nowadays petroleum and coal are used as main energy, but as finite non-renewable energy that would be given out some day. and fueling these may cause a series of environmental problems. however nuclear energy is a new unexhaustible new energy, it does no harm to environment and has a wide developmental prospect. though we can not figure out some nuclear wastes due to the restraint of technology of humanbeings. but i believe one day the nuclear energy will take place of ordinary energy as petroleum and become an important kind of energy .
but as today's nuclear power crisis is just an accident. as long as take rational measure, this kind of events may be prevented.
today we're speaking with janaki alavalapati, head of virginia tech's department of forestry. he said that forest biomass ╟ small diameter trees and brush cleared from forests ╟ can be used to create liquid fuel.
janaki alavalapati: every piece of biomass can be used for one type or another of liquid energy sources.
janaki alavalapati: if you put one unit of energy in you are getting approximately five units of energy out from forest biomass-based liquid fuels.
and ╟ in contrast to corn-based ethanol ╟ fuel made from forest products isn’t created from a human food source.
janaki alavalapati: forest biomass does not attract food versus fuel debates that we recently had across the world.
our thanks today to the american forest foundation, leading the way in conservation and education.
this is e&s, a clear voice for science.
the oldest and most common source of renewable energy known to man, biomass is one of the most important forms of energy production in the united states and elsewhere. since such a wide variety of biomass materials is everywhere – from trees and grasses to agricultural and city- life wastes- biomass promises to play a continuing role in providing power and heat for millions of people around the world.
according to the union of concerned scientists , biomass is a kind of renewable energy source that produces no carbon dioxide , because the energy it contains comes from the sun. when plant matter is burned, it gives off the sun’s energy. in this way, biomass serves as a sort of natural battery(电池) for storing the sun’s energy. as long as biomass is produced continuously – with only as much grown as is used – the “battery” lasts forever.
producing power from biomass helps reduce some 11 million tons of carbon dioxide each year. some homeowners also try to make their own heat by using biomass materials. such practice may save homeowners’ money, but it also produces a lot of pollution. so, the best way is to encourage power plants to use it.
