Can I add Photo-Voltaic units to the pool hall roof to generate electricity & provide power for the pool?

Modern Photo-Voltaic (PV) units provide about 1kW of power for every 7 square metres of PV unit.

And so, an 80 square metre unshaded roof, running East-West will produce about 11kW at peak output.

If sufficient 12 volt batteries and inverters are provided this willl provide about 3 - 4 kW over the year and will provide just enough power for all the pumps and electrical pool equipment.

An auxiliary heat source will be required during the winter months - please see "Best way to heat pool hall air and swimming pool water".