city residential home uses
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.

industrial uses
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.

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