IS SOLAR ENERGY MORE DESTRUCTIVE THAN MINING?
Environmental article by Harold Hough Aug/Sept 2009
According to solar energy advocates, solar energy is the perfect
energy source - renewable, clean, and environmentally friendly.
Therefore, it might surprise you to learn that solar energy
has a larger and more destructive environmental footprint than
your typical mine.
The Bureau of Land Management (BLM) has received over 200 applications
to build solar plants on federal land in recent years. In California
alone, there are 80 proposals on 700,000 acres. In Nevada, BLM
has accepted about 130 applications, including 23 in Clark and
Nye counties, to build solar plants. There are over one million
acres of public land in the six most solar intense states that
are being considered for solar plants.
Imagine the outcry if it were announced that one million acres
of federal land were under consideration for open pit coal mining?
Contrary to the promises of environmentalists, these solar plants
will not have a small footprint when they are constructed. Unlike
many mines, which blend with the local environment, solar plants
will strip the land and then cover them with acres of solar
panels and reflectors. Solar reflector arrays need to be on
flat ground (3% or less of a grade). That means nearly all of
the land will have to scraped; destroying plant life and wildlife
habitat. Mines, on the other hand usually scrape only pit and
road areas. Then, after the mine is closed all the land is reclaimed.
Solar plants, on the other hand will scar the land for decades.
Solar plants also require a lot of resources, including water.
That is quite different from the mining industry were mines
recycle their water. Many mines even pump ground water from
the mine and use it to expand local riparian areas, while recharging
the water table. Solar plants, however, are major consumers
of water and a clear threat to the water table.
Solar panels and reflectors require water in order to stay clean
in a dry, dusty desert environment. And, concentrated solar
power reflectors also require water for steam production and
cooling towers. In fact, for every megawatt produced, six acre
feet of water are required. Unlike mines, which recycle their
water, 92% of the solar plant's water is released into the environment
through evaporation, which requires a constant supply for fresh
water. Nevada's Solar One power plant near Las Vegas uses 400
acre feet to produce its 64 megawatts.
Imagine how much water a national solar energy grid will require.
The five plants planned for Amargosa Valley, Nevada (which will
generate from 150 to 1,000 megawatts), will have to find 10
million extra gallons of water a year. This type of water demand
will rapidly deplete Nevada's water table.
These solar plants also produce "greenhouse gases."
Obviously, there has to be an alternate energy source when it's
dark or cloudy. However, keeping the solar plant on standby
requires burning fossil fuels. In order to keep the water in
the solar reflectors warm during the nights, solar plants have
to use natural gas. Without this heating, the solar reflectors
wouldn't be able to immediately go online when the sun comes
up.
THE PROBLEMS WITH SOLAR CELLS
Are traditional photovoltaic cells better? They do eliminate
the natural gas usage. Not only that, they don't have moving
parts and last for decades. However, photovoltaic panels have
their own set of problems, especially if used for large scale
energy production. And, they still need some water in order
to keep the panels clean
Solar cells range in efficiency from 6% in inexpensive amorphous
silicone based solar cells to over 40% in expensive, high technology
cells. The commercial cells range in efficiency from 14% to
19%. This is a slightly lower efficiency than that that of solar
reflectors, which means more acres will have to destroyed in
order to produce the same amount of electricity.
Ironically, solar cells require a lot of energy to manufacture
because it takes considerable energy to produce silicon from
silicone dioxide (sand). The result is that the energy payback,
according to studies conducted by Tucson Electric Power's Springerville
photovoltaic plant, is that it will take 2.78 years to produce
enough electricity to payback the energy used in producing the
photovoltaic panels and associated infrastructure. Ironically
that means America will have to mine more coal just to produce
the solar panels that are supposed to reduce our reliance on
fossil based fuels.
Despite the great publicity surrounding solar energy, there
remain many problems. One of the greatest is that it will require
damaging our western environment in ways that centuries of mining
never did. In light of that, coal powered electricity remains
a better environmental choice for the foreseeable future.
