Advice would be most welcome on use of PVs to provide hot water and underfloor heating.  We are installing a 6.5kW PV system in addition to a gas boiler and are beginning to look at the systems available.  We have 4 bedrooms, 3 showers (one of which is a bath) and wet underfloor heating in concrete flooring.  Our assumption is that the primary benefit we will get from the PVs is water heating, until such time as battery technology is affordable, but our hot water usage will be modest except when