Since surplus energy is sold at the wholesale electricity market price during the hours when it is fed into the grid, a reasonable question arises: how can this price be calculated?
Clearly, this price varies from quarter to quarter, from day to day, and from year to year. The chart below shows two recent examples: a Friday with high energy consumption in the country, and the following Saturday, when lower consumption led to much lower net-billing sale prices. It also shows an estimate of the average sale price over a 20-year period, based on simulations of how wholesale markets in Greece will evolve over the next two decades.