Solar power is designed to be able to be used in the afternoon as well as at  night, it is similar to electricity that is produced by PLN (Indonesia’s Electricity Company). Electricity which are generated by solar module will be stored in a battery or Accu, therefore electricity could be used or taken anytime.

The design of the solar power system has calculated weather factor throughout the year. If solar power is used as instructed, solar power could be used normally in summer as well in rainy season. It is possible because the size of the solar module and battery/accu has been calculated to consider climate changes throughout the year and daily electricity needs.

Therefore, in rainy season electricity in the battery will slowly decrease because electricity that is produced by the solar module is lower than the  usage. In reverse, electricity that is produced by solar module in summer is higher than the usage, in result the electricity in the battery will be full slowly.

The solar power we meant is Solar Photovoltaic. Solar photovoltaic transformed sun light to electricity whereas solar water heater collects the heat of the sun to heat water, which is categorized as solar thermal. As a result, if the situation is cloudy, solar power still could produce electricity as long as there are still sunlight, whereas solar power heater could not be able to utilize it.

By the release of subsidies on fuel, Solar power is now more economical, if it is compared with electricity produced by genset (diesel) or petromak. Particularly in isolated area where fuel is expensive.

Solar power in principal is a power supply device. The electricity could be used for any kind of needs such as lighting, air conditioning, electronic devices, and even to move car/airplane/ferries.

Solar power could be utilized anywhere as long as there is sunlight, both for isolated areas or cities, and even in outer space (for satellite). The use of solar power in remote or isolated area is still dominating because there are no other option beside solar power. Nowadays in indonesia itself, solar power has been utilized and implemented in cities and buildings. It is seen as a environmental friendly technology, improve electricity and it is technically useful for back up in case of sudden lost of electricity or blackout.

Electricity which are produced by solar module is a DC electricity (Direct Current). If AC electricity is needed therefore solar power system has to be completed with an inverter (transform DC to AC).

In indonesia, most of the solar power still uses small system around 50-100Wp. The use of solar power in large capacity started since year 2000, where solar power is combined with genset (hybrid). It is also implemented for grid connected in some of the buildings in Jakarta, indonesia. Hybrid with the capacity until 100 kW begin to be widely used. The biggest solar power system in the world is 6MW, which is installed in Germany.

OD is total of days without sun. It shows the total amount of days where solar power system could survive (supplying electricity) even though there are no sunlight. In result, OD shows level of reliability of the solar power system. OD has to be determined at the time the system is designed because the needs of OD is different for each purposes and will also determines the capacity of solar power devices used. The greater the OD, then the solar power system will be more expensive, but in return it becomes more reliable.

OD for solar power system in lighting, is set 3 days, but in solar power system for communication the set up could be up to 7 days. in the case for lighting system, even though there are no sunlight in 3 days, the amount of loss is not too big whereas for telecommunication system the risk of being not able to sell credit is big therefore telecommunication company prefer to set the OD high than risking lost of income even though, the fare of the system becomes more expensive.