We have just installed pv’s on our site with a 50% grant from our local council through a low carbon funding scheme. Grants are available and can also cover other items such as heat pumps. We also looked at other options with a local charity that installs panels at no cost and shares the return on payments for electricity sent to the national grid. The trustees decided to go for our own scheme as we had available funds but the alternative could be attractive for an almshouse with limited funds. You would need to consider how your units are supplied with electricity- if directly from the supplier the installations would be separate, each with an inverter so cost will be higher. Our flats are on a single supply with sub-meters to recover costs from each resident so a much simpler installation