Sveriges potential för elproduktion från takmonterade solceller
Teoretisk, teknisk och ekonomisk analys
The Swedish potential of electricity production from roof mounted solar panels has been determined in three steps: accessing the existing roof top areas, simulating the amount of electricity solar panels can produce on these areas and finally analyzing how large the necessary economical change is to make the solar cells profitable.The total existing amount of roof top areas are 319 square kilometers and the area distribution follows the distribution of people. This leads to an installed power of 47,9 GW which are expected to produce 49,0 TWh electricity per year. If the quality of the electricity is prioritized the highest the power is reduced to 3,7 GW, generating 3,8 TWh yearly, but if the hosting capacity is calculated from Sweden?s total electricity need, the capacity is 42 TWh per year.Today, solar panels are not profitable in Sweden for houses, even though there is a subsidy of 35 % of the investment costs, discounted in 25 years. The profitability is calculated with a cost of capital of 5 %, a price on electricity of 1 SEK/kWh and an investment cost of 20 SEK/Wp. With a kept subsidy of 35 %, the price of electricity needs to rise 30 % to make the systems profitable for houses, and the corresponding increase without the subsidy is 95 %. Historically the subsidy has decreased as the costs of solar cells have decreased as well.For apartment buildings solar panels are profitable with the governmental subsidy if the solar systems are at least 3 kWp per house hold. The corresponding price increase without the subsidy is 60 %.