Alternative Energy 101.

Alternative energy refers to any type of energy that is an alternative to fossil fuels. The main fossil fuels are coal, oil and natural gas. Since fossil fuels are non-renewable the term renewable energy has become interchangeable with alternative energy lately.

There are a number of driving forces behind the recent activity in the search for cost effective alternative energy sources. The first one is the rise in costs of fossil fuels. The peak oil theory predicts that worldwide oil production will peak between 2010 and 2020. This peak in production could drive energy prices ever higher creating a gap between supply and demand of oil. We have already seen oil prices hit record levels this year due to supply and demand issues. This same model was used to correctly predict peak production in the United States in the early 1970’s.

Second, the demand for energy is increasing in the United States and is rapidly increasing in the world with the demand for energy in China and India extremely expanding.

The rise in global temperatures often blamed on the consumption of fossil fuels has also propagated the search for alternative fuels. Fossil fuels emit pollutants that can become environmental hazards, so alternative fuels are considered ones that are safe for the environment.

There are a wide variety of alternative energy sources with new ones being developed. Some examples are wind, hydroelectric, geothermal, biomass, biofuels and solar.

Wind and hydroelectric energy is created by using the force of nature to turn a turbine which converts mechanical energy to electrical energy.

Geothermal energy can be used by taking the heat of the Earth and using it to heat a home in a number of ways, such as a ground source heat pump, or to turn a turbine connected to a generator that produces electricity.

The use of biomass is one of the oldest controlled energy sources around. Wood burning is an example of using a biomass fuel. Recent advances in biomass technology have enabled the conversion of solid biomass into liquid biofuels. The challenge with biomass is in order to use it in the transportation industry it needs to have a higher power density. More energy per pound than is typically found in biomass like wood. Plus transportation fuels generally need to be liquid.

Conversion of biomass into liquid biofuels is accomplished in one of two main ways. Either a sugar or starch is fermented creating an alcohol fuel like ethanol or the natural oils and fats from plants and animals can be burned in a diesel engine. The oils are converted into biodiesel. Gasification is being used to create biodiesel or ethanol. Biofuels are a good alternative to fossil fuels because they burn cleaner extending engine life and they do not have the harmful emissions of fossil fuels. The goal is to create biofuels that are carbon neutral or negative and cost effective. This means the carbon dioxide they release as a result of the burning process is reabsorbed by the plants when they are growing. Carbon dioxide is the main culprit in the threat of global warming.

Solar energy is energy used directly from the sun. This energy could be used to passively heat a house from the sun’s radiant energy or actively used and converted to electrical energy using technologies like photovoltaic solar panels.

If you have any questions on this or any other energy-related topic, contact Pedersen at (701) 231-5833 or carl.pedersen@ndsu.edu .