Renewable Energy Brings Water to the World
Most of the electricity generated around the world is produced
using water intensive processes. Thermoelectric power plants use
fossil and nuclear fuels to heat water in large boilers where
steam is created to drive large turbine generators. Water is
circulated throughout the power plants in huge quantities to
cool the turbines, clean scrubbers and boilers, and perform a
number of other tasks. Chemicals are often added to the water to
extend the life of the machinery and prevent biological growth
in the cooling towers. And many power plants return no water to
the source - it is all lost to evaporation. Other power plants
return water to the source at greatly elevated temperatures,
destroying or radically altering the local ecosystems.
These thermoelectric power plants are responsible for creating
enormous levels of stress on local, regional and national water
supplies in the U.S. and around the world. Besides some water
used in module or turbine manufacturing processes and a
negligible amount needed to occasionally clean them, solar and
wind energy systems require no water to keep them operating.
Furthermore, the substitution of on-site solar thermal hot water
systems in place of electric water heaters also saves
considerable quantities of water.
Billions of gallons of water can be saved every day through the
use of solar, wind and other renewable energy systems. According
to a United States Geological Survey report published in 2000,
195 billion gallons of water are withdrawn every day from our
aquifers, lakes, rivers, and oceans to cool thermoelectric power
plants in the US. This water withdrawal represents 48 percent of
total water withdrawals in the United States.
Clean water is one of our most precious resources and it is at
risk. Government agencies from around the world are reporting
that we are on the verge of a worldwide water crisis. Global
climate change, pollution, inefficient irrigation methods, and
population growth are the most common contributing factors we
hear about when this crisis is discussed. But the generation of
electricity using a thermoelectric power plant is also a
significant factor contributing to this crisis and a negative
externality that should not be dismissed.
Water demand is expected to continue to increase at twice the
rate of population growth. A big part of this increase is being
created by the demand for water to cool more power plants. In
the next seven years India, China and the U.S. plan to build 750
new coal-fired power plants. Another 340 coal plants are also
planned throughout the world in the same timeframe. And with the
Federal Energy Bill now passed, new power plants, including the
possibility of a new generation of nuclear plants, are expected
to be built.
The generation of electricity using nuclear energy consumes the
most water - 0.62 gallons per kWh. Coal power plants use 0.49
gallons per kWh and a combined cycle natural gas power plant
uses 0.25 gallons per kWh. Thermoelectric power plants withdraw
39 billion gallons of clean drinking water from our aquifers
every day (20% of total water withdrawals). This is the
equivalent to the daily drinking water requirements of 62
billion people, about 10 times the Earth's population.
As the demand for water increases, competition for water
resource will continue to escalate and it will most likely
result in local and regional conflicts. Communities downstream
from many of these power plants will have less water available
for their crops and for drinking. More conflicts will arise
within communities to determine water use priorities.
Today, water rights are significant issues in the US, Israel,
China, Africa and many other countries. Ismail Serageidin, a
Vice President at the World Bank, said, "If the wars of the 20th
century were fought over oil, the wars of the next century will
be fought over water". And that doesn't mean armed conflicts
over oil, coal, natural gas and access to nuclear materials will
diminish either.
Renewable energy offers a multi-pronged solution. Using
renewable energy and embarking on intensive conservation
programs can significantly reduce the demand for water.
Depending on location, a 100-watt solar panel will save
2,000-3,000 gallons of water over the 25-year warrantee life of
the panel. All that water can stay in the aquifer until the next
generation needs it.
Aquifers are being drained at a record pace, putting the supply
of abundant and clean drinking water at great risk. Today, over
one billion people around the world do not have access to clean
and safe drinking water, and the number of people facing this
crisis is increasing. First-world nations like the U.S. will not
always be insulated from this dilemma.
All too often, the water-saving angle is a forgotten benefit of
renewable energy. We know solar, wind energy, and other
renewable energy technologies provide sustainable, clean sources
of power. And it's now becoming abundantly clear to even the
most skeptical that renewable energy technologies can be real
engines of economic change, and provide some level of
geopolitical security through increased energy independence.
It's time to make sure that water conservation joins the growing
list of reasons to mobilize a real and widespread shift to
renewable energy.