JUNE 2013 / POPULAR SCIENCE ILLUSTRATION BY GRAHAM MURDOCH t long last, energy independence seems tantalizingly close. The U.S. Energy Information Administration projects oil exports will surpass imports for the frst time in 2014. The International Energy Agency forecasts the U.S. could become nearly self-sufcient by 2030—and Citigroup puts the milestone for North America at 2018. Ending reliance on foreign oil could bring more jobs and security, but along with them, potential hazards. Oil will remain part of global markets and subject to price swings. More important, independence won’t stop climate change. Doubling down on fossil fuels could crowd out cleaner options. Today, the U.S. has an opportunity to pursue self- sufciency intelligently, not blindly. “Coal is suddenly on the retreat,” says Daniel Kammen, director of the University of California, Berkeley’s Renewable and Appropriate Energy Laboratory. “If we take advantage of this moment to put in a whole new mix, where the dirtiest fuel is natural gas and renewables are a clean addition, it changes the scenario entirely. Together, they can open up a horizon we didn’t have fve years ago.” Engineers will need to clean up hydraulic fracturing and squeeze more power from solar, wind, water, and waste. Here’s how to do it. — THE EDITORS A OPEN HERE FOR MORE WASTE Municipal trash, heat, and spent nuclear fuel could power the U.S. for decades. 48 WIND Blades get bigger; turbines get smarter. Plus: the pitfalls of energy politics. THE ENERGY GAP When will the U.S. reach energy independence—really? 56 60 OIL AND GAS How to clean up fracking’s bad rep. Plus: efficient new natural gas turbines. 58 WATER Engineering triumphs over wave and tidal forces. Plus: the craziest ideas in power. 54 46 SOLAR Reinventing the array could usher in a new age for solar. Plus: beyond batteries. 50 GLOBAL LANDSCAPES What’s the greatest driver of renewable energy development? Geography. JUNE 2013 / POPULAR SCIENCE / 45 THE ENERGY FIX INSIDE! PSC0613_Energy_1_Opener_FINAL.indd 45 4/17/13 1:23 PM
Transcript
J U N E 2 0 1 3 / P O P U L A R S C I E N C E
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t long last, energy independence seems tantalizingly close. The U.S. Energy Information Administration projects oil exports will surpass imports for the
f rst time in 2014. The International Energy Agency forecasts the U.S. could become nearly self-suf cient by 2030—and Citigroup puts the milestone for North America at 2018. Ending reliance on foreign oil could bring more jobs and security, but along with them, potential hazards. Oil will remain part of global markets and subject to price swings. More important, independence won’t stop climate change. Doubling down on fossil fuels could crowd out cleaner options.
Today, the U.S. has an opportunity to pursue self-suf ciency intelligently, not blindly. “Coal is suddenly on the retreat,” says Daniel Kammen, director of the University of California, Berkeley’s Renewable and Appropriate Energy Laboratory. “If we take advantage of this moment to put in a whole new mix, where the dirtiest fuel is natural gas and renewables are a clean addition, it changes the scenario entirely. Together, they can open up a horizon we didn’t have f ve years ago.” Engineers will need to clean up hydraulic fracturing and squeeze more power from solar, wind, water, and waste. Here’s how to do it. —T H E E D I T O R S
A
OPEN HERE FOR MORE
W A S T EMunicipal trash, heat, and spent nuclear
fuel could power the U.S. for decades.
48
W I N DBlades get bigger; turbines get smarter.
Plus: the pitfalls of energy politics.
T H E E N E R G Y G A PWhen will the U.S. reach energy
independence —really?
56
60
O I L A N D G A SHow to clean up fracking’s bad rep. Plus:
efficient new natural gas turbines.
58
W A T E REngineering triumphs over wave and tidal
forces. Plus: the craziest ideas in power.
54
46
S O L A R Reinventing the array could usher in a new
age for solar. Plus: beyond batteries.
