saves water supplies and wallets
There is a serious global shortage of potable
water. Not just in equatorial countries where populations are
rising, but in the arid southwestern United States. Even in rain-rich
areas, water tables are dropping due to increased consumption,
and what remains is being contaminated by salts from water conditioning,
chemicals from fertilizers, industrial effluences and landfills.
Of a world population of roughly 6.1 billion,
the World Health Organization estimates that more than one billion
people lack access to potable water – five million die each year
from diseases caused by water shortages, poor drinking water,
inadequate sanitation and dirty living conditions.
“Water is going to become more and more of
a crisis in the United States, partially because water infrastructure
is degrading quickly. Water treatment facilities and pipes are
badly neglected, and it’s only going to get worse in my lifetime.
Businesses and technologies that address this problem are only
going to do well in the next 25 years,” said Tom Rooney, CEO
of SPG Solar. SPG is a solar integration company that has built
over 1,500 solar systems in 8 western states, many serving water
supply and wastewater interests.
Solar energy and recycling are both green
industries, but are growing more compatible and synergistic with
each passing year. The many vexing problems of water conservation,
treatment, purification, desalination and pumping are finding
new and intriguing solar powered solutions.
SPG, for example, accidentally discovered
an unexpected water conservation benefit of a solar electric
installation in California that is drawing delegations from as
far away as Australia and Israel to study the phenomena. It’s
The story began several years ago when SPG
engineered a solar system for the Far Niente winery – one of
Napa Valley’s most prestigious. Far Niente wanted solar to power
their vineyard operation and be green, but were reluctant to
give up valuable vine growing space. SPG proposed a novel, first-of-its-kind
solution – use pontoons to float 994 photovoltaic panels on a
1-acre spring-fed pond to create 207 kW of power adjacent to
a land installation of 271 kW.
“We know how much land we saved, but after several years other
benefits emerged that are incredibly interesting,” said Rooney.
Panels float on water which is a natural heat sink and they remained
cooler than land-mounted panels for an unexpected increase in
electricity production. The winery found they no longer had to
put chemicals in the pond to control algae – saving in labor
and cash, and keeping chemicals out of the water. They also had
much more water than ever before for irrigation. And in California,
water is a precious commodity.
“We figured it had to be due to sun shading,
but went further and had academics study it. It turned out that
evaporation in that geography is huge. Seven to eight vertical
feet of water evaporate every year. The panels block about 80
percent of the evaporation on the surface they cover because
they shade it from the sun. But the panels also block wind from
blowing on the surface, and physically cap the surface so it’s
not exposed to air,” Rooney explained.
Southern California is in the midst of an unprecedented water
crisis that that is burdening many farmers and growers with ever
higher water prices, or even outright unavailability that is
closing farms and uprooting vines and orchards.
California has thousands of water district
retention ponds and reservoirs that prohibit recreational activities
such as swimming, boating and fishing. Floating solar panels
on portions of these waters have the potential to generate clean
electricity while annually conserving millions of acre-feet of
SPG has patented the technology and invested nearly a million
dollars over the past year in developing the next generation
of floatovoltaics. “We are now talking to large water districts
like Los Angeles. EPA is coming out with new standards for major
water suppliers on how much chlorine can be put into water because
it creates bromates and other chemicals that are carcinogenic.
EPA water standards have already changed in the last two years
and places like Los Angeles may be forced into multimillion dollar
third-stage treatment facilities because of the chlorine,” said
Solar energy is a hot topic and heavily featured in the media,
but should be understood in the context of overall American energy
consumption. According to the United States Energy Information
Administration, all renewable sources, including solar, represent
only 7.3 percent of the States’ energy consumption and of that
figure wind represents 71 percent. Solar accounts for less than
one percent and has reached its current market share only because
of generous taxpayer funded state rebate programs, mandated state
renewable energy targets and federal investment tax credits.
But all that subsidization appears to be a wise investment. It
has driven competition to technology advancements and economies
of scale that may soon make solar energy as competitive as many
other energy sources with the benefit of being non-polluting.
Solar energy is growing at an impressive rate. According to the
Solar Energy Industries Association (SEIA), at the end of 2009
the total installed utility-scale capacity including solar thermal-electric,
and photovoltaics was 517 megawatts. “We expect to see more than
200 megawatts of utility-scale projects installed in 2010. Most
interesting are the 100-plus projects in the pipeline, many with
utility power purchase agreements (PPAs) in place, totaling 17
gigawatts.” said Monique Harris, director of communications for
Tom Rooney sees the cost of solar dropping every day. “The price
of solar panels has come down dramatically. From a year and a
half ago, totally installed, it’s down from about $7.50 to $8.00
dollars per watt to $4.00 to $5.00 dollars per watt depending
on the application. Rooney believes that over the next five years
incentives will go to zero and the cost of solar will drop to
a point where it does not need incentives. “I’m not saying that
solar will replace every form of electricity, but I think it
will become a mainstay of domestic energy production.”
