7.1% of electric power comes from conventional hydroelectric while other
renewables (biomass, geothermal, solar
and wind) and other miscellaneous energy sources currently generate 3.6%. (The
rest comes from coal, petroleum, natural
gas, other gases and nuclear).
In the solar industry, 2009 market
research from Solarbuzz reports that
5.95 GW (gigawatts) of new photovoltaic
capacity was installed worldwide in
2008, an increase of 110% over 2007.
Solarbuzz said solar cell production in
China and Taiwan reached 3304 MW
(megawatts) in 2008 followed by Europe
at 1729 MW and Japan at 1172 MW in
2008. U.S. manufacturers, meanwhile,
contributed 375 MW in 2008.
Until recently China believed solar
power could not compete with coal,
according to Guardian.co.uk, but it is
now moving ahead rapidly on solar power
as part of an effort to increase renewable
energy to 20% of domestic consumption
by 2020.
As far as wind energy, installations
worldwide and here in the United States
are growing rapidly. A U.S. Department
of Energy Report (20% Wind Energy by
2030: Increasing Wind Energy’s Contribution to
U.S. Electricity Supply), addresses how this
country might achieve the goal in that
title. In China, ChinaFAQs reports that in
just the first three quarters of 2008, 5.59
GW of wind power projects were commissioned, and guardian.co.uk says plans
call for 100 GW of wind capacity by
2020.
The world leader in wind power on a
per-capita basis is Denmark. There, wind
power supplies more than 20% of electricity consumption, and that number will
be 50% by 2025, according to the Danish Wind Power Association.
Meanwhile, the geothermal industry
may be helped along in the U.S. by recent
government activity. Last fall, the U.S.
Department of Energy announced up to
$338 million in Recovery Act funding for
exploring and developing new geothermal fields and research into
advanced geothermal technologies. These
grants will support 123 projects in 39
states, with recipients including private
industry, academic institutions, tribal
entities, local governments and DOE’s
PHOTO: PETER CLEAVELAND
els and biomass energy. For example,
biofuel company Qteros recently reported success in using municipal sewage to
produce ethanol, and an American
Chemical Society magazine has featured
articles on converting coffee grounds to
biodiesel and producing biodiesel from
feather meal, a byproduct of the poultry
industry.
Actuators and valves stand to play an
important role in all of these alternative
forms of energy.
Figure 1. Part of the 81,000-square-foot,
904 k W solar power system on the roof of the
FedEx Express Oakland Airport international
hub
National Laboratories. The grants will be
matched more than one-for-one with an
additional $353 million in private and
non-federal cost-share funds.
Biofuels, particular corn-based
ethanol, have recently suffered from criticism that they are driving up the price
of food, followed by a crash in the industry caused by overinvestment. But biofuels are not going away any time soon.
According to the Energy Information
Administration’s Annual Energy Outlook
2009, overall consumption of marketed
renewable fuels grows by 3.3% per year,
much faster than the 0.5% annual
growth in total energy use.
Researchers also regularly report
progress on new ways to produce biofu-
SOLAR: HEADED IN THE
RIGHT DIRECTION
In the valve industry, people tend to
think of actuators as a tool for operating
valves. But they are also used to move
the mirrors and collectors in utility-scale
solar power applications.
Solar energy installations fall into two
general classes: photovoltaic and solar
thermal. Photovoltaics create electricity
directly from sunlight. They are expensive to construct on a per-kilowatt basis,
and even larger projects are fairly modest
in size (Figure 1). The largest utility-scale photovoltaic installation is the 60
MW Olmedilla plant in Spain; and
recently, First Solar signed an agreement
with China for a 2 GW installation to be
built in the Mongolian desert in 2019.
The Solel Solar Field Application to Power Plant
Solar field
Oil expansion
vessel
Super
heater
Turbine
LP
Oil
heater
Hot oil loop
Steam
generator HP
Generator
Preheater Condenser
Cooling
tower
Solar
steam loop
Cooling water loop
ILLUSTRATION COURTESY OF SOLEL
Figure 2. In a solar trough field, a set of parabolic mirrors focus sunlight onto oil-filled tubes; the
heated oil then heats steam generators to produce steam for turbines. Actuators keep the
mirrored troughs pointed at the sun and stow them in case of high winds and at night.
