How Does Solar Power Work?

The Sun has been compared to a cosmic power plant. It has the capacity to supply all the Earth’s power needs many times over, it’s free and it will never run out. At least not for the foreseeable future. The problem is that man has been very slow to take advantage of this brilliant cost-free resource.

Even the fossil fuels we still burn to generate power – despite the carbon dioxide and cost issues – release energy that originally came from the Sun. Many thousands of years ago, the energy to be found in coal, petroleum and other fossil fuels was originally converted from sunlight by photosynthesis. We sometimes forget that the Sun is essentially the source of everything on this planet. Even wind and the sea’s waves comes about from the effects of the Sun heating the earth.

What Are The Types Of Solar Power?

The Sun’s energy can be converted into electricity in two ways:

Solar Thermal Power Plants make electricity by concentrating sunlight to heat a fluid, which makes steam, which is used to power a generator.

Solar Cells – otherwise known as Photovoltaic (PV devices) – are able to change sunlight directly into electricity. A solar panel consists of individual PV cells. Arrays of panels can be used in many different ways, ranging from single small cells that charge watch, portable radio and calculator batteries, to systems that generate enough power for individual homes, to huge commercial power plants covering many acres.

The Science Of Solar Energy: So, How Does Solar Power Work?

So what’s the science? Light from the Sun contains energy. What usually happens is that light strikes an object and turns the energy into heat. This is the process that gives us sunburn. The basis of solar power is that when light hits certain substances (such as silicon) the energy turns into an electrical current instead of heat. This is the basic answer to the question how does solar power work.

The first commercially available solar panels contained large crystals made out of silicon. Most substances jiggle about when exposed to light, producing heat, but in the case of silicon the electrons in the crystal rise and electricity is generated. The main drawback to this is that large crystals of silicon are expensive and difficult to grow.

A cheaper alternative to traditional solar panels is called “thin-film” solar technology. This uses cheaper crystals, such as copper-indium-gallium-selenide, which are much smaller than their silicon equivalent and are able to be shaped into flexible films. The downside is that thin-film panels are not as efficient as silicon in converting light into energy.

Solar Power Advantages And Disadvantages

The two chief benefits of solar energy:

  • Solar energy systems do not cause pollution or produce excess carbon dioxide.
  • Solar panels on roof-tops have no discernible impact on the environment.

Two main disadvantages of solar energy:

  • The production of solar power is limited by many factors, including cloud-cover, seasons and geographic location. It is not possible to predict the amount of energy that can be generated and supplies are not constant.
  • A large surface area is required to generate power using solar panels. This is because the energy coming from the Sun is not concentrated – which is just as well for us, otherwise wed be fried like bacon in a skillet! Because the concentration of energy in sunlight is relatively low, it means that we have to distribute panels over wide areas. Until someone invents more efficient solar receptors, that is…

Some Facts About The Sun

The Sun is almost perfectly spherical and is made up of hot plasma interwoven with magnetic fields. Something like 75% of the Suns mass consists of hydrogen, with the rest mostly taken up by helium. At roughly 1,392,684 kilometres, the diameter of the Sun is approximately 110 times larger than the Earths. The mass of the Sun is said to account for 99.86% of the total mass of the Solar System.
It is estimated that the power output of the Sun is roughly 388 trillion megaWatts. The surface temperature of the Sun, (called the photosphere), has a temperature approaching 6,000 degrees Centigrade. Thats hot.