Alternative and Renewable Energies

Back at blogcentral today, working very hard on producing some utterly useless data (shown above). So far the past two days, 14 hours in the lab, zero chucks of useful data. I am told this is how the isotope cookie crumbles on a daily basis, so I had better get used to it.

Anyway, I wanted to discuss what exactly “alternative energy” and “renewable energy” means because I think the media often muddles the two expressions, and the definition is lost in the resulting fracas.

An alternative energy source is one that comes from a non-fossil fuel source.

A renewable energy source is one that the fuel or energy source is rejuvenated quicker by natural processes than we consume the fuel.

Let’s look at a few examples of energy sources and try to categorize them in terms of the definitions above.

Coal

Alternative: Coal is not an alternative fuel, as it is a fossil fuel.
Renewable: Coal is not renewable. Even though it is slowly regenerated, it is produced on a timescale much slower than we consume it.
Environmental Impact: Coal burning is a leading cause of emission of carbon dioxide, sulphur dioxide, and nitrogen bearing compounds to the atmosphere. The process of mining coal is also quite damaging to the environment, and generally to human health.

Natural Gas and Oil

Alternative: Natural gas and oil are not an alternative fuels, as they are fossil fuel.
Renewable: Natural gas and oil are not renewable.
Environmental Impact: Natural gas burning and oil consumption are the leading cause of emission of carbon dioxide to the atmosphere. Burning of natural gas and oil produces also generally produces volatile organic compounds and releases nitrogen oxides to the atmosphere. The process of extraction is damaging to the environment, and is expected to become moreso when we extracting oil shale and tar for oil.

Nuclear Energy

Alternative: Nuclear energy is an alternative fuel since it does not consume fossil fuels.
Renewable: Nuclear energy is not renewable. Uranium and plutonium ore are a limited resource.
Environmental Impact: Nuclear waste is an obvious concern. Retrieval of uranium and plutonium for refinement by means of strip mining can be quite damaging to the environment. Accidental releases, contrary to public opinion, from nuclear power plants are not a legitimate concern given significant advances in nuclear technology over the past 30 to 40 years.

Biofuels

Alternative: Biofuels are alternative fuels as they are not fossil fuel derived. Ethanol produced from corn should be considered a fossil fuel as significant quantities of fossil fuels are required to produce it.
Renewable: The major draw of biofuels is that is renewable. To be truly renewable in the long run, sustainable farming practices must be developed.
Environmental Impact: Varies strongly from biofuel to biofuel. Biofuels include wood, ethanol from corn or sugarcane, manure and vegetable oils. Some are relatively low impact, others like corn based ethanol are environmentally irresponsible and cause significant harm.

Solar

Alternative: Yes. Solar power is an alternative to fossil fuel.
Renewable: Yes. So long as there is a sun, we have solar power available.
Environmental Impact: The major challenge with solar power is improving the technology of converting sunlight to useable energy. Short of conversion of natural terrain to solar farms, the impacts of solar technology on the environment is minimal.

Hydro-Electric

Alternative: Yes. Hydro-electric is an alternative to fossil fuel.
Renewable: Yes. So long as there is a rain and the tides, hydro-electric power available.
Environmental Impact: Varies from application to application. The use of hydro-electric dams can impact rivers and lakes. The use of tidal dams or tidal turbines is somewhat less damaging.

Wind

Alternative: Yes. Wind is an alternative to fossil fuel.
Renewable: Yes. So long as there is a sun creating heating thermal imbalances on the Earth, we have wind power available.
Environmental Impact: Wind power is the most promising alternative energy source because wind is abundant and cheap. The challenge is placing wind turbines in the appropriate location. Chris J brought up some interesting thoughts regarding the viability of wind turbines in an urban environment that I will address in a future post.

Hopefully that clears up the difference between an alternative energy source and a renewable energy source. Next time we’ll pick up with alternative energy production in urban in the New York environment. We’ll try to tackle the question, what are the challenges and opportunities associated with each type of energy?