Photovoltaic energy systems still a rarity in Greek homes
One of the sectors where the state has dragged its feet on moves to conserve energy is in incentives for renewable energy sources, such as photovoltaic systems for private homes. While the law provides for a subsidy of up to 40 percent of the cost of constructing photovoltaic energy farms, there is none for individuals wanting to provide power for their homes, whether off-grid or as part of a hybrid system, from the sun, a source of energy in plentiful supply in Greece. According to the Hellenic Association of Photovoltaic Companies (HELAPCO), commercial PV systems are eligible for grants ranging from 20-40 percent but these do not apply as yet to domestic applications – the only incentive for these is a small tax deduction. «To be eligible for the subsidy, the minimum cost of the installation is set at 100,000 euros,» said Giorgos Messaritis, whose firm specializes in the construction of commercial photovoltaic systems. «Most domestic systems do not cost that much, so they do not qualify for the subsidy. The state is not providing incentives to promote the use of these systems, in contrast to other countries like Spain.» Problems involved in the use of these systems in private homes include the relatively high cost of the equipment and installation and the lack of subsidies, while conditions need to be ideal for maximum efficiency. According to Messaritis, amortization on rooftop systems takes at least 10 years, compared to six to seven years for a photovoltaic park. And, in order to obtain maximum operating efficiency, conditions such as the orientation and exposure to the sun throughout the day need to be ideal, something that is not always possible if the home is shaded by other buildings for part or all of the day. However, when conditions are right and the initial cost is not a problem, homeowners find they have a maintenance- and cost-free supply of power for their homes. According to a Greenpeace Hellas report on solar-powered homes, PV systems in Greece are more often used in isolated areas far from the main power grid and where the economic benefits are greater, given the higher cost of running a fuel-powered generator. Firms such as Conergy have constructed several off-grid systems for use in homes. In one home in Crete (covering 125 square meters), the off-grid system provides 23.8 KWh per day in summer and an average 10.4 KWh a day in winter. An electrical generator supplies backup power when necessary. Another of the firm’s projects was a system providing power to a 500-square-meter residential building in Attica with a water pumping and treatment plant, refrigeration and air conditioning from a 12 KWp solar generator, a small wind turbine, a diesel generator and battery bank. Hybrid systems, meanwhile, can receive energy from the main grid when the solar supply is low. Conversely, when the latter is producing more power than required, it can be fed into the grid by means of an inverter, or stored in batteries. The benefits in a country such as Greece are clear, given that maximum solar energy is available in the summertime during the hours of greatest demand, according to the Greenpeace report.
