The results of a survey conducted by the Renewable Energy and Energy Efficiency Organization (Satba) demonstrate the potential of floating photovoltaic (FPV) systems to contribute to the power sector, the state-run firm’s deputy for Technical and Engineering Department said.
“Several manmade water bodies, including industrial pools, dam reservoirs and artificial lakes, were identified as being suitable to produce at least 1,000 megawatts of electricity with the help of FPV generation,” Mohammad Ali Ramezani was also quoted as saying by the Energy Ministry’s news service Paven.
Many of these eligible bodies of water are in water-stressed areas with high land acquisition costs, suggesting multiple benefits of FPV technologies, he added.
FPV systems, also called floatovoltaics, are a rapidly growing technology in which solar photovoltaic (PV) systems are placed directly on water. It is an eco-friendly method of generating electric power that combines marine technology and renewable energy technology. Solar modules are made to float on the surface of water, such as a dam or a reservoir. Electricity is sent through underwater cables to a transmission tower.
The water-based configuration of FPV can not only reduce evaporation and algae growth but also lower PV operating temperatures and potentially reduce the costs of solar energy generation.
Although there is growing interest in FPV, to date there has been no systematic assessment of technical potential in Iran.
“Satba provides the first national-level estimate of FPV technical potential using a combination of datasets, site-specific PV generation models and geospatial analytical tools."
Land-Use Efficiency
Citing the benefits of FPV, Ramezani noted that it promotes land-use efficiency, as the land can be used for other purposes when a floating PV energy system is set up on water.
The system requires no construction on land or conversion of forest and farmlands for solar power facilities, while generating high-energy yield.
The increased energy generation is due to the natural cooling effect of the water, which reduces the temperature of solar modules.
According to the official, it also saves water resources and reduces evaporation in reservoirs by blocking the sunlight. Floating solar panels can shade the water they float on and reduce evaporation by up to 70%. The rapidly increasing efficiency (at least 19%) of solar panels over water has led to the construction of large-scale floating solar farms in China, India, the UK and Japan.
Last but not least, it uses an eco-friendly system. Natural fish farms thrive under the platform.
Nonetheless, floating systems present specific challenges related to anchoring and mooring them in place, accounting for possible water level variations, the reservoir’s bed type and depth, and extreme weather situations such as high winds and waves.
Accordingly, engineering and construction costs are usually higher than those of a ground-mounted solar farm.
A floating solar power plant is composed of the solar module, buoyancy body and anti-rust material, which includes the vertical frame and horizontal frames, inspection footrest and module mount assembly.
“Iran’s first small-scale floating solar farm became operational in Mahabad Petrochemical Plant in West Azarbaijan Province last year,” Ramezani said.
“The floating photovoltaic plant annually supplies 200,000 kilowatt hours of electricity to the national power grid.”
Paid for by petrochemical company, the panels mounted on floating platforms were designed, built and installed by Iranian engineers and technicians.
The panels are mounted on 400 square meters of an industrial lake for generating electricity, reducing environmental pollutants and controlling water evaporation.
Susceptible to Drought
In addition to water retention, which is particularly useful in areas susceptible to drought, the bodies of water that host floating solar arrays help cool the solar equipment, which means the panels produce electricity at higher efficiency in the hot climate.
Solar panels are durable and can perform under high temperatures. But as with other electronics, with higher temperatures come decreased power output. Solar panel performance tends to decline as the mercury rises, which can be a concern for those wanting to install panels in hot and sunny regions.
Furthermore, work is in progress at a floating solar farm in Shahid Mohammad Montazeri Power Plant in the central province.
The 1 megawatt floating PV farm is being built since last year on 1.5 hectares of an industrial lake in the power plant. The farm is designed to annually produce 1.9 million kWh.
According to the World Bank, 10% of manmade freshwater reservoirs in Europe has the potential to produce over 200 gigawatts of power if floating panels were installed.
Currently, 900 MW of electricity are produced through renewable resources, accounting for about 1% of the total power production capacity in the country (85,000 MW).
