Greening and Improving Doynton Village Hall installation of PV Cells

We have installed an air to air source heat pump, which works very well. We have also installed double glazed units to all windows and trifold doors opening onto the grass, now cut to form a lawn.
We have removed the old heating system.
We now want to install a 10kW PV electricity generating system to the South-facing roof. This should generate an income from FIT for 25 years.
We already have 3 phase electricity needed to run such a system.
We have no formal environmental policy, but are committed to recycling, saving energy and reducing our carbon footprint.