The most important criterion in the construction of a solar power plant is its capacity. In order to maximize the profitability of the plant, it should at least be able to cover the on-site consumption needs as minimum. When calculating the power plant capacity, it is possible to rely on the average amount of electricity produced by Estonian solar power plants ─ approximately 1000 kWh per year from 1 kW power plant. So, if your house consumes 7800 kWh per year, you would need at least a 7.8 kW power plant. A larger plant may always be built. In that case, the electricity left over from own consumption can be sold back to the grid.