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What is Solar Power?

How much of our energy is coming from the Sun?

In Direct sunlight, the sun is providing around 90 watts per square inch at the surface of the Earth, or 1000 watts per square meter. The intensity that this refers to is what energy scientists call 1 sun, and is sufficient to power ten 100-watt light bulbs, or fifty 20-watt fluorescent light bulbs. As opposed to what is sometimes claimed by solar energy opponents is solar power not at all weak or diffuse.

The amount of sunlight that falls on even a tiny portion of a home’s roof is in general actually already enough to take care of all the home’s energy needs. Or said in another way, if we would cover not even 1 percent of all U.S. land area with solar power panels, we could be providing all of our current energy needs.

We could also consider the massive amounts of energy that surrounds us in various geophysical flows, such as ocean currents, the sunlight, clouds, and wind. The energy in systems like these is just enormous, and is actually dwarfing the scale on which human energy is used. Ultimately, practically all of this energy is originating from solar power. Thermal air upwelling, the hydrological cycle, and the warming of our oceans’ surfaces, they all are connected to the Sun’s activity.

One more example is even closer by. You, the reader, are also solar-powered. All of your energy is obtained from food, which is produced with solar power via sugar in plants or photosynthesis.

Solar Energy Technologies

There are a number of leading solar energy technologies such as

  • Photovoltaics (for solar electricity)
  • Passive Solar Thermal (for solar heating, hot water systems, or natural cooling)
  • Active Solar Thermal (for solar hot water or air collectors)
  • Solar Thermal Electricity (for small or large scale electricity production from solar heat)
  • Solar Cooking Systems
  • Solar Distillation Systems
  • Solar Water Pumping Systems

Passive Solar Systems are solar water- or space heating systems that capture and move sun-heated water or air through buildings, without the explicit use of collectors, fans, or pumps. Active Solar Systems are using collectors and are moving sun-heated water or air by using fans or pumps. Nowadays there are many homes that include several applications such as photovoltaics or passive solar design or some other renewable energy source like a wind system. There are also quite a few off-grid homes that are entirely water and energy self-supporting, including their sewer system.

Energy Conservation and Saving Energy

More and more of the energy we use is renewable energy, such as wind, solar, hydro, or geothermal energy. These energy types are characterized by the fact that they can continually be restored or renewed. Yet most of the other energy forms that we use do not have that capacity. It took millions of years for fossil fuels to be created and they cannot be renewed over night.


And, of course, there are limited or finite quantities of these non-renewable sources of energy, meaning that we cannot renew or replenish them. One day they will be gone, and they cannot be replaced, so we all have to contribute to energy saving as much as we possibly can. At your home, you have the possibility to save a lot of energy if you turn off some appliances, so switch off the radio or TV if you don’t use it, and turn off the lights when there’s no one around.

If you put insulation in your home’s walls you can reduce the energy needed for heating or cooling, and the idea of insulating your home is just like you would put on a jacket or sweater when you feel cold. Insulation ensures that the outer layers will be trapping the heat inside your home, so it will stay nice and warm. Modern space-age materials have been developed to ensure even better insulation. Check out some materials that have been created by firms like Lawrence Berkeley National Laboratory (Aerogel Insulation Material), great solutions.