What is solar energy?
Solar energy is radiant heat and light from the sun and is one of the most available renewable energy sources on earth. On a bright, sunny day, the sun’s rays give off around 1,000 watts of energy per square meter of the earth and therefore can be used for practical means. Humans have been harnessing energy from the sun since ancient times using a range of ever-evolving technologies. Solar technologies are generally characterised as either passive or active solar energy depending on the way they capture, convert and distribute solar energy. The most common way of harvesting energy from the sun is through the use of solar panels, also known as photovoltaic panels and solar thermal collectors. Using solar panels to generate electricity is an active solar technique. They operate by absorbing light energy from the sun in a semi-conductor material that then knocks electrons loose allowing them to move freely [1]. Passive solar techniques on the other hand would involve things like carefully designing a space that can naturally circulate air or selecting materials with thermal mass or light dispersing qualities, or even orienting a building towards the sun [2].
There are many technologies surrounding the use of solar cells that use the sun’s energy and light to provide heat, light, hot water, electricity, and cooling for homes, businesses and industry. There are two main types of photovoltaic cells that exist: solar electricity panels that generate electricity; and solar hot water panels that heat the water we use. Nowadays it is evident that new solar panel designs are becoming more efficient making them a viable (and cheap) alternative to fossil fuels and encouraging their use among businesses and homeowners [3]. It is evident that this technology is becoming more prominent in new devices all the time, from calculators to emergency road signs to electric vehicle charging stations to powering satellites.
What are the benefits of solar energy?
The sun is 150 million kilometers away and is astonishingly powerful. Not only does the sun provide solar energy directly, but it creates other renewable energy sources such as geothermal and tidal power. Only a tiny fraction of the sun’s energy is enough to meet all our power needs. In fact, every 60 seconds, enough solar energy arrives at earth to meet our demands for an entire year! The only limit is human ingenuity in finding ways to harness that energy efficiently [4]. Furthermore, solar energy is renewable: it is a consistent power source therefore we never have to worry about running out of sunlight or using it all up.
Solar energy is environmentally friendly as solar cells do not release emissions unlike fossil fuels. Investing in solar energy is essential in reducing the UK’s carbon emissions, of which remain well above the world average, and it is up to individuals, businesses and the government to support the renewable industry. Whether you are a homeowner or growing professional, it is time to learn about solar energy and its benefits. Solar energy is the nation’s fastest growing renewable energy source and is vital to the UK’s economic recovery [5].
If you invest in solar technology the government will give you a grant of up to £400 to help cover the cost of installation while your energy bills will be reduced by up to 70%. This grant, coupled with the fact that there is a huge variety of solar and hot water panels available with a huge range in prices, means that anyone can get into solar. In addition, solar panels are reliable (there are no moving parts so no need for replacing anything), silent in operation, require little space and do not need to be connected to the power grid so you can be completely self-sufficient and never pay a monthly bill. It is quite possible for a household to run entirely off photovoltaic electricity if your solar panel is large enough and if you build a large enough solar panel system, you could potentially sell excess electricity to neighboring companies. Information on this can be found at your local power company. An average sized solar panel can still provide a substantial amount of electricity and reduce energy bills significantly.
Lastly, one of the greatest benefits of solar power cells is that, apart from producing electricity in the daytime when we need it most, they often have a back-up system that kicks in when utility power fails (for example for systems that work 24 hours a day). The benefits of encouraging solar manufacturing clearly outweigh the costs; therefore it makes economic sense to support solar cell development.
How can I use it at work or at home?
There are a variety of technologies available that have been developed to take advantage of solar energy. These include:
- Photovoltaic systems which produce electricity directly from sunlight. They have a variety of applications. For example, they are often used to power calculators and watches and can also be attached to buildings with a tracking device that follows the sun enabling them to capture the most sunlight. They can often provide enough power for a household. Businesses can interconnect several to form a single, large PV system. Solar cells can also double up as roof tiles or a glazing for skylights. Solar panels should be mounted on a south facing roof at a 30 degree angle and away from any shadows from trees, chimneys or surrounding buildings. These cells generate electricity in a clean, quiet and renewable way and now come in all shapes and forms such as portable chargers for mobile phones, Ipods and car batteries [6].
- Solar hot water heating systems work by tubes carrying water to a very well insulated box mounted on the roof facing the sun. The sun simply heats the water in the box and pipes which is then stored in a hot water tank. The pipes are non-toxic and contain anti-freeze. These are the most popular form of solar energy used in the UK and they can produce over half of households’ hot water requirements. A good solar hot water panel system is able to provide an average household with around a third of its annual hot water supply. This can reduce energy costs by a considerable amount.
- Passive solar heating is the simplest form of solar energy. Buildings can be designed to utilise the energy of the sun as effectively as possible. For example, they should be south facing (receives the most sunlight) with large windows and building materials that absorb the sun into walls and floors. These materials will heat up during the day and release heat slowly at night. By careful planning like this, you can fully maximise free solar gain [7]. In summer when passive solar heating makes buildings too hot, overhangs can be used to shade windows when the sun is high.
- Solar process heating systems are designed to heat large buildings while keeping them well ventilated. It involves solar collectors that work along with a pump, heat exchanger and a large storage tank. They can also be used for cooling a building just like an air conditioner would [8].
Furthermore, combining these solar energy systems in a home or business could significantly reduce energy and electricity bills. These could even be combined with other renewable energy technologies such as a wind turbine to create a source of cheap, clean renewable energy. It is wise to consult an expert for a solar power analysis to evaluate your building’s current and future energy needs, layout, location, construction and financing options before planning installation.
[3] www.clean-energy-ideas.com
[6] www.solartechnologies.co.uk
[7] www.nef.org