50
G L O B A L L A N D S C A P E SWhat’s the greatest driver of renewable
The solar market has been on fire. In the U.S., it’s grown by 600 percent over the past five years, culminating in 3,313 installed megawatts in 2012. This past March, seven solar projects added the only new utility power of any kind to the U.S. grid. But solar energy isn’t quite cost-competitive yet. Bridging the final gap requires breakthroughs that increase efficiency while cutting costs.
S O L A R
▶ Even for photovoltaic (PV) panels, there’s such
a thing as too much sun—when cells overheat, they
become less efficient. V3Solar solved that problem
with Spin Cell, a conical array that floats on magnets.
An outer cone made of specialized lenses concentrates
bands of sunlight on an inner cone covered with PV
cells. The cells capture light energy but spin away
before thermal energy can transfer. This constant cool-
ing means V3Solar can use cheaper, less heat-tolerant
material than other light-concentrating systems.
Conical Solar Panels
THE DR AMATIC REIMAGINING
I LLUSTR ATION BY GR AHAM MURDOCH
PSC0613_Energy_2_Solar_R1.indd 46 4/19/13 10:55 AM
J U N E 2 0 1 3 / P O P U L A R S C I E N C E
JUNE 2013 / POPULAR SCIENCE / 47
In order to deliver steady power, renewable energy systems require storage—a place to temporarily offl oad electrons. Facilities for compressed-air energy storage last much longer than grid-scale batteries. They use power produced during off -peak hours to compress air into underground caverns and then release it through a turbine to generate electricity when demand is high. LightSail Energy made that process mobile and modular by designing air-storage tanks that fi t inside shipping containers. Plus, the company uses water to capture waste heat and boost effi ciency.
B E Y O N D B A T T E R I E S
STOR AGE
Arrays That Mimic Plants
THE BACK-TO -NATURE SOLUTION
Spin Cells don’t need the
racks or permits required
for rooftop arrays, so
V3Solar says the cost to
homeowners could be half
that of traditional panels.
For greater power density,
V3Solar plans to sell a Power
Pole with Spin Cells arranged to
minimally shade one another.
The first commercial Spin
Cells, slated for 2014,
should produce about
1,000 watts of electricity.
The inner cone of PV uses
about 10 watts to spin.
1
As pistons
compress air,
a fi ne mist of
water absorbs the
released heat.
2
The compressed
air sits in low-cost
tanks for storage.
3
Thermal energy is
stored separately
or routed to
nearby buildings
to heat them.
4
As air expands
again, it absorbs
heat from water
and converts that
to mechanical
energy for power.
▶ Concentrated solar farms typically use heavy-duty
steel drives and motors to direct sunlight from rows of
giant mirrors (called heliostats) onto a central tower. San
Francisco–based Sunfolding devised a way to get the job
done far more cheaply. Inspired by plants, which use tiny
shifts in internal pressure to crane toward the sun, engi-
neers designed Sunfolding’s heliostats to use compressed
air to pivot into position. Made from plastic, the miniature
drive system can be mass-produced at one fifth the cost of
conventional models.
▶ Would embedding solar cells in every
bolt of fabric make a dent in our fossil-fuel
consumption? It’s worth a shot. Greg
Nielson, a Sandia National Laboratories
researcher —and 2012 POPSCI “Brilliant
10” honoree—has developed solar glitter
that could turn nearly any surface into a
power source. Clusters of the dust-size
cells (as small as 250 microns across)
could be incorporated into standard PV
panels, doubling their effi ciency, or into
the material for bags and clothing.
Solar couture is also a future goal
of the New York City fi rm Pvilion, which
produces power-generating fabric for
larger-scale commercial applications. Its
fl exible panels can be as effi cient as rigid
ones but far easier to manipulate into
structures like canopies for electric-vehicle-
charging stations. Pvilion engineers are
currently designing a covered footbridge in
Florida and curtains for a building in New
York City—in both cases, the fabric will
power lighting for the entire structure—and
a 124,000-watt solar facade membrane
for a new U.S. embassy in London.
