On a hot day, a mother is drying her laundry on her backyard clothesline. Her son, a budding scientist, is holding a magnifying glass over blades of grass and watched them burn. Inside, her husband is balancing his checkbook using his trusty solar calculator. The mother checks her solar-powered wristwatch and heads back inside. It’s time.
Harnessing the Sun
Living with the sun is nothing new. Solar technology has been used by man for practical purposes since time immemorial. Legend has it that Greek soldiers used polished shields that reflect sunlight to blind their enemies. Romans have built the Pantheon around the sun, using daylighting techniques to provide natural interior illumination and to showcase the beauty of sunshine.
Global energy consumption drastically increased during the 19th century Industrial Revolution. The growth of factories necessitated the use of more powerful sources of energy such as wood and coal. Thus, energy sources rapidly transitioned from solar-based to fossil fuels. The oil embargo and energy crisis in recent decades led world leaders to rethink their energy policies and focus on developing alternative energy With the outpouring of environmental awareness, vast possibilities of solar power are once again being discovered and untapped.
Being able to utilize the sun to generate electricity is one of man’s greatest achievements. Though prehistoric man knew how to use bits of glass to reflect the sun’s rays to start a fire, the technology to directly turn sunlight into electricity is only a few decades old. Solar power is currently being used in agriculture, chemical and metal industries and in households. The use of evaporation ponds to get salt from sea water is one of its older applications. Single solar cells are used to power on calculators, wrist watches and highway signs. Solar water heaters heat swimming pools, greenhouses control the use of light to grow crops, solar distillation provides potable water to households, and solar energy provides the high temperature needed for metal smelting and chemical production.
How solar energy works
Solar energy – the energy from the sun in the form of heat or light – is being harnessed by technology that controls the use of the sun’s energy. Sunlight is converted into electricity by photovoltaics, a system which produces a reliable and non-polluting form of energy without using any fossil fuels.
Photovoltaic cells directly convert sunlight into electricity. Also known as solar panels, these cells are made up of the element silicon, the second most abundant material on earth. However, due to its difficulty to make, solar panels can still be quite expensive. To make the panels, silicon is heated to extremely high temperatures and chemicals such as boron and phosphorus are added. This makes the silicon atoms unstable so that when sunlight hits the solar panel, the modified silicon’s electrons are jarred, thus causing electricity to flow and provide electric power. When sunlight hits a solar panel, the electrons in the silicon start to move. This movement causes energy to flow through wires built inside the panels, producing electricity.
Pros and cons of solar energy
The biggest advantage of solar energy is that it is non-polluting. Unlike oil and fossil fuels, solar energy is a renewable resource. Solar cells are also easy to install and require very little maintenance. Although investing in solar panels can be a bit pricey at first, reduced electricity bills will definitely still save money in the long run. After all, the sun is ours for free.
The main disadvantage of solar energy is the restrictive financial cost of investment in solar panels. Installation also requires a large area, thus making solar power inefficient in places where space is expensive and limited. However, as newer technologies in solar energy develop, prices have dropped and more efficient styles are being produced. This is indeed very good news, as solar energy is increasingly becoming popular and available to many. Hopefully, this will encourage people to use solar energy for their electricity needs – not only because it is a hot, new trend but because it is right.