Photovoltaic Thermal (PVT)


  • See this post on Photovoltaic, PVT Vs PV or PT.
    – it seems that PVT just doesn’t yet work, and may never work as they have very different optimal temperatures.

Photovoltaic Thermal (PVT) with New Form Energy ?

In late Feb 2012 I dropped an message to (via their on-line enquiry form) for a call to chat over the Silver Spray project.

  • Saying that  the current plans (pre planning application) have allocated a 8 x 5 m (approx) flat roof area for solar panels.This is on the south facing side of the building. The long north to south edge is just over 8m, the short edge is just under 5m (about 4.8m).
  • I’ve not had a reply / response and that was almost a month ago. Not ideal. OK I know a single email from their site form could get lost but ……

Origional Post:

Photovoltaic Thermal (PVT) is relativly new, but regarded as the most efficient at year round producing electricity and hot water.

” A well insulated 200m sq. house would need a 4kWp system costing around £20,000 installed, including a heat pump and hot water cylinder.” Homebuilding and Renovation magazine.

Supplier:, where they claim:

  • A drawback with Photovoltaic panels (PV) is that as the surface temperature of the panel rises, the output drops. PV panels typically lose efficiency of up to 0.5% per degree rise in panel temperature.
  • Solar thermal collectors for hot water can give little or no hot water when there is little or no sun.
  • Although heat pumps are potential greener than burning fossil fuels, they do still use large amounts of electricity.

So a combined system:

  • One panel for PV and thermal means that:
    • 1st the growing heat is drawn away from the panel
    • 2nd, less total roof area needed for same output.
      • The Hybrid Solar Solution, with PowerVolt panels installed on a UK house with 28m2 of available south facing roof area, will produce the equivalent annual electrical output from 38m2 of conventional monocrystalline photovoltaics. The same area of PowerVolt collectors will offset approximately the same amount of thermal energy as 8m2 of conventional solar thermal collectors (without any contribution from the heat pump). Using separate PV plus solar thermal systems would therefore require 46m2 to generate the same electrical and thermal energy produced by 28m2 of PowerVolt thermal collectors.In addition, with the size of solar installation referred to above, the heat pump can produce up to 22,000kWh of heat in winter months when the demand is highest.
  • Solar thermal+ heat pump, means that at night or when low sunlight, the panel can act as a thermal collector (not a solar collector). This, then via the heat pump generates hot water.


  • All year round solution
  • Significantly increases your electricity production
  • Fastest payback of all renewable heating systems
  • Low maintenance and user friendly
  • Solution that optimises efficiency, saves space and money.