How to Fix Global Warming

Posted by Jeffrey St. Clair on December 19th, 2008 | Link

HOW TO FIX GLOBAL WARMING AND GAIN ENERGY SECURITY

By Peter Montague

A detailed new report from Stanford University reviews and ranks
major energy-related solutions to global warming, air pollution
deaths, and energy security. The report is available now online with
extensive supplementary materials, and will soon appear in the
journal Energy & Environmental Solutions. The author is Mark Z.
Jacobson, director of the Atmosphere/Energy Program at Stanford in
Palo Alto, Calif.

[Read Stanford's press release announcing the study or this news
story from R&D Magazine, or watch a video of Mark Jacobson
discussing his new study.]

The report assumes that all U.S. gasoline-powered vehicles will shift
entirely to electric power or ethanol fuel, and it then compares 10
ways of generating the necessary electricity and two ways of making
ethanol fuel (basically, from corn or cellulose). Each of these 12
options is then evaluated against 11 different criteria and a final
ranking is calculated.

The power-source technologies considered are:

(1) Solar photovoltaics — the dark blue glassy panels that convert
sunlight directly into electricity;

(2) Concentrated solar power — arrays of mirrors (or lenses) that
focus sunlight to heat a fluid to high temperature in a collector
(such as a pipe), generating steam to turn a turbine to make
electricity;

(3) Wind turbines, each up to 5 megawatts in size, with blades 160
meters (525 feet) long, which turn a turbine to make electricity.
storing the electricity in batteries;

(4) Wind turbines making electricity (see paragraph above) but storing
the energy as hydrogen;

(5) Geothermal — extracting some of the heat that lies deep below the
surface everywhere on earth;

(6) Hydro dams — like Hoover dam — a well-known technology that
currently provides 17.5% of the world’s electricity, more than any
other single technology;

(7) Ocean wave energy — machines that move with the waves (for
example, a bobbing buoy) to generate electricity;

(8) Tidal energy — machines that extract energy from flowing tidal
waters and convert it to electricity;

(9) Nuclear power plants that split (fission) atoms of enriched
uranium, or plutonium, to generate heat to boil water to turn a
turbine to make electricity;

(10) Coal-fired power plants that burn pulverized coal, which could be
fitted with end-of-pipe filters to capture carbon dioxide gas,
compress it into a liquid, pipe it to a “suitable location” and bury
it a mile or so underground, hoping it will stay there forever.

(11) Ethanol (alcohol) made from corn (or from sugarcane, wheat, sugar
beets or molasses);

(12) Ethanol made from cellulose (switch grass; wood waste; wheat or
corn stalks; other stalks; or miscanthus grasses).

The report evaluates each of these 12 sources of energy by 11
different criteria, as follows:

(1) Abundance of the resource; each of these resources is available in
vast quantities but some are far more abundant than others. Solar
photovoltaics lead the pack by far — converting just 1% of available
sunlight to electricity could supply more than the world’s total power
needs (not just the world’s electricity needs). Wind power is
abundant, too: available wind power is five time as large as the
world’s total energy needs and 20 times as large as the world’s
electricity needs.

(2) Climate-relevant emissions (carbon dioxide, plus other greenhouse
gases, such as methane, converted to their carbon-dioxide equivalent
based on their global-warming potential). This is expressed as grams
of CO2-equivalent emitted per kiloWatt-hour of electricity (or
electricity equivalent, in the case of ethanol) for each of the 12
technologies. This calculation takes into consideration direct and
indirect emissions throughout the life cycle of a machine (whether a
wind turbine or a nuclear power plant).

The study factors in “opportunity cost emissions” — emissions that
will occur from existing dirty sources of power during the delay
period while new machines are being brought online. For example, a
wind farm can be brought online in 2-5 years but a nuclear power plant
requires 10 to 19 years and a coal-with-CCS plant requires 6 to 11
years. Thus a wind farm can displace existing CO2 and air pollution
emissions much faster than either nuclear or coal-with-CCS, raising
the “opportunity costs” of nuclear and coal plants because of inherent
delays in construction.

The results in this section are startling. For example, coal-with-
carbon-capture emits 60 times as much CO2 as wind energy for each
kiloWatt-hour of electricity generated,

(3) Human deaths from air pollution are calculated for each of the 12
technologies; here corn and cellulosic ethanol fare worst, with coal-
with-CCS and nuclear second-worst. Wind-power is best by far. This
report breaks new ground, tackling some of the difficult questions
surrounding proliferation of nuclear power plants, which unavoidably
increase the odds that some time in the next 30 years a rogue nuclear
weapon will be detonated with great loss of life.

