Renewable energy sources can be replenished in a short
period of time. The five renewable sources used most often include
hydropower (water), solar, wind, geothermal, and biomass.
Renewable energy's impact on the world's energy picture is significant.
Many important events have occurred during the history of using renewable
sources to generate electricity - but the overall use of these fuels
has declined by about 17 percent from their 1996 peak to about 6 quads
The use of renewable energy is not new. Five generations (125 years)
ago, wood supplied up to 90 percent of our energy needs. Due to the
convenience and low prices of fossil fuels, wood use has fallen. Now,
the biomass which would normally present a disposal problem is converted
into electricity (e.g., manufacturing wastes, rice hulls, and black
liquor from paper production).
Historically, low fossil fuel prices, especially for natural gas,
have made growth difficult for renewable fuels. The deregulation and
restructuring of the electric power industry could have a major impact
on renewable energy consumption. Demands for cheaper power in the
short term would likely decrease demand for renewable energy, while
preferences for renewables included in some versions of proposed electricity
restructuring legislation would breathe new life into this industry.
Use of renewables in the United States is not currently expected to
approach that of the major fuels, and due to their limitations (e.g.,
their intermittent nature - cloudy days have no solar gain, quiet
days mean no wind blows to drive wind turbines, dams are primarily
for flood control, so hydroelectricity production varies as dams'
water levels change), renewables may never provide "the" answer to
all energy problems. Around the world, renewable energy is proving
to be of great value.
In 2003, about 6.2 Quadrillion Btu (Quads) of US energy came from
renewable fuels. Each of the energy sources we use is measured, purchased,
and sold in a different form. Many units of measurement are used to
measure the energy we use each day. Learn more about converting energy
units in the Units of Measurement section.
Last Revised: January 2004 Sources: Energy Information Administration,
Energy INFOcard, October 2004.
Biodiesel -- a Renewable Fuel
FROM VEGETABLE OILS AND ANIMAL FATS
a renewable fuel that can be used instead of diesel
fuel made from petroleum. Biodiesel can be made from vegetable
oils, animal fats, or greases. Most biodiesel today is made from
soybean oil. About half of biodiesel producers are able to make
biodiesel from used oils or fats, including recycled restaurant
most often blended with petroleum diesel in ratios of 2 percent
(B2), 5 percent (B5), or 20 percent (B20). It can also be used as
pure biodiesel (B100). Biodiesel fuels can be used in regular diesel
vehicles without making any changes to the engines. It can also
be stored and transported using diesel tanks and equipment.
with biodiesel has just started to catch on, but this isn't a new
idea. Before petroleum diesel fuel became popular, Rudolf
Diesel, the designer of the diesel engine, experimented with
using vegetable oil (biodiesel) as fuel.
A TRANSPORTATION FUEL
buses, and tractors in the United States use diesel fuel. Diesel
is a nonrenewable fuel made from petroleum. Using biodiesel means
that we use a little bit less petroleum. Biodiesel results in less
pollution than petroleum diesel. Any vehicle that operates on diesel
fuel can switch to biodiesel without changes to its engine.
Because it is
so clean burning and easy to use, biodiesel is the fastest growing
and most cost efficient fuel for fleet vehicles. Many school districts
are switching to biodiesel blends for their school buses. Biodiesel
is also being used for fleets of snowplows, garbage trucks, mail
trucks, and military vehicles. So far, the use of biodiesel has
been limited to fleets of vehicles that have their owner fueling
stations. As the number of public fueling stations that offer biodiesel
grows, it may become more popular with individual consumers.
B100 and biodiesel
blends are sensitive to cold weather and may require special anti-freeze,
just like petroleum-based diesel fuel does. Biodiesel acts like
a detergent additive, loosening and dissolving sediments in storage
tanks. Because biodiesel is a solvent, B100 may cause rubber and
other components to fail in older vehicles. This problem does not
occur with biodiesel blends.
AND THE ENVIRONMENT
renewable, nontoxic, and biodegradable. Compared to diesel, biodiesel,
is significantly cleaner burning. It produces fewer air pollutants,
like particulates, carbon monoxide, hydrocarbons, and air toxics.
It does slightly increase emissions of nitrogen oxides, though.
Biodiesel produces less black smoke, and smells better, too. Sometimes
biodiesel smells like french fries!
fuel contains sulfur. Sulfur can cause damage to the environment
when it is burned in fuels. New environmental laws will require
the amount of sulfur in diesel fuel to be dramatically reduced over
the next few years. When sulfur is removed from regular diesel fuel,
the fuel doesn't work as well. Adding a small amount of biodiesel
can fix the problem. Biodiesel has no sulfur, so it can reduce sulfur
levels in the nation's diesel fuel supply while making engines run
The information for the Bio-Kids sections of this web site have
been graciously loaned to Envira Fuels by the Department of
Energy's - Energy Information Administrations: Energy
Kid's Page at: http://www.eia.doe.gov/kids/energyfacts/sources/renewable/biodiesel.html
Sources: Energy Information Administration, Annual Energy Review
2003, September 2004.
The National Energy Education Development Project, Alternative
Fuels: What Car Will You Drive?, 2004.
US Department of Energy, Energy Efficiency and Renewable Energy,
Alternative Fuels Data Center, October 2004.