Low Energy


Energy is not just the amount to keep the house at a comfortable level to live in, but also the amount of energy used to build the house. The embodied energy of the materials used, if they are recycled, if they can be recycled in the future, if there can be minimum construction and on-going materials waste.

  • There are a lot of houses about that are “eco” with what I would consider a high and needless level of embodied energy (steel, concrete).
  • There are also a lot of houses about that are “eco” by being very energy efficient, but the materials to achieve this are hard to recycle eg lots of polystyrene and foam guns.

Electricity & Heating

  • Photovoltaic solar panels for electricity.  Link to a feed in tariff. I currently use Ecotricity for electricity because I like their ethical position. When I last looked they had  the UK’s most generous feed in tariff.
  • Solar panels to heat / pre-heat wate for under-floor heating and hot water in general?
    • An evaluation of Thermodynamic Panels comes out that they’ll work, but they don’t qualify for the UK government Renewable Heat Incentive ( RHI ).
  • Look at Cornwall based R-ECO, the Renewable Energy Co-operative, “the UK’s only employee-owned installer of solar PV systems”.
  • Also have an updated chat with Perranporth based Natural Generation.
  • The ideal angle for solar panels in Cornwall is for them to be at 30 degrees (and south facing).
  • A 4 Kw system will typically take up an area 8 x 3 meters.
    • This is improving all the time (more power potential from smaller and smaller panels). So it’s worth getting a check on which panels closer to their instalation point.

Heat Loss / Heat Exchange

Domestic Hot Water Heat Recovery

Further heat recovery / heat exchange ideas:

  • Put the output pipe for the MVHR so that this still warm air flows over the Thermodynamic Panels.
  • Put the Thermodynamic Panels under the Photovoltaic solar panels for electricity.
    • This will benefit both:
      • Photovoltaic solar panels for electricity want to be kept cool
      • The Thermodynamic Panels will “grab” the heat energy from the Photovoltaic solar panels.


  • See the kitchen notes re energy efficient induction cooktops and ovens.