Economic premises for SOFC cogeneration in Finnish households

In this paper, we present the economic analysis of a solid-oxide fuel-cell (SOFC) micro-cogeneration plant in a single-family low-energy house in Finland. Here, we implement a new solid-oxide fuel-cell (SOFC) model in the dynamic building simulation software IDA Indoor Climate and Energy to obtain a match between energy demand and supply. In our computational study, we first estimate the break-even values for both the buyback price of electricity and plant investment that make an SOFC plant financially viable in a comparison with a water-based gas boiler heating system without cogeneration. Second, we determine the sensitivity of break-even prices in terms of the electrical power, overall efficiency and two operational strategies. Our results suggest that the optimal operation would encompass a constant run with electrical power no more than 1 kWe. In the above case, the break-even buyback price would remain less than 0.04 EUR kWh-1, provided that the overall efficiency exceeds 80 %.