We tend to think of solar energy as a fairly recent invention, but the truth is solar power has been around for a very long time – at least 4.7 billion years in fact, based on the age of the sun itself, although human involvement obviously came a little later! The sun is smaller than it was back then , of course, having already burnt up the equivalent of around 100 Earths – but in a mass which still accounts for almost 99.9 per cent of the entire solar system, it isn’t exactly easy to spot the difference.
Even in the relatively short amount of time that people have been interested in harnessing the power of the sun, a huge amount has been achieved. Here’s a quick peek into some of the fascinating facts of the past, present and future of solar power.
Over the years, some of the world’s greatest minds have been attracted to the idea of using solar energy in one form or another. These are only a few of their achievements:
- You just know that a mind as inventive as Leonardo Da Vinci’s wouldn’t miss the chance of thinking solar thoughts; back in the 15th Century, he came up with the idea of using concave mirrors to heat water by focussing sunlight.
- Two-and-a-half centuries later, Horace de Saussure invented his ‘hot box’ – the world’s first solar collector device.
- Fifty years on from that, while on an expedition to Africa, the famous astronomer, John Herschel, cooked his food using a solar thermal collection box.
- By the end of the same decade, Alexandre-Edmond Becquerel had discovered the photovoltaic effect – although a functioning PV cell wasn’t to be invented for another 100 years or so.
- In 1921, no less a scientist than Albert Einstein won the Nobel Prize for his experiments on PV and solar energy.
These days, solar energy is for everyone, so whether you’re looking to heat your water, generate electricity for your home or push the limits of PV, here are a few things you might like to know.
- According to the latest UK National Photovoltaics Status Report, Britain has a total installed PV generation capacity of 22.5 MW(peak).
- You need around eight square metres of PV panels to generate 1kW(peak).
- Each kW(peak) of PV produces between 800 – 1,200kWh, which means with a 2.2 kW(peak) system, under ideal conditions the average household can generate about 40 per cent of its annual electricity and cut its carbon footprint by as much as a tonne.
- Using a solar thermal system, covering three to four square metres of a south-facing roof should meet about a third of the average household’s hot water needs for the year, and avoid around 325kg of carbon.
- Each year there is a World Solar Challenge held in Australia as a showcase for the state of solar technology, where solar powered cars compete to cover a course running for over 3,000km, from Darwin to Adelaide.
Where will the future of solar power take us and what new facts will feature in the ‘past’ and ‘present’ list in 20 or 30 years time? It’s difficult to know without a crystal ball, and if you think about those TV shows that set out to tells us how we’ll all be living in 50 years, it’s pretty clear that any attempts to predict how science and technology will pan out is pretty much doomed to failure from the start. When the first practical PV cell was invented by researchers working for the US Bell Telephone company back in 1954, for instance, it would have been impossible to guess how successful it would ultimately become. PV’s rise to global importance began as a result of its invaluable appeal to space agencies as a way to power satellites, and the first of those – Sputnik 1 – wasn’t going to be launched for another three years.
We’ll all just have to wait and see what happens next, but that’s OK; we do have plenty of time to develop solar technology, after all. The sun won’t burn itself out for at least another 5 billion years, which should give us a chance to come up with lots more clever ideas, long before then. Whichever way you look at it, it seems solar power is a very old idea, with a long and bright future!