Solar energy is the energy obtained from the sun, which drives almost every known physical and biological cycle in the Earth system. This energy is unlimited, and so long as the sun shines we are able to capture and utilise its power.
A Brief History
The powerful effects of the sun have been known for over a century, with Edmond Becquerel discovering the photovoltaic effect in 1839; which is the direct conversion of sunlight into electricity. The first solar cell was invented in 1883 and in 1884 the world’s first solar panel was installed on a rooftop in New York. However, it wasn’t until 1980’s and 90’s that the technology became more affordable and an availability in the raw materials triggered a 50% cell production growth rate from 2006 to 2007. Panels also reached 40% efficiency for the first time at this point.
Solar Cells & Solar Thermal Tech
It is possible to capture solar power through solar cells (photovoltaic PV panels) or through solar thermal technology which uses the sun to heat water – and then produce electricity. Solar thermal is considered more efficient at collecting heat and fueling hot water systems as well as being more space efficient. However, PV panels have a longer lifespan and work well in both sunny and cold climates; whereas thermal is better suited to deserts and tropics. There may be many pros and cons to the different solar power systems to choose, but it really comes down to what it is being used for and how much it will cost.
These days, you can get one 100w solar panel kit for close to £100 and panels are expected to last around 25 years. The installation is easy and there is very little maintenance. However, there are some advantages and disadvantages to consider, when faced with whether or not to make the switch.
The Pros of going Solar
The big advantage of solar energy compared with other sources is that it is a completely free, clean, renewable resource; meaning that it occurs naturally and can be replenished over time. Unlike other finite sources, such as coal and oil whose reserves will eventually diminish, the sun is here to stay.
The energy of the sun is abundant; we receive more energy from the sun in one hour than all of humanity uses in an entire year. And although the Earth receives around 173 petawatts of energy continuously, we are only able to harness merely 0.0001% of this vast amount; the solar energy we get is around 10,000 times greater than what we actually use on the Earth. Because of this potential, it has been heralded as the energy of the future.
The International Energy Agency stated “solar energy can make considerable contributions to solving some of the most urgent problems the world now faces: climate change, energy security, and universal access to modern energy services.”
What’s more, solar energy is not only an abundant, clean and free source of energy, but also a source of income. Installing solar panels on your roof will therefore reduce your carbon footprint as well as your electricity bills since you will use less energy from your supplier. If you are eligible for the Feed-in Tariff, you can even get paid for the electricity you produce.
One of its limitations is the fact that solar technologies can not be used during the night, and that the amount of heat or electricity they generate depends on the location, time of the day and the weather changes. George Monbiot considers these constraints to severely impact its potential, as peak electricity usage in the UK is early evenings in the winter (when there’s little sunlight).
Solar panels often contain lead, cadmium, and other toxic chemicals that cannot be removed without breaking apart the entire panel. Approximately 90% of most PV modules are made up of a glass, which cannot be recycled as float glass due to impurities.
In 2016 The International Renewable Energy Agency (IRENA) estimated there were about 250,000 metric tonnes of solar panel waste in the world, which could even reach 78 million metric tonnes by 2050.
This highlights waste management as being an important part of the solar power future, especially if production rates are to continue to increase. Thankfully, recycling technology is improving and investment in the circular economy increasing; with some recent studies on recycling solar PV panels resulting in 96% efficiency.
Getting Set Up
One important thing to consider is that there are grid-connected and off-the-grid solar systems. The first option is good if you wish to benefit from the Feed-in Tariff and also if you want to have access to electricity during the night. Off-the-grid systems are more suitable for cottages that have no access to the national grid, and most often go along with batteries to power the house when there is no sun.
Under the government’s Feed-in Tariff (FIT) scheme, you receive cash in return for generating your own electricity using renewable energy. All proceeds you make are tax-free. Electricity price increases will affect how much you save on your electricity bills and the higher electricity prices go, the greater your savings. The cost of solar panel installation has fallen swiftly since the launch of the FIT scheme, and, if this trend continues, the rate of return from your solar panel could be potentially higher than its cost very quickly. Most countries offer similar schemes.
Finally, it is important to check if your panels and installer are high quality and guaranteed. In the UK, use installers that are Micro Generation Certified as well as a members of RECC (Renewable Energy Consumer Code).
American solar power offsets over 70 million metric tons of carbon dioxide every year, which is like planting almost 1.2 billion trees.Solstice Solar Energy
Solar on a Large Scale
Solar energy can not only power our homes but it is used to power companies, and even countries. As of 2017, India and China took over as leaders in large scale solar farms, with China housing the largest plant by far in The Tengger Desert, Zhongwei, Ningxia. The solar field covers 1,200 Km (3.2%) of land and produces 1547MW solar power. USA, Spain, Germany and Portugal are also responsible for harnessing huge amounts of energy through solar; and with the world doubling its solar power capacity in 2016, this is one renewable resource to keep an eye on.
Sources & further reading
- “Directive (EU) 2018/2001 of the European Parliament and of the Council on the promotion of the use of energy from renewable sources” - Official Journal of the European Union
- “Climate & Earth’s Energy Budget” - Nasa Earth Observatory
- “Solar Energy in Energy sources” - Science Direct
- “Solar Energy in Managing Global Warming” - Science Direct
- “The Switch” - Profile Books