Drape the Planet with Solar Fabric
THE WHY NOT? PL AN
PSC0613_Energy_2_Solar_R1.indd 47 4/19/13 10:55 AM
48 / POPULAR SCIENCE / JUNE 2013
STORY BY DAVID FERRIS I LLUSTR ATION BY TREVOR JOHNSTON
T H E F U T U R E O F E N E R G Y
W A S T E The world throws away enormous amounts of energy each day. In the U.S. alone, waste streams could account for 100,000 megawatts of untapped electrical capacity. New technology could convert those over-looked sources into usable power.
▶ Producing biofuel typically requires growing a
feedstock, such as switchgrass, that consumes valuable land
and water. But any carbon source could provide that bio-
mass, including garbage. Fulcrum BioEnergy says the plant
it plans to build near Reno, Nevada, in 2015 could convert
160,000 tons of municipal trash into 10 million gallons of
transportation fuel per year —and for less than 70 cents a
gallon. Machines would shred wood, fabric, and non-
recyclable paper and plastic into two-inch bits and feed them
to a gasifi er. A chemical reaction would then convert the
gases into ethanol, jet fuel, or diesel.
Gas from TrashTHE OPPORTUNIST
▶ U.S. factories blow off as much as 13 quadril-
lion BTUs of waste heat each year. Alphabet Energy
believes it can convert some of that heat back into
electricity, improving the effi ciency of plants by several
percent. The company’s system sandwiches a thermo-
electric material between two heat exchangers, one
containing exhaust gas and the other a coolant. The
material generates electricity from that temperature
gradient. And because it’s made of silicon, it can be
produced with standard semiconductor equipment.
Heat to Electricity
THE SCAVENGER
Water in a third loop
absorbs heat from the
molten salt and converts to
steam, which spins a turbine
to produce electricity.
PUMP
TURBINE
A chilled plug of salt below
the reactor would liquify during
a power failure, allowing molten
salt to fl ow into a containment
vessel and solidify.
REACTOR CORE
▶ U.S. nuclear reactors store nearly 70,000
metric tons of commercial spent fuel, which
remains dangerously radioactive for tens of thou-
sands of years. Engineers at a start-up called
Transatomic Power say a reactor they designed
could use this stockpile to meet the nation’s
energy needs for 70 years. Their 500-megawatt
Waste-Annihilating Molten Salt Reactor (WAMSR)
is based on a fl uoride molten salt reactor devel-
oped at Oak Ridge National Laboratory in the
1960s. But two Transatomic cofounders, PhD
candidates at MIT, made crucial modifi cations:
They shrunk the reactor by a factor of 20 and
engineered it to capture 98 percent of the energy
in spent fuel pellets. Half of WAMSR’s own
waste product, which totals only four kilograms,
becomes inert within a couple of hundred years.
Next-Next-Gen Nuclear Power
THE R ADIOACTIVE OPTION
CONTAINMENT
VESSEL
WASTE-ANNIHILATING MOLTEN SALT REACTOR
A mixture of molten
salt and spent fuel
pellets fl ows from the
reactor core through
a loop of pipes.
Molten salt in
a second loop
absorbs heat
from the salt-fuel
mixture.
PSC0613_Energy_3_Waste_FINAL.indd 48 4/16/13 11:44 AM
2000 to 2011
Percentages reflect countries’ production within each subcategory.
Top per-capita production in each category
17.06 Quadrillion BTUs
50 / POPULAR SCIENCE / JUNE 2013
G L O B A L L A N D S C A P E S
S O U R C E : W O R L D P O P U L A T I O N D A T A A N D
STORY BY K ATIE PEEK I LLUSTR ATION BY FATHOM INFORMATION DESIGN
HOW GEOGRAPHY DRIVES ENERGY DEVELOPMENT
RENEWABLE ENERGY
as a proportion of total
produced
WORLDWIDE RENEWABLE energy
production reached 66.83 quadrillion
BTUs in 2010. The countries in the
Organisation for Economic Co-
operation and Development—which
keeps detailed records for its 34
members [see map]—produced 16.50
quadrillion BTUs that year. Which
technology works in which country is
often a matter of topography.
