Environmental Assessment of Solar Cell Materials

Abstract

In today's world, fossil fuels, including coal, oil, and gas, are the primary energy sources from which electricity is obtained. As they are exhaustible and their exploitation has a negative impact on the natural environment, they should be, at least partially, replaced by renewable energy sources. The implementation of this goal depends on a number of factors, including social and political, the existence of investment support programmes, and the need to lower electricity prices and ensuring energy security. One of these sources is solar energy. Each year, the Earth receives around 1 · 1018 kWh of solar energy, which is more than 1000 times the current global energy demand. This is therefore a vast source of energy that can be tapped to satisfy human energy requirements. The use of solar energy releases no CO2, SO2, or NO2 gases, and does not contribute to global warming. Photovoltaics is one of the technologies that makes it possible to generate electricity in an environmentally friendly manner. By using the energy of solar radiation, a photovoltaic cell converts energy without emitting harmful substances to the atmosphere, noise, and waste. Photovoltaics is the cleanest technology among all the technologies that use renewable energy. Considering the shorter and shorter times needed to generate energy equal to that required by the module production process, during its lifetime it will produce much more electricity than was used to produce it. This results in a reduction in greenhouse gas emissions. For example, during its lifetime, a 200 Wp module prevents the emission of over four tonnes (Mg = 106 g) of carbon dioxide. Although the technologies for the production of photovoltaic cells and modules entail a lower environmental burden compared to other sources of electricity, it is necessary to remember about the risks associated with the use of chemicals at the stage of module production, which threatens their release to groundwater or air, and the need to recycle modules after their disassembly. Also, the energy consumption in the production phase of PV systems significantly worsens the ecological balance. This article presents an analysis of the impact of the materials and technologies used on the result of the environmental analysis of PV installations. In the article a detailed energy balance analysis of the EPBT value has been carried out. The values of greenhouse gas emissions throughout the life cycle of the solar module were determined. Methods of limiting the impact of photovoltaic technologies on the natural environment were indicated.