Essential Guide to Solar Energy

Solar power has gained popularity over the last few years. Here’s our essential guide to why people are getting interested in solar energy.

Ultimately all of our energy comes from the sun. The sun drives the weather systems that turn wind turbines and the water cycle, which powers hydroelectric stations. Even oil, coal and gas are the remains of plants that grew thanks to photosynthesis.

However when people talk about “solar energy” they are usually talking about technologies that allow us to generate power directly from the sun’s rays. These technologies fall into two categories: solar photovoltaic, for generating electricity and thermal solar, for generating heat.

Solar photovoltaic

Photovoltaic solar panels – or PV panels for short – convert sunlight directly into electricity. Each panel consists of many small individual “cells”, which contain a semiconductor material that generates an electric flow when struck by solar rays.

The semiconductors used in most solar panels are based on silicon – the same substance that sand and glass are made of. However nanotechnology is now being used to create other materials that can convert sunlight directly into electricity.

PV panels are most commonly located on the roofs of individual buildings. The typical installation cost for domestic systems is around £10,000 / $20,0000, but a solar roof could still be a sensible investment depending on a number of factors. These include: the lifespan of the panel, the future price of other energy sources, and how much electricity you consume in the daytime (when the panel is working).

You can find out more information about installing a Solar PV system in our Guide to Generating Solar Electricity at Home.

Thermal solar

Thermal solar panels, also known as solar “collectors”, work differently from photovoltaic panels. Instead of creating electricity, they capture the warmth of sunlight and use it to heat water. When you consider that up to 40 per cent of a homes energy bill is used to heat water, you can see what a big saving this can be.

On a domestic level, thermal solar generates hot water that can be topped up with a regular boiler or electric heating element as required. A typical installation costs around £3000 / $6000 and cuts household emissions by around 15 per cent.

On a bigger scale, thermal solar can be used to create power plants in hot countries. Arrays of huge mirrors known as “concentrators” direct large amounts of sunlight onto a small area, boiling a fluid and generating electricity.

The future of Solar Power

Solar technology currently provides only a tiny fraction of the world’s electricity and heating energy, but that looks set to change over the coming decades.

As the panels get cheaper and less energy-intensive to produce they should become more affordable, as well as more environmentally beneficial.