Farmland—and farm
subsidies—have
made corn ethanol
the major driver
of biofuel growth
in the U.S.
The OECD collects
and analyzes data
to make policy
recommendations
for its member
countries.
Finland is the
second-most forested
country in Europe—
the most forested
is Sweden. In both
countries, biofuel is
largely a by-product
of the forest industry.
Germany aims to
produce 30 percent
renewable energy by
2020. Lacking ready
access to new hydro
or geothermal, the
country has focused
on wind and solar.
Canada’s hydropower
plants generate
63 percent of the
country’s electricity.
Iceland’s volcanism allows it to
produce 78 percent of its energy
geothermally. The rest of the
energy it produces is hydropower.
Denmark has 5,078 wind turbines,
or one for every 1,100 people. The
country’s position in the North Sea
makes wind an effective resource.
Solar 2%
Wind
7%
Geothermal
8%
Hydro
28%
Biofuel
& Waste
55%
Hydroelectric dams
are a big slice of
the renewables pie
because they’re a
mature—and thus
relatively cheap—
technology.
“Biomass is the
oldest energy being
used by mankind,”
says Cédric
Philibert, an analyst
at the International
Energy Agency,
“but the long-term
potential is much
lower than solar
and wind.”
U.S. 27%
Mexico 17%
U.S. 24%
Canada 27%
Germany11%
U.S. 37%
U.S. 36%
Germany 14%
Germany 21%Israel 11%
Denmark 2.9%
Iceland 11%
Iceland0.9%
Norway8.7%
Finland3.3%
France5.3%
PSC0613_Energy_4_Infog_R1.indd 50 4/16/13 3:53 PM
T H E F U T U R E O F E N E R G Y
STORY BY ERIK SOFGE I LLUSTR ATION BY NICK K ALOTER AKIS
54 / POPULAR SCIENCE / JUNE 2013
Water is 800 times denser than air, and building a gen erator able to withstand the tremendous force it generates has hampered the development of next-gen hydropower. If engineers can harness its energy, water holds great potential: about 1,420 terawatt-hours per year, or roughly a third of U.S. annual electricity usage.
WAT E R
▶ Tidal currents are among the most predictable energy sources on Earth.
Until recently, the only way to capture their power was to construct massive
dams that impeded the flow of water, often in sensitive marine areas. The
TidGen, developed by the Ocean Renewable Power Company (ORPC), sits at
the bottom of a free-flowing deep river or bay instead. The company installed
its first commercial unit in Maine’s Cobscook Bay last summer, and it began
delivering electricity to the U.S. grid shortly thereafter. A TidGen can produce
up to 150 kW, or enough electricity to power 25 homes, but ORPC plans to
add 5 megawatts of capacity within three to five years.
Tame the Tide
THE BOT TOM FEEDER
ACTUALLY HAPPENING
S O C R A Z Y I T
C O U L D W O R K ?
Energy independence will
require big ideas--maybe even
bizarre ones. Here are 12
that someone, somewhere, is
actually hard at work on.
Engineers designed TidGen, which
is 98-feet wide and 31-feet tall, for
tidal bodies, such as bays, between
60 and 150 feet deep.
