Solar thermal panel feeds thermal store. This is backed up by new gas boiler. Separate temp controls for top and bottom of store. Top of thermal store (65deg) provides DHW at mains pressure whereas bottom (at 40 deg) provides underfloor heating in two zones. Rest of house (older part) still uses radiators but all new and at mains pressure so quick response. All heating controlled by excellent Heatmiser system with 4 zones.
We have also installed Heat Recovery Ventilation for the whole house. The effect of these changes has been to reduce our gas consumption by over 50% and electricity by 15% measured over the last 4 quarters. Have just (Nov 2011) fitted 3.3kWp of Solar pv. Originally run as a single string (unavailability of specified inverters) we now have our chosen 2 string inverter (Aurora 3.6), as we suffer from dappled shade at this time of year. Our output seems to have risen noticeably. significantly.