The graph shows a typical heat output from a three square metre Viridian Solar Panel on an averaged sized "three bed semi". The energy increases each month as you move from the short days of winter to brighter summer weather. Hot water demand stays the same through the year, but the temperature of incoming water to the property increases in summer, so less energy is needed to heat it up.

The amount of solar energy as a proportion of hot water demand (called the solar fraction) can be increased by installing a greater area of panel, but this follows a diminishing return profile. For example, adding another meter square of solar panel to this installation (+33% in area), will increase the energy collected by only around 130kWh (+10%).