(4) The “footprint” of each technology — the area of land and/or
ocean required. Here the ethanols fare far worse than all the others.

(5) Spacing — This is the area required by the “footprint” (see
preceding paragraph) plus the spacing needed between
installations of wind, tidal, wave and nuclear plants (which require
security buffers).

(6) Water use; again the ethanols are far worse than any of the
alternatives;

(7) Effects on wildlife and the natural environment are considered
separately for each of the 12 technologies. Here we can only hit the
highlights of this long section of the report. For example, this
section explicitly addresses the concern that wind turbines kill large
numbers of bats and birds each year. The report concludes that, in the
worst case, if 1.4 to 2.3 million 5-megawatt wind turbines were
installed worldwide to eliminate all human-created CO2
emissions, total global bird kill would be 1.4 to 14 million birds per
year. This large number represents less than 1% of birds killed each
year by humans including by communication towers and their guy wires
(which birds smash into at night, attracted by lights), window panes,
and pet cats or former-pet feral cats. Although killing 1.4 to 14
million birds per year is not trivial, it can be weighed against
eliminating enough air pollution to save an estimated 2.4 million
human lives each year and a large (though not well-quantified)
reduction in harm to wildlife by eliminating toxic air and water
pollution. Wild animals, including birds, are harmed by pollution just
as humans are.

(8) Thermal pollution — heat released from machines locally –
particularly nuclear and coal plants — often as hot water from
cooling towers;

(9) Releases of toxic chemicals and radioactive materials; again,
wildlife and humans would both benefit very substantially if we
replaced existing fossil-fueled technologies and nuclear technologies
with cleaner alternatives.

(10) Energy supply disruption. It is important to evaluate the
potential of each technology to be disrupted by terrorism, war, or
natural disaster. Here the dispersed technologies (wind, solar
photovoltaics, wave and tidal) fare best and the most centralized
(nuclear, coal-with-CCS, and concentrated solar) fare worst.

(11) Intermittency. This is an important consideration because we need
power 24/7 but the sun does not shine at night and the wind sometimes
dies down at any given locale.

The issue of intermittency is crucial to the success of power systems
dependent on wind and sun, and the report treats it as an engineering
problem that can be solved. The report says, “Whether or not
intermittency affects the power supply depends on whether effort[s] to
reduce intermittency are made.” The report then describes 5 ways to
reduce intermittency:

(a) Interconnecting geographically-dispersed naturally-intermittent
energy sources (e.g., wind, solar, wave, tidal). The author of this
report, Mark Z. Jacobson, published an earlier detailed study of the
reliability benefits that could be gained by modernizing the
transmission grid to interconnect dispersed energy sources;

(b) Use a reliable energy source, such as hydro dams, or geothermal
power plants, to smooth out supply or to match demand;

(c) Use smart meters to provide maximum electric power to charging
vehicle batteries when power generation is high, reducing the power to
charging vehicle batteries at other times, thus smoothing out demand
to match supply;

(d) Store electric power for later use; electricity can be stored as
hydrogen, or in the batteries of all the electric vehicles plugged
into the grid at any moment; or as pumped hydroelectric storage (water
pumped uphill at night runs back down during the day, generating
power); or as compressed air in underground vaults or turbine
nacelles; or in flywheels; or in molten salts (as is being done with
some concentrated solar plants today). The disadvantage of stored
power is conversion losses in both directions rather than just one.

(e) Forecast short-term weather to plan better for energy needs; in
many locales, with a good database of measurements, weather can be
forecast one to four days in advance with good accuracy, helping grid
managers anticipate both demand and supply.

The 12 energy sources are rated on the 11 criteria and then a
weighting factor is applied. The weighting factor indicates the
importance of the criterion — global warming and air pollution deaths
are given a weight of 22, while thermal pollution has a weight of 1.
The weighting factors themselves sum to 100. Then a total rank is
calculated (1 is best, 12 is worst) assuming that all vehicles in the
U.S. are converted to electricity and powered by the particular
technology being ranked.

