Photovoltaics (PV) is the process of converting sunlight into electricity.

A photovoltaic cell is a device that converts solar energy into electricity by the photovoltaic effect.

A photovoltaic module is a packaged interconnected assembly of photovoltaic cells (solar cells).

A photovoltaic panel (solar panel) is a collection of solar modules that are mechanically fastened together, wired, and designed to be a field-installable unit, sometimes with a glass covering and a frame and backing made of metal, plastic or fiberglass.

An inverter is a device that converts DC electricity (direct current) from solar panels to AC household electricity (alternating current)

A group of interconnected solar panels are installed on the roof of your building. These panels are connected to an inverter box in your house. The inverter is connected to your home electric wiring. The inverter is also connected to your electric meter.

When sunlight shines on the solar panel, the solar cells in it create DC electricity (direct current). This DC electricity to sent to an inverter that converts it to household AC electricity (alternating current). The inverter sends the electricity to the electric wiring of your house. All the lights and appliances in your house are now working off the energy of the sun. Extra electricity that is not used by your lights and appliances is sent to your electric meter which measures it and sends it out to the electric grid of your neighborhood. The electric company will pay you for that extra electricity (your electric meter runs backwards).

- Your electricity costs are fixed for the long term

- While you are generating electricity, you are not subject to blackouts / brownouts that occur in your neighborhood

- The Israeli Electric Company will buy back any access electricity you generate for the next 20 years

- Companies that purchase and install systems on their factory roofs (or ground systems) can write-off parts of the system as a business expense

- Financing is available from selected banks for purchasing systems.

- You contribute to lessening the fossil fuels that are burned by the electric company to generate electricity

Photovoltaic systems are still expensive for the average household and most roofs, of shared apartment houses, do not have enough space to fit the number of solar panels needed.

Just as the first computers in the 1980's were very expensive and large, technology advances and mass production have brought down the size and cost. Manufacturing solar cells today is expensive and uses various qualtities of silicon material which is expensive and in short supply (this is the same material used in manufacturing computer chips). There are many companies working on developing solar cells using cheaper materials and manufacturing processes. This includes "thin film" material that may soon be incorporated onto roofing tiles that would reduce manufacturing and installation costs.
There are also comapnies developing super efficient panels that may dramaticly reduce the amount of roof space needed to install a system.

As the availability of fossil fuels becomes more limited, and more expensive, many companies and governments will put more resources into developing and promoting cheaper photovoltaic systems.

During the night, your electric system will draw electricity from the electric company. In the future, there may be inexpensive battery technology that would store enough electricity you generated during the day for use at night.

Several factors are needed in determining the size of the PV system you need to install:

- How much energy do you use on a day to day basis? An energy audit will enable you to track down where every watt goes.

- How much extra energy you would like to generate for sale to the electric company ? Note that the electric company has set a residential and commercial cap

- How much room you have on your roof for solar panels ?

- How strong is the sun in your geographical location ?

As of July 2008, the Israel Electric Company will buy electricity, at NIS 2.01 per kilowatt, from individuals and companies who install a photovoltaic solar panel system on their roofs. The rate is approximately four times the rate it cost to purchase your regular electricty. The electric company will committ to purchase electricity from you for 20 years. This is a good incentive to encourage installations of PV systems that are larger than your daily electric needs.

The following is a general estimate (July 2008) on the size and cost of a home PV system in Israel:

1 KWp system requiring 10 square meters = 25,000 Shekels
2 KWp system requiring 20 square meters = 50,000 Shekels
3 KWp system requiring 30 square meters = 75,000 Shekels

The average Israeli home needs a 3 KWp system

Israeli banks are making loans available specificly to purchase and install PV systems.

Selected vendors give a 25 year warrenty for both the collectors and inverter.