Solar water heating
Practical Action
A more extensive list has been produced by an organisation in Lebanon, following the
installation of solar water heating systems in four hospitals. These installations are described
further in the section “Success stories around the world”.
Costs
Due to the wide range of size, type and complexity of systems installed around the world,
alongside the economic schemes that may exist under various Governments, it is difficult to
accurately advise of the costs incurred when designing and installing a solar water heating
system.
A typical domestic installation in the UK is 3-4m2 costing between £3000 and £5000,
whereas simple passive and direct systems developed in countries such as Brazil and India
that are produced from recycled materials are vastly less expensive. This is a reflection of the
relative wealth of the local beneficiaries. (Capturing Solar Energy, 2009)
For example, a local initiative introduced in the Cote d’Ivoire on the west coast of Africa, with
the support of an organisation, has enabled the mobilisation of cooperatives to produce solar
water heaters locally and therefore reduce costs incurred to around $200-$400. This is
described in more detail in the section “Success stories around the world”.
Health & Safety – Things to be aware of
Legionella Pneumophilia
When a water temperature of between 20°C and 46°C is maintained for prolonged periods of
time, the risk of bacterial growth in the water increases. As the heating of water by solar
energy is not fully controlled, it is advisable to couple a solar hot water heating system with an
alternative instantaneous hot water heater to ensure the water is heated to a minimum of
60°C, thus reducing the risk of the bacterium legionella pneumophilia growing and
legionnaires’ disease being contracted.
Should legionnaires’ disease be contracted, the following symptoms may be experienced:
High temperature
Fever
Cough
Muscle pains
Headache
Diarrhoea
Mental confusion
Pneumonia
(www.hse.gov.uk)
Success stories around the world
A notable increase in the widespread application of solar water heating is evident around the
world with systems varying in levels of complexity, from large commercial to small, very simple
domestic applications. The 2010 Survey of Energy Resources by the World Energy Council
provides an overview of the progress made by 43 countries across the globe. This is a useful
document for those wishing to know how successful, or unsuccessful, solar water heating has
been in their country or continent. If a country has so far been unsuccessful, an explanation is
often provided as to why and future plans to overcome this are noted. An encouraging point to
note is that increased application of this technology has not been limited to developed
countries.
Solar water heating systems have been installed around the world in varying levels of
complexity, from large commercial to small, very simple domestic applications.
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