So you've forked out a reasonable sum of money for solar panels on your roof but they don't seem to be performing to the maximum advertised capacity, even on a bright sunny day. Why is this?
Consider...
Taking into account the optimal orientation, angle and position when designing your roof to maximise the gains from solar power. Ensure there are no overhanging structures or trees that could cast shadows across the solar panels.
A solar panel installer will always be able to determine the optimal position of solar panels for any roof, but that's not the same as having a roof that's optimised for solar panels. The latitude and longitude of each house means each roof has a unique, theoretical optimal design that will maximise the gains from solar panels - so if you're intending to install solar panels, ensure your architect takes this into account when designing your house.