Whether for household use, industrial processes, wastewater treatment
or irrigation, water requires a tremendous amount of electricity
to power pumps and is the single largest expense for most water
and wastewater jurisdictions.
It happens that solar energy, perhaps better than any other type
of power generation, is particularly suited to water conservation
and recycling for several reasons.
Solar electric production reaches its zenith during the hottest
part of the day when many utilities charge the highest rates.
Last year the Valley Center Municipal Water District in San Diego
County, California completed a 1.1 megawatt solar system. Installed
by WorldWater & Solar Technologies, Inc. it will offset 20
percent of the electricity needed by their largest pumping station.
In addition, if the grid fails they can independently operate
two or three 350 hp pumps on solar alone – a huge benefit during
Solar electricity can pump, purify, treat and desalinate water
while the sun shines and store it until sunset in tanks or reservoirs.
Water pumped to higher elevation ponds or reservoirs during the
day can be released as pumped storage and drive turbines to generate
electricity. Purified water can be dispensed via gravity for
drinking at anytime.
A number of municipal water treatment authorities around the
country have adopted solar energy to recycle wastewater and reduce
electric costs. One of the largest municipal systems is a one
megawatt photovoltaic plant nearing completion in Colorado for
the City of Boulder’s wastewater treatment facility.
Comprised of 4,452 solar panels, it is capable of producing 1,552,000
kilowatt hours of electricity each year – 15 to 20 percent of
the need. Developed by EyeOn Energy, Ltd. under a power purchase
agreement, it will reduce the city’s electricity costs by an
estimated $43,000 annually. Alex Kramarchuk, EyeOn’s president
noted: “We bookend the entire solar process and package the PPA.
Many investors are unaware about solar as an asset class.”
Solar has also found a niche for off-grid purification of contaminated,
brackish and salt water in developing countries, and in disaster
situations. WorldWater, a Princeton, New Jersey based company,
has pioneered its Mobile Max Systems. These small, portable,
solar units are easily transported and can be operational within
30 minutes after arriving on site. Four cube-like units fit into
a standard 40-foot container. An unfolding solar panel array
provides power to operate an on-board water purification system
to handle contaminated water and can produce up to 30,000 gallons
of drinking water per day. A battery bank runs lights, power
tools, computers and satellite phones. Other on-board filtration
systems process brackish or seawater.
The prototype technology was first used after hurricane Katrina
where it purified contaminated water for the entire town of Waveland,
Mississippi for over seven months. Improved units have been used
around the States, in Iraq, Afghanistan, Darfur and Ethiopia.
“We had two machines in Haiti after the 2008 hurricanes providing
drinking water for victims through the French Red Cross and other
aid groups. They were still operating there when the earthquake
happened. We shipped another unit after the earthquake and have
another on the way,” said Mickey Ingles, WorldWater’s vice president
With predicted shortages of fresh water for drinking and irrigation
in the western states, it is likely that solar will play an increasing
role in generating electricity to recycle seawater into freshwater
at desalination plants. According to the International Desalination
Association, there are over 13,000 desalination plants worldwide
producing over 12 billion gallons of fresh water per day. But
there are only a handful of small plants in the United States
due to the current high costs of energy needed for desalination
and the general availability of inexpensive fresh water.
But things are changing. Southern California currently imports
over 90 percent of its water, primarily from the Colorado River
and northern California. Despite aggressive conservation measures,
shortages are occurring most severely in agriculture. Several
pilot and small desalination plants are currently operating on
the west coast and mega plants capable of producing up to 50
million gallons per day are under development.
While the intermittency of solar electric generation is problematic
for grid operators, it will be of less concern to desalination.
It can help plants cut peak rate prices from utilities as well
as power pumped storage to hopefully deliver affordable water.
Tom Rooney at SPG Solar had a parting prediction. “I believe
you are going to see the confluence of three major technologies
over the next ten years: solar becoming so economically competitive
that it’s mainstream; battery technology advancing so solar energy
can be stored and dispensed day or night; smart grid technology
that breaks down the exchange of electricity like the Internet.
We will morph from massive utility plants with huge transmission
lines to millions of nodes of clean electrical production with
the capability of trading electrons back and forth using a smart