Trying to capture more of the sun’s energy seems like such a modern endeavor. But, the fact of the matter is, solar energy has been in use in various forms for thousands of years. Apart from the obvious fact that the sun provides the energy for plants to grow that feed us, there are more technological uses that go back millennia.

Steam power was harnessed by the ancient Greeks, and solar energy played a large role in some of their methods. Pre-industrial, they regarded the devices as amusing toys, primarily. But some applications were taken seriously. Archimedes designed and had built a large magnifying-type glass that was used to set enemy ships on fire. The Romans adopted some of this technology, as they did much of Greek science.

Through the centuries, heat storage containers, thermometers and many other devices were created that relied on energy from the sun. Over time, those devices became more sophisticated and more diverse. In 1839 another big leap occurred when Becquerel discovered the Photovoltaic effect even though it would take another 100 years for devices based on it to become practical.

When sunlight hits certain materials, it causes the electrons in the atoms to get knocked loose 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 electricity isn’t the only form of solar power. In the 1920s some public heating systems used large storage tanks to trap solar energy. The heated water was then supplied to homes. Eventually, those systems couldn’t compete economically. Gradually, the cost of gas and electricity decreased to the point that it was below those systems’ operating costs.

Those systems fell into disuse and were eventually forgotten. But the technology existed as a mainstream method, not a crank alternative. It worked and was, for the time, 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 have used 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. Closer to home, the same kind of technology 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 are too far from the utility company lines to get electricity that way.

The increasing popularity of utilizing more of the sun’s power has a lot to do with the fact that the cost of getting involved can be very reasonable. 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 can’t yet compete with large scale electricity generation by big utility companies. But costs are coming down and the applications are growing. It’s had a long past, but the future of solar power is looking bright.