A Happy Bonus

As you can see, a large fraction of this roof is covered by photovoltaic panels. The panels have an air gap above the tiles to ensure that heat can be drawn away from the panels by rising air. This improves their efficiency. A happy bonus is that my roof is now well shaded from the summer sun. The room inside is distinctly cooler, which is most welcome. This silver lining comes at no cost in money or energy. It is a completely free byproduct of having the panels. Now that's a happy bonus.