Problems With Renewable Energy Resources

With reports of global warming increasing with every year, nations across the world today are slowly developing alternate sources of energy. Unlike traditional fossil fuels, which will eventually become depleted, renewable energy resources are naturally replenished over time and emit none of the greenhouse gases that contribute to climate change. Thus, the major advantage with renewable energy is its clean, unlimited availability. As the U.S. in particular moves to increase the growth of various renewable energy sectors, it is important to identify the hurdles these technologies face in reality.

Wind

• Wind turbines take advantage of natural wind currents to generate electricity.

  Wind power uses the planet's natural wind currents to run specialized wind turbines. These turbines are usually placed within wind farms located offshore and at high altitudes, where winds are at their greatest speeds. Turbines usually have two to three blades attached to a rotor; as wind spins the shaft, electricity is produced by the generator. Common problems with wind energy are its availability and capacity. Wind droughts are common; without wind, the turbines cannot generate any energy. Also, wind farms must be built in large numbers to produce sufficient energy for a given area.

Hydropower

• Hydropower generates electricity from falling water. When a dam is constructed in a valley, water that flows through the dam's tunnels turns turbines, thus generating electricity. Hydropower itself is very cheap and environmentally friendly. However, hydropower is available only in areas with larger bodies of running water. Another problem with renewable hydropower is the enormous cost of constructing the dam itself. The construction project takes many years and an even larger monetary investment.

Biofuels

• Using crops for fuel reduces the world's food supply.

  Biofuels include a range of fuels obtained from biomass sources. Common examples include bioethanol and biodiesel. The most widely used method to obtain biofuels is to ferment the sugar components from starch crops to produce ethanol, which can be used as a gasoline alternative. Currently, biofuels provide only a marginal percentage of the world's transport fuel because of a number of obstacles. A large amount of plant material is required to produce the biofuel. Starch crops used for fuel cannot be used for food, which decreases the world's food supply. Additionally, intensive crop planting and harvesting causes soil erosion and harms the environment over the long term.

Solar

• Solar power results from converting sunlight into usable electricity. The current methods involving solar power include photovoltaic cells, solar water heating and solar furnaces. Recently, solar energy experienced a marked upturn in both usage and development. Yet many problems continue to exist within this sector. Most notably, solar power is useful only when there is sunlight. On cloudy days, photovoltaic cells cannot generate sufficient electricity for practical use. Also, solar panels and devices can be quite costly to the individual, and large expanses of solar cells must be constructed to harness energy efficiently and in a large enough quantity to provide power on a large scale.