The Results: Hand Me the Envelope, Please

Wind-powered battery-electric vehicles are ranked #1, best by far with
a weighted average of only 2.09. Second is wind-powered hydrogen-
storage vehicles (weighted average, 3.22); third is concentrated
solar-powered battery-electric vehicles (weighted average, 4.28);
fourth place goes to geothermal-powered battery-electric vehicles
(weighted average, 4.60); fifth is tidal-powered battery-electric
vehicles (weighted average, 4.97); sixth is photo-voltaic-powered
battery-electric vehicles (weighted average, 5.26); seventh is wave-
powered battery- electric vehicles (weighted average, 6.11); eighth
place goes to hydro- dam-powered battery-electric vehicles (weighted
average, 8.40); ninth place goes to two technologies that are tied
with equal scores — nuclear powered battery-electric vehicles
(weighted average, 8.50) and coal-with-CCS-powered battery-electric
vehicles (weighted average, 8.47); 11th place goes to vehicles powered
by corn-based E-85 fuels (weighted average, 10.6) and 12th place
goes to vehicles burning cellulose-derived E85 fuel (weighted average,
10.7).

According to the report, both methods of producing ethanol make the
global warming problem worse, not better. Given that the U.S. Congress
has bet the farm on ethanol (so to speak), this finding does not
inspire confidence that Congress will make rational choices based on
the kind of data found in this report. Where is the Congressional
Office of Technology Assessment when you need it? (Gone the way of the
Dodo bird in 1995, during the reign of Newt Gingrich.)

To get all this into perspective, the report points out that we could
power all our light-duty and heavy-duty gasoline-powered vehicles with
wind — by converting them to electricity and supplying their power by
deploying 73,000 to 144,000 5-megawatt wind turbines. Is this doable?
Of course it is. During the four years of World War II, the U.S. built
more than 300,000 airplanes. Deploying half that number of wind
turbines is definitely doable. Is it affordable? The Stanford report
does not address questions of dollar cost. But we can do a crude
calculation: given that the U.S. economy generates roughly $14
trillion each year, even if we were to spend $2 trillion on renewable
energy during the next 15 years, it would represent less that 1% of
gross domestic product (GDP) during the period.

Deploying 144,000 wind turbines would reduce our global warming
emissions by 33% and would eliminate about 15,000 deaths from air
pollution each year in the U.S.

Carrying the argument further, the report points out that the U.S.
could eliminate 100% of its global-warming emissions by powering the
economy with 389,000 to 645,000 5-megawatt wind turbines. Going even
further, the report points out that worldwide emissions of fossil-
fuel carbon could be eliminated entirely by powering the world
economy with 2.2 to 3.6 million 5-megawatt wind turbines. No one
expects the world to rely exclusively on wind-power, but the
calculation reveals just how large and clean the wind resource really
is.

Some limitations of the study

By design, this study does not take into account energy savings that
are readily available through improved efficiencies — it only
discusses efficiencies inherent in shifting from gasoline-powered
internal combustion vehicles (with a tank to wheel efficiency of 17%)
to battery-electric vehicles with a plug-to-wheels efficiency of 86%).
It omits discussion of the many efficiencies that are readily
available at reasonable cost in the built environment, including
better insulation, less energy-intensive materials, combined heat-and-
power installations, and so on.

The study will be criticized (unfairly, it seems to me) for assuming
that we will meet the ever-expanding power demands of ever-growing
economies, rather than looking for ways to shrink demand. The purpose
of the study was to evaluate energy-supply alternatives, which it has
done remarkably well.

The study does not take into account the large number of human deaths
caused each year by burning coal and oil — including not only fine
and ultrafine particles released from smoke stacks, exhaust pipes, and
chimneys (from coal plants, diesel vehicles and oil-fired home
furnaces) but also the 120 million tons of coal combustion waste
produced each year in the U.S., most of which gets buried in the
ground somewhere, often contaminating ground water with various toxic
metals and organic compounds (polycyclic aromatic hydrocarbons,
dioxins, furans, and so on).

Despite these limitations, this is an exceedingly important study that
breaks new analytic ground and provides clear guidance for policy
makers. Unlike some previous energy studies from Stanford and
Princeton, which promoted coal-with-carbon storage and were funded by
the oil, coal and automobile industries, the present study was not
supported by any interest group, company, or government agency.

We can only hope that members of Congress — and Mr. Obama’s choice
for Secretary of Energy, Steven Chu — are sufficiently on the ball to
read this new report carefully, consider the options it evaluates, and
then act upon it in time to avert catastrophe.