Solar Power History

Human use of the sun’s energy may seem like a recent phenomenon but solar energy has been in use in various forms for thousands of years. The sun is necessary to the growth of the plants that we eat and there are also more technological uses of the sun’s energy that go back millennia.

The ancient Greeks knew how to harness steam power, some of it generated by solar radiation. In a pre-industrial age they regarded the devices primarily as amusing toys, but some applications were taken seriously. Archimedes designed and had built a large magnifying glass that was used to set enemy ships on fire. The Romans adopted some of this technology, as they did much of Greek science.

..public heating systems and large storage tanks of the 1920s were used to trap solar energy..

Over the centuries many other devices such as thermometers and heat storage containers that relied on energy from the sun were created. As time went by those devices became more sophisticated and more diverse. In 1839 Becquerel discovered the photovoltaic effect although it would take another 100 years for devices based on it to become practical.

When sunlight hits certain materials, it causes electrons to become separated from their associated atoms. Electrons moving within material constitute an electrical current when that current is connected to a circuit, the power generated by the electrical flow can light bulbs, heat water or power a computer – but solar power is used for more than the creation of electricity.

The public heating systems and large storage tanks of the 1920s were used to trap solar energy and supply homes with heated water. Eventually, those systems couldn’t compete economically because the cost of gas and electricity decreased to the point that it was cheaper than the operating costs of these systems. The 1920s’ systems fell into disuse and were eventually forgotten but the technology existed as a mainstream method, not a crank alternative and at the time it was a cost-effective solution.

Now there are hundreds of viable applications of solar power, which in one way or another, convert sunlight received at the surface to power devices, heat water and supply other energy needs. Satellites use solar panels and associated technology to supply needed power. The systems are expensive, but compared to the total they’re a very small fraction of the cost – the same kind of technology also powers phones or lights along some highways. And it isn’t just esoteric applications that benefit from solar power either.

Solar heating systems are employed in thousands of homes. Though solar powered electrical systems are less common than utility power, they are in wide use in rural areas where people want or need to supplement their supply. Many cabins in the Pacific Northwest for example, are too far from the utility company lines to receive electricity.

Not all devices or systems are hugely expensive, either, low-cost solar powered lawn lights are dotting many homes today. Calculators powered by tiny solar panels are so cheap they’re often given away as promotional items by advertisers.

Solar power cannot yet compete with the large scale electricity generation of the big utility companies; but costs are coming down and the applications are growing. The future of solar power looks bright.