Per the Natural Resources Defense Council (NRDC), “Renewable energy comes
from natural sources that are constantly and sustainably replenished.” As we understand more and more about the dangers of burning fossil fuels, these valuable resources are becoming an integral part of the shift toward 100% clean energy for all.


Hydroelectric

This is energy derived from the movement of water, usually through dams on rivers. The largest source of renewable energy currently being used, hydroelectric power generation accounts for six percent of the nation’s electricity, according to NRDC. It’s important to point out that while the water itself is renewable, local ecosystems are adversely affected by damming rivers. For this reason, few sites are available for building new dams.

Another form of hydroelectric energy that’s newly being researched is marine hydrokinetic power, in which the power of ocean waves and tides is harnessed. This is still in early phases of development, but it has intriguing potential since the force of gravity can’t be depleted.


Wind

Pollution-free and inexhaustible, wind power is growing in importance, and in many areas, it can now compete with the price of building new plants powered by coal and gas. The United States should generate enough wind energy in 2014 to power 11 million homes, and about 75,000 Americans have jobs related to manufacturing and maintaining wind generation plants. The U.S. Energy Information Administration estimates that in the future, wind farms could generate up to 30 percent of the nation’s power.


Solar

This is one area where consumer technology is exploding with new, cheaper and more efficient technologies. The NRDC states that by the end of this decade, solar power may be less expensive than conventional energy in some regions. Already, many individual homeowners are realizing the benefits of switching over to solar power, and a growing number of businesses and public institutions are also converting. New structures throughout the west and southwest are incorporating solar panels in their initial designs, and by the end of this decade, the burgeoning solar industry is on track to employ hundreds of thousands of Americans.


Geothermal

Beneath the earth’s surface are large reservoirs of hot water and steam that are heated by contact with molten rock (magma). The heat from these sources can potentially be tapped for energy generation, although accessing underground resources requires some form of drilling and needs to be strictly evaluated from an environmental perspective. Small-scale geothermal installations in California and Nevada are used to heat greenhouses, pools, homes and a dehydration plant, but large-scale geothermal energy is not in our near future.


Biomass and Biofuel

When you burn plant materials, you generate energy; the ethanol in your gasoline is derived from corn and forest products. The problem is that large amounts of land and water are dedicated to growing these fuel crops, and that may not be sustainable in the long term. Furthermore, the NRDC points out that in some cases, trees are “co-fired” along with coal, and the process creates pollution that increases global warming. New methods are currently being developed that use existing agricultural and logging industry waste products for fuel production rather than growing dedicated fuel crops. Massachusetts is leading the way in encouraging sustainable biomass fuels, and there is promise that such programs can eliminate the current hazards.

We draw on the earth and sun for our energy, but currently over 80 percent of our country’s energy is derived from nonrenewable sources: petroleum, natural gas and coal. We can look to the future with far greater hope if we focus today on deploying permanently renewable energy to power our society.