the differences between countries are due to differences in load factors and the cost of backup capacity the system costs of the three key technologies increase from onshore wind to offshore wind and solar pv these systemlevel costs come over and above the higher plantlevel costs of renewables including the latter based on the figures contained in the ieanea study on the projected costs generating electricity as well as more recent figures for solar power increases total generating costs by up to for onshore wind up to for offshore wind and up to for solar energy