Common Solar Uses
Solar energy has a diverse array of uses in both residential and commercial applications. Learn about some of the most popular ways people put Solar Energy to work for them.
Every home or business needs hot water and electricity. These two basic needs are the goals of Solar PV and Solar Thermal systems.Recent years have seen rapid growth in the number of installations of PV on to buildings that are connected to the electricity grid. This area of demand has been stimulated in part by government subsidy programmes (especially Japan and Germany) and by green pricing policies of utilities or electricity service providers (e.g. in Switzerland and the USA). The central driving force though comes from the desire of individuals or companies to obtain their electricity from a clean, non-polluting, renewable source for which they are prepared to pay a small premium.
In these grid-connected systems, a PV System supplies electricity to the building and any day-time excess may be exported to the grid. Batteries are not required because the grid supplies any extra demand. However, if you want to be independent of the grid supply you will need battery storage to provide power outside daylight hours.
Solar PV modules can be retrofitted on to a pitched roof above the existing roof-tiles, or the tiles replaced by specially designed PV roof-tiles or roof-tiling systems. If you are planning to put a PV system on to a building and have it connected to the grid supply there are likely to be local regulations that need to be met, and permission required from your utility or electricity service provider. The level of credit for any exported electricity will vary depending on local schemes in place.
Photovoltaic Systems are frequently the preferred solution for holiday homes, which have no access to the electricity grid. These solar systems are configured to meet power needs less expensively than extending the grid to reach your location. Remote homes in sunny locations can obtain reliable electricity to meet basic needs for lighting (using energy efficient fluorescent lamps) and radio or television with a simple PV system comprising a PV panel, a rechargeable battery to store the energy captured during daylight hours, a regulator (or charge controller) and the necessary wiring and switches. Such systems are often called "solar home systems" or SHS for short.
The size of the PV module and battery is designed to provide enough power and storage to meet peak energy requirements - this is called "sizing" the system. . All systems with battery storage should use solar batteries of the right design and specification for the system, car batteries will not do! Also, high quality compact fluorescent lamps are available with good lifetimes; poor quality lamps will blacken quickly and their light output will drop off. The quality of the regulator is a key factor in the reliability of the overall system. The PV modules are usually mounted on a pole, or on the roof.
In this application, 50 to 100W modules would probably be required although smaller panels of 10 to 15W might provide sufficient power for the most basic single lamp system.
Central Power Stations
Central Power applications use solar energy in the same configuration that a Utility would utilize a major power station. This is distinctly different from the other applications on this page, which are known as "distributed power" or power distributed in small aggregate amounts of power, usually close to the point of use of the electricity.
Central solar power generation plants have been installed in Italy, US and Spain, for example. However, all these plants are "pilot" in nature. Central solar plants may be attractive under certain conditions, but they do not capitalize on the competitive strengths of solar PV in terms of its flexibility of location (i.e. being located close to the customer) and its ability to be installed incrementally.
Other Recreational Applications
Solar Water Heating Systems
For many years, Solar Energy has been the power supply of choice for Industrial applications, where power is required at remote locations. This means in these applications that solar power is economic, without subsidy. Most systems in individual uses require a few kilowatts of power.
The examples are powering repeater stations for microwave, TV and radio, telemetry and radio telephones.
Solar energy is also frequently used on transportation signalling e.g. offshore navigation buoys, lighthouses, aircraft warning lights on pylons or structures, and increasingly in road traffic warning signals. Solar is used to power environmental and situation monitoring equipment and corrosion protection systems (based on impressing a current) for pipelines, well-heads, and bridges or other structures. As before, for larger electrical loads it can be cost effective to configure a hybrid power system that links the PV with a small diesel generator.
Solar's great benefit here is that it is highly reliable and requires little maintenance so it's ideal in places that are hard to get to.
Water Pumping, lighting, heating in the Developing World
Apart from off-grid homes, other remote buildings such as schools, community halls, and clinics can all benefit from electrification with Solar Energy. This can power TV, video, telephony and a range of refrigeration equipment, which is available to meet World Health Organisation standards for vaccine refrigeration, for instance . Rather than base Solar power generation on individual dwellings, it is also possible to configure central village power plants that can either power homes via a local wired network, or act as a battery charging station where members of the community can bring batteries to be recharged.
PV Systems can be used to pump water in remote areas e.g. as part of a portable water supply system. Specialized solar water pumps are designed for submersible use (in a borehole) or to float on open water. Usually, the ability to store water in a tank means that battery power storage is unnecessary. Large-scale desalination plants can also be PV powered. Larger off-grid systems can be constructed to power larger and more sophisticated electrical loads by using an array of PV modules and having more battery storage capacity.
To meet the largest power requirements in an off-grid location, the PV system is sometimes best configured with a small diesel generator. This means that the PV system no longer has to be sized to cope with the worst sunlight conditions available during the year. The diesel generator can then provide the back-up power, but its use is minimised during the rest of the year by the PV system, so fuel and maintenance costs are kept low.
Solar energy can also power area lighting to enable more outdoor activities after dark or improve security, and to illuminate signs or advertising boards.
On an office building, atria can be covered with glass/glass PV modules, which can be semi-transparent to provide shaded light. On a factory, large roof areas have been the best location for solar modules. If they are flat, then arrays can be mounted using techniques that do not breach the weatherproof roof membrane. Also, skylights can be covered partially with PV.
The vertical walls of office buildings provide several opportunities for PV incorporation. The first is as a "curtain wall system" that constitutes the weather barrier of the building. The second, as a "rainscreen overcladding system" where there is an underlying weather barrier that provides the insulation and sealing of the building.
The third option is to create sunshades or balconies incorporating a PV System. Sunshades may have the PV System mounted externally to the building or have PV cells specially mounted between glass sheets comprising the window.