CAPTURE
WASTE HEAT
FROM
CREMATING
DEAD BODIES
UNLEASH
ANACONDA,
THE WAVE-
EATING ENERGY
SNAKE
AMPLIFY
THE POWER
OF DANCE
MOVES WITH
PIEZO ELECTRIC
FLOORS
COVER
EVERYTHING
WITH PEEL-
AND-STICK
SOLAR
STICKERS
HAVE STUNT
KITES PULL
VEHICLES THAT
GENERATE
MECHANICAL
POWER
PSC0613_Energy_6_Water_R1.indd 54 4/24/13 10:27 AM
JUNE 2013 / POPULAR SCIENCE / 55
ON SOMEONE’S WORKBENCH FAR OUT BY ALL DEFINIT IONS
▶ Wave energy is more evenly distributed across the
globe than tidal currents, but it’s also more violent:
Generators floating on the surface of the ocean must
function while being thrashed around. London-based
40South Energy built a wave-energy converter that cleverly
avoids abuse. It remains submerged in the water column,
automatically adjusting its depth to find optimal conditions
Catch the Waves
THE STORM CHASER
and dodge rough storms. The machine generates energy
as its top half, attached to a suspended platform, pulls
against the bottom half, moored to the seafloor. 40South
plans to deploy its first commercial unit, the 150-kilowatt
R115, near Tuscany, Italy, this summer. It’s also developing
a 2-megawatt version and setting up pilot wave-energy
parks in India, Italy, and the U.K.
A power-and-data
cable connects
an array of up to
a couple of dozen
TidGen units to an
onshore substation.
The TidGen’s helical
turbines have teardrop-
shaped foils and rotate
in a single direction,
regardless of the flow
of the current.
A permanent-magnet generator
mounted between the four turbines
produces up to 150 kw.
USE BODY
HEAT TO
POWER
PERSONAL
ELECTRONICS
TAP TREES
FOR BIOFUEL
INSTEAD
OF SAP
TRAP
RAINBOWS
TO IMPROVE
SOLAR PANEL
EFFICIENCY
MASS
PRODUCE
MINIATURE
NUCLEAR
REACTORS
HARNESS
MANMADE
TORNADOES
TO DRIVE
TURBINES
CAPTURE
ENERGY FROM
SMALL DAILY
TEMPERATURE
CHANGES IN
AMBIENT AIR
FUEL
HYDROGEN
VEHICLES
WITH TANKS
OF SUGAR
PSC0613_Energy_6_Water_R1.indd 55 4/24/13 10:27 AM
T H E F U T U R E O F E N E R G Y
STORY BY ERIK SOFGE I LLUSTR ATION BY GR AHAM MURDOCH
56 / POPULAR SCIENCE / JUNE 2013
In 2012, wind power added more new electricity produc-tion in the U.S. than any other single source. But even with 60 gigawatts powering 15 million homes, wind supplants just 1.8 percent of the nation’s carbon emissions. Tomorrow’s turbines will have to be more efficient, more affordable, and in more places.
W I N D
▶ Big rotors generate more electricity, par-
ticularly from low winds, but oversize trucks
hauling blades the length of an Olympic pool
can’t reach many wind-energy sites. Blade
Dynamics fabricates its 160-foot, carbon-fiber
blade in multiple pieces, which can then be
transported by standard trucks and assem-
bled at a nearby location. It’s a stepping-stone
for 295-foot and 328-foot blades now being
designed for offshore turbines. (Currently, the
world’s longest prototype is 274 feet.) The
colossal size should enable 10- to 12-mega-
watt turbines, double the generation capacity
of today’s biggest models.
Bigger Blades
THE SUPERSIZE ROUTE
Metal inserts built into the
carbon-fiber blade during
manufacture mean the root
end, bolted to the hub,
can be slimmer,
stronger, and more
aerodynamically
efficient.
Statue of Liberty Boeing 747
151ft 232ft
300ft
PSC0613_Energy_7_Wind_R2.indd 56 4/24/13 10:25 AM
JUNE 2013 / POPULAR SCIENCE / 57
▶ Reducing the variability of wind energy
could position it to compete as a stable
source of power. General Electric’s new
2.5-megawatt, 394-foot-diameter wind turbine
has an optional integrated battery for short-
term energy storage. It also connects to GE’s
so-called Industrial Internet so it can share
data with other turbines, wind farms, techni-
cians, and operations managers. Algorithms
analyze 150,000 data points per second to
provide precise region-wide wind forecasts
and enable turbines to react to changing
conditions, even tilting blades to maximize
power and minimize damage as a gust hits.
