that equation somewhat in my favor, but it’s ever harder to calculate anything usable with those as it depends if the battery can get charged during the day. In any case, a solar panel installation with batteries is around €20000.

sigg3 4y ago
Yes, the ROI takes years to achieve but the alternative is to keep throwing money at the power company (and some of that energy will likely be from coal nowadays). Since I bought an electric car I've been drooling over the idea of having the car powered by the sun. I go into the office only on occasion so I don't need to charge fast either. But you need an available roof and an okay topography. But in Scandinavia, I bet most energy goes to heating so improving insulation and adding ground thermal will probably be more efficient. The idea of a sun powered car is just so enticing, however. It's kinda sci-fi.
- 8fingerlouie 4y ago
  > but the alternative is to keep throwing money at the power company (and some of that energy will likely be from coal nowadays). This is Denmark, where a large part of our power grid is based on renewables, and backup power is based on natural gas. There is no coal involved. When we import power it's from Norway/Sweden or Germany, so either renewables or nuclear. We're not at Norwegian CO2 levels (yet), but it's getting better :) You can check for yourself here : https://app.electricitymap.org/map https://app.electricitymap.org/map > Since I bought an electric car I've been drooling over the idea of having the car powered by the sun. Denmark has outlawed sales of new ICE cars from 2030, so at that point solar will make MUCH more sense, as i can charge my car for "free", and the time to ROI will be much shorter. > But in Scandinavia, I bet most energy goes to heating so improving insulation and adding ground thermal will probably be more efficient. I thought so to, but currently, in no small part due to the Ukraine situation, lots of people are replacing oil and natural gas heaters with heat pumps or central heating, and the central heating providers are installing large heat pumps as well. As part as getting a heat pump, my house (built 1970's and renovated 2010's) has a total heat demand of roughly 13000 kWh. Assuming a heat pump with a SCOP of 3.5, that means i will need about 3700 kWh of electricity to heat it, which means that our total electricity consumption ends up around 7500 kWh, so about half the energy (in my case) being used for heating.