The Energy Showcase

A Pioneering Solar House

Reduced Electricity Consumption


The building is full of energy-efficient lighting. At least 50% of the light comes from ‘eco’ T5 fluorescent lighting, based on the GE(US) Wattmiser technology and with a luminous efficacy of just over 100 lumens per watt. 50% comes from compact fluorescent lamps and light emitting diodes (LEDs). These offer an efficacy of 50-60 lumens/watts (lm/W) averaged over their lifespan.

Soon, LEDs should offer an efficacy of over 100 lm/W and a colour rendering index as good as halogen lamps or full-spectrum fluorescent lamps. We have not quite reached this point yet, though.

Electricity consumption for lighting is cut by 82% compared to a normal house. It will drop by 88% once LEDs improve in energy efficiency and light quality / colour rendering to T5s now.

led light

LED ‘light bulb’.
Picture ©


Very energy-efficient domestic appliances are in use. The anticipated result is:

  • Total electricity consumption for domestic purposes = 900 to 1,000 kWh per year (kWh/y),
    costing around £180/year at today’s prices;
  • Electricity generated from a small solar PV system of only 1.2 kW = 1,020 kWh/y
    supplies as much electricity as the house consumes.

An example of high energy efficiency is the refrigerator-freezer which will be installed shortly in the house. It consumes 121 kWh/y. A UK refrigerator-freezer bought in the last ten years typically consumed 350 to 500 kWh/year.


Example of a very energy-efficient refrigerator-freezer.
Picture ©