Solar PV Sources Emit More CO2 Than Geothermal : Study

New research published in the journal Geomechanics and Geophysics for Geo-Energy and Geo-Resources has revealed that Solar photovoltaic (PV) cells emit more carbon dioxide (CO2) than geothermal power plants during their lifetime.

According to the recent study conducted by the civil engineering department at the Indian Institute of Technology-Hyderabad, the total CO2 emissions during the lifecycle of a solar photovoltaic (PV) cell is about 3312 × 106 kg, which is far higher than a geothermal energy source emitting about 450 g/kWh.

The life cycle of the solar cell is explained as follows, the quartz that is required to manufacture solar cells that can generate 1 MWe weighs about 10 tons, and the manufacture of PV cells involves two important stages: metallurgical grade silicon (MGS) and electronic-grade silicon (EGS). In the first stage, an amount of 1756 × 106 kg of CO2 is released, and a similar amount of CO2 is released during the conversion of EGS to ingots. Thus bringing the total CO2 emissions during the lifecycle of a solar PV cell at about 3312 × 106 kg.

“Solar PV cells may not emit CO2 during the generation of electricity, but in their lifetime, emissions are considerable. Therefore, solar PV cannot be considered a zero-emission source,” said the research titled ‘CO2 emissions from renewables: Solar PV, hydrothermal and EGS sources’.

The research paper added that apart from the emissions related to the manufacture of solar PV cells, solar panels and solar cell waste management were also of great concern.

“Globally the generation of solar panel waste will be of the order of 78 million tonnes. Countries involved in the manufacture of solar PV cells will emit considerable amounts of CO2 emissions from this source in addition to coal-based thermal power plants,” it said.

The life cycle analysis of solar cells looks at the material needed in producing them, coupled with their environmental impact during construction, operation and decommissioning stages.

According to the International Energy Agency (IEA), under the sustainable development policy proposed for adoption to mitigate CO2 emissions, nearly 54 × 109 cells are required to meet the generation target of 14,139 TWh. “Of solar PV and geothermal energy sources, geothermal energy is the best option under this policy scenario to mitigate CO2 emissions and to control global temperatures,” the researchers added.

The report concluded by stating that countries involved in the manufacture of solar PV cells will emit considerable amounts of CO2 from this source in addition to coal-based thermal power plants. Solar PV cells may not emit CO2 during the generation of electricity, but during their lifetime emissions are considerable. Therefore, solar PV cannot be considered a zero-emission source.

Source: saurenergy.com