▶ Solar Wind Energy’s downdraft tower is either
ingenious or ludicrous. The proposed 2,250-foot-high
concrete tower will suck hot desert air into its hollow
core and infuse it with moisture, creating a pressure
differential that spawns a howling downdraft. “You’re
capturing the last 2,000 feet of a thunderstorm,”
says CEO Ron Pickett. The man-made tempest
would spin wind turbines that could generate up to
1.25 gigawatts (though it’s designed to operate at
60 percent capacity) on the driest, hottest summer
days—more than some nuclear power plants. The
Maryland-based company plans to break ground in
Arizona as soon as 2015, provided it can secure
$900 million in funding—a large sum but perhaps
not outlandish when compared with a $14-billion
nuclear reactor now under construction.
Smarter TurbinesMan-Made Thunderstorm Power
THE NET WORKED SOLUTION
THE HYBRID HAIL MARY
FOR MORE THAN 40 YEARS,
MIT has been at the forefront
of fusion research, thanks to
its tokamaks —powerful devices
that use magnets to confine
plasma. Alcator C-Mod, the
latest version, is one of just
three tokamaks in the United
States. It’s responsible for the
livelihood of 100 staffers and
30 current PhD students, in
addition to the dozens of fusion
physicists that preceded them.
As of press time, C-Mod will
likely be forced to shut down.
Standoffs in Washington have
triggered more than $1 trillion
in federal budget cuts, and
the president’s 2014 budget
slashes spending for domestic
fusion research beyond reduc-
tions first proposed for 2013.
MIT’s fusion lab stands to lose
as much as 70 percent of its
funding, which would lead to
dismantling C-Mod and the
entire program—no tokamak
means no new PhD students.
“We’re giving up the leader-
ship in fusion,” says Miklos
Porkolab, director of MIT’s
Plasma Science and Fusion
Center. “We had a world-class,
first-rate program, and we’re
letting it disappear.”
The C-Mod is not the only
program in jeopardy. Even
the Department of Energy’s
ARPA-E initiative, which
supports dozens of solar, wind,
and energy-storage projects
each year, is up for reautho-
rization under the America
Competes Act.
As U.S. programs face cuts,
there’s a surge of investment
overseas, including billion-
dollar-class fusion reactors in
China, Germany, and Japan
and the internationally funded
ITER in France. When ITER
achieves high-burning plasma
in 2020, it will be the world’s
largest fusion reactor, made
possible by some $2 billion in
U.S. contributions. “And we’re
not going to be able to use
it,” says Porkolab. Even if we
have the will, we may not have
enough physicists.
P R O J E C T S O N T H E
C H O P P I N G B L O C K
ENERGY POLITICS
Fabricating the carbon fiber in
modular pieces, rather than
one long blade, ensures the
material’s consistency and
reduces the risk of failure.
An erosion-protection material
molded into the leading edge of
the blade reduces wear and tear
over the blade’s lifetime.
J U N E 2 0 1 3 / P O P U L A R S C I E N C E
PSC0613_Energy_7_Wind_R2.indd 57 4/24/13 10:25 AM
T H E F U T U R E O F E N E R G Y
STORY BY CURTIS BR AINARD I LLUSTR ATION BY GR AHAM MURDOCH
58 / POPULAR SCIENCE / JUNE 2013
Hydraulic fracturing and horizontal drilling have opened up huge reservoirs of oil and gas across the U.S. The Energy Information Administration predicts that production of shale gas in particular will continue to rise steeply, increasing 44 percent between 2011 and 2040. If fossil fuels are to remain a large part of the nation’s energy mix, engineers need to reduce their environmental impacts.
