POWER October 2012 - 8

Germany's Reliance on Coal Grows
This August, instead of the usual fanfare at the official commissioning
ceremony of RWE's twin-unit 2.2-GW coal-fired BoA Units
2 and 3-a $3.3 billion lignite-fired power plant in GrevenbroichNeurath
near Cologne (Figure 1)-Germany's premier of the state of
North Rhine-Westphalia, Hannelore Kraft, and the newly installed
federal minister of the environment, Peter Altmaier, requested a
rapid cutback in power production. As 400 guests watched, the
output of one unit was reportedly reduced by more than 150 MW
in five minutes, and then restored just as fast. The demonstration
was to show how quickly the plant could offset the intermittency
of wind and solar power, the officials said, proclaiming the plant
an " important element " of Germany's energy strategy.
As Kraft noted, since Chancellor Angela Merkel's government
shuttered seven of the nation's 17 nuclear plants and announced
a complete nuclear phase-out by 2022-a loss of about 12.7
GW-coal and gas have been needed to sustain the country's
future, even as it invests " heavily in renewables and distribution
systems. " Modern coal and gas plants are " indispensable " while
renewables are intermittent power sources, she said, echoing
sentiments that have been expressed commonly by politicians
countrywide of late, including Chancellor Merkel. Calling the
country's energy transformation " a huge challenge for all areas of
society, " Kraft urged cooperation among the federal government,
states, municipalities, and energy companies.
The problem is complex. Germany wants to cut its greenhouse gas
emissions by 40% from 1990 levels by 2020. After it instituted a
nuclear phase-out policy following the Fukushima crisis, Berlin envisioned
an energy future in which renewables would make up 35% of
its power profile. The other 65% would have to come from different
sources, as Environment Minister Altmaier told German publication
Die Zeit. As of 2011, however, coal's share of Germany's generation
total stood at 42.8%, compared to 18.3% for gas. And because coal
is championed by politicians and energy companies, the nation's
future reliance on the fossil fuel is likely to grow.
Several more coal units are planned by power generators in
Germany. By some estimates, 10.7 GW of coal and 1.7 GW of
gas units are under construction. Coal is winning out, for now,
because natural gas is costlier. According to Reuters, power from
coal for sale in 2013 is more than €16 ($20)/MWh more profitable
than generating it from gas. Utilities in Europe have had to postpone
plans for new gas-fired plants because weakened demand
from countries affected by the euro zone crisis has pushed prices
of wholesale European power to two-year lows. E.ON, Germany's
largest utility, for example, announced plans to shut down some
gas-fired plants in southern Germany because they aren't profitable.
Norwegian power firm Statkraft in February said it would
shutter a 430-MW gas-fired plant in the German North Sea port of
Emden for similar reasons. Even RWE has considered mothballing
older coal- and gas-fired plants, saying low power prices are putting
margins under pressure.
But coal's popularity has another surprising source. About 14
months after it set targets to procure 35% of its power from renewables
by 2020, Germany's heavily subsidized renewables sector
is already generating a full 25% of its power needs. German
solar capacity, for example, will exceed 25 GW in 2012. However,
subsidies of renewables have caused the cost of carbon permits
to collapse to historic lows, encouraging developers to expand
coal capacity, experts speculate.
8
A fall in gas prices between now and 2020 could reverse the
situation-which could be possible if, as some analysts expect,
Europe sees a surplus of conventional gas from Azerbaijan, Iraq,
and Cyprus. Germany could also increase interconnector capacity
with neighboring countries, increasing access to hydro capacity.
Experts point out, however, that this would open up the country
for more imports of electricity produced from nuclear power-an
energy source it was hoping to avoid.
Powering Curiosity on Mars-And Beyond
With the precarious descent of NASA's Mars rover Curiosity into
the Red Planet's Gale Crater a success, NASA now plans to gather
geological and environmental data from the Martian surface to
determine whether the planet has ever offered environmental
conditions favorable for life-and collect data for a manned
mission. The 1-ton, six-wheeled rover has been outfitted with
a jackhammer at the end of a 6-foot robotic arm to break up
rocks, and can scoop the sample into its onboard spectrometer,
but it can also fire its laser at a rock, vaporizing it for analysis.
It must do all this while operating on the Martian surface, where
temperatures range from freezing at the height of the Martian
summer to well into negative double digits at other times.
So how is Curiosity powered? It uses an advanced version of a
radioisotope power system (RPS) used in previous deep space probe
missions, says NASA's Mars Science Laboratory. In the most basic
terms, these are nuclear batteries-generators that produce electricity
from the natural decay of plutonium-238 using a set of solid-state
thermocouples. The thermocouples in radioisotope thermoelectric
generators (RTGs) use heat from the natural radioactive decay of
plutonium-238 to heat the hot junction of the thermocouple and
use the cold of outer space to produce a low temperature at the cold
www.powermag.com
POWER | October 2012
1. Where coal will be king. Germany's policy to phase out
nuclear power by 2022 and procure at least 35% of its power from
renewables by 2020 has encouraged developers to build more coal
plants, for a variety of reasons, even though Berlin wants to cut the
country's greenhouse gas emissions by 40% from 1990 levels by
2020. The newest are RWE's coal-fired BoA Units 2 and 3, a 2.2-GW,
$3.3 billion lignite-fired power plant in Grevenbroich-Neurath near Cologne.
Courtesy: RWE
http://www.powermag.com
POWER October 2012

Table of Contents for the Digital Edition of POWER October 2012
