Green power is another name for renewable energy - electricity generated from sustainable resources, by producing few or no hazardous emissions or pollutants, and having minimal impact on fragile ecosystems.

Why not all green, all the time? The answer is complicated, but it boils down to a few key factors:

  • Fuel cost: Coal has always been the most cost-effective way to make the large amount of electricity needed for modern life. Producing electricity from renewable resources like wind and biomass is simply more expensive. In addition, green technology doesn't have the entrenched infrastructure that fossil fuels have developed over the years, making the initial cost of building green power facilities more expensive.
  • Location: Fossil fuel power plants can be placed almost anywhere, as long as a railroad or pipeline can reach the site. In contrast, the areas where green energy like wind, water or solar power can be utilized are limited by the landscape.
  • Reliability: Utility companies can easily stockpile coal to meet the ever-changing demand for electricity, especially during "peak" times in the summer. Most renewable energy sources can't be stored to provide for future use - the amount of electricity produced depends on how hard the wind blows, how fast the river flows, or how much the sun shines.
  • Customer cost: While almost all utility customers would agree that green power is best, only some would be willing to pay a higher price for it, and few would be willing to give up the 24-hour reliability of a fossil-fuel power plant. Researchers are investigating new technologies like microturbines and fuel cells that could eliminate some of these concerns.

Types of renewable energy

There are five main types of renewable energy.