Alternative energy projects stumble
on a need for water
Sep 29, 2009 - Todd Woody - The New York Times
AMARGOSA VALLEY, Nev. — In a rural corner of Nevada
reeling from the recession, a bit of salvation seemed
to arrive last year. A German developer, Solar Millennium,
announced plans to build two large solar farms here
that would harness the sun to generate electricity,
creating hundreds of jobs.
| Ed Goedhart, a farmer and Nevada
legislator, said farmers would grow less of alfafa
if they decide to sell their water rights. Isaac
Brekken for The New York Times
But then things got messy. The company revealed that
its preferred method of cooling the power plants would
consume 1.3 billion gallons of water a year, about
20 percent of this desert valley’s available water.
Now Solar Millennium finds itself in the midst of
a new-age version of a Western water war. The public
is divided, pitting some people who hope to make money
selling water rights to the company against others
concerned about the project’s impact on the community
and the environment.
“I’m worried about my well and the wells of my neighbors,”
George Tucker, a retired chemical engineer, said on
a blazing afternoon.
| An irrigation riser at Ponderosa
Dairies farm in Amargosa Valley, Nev. Isaac Brekken
for The New York Times
Here is an inconvenient truth about renewable energy:
It can sometimes demand a huge amount of water. Many
of the proposed solutions to the nation’s energy problems,
from certain types of solar farms to biofuel refineries
to cleaner coal plants, could consume billions of
gallons of water every year.
“When push comes to shove, water could become the
real throttle on renewable energy,” said Michael E.
Webber, an assistant professor at the University of
Texas in Austin who studies the relationship between
energy and water.
Conflicts over water could shape the future of many
energy technologies. The most water-efficient renewable
technologies are not necessarily the most economical,
but water shortages could give them a competitive
In California, solar developers have already been
forced to switch to less water-intensive technologies
when local officials have refused to turn on the tap.
Other big solar projects are mired in disputes with
state regulators over water consumption.
To date, the flashpoint for such conflicts has been
the Southwest, where dozens of multibillion-dollar
solar power plants are planned for thousands of acres
of desert. While most forms of energy production consume
water, its availability is especially limited in the
sunny areas that are otherwise well suited for solar
At public hearings from Albuquerque to San Luis Obispo,
Calif., local residents have sounded alarms over the
impact that this industrialization will have on wildlife,
their desert solitude and, most of all, their water.
Joni Eastley, chairwoman of the county commission
in Nye County, Nev., which includes Amargosa Valley,
said at one hearing that her area had been “inundated”
with requests from renewable energy developers that
“far exceed the amount of available water.”
Many projects involve building solar thermal plants,
which use cheaper technology than the solar panels
often seen on roofs. In such plants, mirrors heat
a liquid to create steam that drives an electricity-generating
turbine. As in a fossil fuel power plant, that steam
must be condensed back to water and cooled for reuse.
The conventional method is called wet cooling. Hot
water flows through a cooling tower where the excess
heat evaporates along with some of the water, which
must be replenished constantly. An alternative, dry
cooling, uses fans and heat exchangers, much like
a car’s radiator. Far less water is consumed, but
dry cooling adds costs and reduces efficiency — and
The efficiency problem is especially acute with the
most tried-and-proven technique, using mirrors arrayed
in long troughs. “Trough technology has been more
financeable, but now trough presents a separate risk
— water,” said Nathaniel Bullard, a solar analyst
with New Energy Finance, a London research firm.
That could provide opportunities for developers of
photovoltaic power plants, which take the type of
solar panels found on residential rooftops and mount
them on the ground in huge arrays. They are typically
more expensive and less efficient than solar thermal
farms but require a relatively small amount of water,
mainly to wash the panels.
In California alone, plans are under way for 35
large-scale solar projects that, in bright sunshine,
would generate 12,000 megawatts of electricity, equal
to the output of about 10 nuclear power plants.
Their water use would vary widely. BrightSource Energy’s
dry-cooled Ivanpah project in Southern California
would consume an estimated 25 million gallons a year,
mainly to wash mirrors. But a wet-cooled solar trough
power plant barely half Ivanpah’s size proposed by
the Spanish developer Abengoa Solar would draw 705
million gallons of water in an area of the Mojave
Desert that receives scant rainfall.
|The German developer Solar Millennium
hopes land in the valley, above, can be home to
solar plants. Public opinion, partly because of
water issues, appears to be split.
