Installation

The various possibilities of installing a small scale renewable source into or onto a typical dwelling is shown in the sketches. It is usually possible to install more than one source as the sketch illustrates.

The roof is the most suitable place for installing a solar photovoltaic panel or a solar water heater panel. An inclined roof facing south is ideal for maximising the solar gain. North facing is not suitable and west is better than east.

Wind turbines should be mounted at least two metres higher than the top of the roof either off the roof or on a separate pole.

The biomass boiler will require a chimney and flue and use can be made of existing facilities if suitable.

The heat pump collector needs to be buried in the ground or water if these are used as the source. A vertical collector requires less space than a horizontally laid collector as space is only required for the drilling machine.

Also illustrated in the sketch are three passive solar means of reducing the solar gain during the summer to remove the need for active cooling. Blinds and shutters can be fitted to most dwellings, deciduous trees, whose leaves fall to the ground in winter, can be planted in gardens.

For people living in the countryside or in small villages, it should easy to install one or more of such sources. For town or city dwellers there will be fewer opportunities to apply these technologies to single dwellings. However for small groups of housing, a small communal heating or electricity generating scheme might be more possible and would like be cheaper than installing individual systems to dwellings.

Combined technologies are unusual but there is no reason why they should not be considered other than cost. Solar water heating is most common in southern Europe, biomass in central and northern Europe. Heat pumps are installed throughout Europe with reversible systems in the south for summer cooling and heating only in north Europe.

Wind turbines and solar cells are complementary because the sun peaks in the summer and the wind in winter. So if it is favourable to fit both systems, this should be done to maximise the amount of renewable electricity generated. There are some synergies between the two techniques which will lead to some savings in electrical components.

Suitability of renewable energy sources for your home

There are certain criteria that need to be met before considering the installation of a renewable energy source.

• Biomass heating is a possibility if:
  • there is no clean air zone
  • there is sufficient storage space (about 2 m²)
  • there is a local source of biomass
  • there is local knowledge of installation and maintenance
• heat pump heating is possible if
  • there is access to a ground or water source (or air if mounted on an external wall)
  • there is a high level of thermal insulation to the building
  • the heat pump system is able to supply the current distribution system
• solar thermal heating is possible if
  • the roof orientation is south or south west
  • there is little shadow during the day i.e. no tall trees or high buildings to shade the array from direct sunlight for any appreciable part of the day
  • the roof structure is able to carry the extra load of the installation
  • the new system is able to connect to the existing hot water system
• a wind turbine could be installed if
  • the average wind speed is greater than 4 m/s
  • it can be mounted to the side of the house
  • the installation would be clear of higher buildings or trees in the prevailing wind direction(s)
• photovoltaic electricity is possible if
  • the roof orientation is south or south west
  • there is little shadow during the day i.e. no tall trees or high buildings to shade the array from direct sunlight for any appreciable part of the day

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