Solar Energy is a primary source of renewable energy in the world. It offers significant reductions in greenhouse gas emissions as well as reduced pollution.
Solar power works anywhere with sufficient sunlight; however, homeowners must prepare themselves in case there are periods when no sun shines by keeping battery backups handy.
Solar cells
Solar cells convert sunlight into direct current electricity, which can be used to power devices such as calculators, radios, satellites and spacecraft. Solar cells convert the sun’s rays into direct current electricity for electronic devices using two main processes: absorption of photons energy, which creates electron-hole pairs within semiconductor materials; and charge carrier separation. Silicon is typically the material of choice used for these processes in conventional p-n junction solar cells.
The electric field is applied to the layers of n and p type silicon to create an imbalance in electrical charges. This causes electrons to flow from one layer into another to fill holes. These electrons then flow out of external connections through external wires, producing electricity. Solar cells are typically enclosed within glass housings and aluminium frames encased with Mylar/Tedlar backsheets as well as polymers like EVA backsheets which create additive voltage before connected in series to create additive voltage before stacking into panels with metal contacts.
Concentrated solar power plants
Solar thermal power plants focus and concentrate natural sunlight to create high-temperature beams. They then use this heat to generate electricity or to decarbonise industrial processes, like at the Mars Petcare plant in Wodonga that uses a graphite batteries at 900C for energy storage and to reduce fossil fuel consumption.
CSP systems come in three main varieties, linear concentrator, dish/engine and solar power towers. With linear concentrators, sunlight is focused on a boiler to produce steam which in turn drives a turbine and creates electricity. Solar power towers, however, use solar energy directly to create electricity.
Other systems use mirrors to direct light onto receivers at the top of a power tower holding fluid like molten salts that is then used directly to generate electricity directly. One such example is Morocco’s Ouarzazate solar power station using both trough and tower technology and several hours of energy storage; all three technologies boast efficiency rates between 7%-25% depending on factors like system type used and other considerations.
Solar power towers
Solar power towers employ thousands of computer-controlled mirrors — known as heliostats — to focus sunlight onto a central receiver at the top of each tower, where heat generated in its receiver can boil water and power turbine generators for electricity production. Other advanced designs may use molten salts stored in hot tanks until needed later to produce energy production.
This industry requires large, flat areas that are exposed to the sun. They should be situated in a country with a lot of sunshine and little cloud cover. Furthermore, as these systems use potentially hazardous fluids for heating and cooling systems, protecting the ecosystem surrounding them must also be taken into consideration.
Solar thermal power plants are also heavily reliant on water resources. This is often used for the cleaning of heliostats or operations. These can pollute local environment and cause habitat loss. Solar thermal plants use water cooling as part of their operation which may harm wildlife populations.
Solar energy pros and Cons
Solar energy is an environmentally friendly and sustainable source of energy that doesn’t produce greenhouse gasses. Solar energy systems can be expensive to install and can take years before they pay for themselves. However, this investment will pay off in the long run.
Solar energy systems paired with battery storage are ideal for remote locations that lack utility power lines; however, the higher cost and required maintenance make this option not ideal. It is important to weigh the pros and cons of each green energy option before making a decision.
