By Ira Leiviskä
 |
The Hoover Dam in Nevada, United States
|
The dilemma
Hydropower is considered to be a green,
environmentally friendly source of energy. After all, it is based on moving
water, which earth has a vast supply of. Surely it is a better alternative to
fossil fuels, which release major greenhouse gas emissions. Or is it?
What is hydropower?
The most common way of utilizing hydropower is through
a power plant which is usually situated in a dam that has been built into a
river. The plant normally has three parts: the plant where the electricity is
generated, the dam which controls the flow of the water, and a reservoir where
the water is stored. The water flows through turbines which spin a generator
and transform the movement into electricity. Then it can be transported into
homes and factories via electric lines.
Hydropower can also be produced with the tidal
movements of water, but tidal plants are still few and far between. This way of
producing hydroelectricity is nonetheless being studied, and could possibly be
a success in coastal areas.
A cheap and clean choice
Hydropower is a good source of electricity in the
sense that once the plant has been built, there are very few costs. The river
flow is basically free and infinite as long as rain falls and snow melts. Also,
the reservoir enables the flow of water through the system to be controlled, so
that the power plant can respond to demand more easily. From this point of
view, it is better than other so called renewable energy sources, like wind and
solar power. Hydropower is also clean in the sense that there are no such
greenhouse emissions as when burning fossil fuels, nor radioactive waste like
in nuclear plants.
Destroying natural habitats
Although hydropower may sound like a dream solution to
the global warming problem, this is not quite true. It has been measured that
large reservoirs in tropical areas cause greater carbon and methane emissions
than burning coal or natural gas. This is due to the large amount of vegetation
which decomposes in anaerobic conditions under the
water. This may also happen in colder environments, where the excess nutrients
in the water cause algal blooms.
Another environmental detriment of reservoirs is that
they harm wildlife by filling their habitat with water. Large reservoirs can
even destroy forests and agricultural lands. In addition, dams prevent
migrating fish like salmon from swimming upstream to spawn.
So what to think?
There are disadvantages in every form of energy
production, so to avoid all the negative effects is nearly impossible. Still,
the use of renewable energy sources has far fewer disadvantages than the use of
non-renewable alternatives, such as fossil fuels. For example, hydro power
doesn’t produce air pollutants, unlike coal and natural gas, which can cause
health effects such as breathing problems, neurological damage and cancer. Coal
burning emits also sulfur, which produces acid rain and leads to damages in the
forests and aquatic ecosystems.
Although, hydropower is already a better solution than
non-renewable energy sources, there are still problems that need to be faced.
To minimize the environmental effects of hydropower, the industry should favor narrow
and deep riverbeds that can store more water with less damage to the
surrounding environment. The reservoirs can also be used, for example, in agricultural
irrigation, flood control and for recreational purposes in order to make the
best out of the situation. In addition, to ensure that the nutrient levels stay
optimal and that the anaerobic decomposition is avoided, the reservoir water
needs to be aerated regularly. It is also important to assist the upstream
migration of fish by providing fish ladders and cannons. To read more about
this subject, check Rena’s upcoming blog post about fish cannons.
The future of energy production lies in the
development of the sustainable and renewable energy sources, so be conscious
and keep on reading this blog to get more information about environmental
issues!
Ira Leiviskä
Student,
Degree Programme
in Energy and Environmental Engineering,
Tampere
University of Applied Sciences
LINKS
I agree with you in the fact that this kind of energy production is a really clean option, since the pollution comes just during the building process of the plant, but after the construction, the electricity generation does not pollute at all.
ReplyDeleteIt is a reliable and flexible energy source. As long as there is water running through the turbines, you can get energy and the output of water can be controlled by the workers, contrary to other sources of energy, such as wind power, which depends totally in the wind speed.
By Paola Israde Burrola
For green house cleaning I prefer using green safety towels or soft microfiber cloths. And natural glass & surface cleaner with its ready to use trigger sprayer for glass and other smooth surfaces.
ReplyDelete