Two professors from the Hebrew University of Jerusalem, Prof. Lioz Etgar of the Institute of Chemistry and Prof. Haim Rabinowitch of the Smith Faculty of Agriculture, Food, and Environment, have now worked together to create a prototype for a revolutionary PV cell. The new cell's performance has the potential to alter the laws of the solar energy and agricultural production game because its efficiency has been technologically shown.
The innovative solar cell is made to cover completely agricultural areas, such as greenhouses, orchards, fields, and water bodies, while generating green electricity and agricultural production simultaneously, without interfering with the natural habitats beneath the PV panels, without depleting natural resources, and without endangering the environment.
The team estimates this breakthrough will lower Israel's energy costs by 75%. In fact, they think that if Israel covered half of its greenhouses with these new cells, green electricity output would exceed Israel's national target for that year.
The new solar cells are built on crystals of perovskite, a mineral that was first found in 1839 and is a calcium titanium oxide that is reasonably simple to produce using inexpensive and readily available materials.
A chemical substitution makes the solar cells transparent to the most efficient area of the light spectrum that drives photosynthesis. A great part of the rest of the light energy is transformed into electricity.
“For years, it has been obvious that most light energy in agricultural greenhouses is wasted, as plants use only a fraction of the sunlight energy, while the rest is radiated back into the atmosphere,” Etgar explained. “In greenhouses, it becomes heat energy that growers need to get rid of during most months of the year. Our solution maximizes the production of solar electricity on agricultural land by up to 300%.”
Compared to silicon-based photovoltaic cells, the new cells are expected to have significantly reduced production costs. They will probably also significantly improve cultivation conditions in greenhouses by reducing heat, lowering greenhouse gas emissions and evapotranspiration, saving water, and protecting crops from weather damage.
All currently used methods for producing green energy on agricultural lands use silicon-based photovoltaic cells that are entirely or somewhat opaque to most visible light spectrums or are arranged in different arrays. Because of this, power generation is less efficient and agricultural production is consequently decreased.
Rabinowitch added, “This new development, which can be installed over any agricultural lands and any bodies of water, will make it possible to fully replace the roofs of most agricultural greenhouses, reduce heat levels and evapotranspiration in orchards and fields, and impairment of many fresh-water and coastal marine ecosystems on which rafts, or islands of solar cells are installed.”
Using these new cells will reduce agricultural costs and raise agricultural income and profitability, according to calculations based on existing data. The researchers declared that this was nothing short of a revolution.
Israel has around 90,000 dunams [approximately 35 square miles] of greenhouses. Covering half of the greenhouse roofs with the new solar cells will provide a quantity of green electricity that enables Israel to exceed its 2050 national targets for green electricity production and carbon emission reduction. To put this development into perspective, the Mediterranean basin alone holds around two million dunams (770 sq. mi.) of greenhouses.