Isaac Brekken for The New York Times
One of the most contentious disputes is over a proposed
wet-cooled trough plant that NextEra Energy Resources,
a subsidiary of the utility giant FPL Group, plans
to build in a dry area east of Bakersfield, Calif.
NextEra wants to tap freshwater wells to supply the
521 million gallons of cooling water the plant, the
Beacon Solar Energy Project, would consume in a year,
despite a state policy against the use of drinking-quality
water for power plant cooling.
Mike Edminston, a city council member from nearby
California City, warned at a hearing that groundwater
recharge was already “not keeping up with the utilization
The fight over water has moved into the California
Legislature, where a bill has been introduced to allow
renewable energy power plants to use drinking water
for cooling if certain conditions are met.
| George Tucker opposes a water-cooled
solar plant. “I’m worried about my well and the
wells of my neighbors,” he said.
Isaac Brekken for The New York Times
“By allowing projects to use fresh water, the bill
would remove any incentives that developers have to
use technologies that minimize water use,” said Terry
O’Brien, a California Energy Commission deputy director.
NextEra has resisted using dry cooling but is considering
the feasibility of piping in reclaimed water. “At
some point if costs are just layered on, a project
becomes uncompetitive,” said Michael O’Sullivan, a
senior vice president at NextEra.
Water disputes forced Solar Millennium to abandon
wet cooling for a proposed solar trough power plant
in Ridgecrest, Calif., after the water district refused
to supply the 815 million gallons of water a year
the project would need. The company subsequently proposed
to dry cool two other massive Southern California
solar trough farms it wants to build in the Mojave
“We will not do any wet cooling in California,” said
Rainer Aringhoff, president of Solar Millennium’s
American operations. “There are simply no plants being
permitted here with wet cooling.”
One solar developer, BrightSource Energy, hopes to
capitalize on the water problem with a technology
that focuses mirrors on a tower, producing higher-temperature
steam than trough systems. The system can use dry
cooling without suffering a prohibitive decline in
power output, said Tom Doyle, an executive vice president
The greater water efficiency was one factor that
led VantagePoint Venture Partners, a Silicon Valley
venture capital firm, to invest in BrightSource. “Our
approach is high sensitivity to water use,” said Alan
E. Salzman, VantagePoint’s chief executive. “We thought
that was going to be huge differentiator.”
Even solar projects with low water consumption face
hurdles, however. Tessera Solar is planning a large
project in the California desert that would use only
12 million gallons annually, mostly to wash mirrors.
But because it would draw upon a severely depleted
aquifer, Tessera may have to buy rights to 10 times
that amount of water and then retire the pumping rights
to the water it does not use. For a second big solar
farm, Tessera has agreed to fund improvements to a
local irrigation district in exchange for access to
“We have a challenge in finding water even though
we’re low water use,” said Sean Gallagher, a Tessera
executive. “It forces you to do some creative deals.”
In the Amargosa Valley, Solar Millennium may have
to negotiate access to water with scores of individuals
and companies who own the right to stick a straw in
the aquifer, so to speak, and withdraw a prescribed
amount of water each year.
“There are a lot of people out here for whom their
water rights are their life savings, their retirement,”
said Ed Goedhart, a local farmer and state legislator,
as he drove past pockets of sun-beaten mobile homes
and luminescent patches of irrigated alfalfa. Farmers
will be growing less of the crop, he said, if they
decide to sell their water rights to Solar Millennium.
“We’ll be growing megawatts instead of alfalfa,”
Mr. Goedhart said.
While water is particularly scarce in the West, it
is becoming a problem all over the country as the
population grows. Daniel M. Kammen, director of the
Renewable and Appropriate Energy Laboratory at the
University of California, Berkeley, predicted that
as intensive renewable energy development spreads,
water issues will follow.
“When we start getting 20 percent, 30 percent or
40 percent of our power from renewables,” Mr. Kammen
said, “water will be a key issue.”