O I L G A SA N D
▶ Oil and gas companies send millions of gal-
lons of pressurized water —along with chemicals
and sand —down wells to fracture shale. But the
liquid, called flowback, returns to the surface
filled with contaminants, making it unusable
for other purposes—even fracturing new wells.
Water-treatment technology is still in its “45rpm
phonograph” stage says David Burnett, a Texas
A&M petroleum engineer who oversees pilot stud-
ies of prototype systems for the Department of
Energy. Of various methods now in development,
membrane-filtration technology is especially
energy efficient and site adaptable: Engineers can
fine-tune a series of membranes to remove differ-
ent substances from water as it passes through.
Such on-site systems could reduce the need for
freshwater, critical in arid regions of the U.S.
Wastewater Treatment
THE CLOSED CYCLE
Drillers inject a fl uid (almost always water)
carrying sand and other additives into a
well at high pressures. This fractures the
rock and frees natural gas to fl ow back to
the surface—along with some of the drill-
ing fl uid and natural contaminants.
DRILLING FLUID
NATURAL GAS
FRACTURES
PSC0613_Energy_5_Fracking_R2.indd 58 4/24/13 10:24 AM
CO
UR
TE
SY
S
IE
ME
NS
JUNE 2013 / POPULAR SCIENCE / 59
A M O R E E F F I C I E N T
T U R B I N E
POWER PRODUCTION
▶ Ideally, drillers would eliminate the use of
water in hydraulic fracturing, or fracking, altogether.
A Canadian well-fracturing company called GasFrac
has developed a substitute: a gel made from lique-
fied petroleum gas (LPG) and propane. Because
it’s a hydrocarbon, the gel dissolves into the target
oil or gas and returns to the surface with the rest
of the payload. But because the gel does not
dissolve salts or clay in the shale, it doesn’t sweep
natural contaminants back out of the well. Chevron
reported that LPG used in a pilot test conducted in
Colorado in 2011 significantly increased natural-
gas production while minimizing water usage.
▶ In 2011, oil and gas operations flared or
vented almost 210 billion cubic feet of natural gas
that they couldn’t use or store—enough to heat
more than two million homes for a year. In North
Dakota’s Bakken shale formation, drillers flared or
vented 32 percent of the gas produced during oil
extraction (the national average is less than 1 per-
cent) because they lacked sufficient pipelines and
processing facilities. A consortium that includes the
National Renewable Energy Laboratory launched a
project in January to convert the surplus gas into
diesel or jet fuel. Scientists will genetically engineer
microbes that naturally feed on methane to boost
the amount of lipids they produce. They will then
convert those lipids into a feedstock that could be
piped to a refinery or used on-site.
Waterless Fracking Methane Recapture
THE HYDROCARBON FIX THE MICROBIAL RESCUE
GAS-FIRED ELECTRICITY generation grew 3 percent from 2010 to 2011 while coal-fi red generation fell 6 percent—positive trends for the climate. Burning natural gas produces half as much carbon dioxide as coal and also fewer nitrogen and sulfur oxides. More effi cient turbines could make gas even cleaner. The Siemens H-class turbine operates at higher temperatures and pressures, raising the effi ciency of a combined-cycle power plant to more than 60 percent. (The average effi ciency of gas plants in the U.S. is 42 percent.) Combined-cycle plants use both gas and steam turbines; as a result, they can ramp up and down quickly, making them good grid complements for intermittent energy sources such as wind and solar. In September 2012, GE announced that its new FlexEffi ciency gas turbines will drive a combined-cycle plant that surpasses 61 percent effi ciency.
Flaring natural gas
converts methane
to carbon dioxide,
which is a less
potent greenhouse
gas. But methane
can also leak or be
vented directly into
the atmosphere.
Tanker trucks typically
deliver between two and
fi ve million gallons of
water to fracture one well.
PSC0613_Energy_5_Fracking_R2.indd 59 4/24/13 10:24 AM
