Only a Matter of Time? Space-Based Solar Power - Energy Smith

Review Space-baSed SolaR poweR
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Only a matter of time?
Scientists and renewable energy advocates have debated the
potential of space-based solar power (SBSP) for decades.
Now, several companies are working hard to make it a
reliable source of energy in the next decade and one utility,
PG&E, has signed a power-purchase agreement for SBSP.
Peter Sage, Director of Global Marketing and
Communications, Space Energy, Switzerland,
says that for the price it takes to build a new coal
fired power plant – approximately US$ 300 million –
his company could launch a 5 to 10 kW demonstration
SBSP plant within two years, which would jump-start
the SBSP industry. “The promise of SBSP warrants a
US$ 300 million investment”, states Sage. “It is almost
ludicrous to deny the opportunity to test the viability of
SBSP.”
SBSP has the potential to provide massive
amounts of energy and solve many global issues, he
adds. “What it can do for education, the developing
world, the water crisis, and a predetermined global
war for resources is monumental”, says Sage.
Massive potential
Space-based solar power (SBSP)
has the potential to provide massive
amounts of energy, but no actual solar
collectors have been built so far.
Photo: Space Energy
In 2007, a study by the US Defense Department’s National
Security Space Office concluded that countries
with SBSP potential could improve their energy security,
economic development, environment and overall
national security. “A single kilometre-wide band of
geosynchronous earth orbit experiences enough solar
flux in one year – approximately 212 terawattyears
(TWa) to nearly equal the amount of energy contained
within all known recoverable conventional oil
reserves on Earth today (approximately 250 TWa)”,
says the report.
Space-based solar cells are six to eight times
more efficient than comparable solar cells on the
Earth’s surface, according to Space Energy. Groundbased
solar power is limited by weather, variable seasons,
atmospheric blocking, and partial sunlight,
whereas SBSP collects solar energy 24 hours a day,
365 days a year. “That means space solar can be a
Sun & Wind Energy 10/2009

ase load resource, not an intermittent source of
power”, explains Gary Spirnak, CEO, Solaren Corporation,
California. Earth-based solar and other renewable
energy sources are intermittent, meaning they
often need natural gas or coal back up in order to provide
reliable and consistent energy to customers.
At least one utility is willing to bet on SBSP. PG&E
announced that it plans to purchase 200 MW of SBSP
from Solaren, beginning in 2016.
Hesitant investors
Despite the potential, SBSP companies face high initial
costs, including launch costs, which are the most
expensive components of the project. Launch prices
are US$ 3,000 to US$ 10,000 per pound of cargo, according
to Space Energy.
Sage hopes that governments and private launch
companies will realize the benefits of SBSP and cooperate
to reduce the high cost. Investors are wary of
backing something with such high initial launch
costs. This remains a problem for Space Energy,
which has not obtained an investor willing to risk
US$ 300 million. “We have a solid business plan for
investors, we have independent finance evaluations,
legal, technical, and financial representation, endorsements
from credible scientists, and have negotiations
with large utility firms in the US and Europe
who are interested in our power,” declares Sage.
“There is nothing else but finding the investor.”
In addition to high initial costs, finding qualified
and knowledgeable employees willing to take a risk
on space power is a challenge. “Securing personnel
and talent is hard”, says Sage. Additionally, it is difficult
for companies to find people who understand the
technical aspects of space power and the marketing
and business strategies necessary to get a business
off the ground. “There is a place for technical people,
but there is also a need for entrepreneurs”, adds
Sage. “You need to have a strong marketing and business
plan.” The key is getting investors and governments
to believe in the benefits of SPSB, which may
seem like a far-fetched idea to most people, he says.
Wireless transmission
Despite the developmental hurdles, SBSP may provide
a solution to other problems on Earth, which
may make test projects attractive to investors. Real
estate in space is still free. Purchasing land and the
land permitting process are often the most time consuming
and costly aspects of Earth-based utility scale
renewable energy projects. The only land required for
SBSP is for energy receiving stations, which can be
located near existing transmission lines. This could
reduce the delays that typically face some renewable
power developers whose projects are sited far from
existing transmission lines, explains Spirnak.
SBSP solves transmission issues because transmission
can be wireless. Energy produced in spacebased
stations is converted into radio waves at a
similar frequency to cell phone and wireless internet
Sun & Wind Energy 10/2009

Review
This is what an artist envisioned
the Solar Power Satellite
would look like. Shown is
the assembly of a microwave
transmission antenna. The
solar power satellite was to be
located in a geosynchronous
orbit, 36,000 miles above the
Earth’s surface. Photo: NASA
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Space-baSed SolaR poweR
signals – 2.4 GHz – and transmitted to collecting stations
on Earth. From these collection centers, radio
waves may be converted to energy and transmitted
along existing transmission corridors or transported
to any part of the globe via radio waves. This way, the
power can be sent to rural areas without using existing
lines or building new ones.
“There are rural areas that cannot get on the
grid”, says Sage. For example, small, remote villages,
which are not cost effective for utilities to deliver
power to, can finally get online. “Using radio waves
means the power can be delivered wirelessly. The implications
of this are huge”, he adds.
In addition to connecting remote locations with
energy, SBSP may also play an integral part in solving
the global water crisis, says Sage. Desalination – the
production of fresh water from salt water – is a viable
technology, but takes an enormous amount of energy
and is not feasible with today’s energy sources and
prices. SBSP is the only clean energy source that has
the potential to deliver the energy needed to have desalination
become a cheap and practical reality,
claims Sage.
Pioneer companies
Because of the advantages SBSP may offer in the future,
several companies are taking steps to make it a
reality. Once Space Energy finds an investor – which
Sage believes will occur this year – commercial delivery
of SBSP could be only five to seven years away. “It
will only take two years for a demonstrator and five
years for the commercial applicator”, he promises. In
15 years Space Energy could provide 15 GW of energy.
“This amount of energy isn’t going to tip the balance
on climate change, but it will kick-start the space
solar power industry,” announces Sage. “Once we
make it work, it becomes far easier for other companies
to follow our path.”
Another company, Solaren Co., is also making
progress with its 15-year power purchase agreement
with PG&E. “We are required under this power purchase
agreement to deliver the contracted 200 MW of
base load power on the contracted start date to PG&E,
and Solaren is committed to making that date”, declares
Spirnak.
New technologies
Additionally, PowerSat Corporation, Washington,
filed a patent for two technologies: BrightStar and
Solar Powered Orbital Transfer (SPOT). These two
technologies together reduce launch and operation
costs by roughly US$ 1 billion for a 2,500 MW power
station. “This patent filing is a watershed moment not
only for PowerSat but for a renewable industry that,
until now, could neither compete economically nor
generate power at the base load scale of oil or coal”,
says William Maness, CEO, PowerSat. BrightStar allows
individual solar panels to form a wireless power
transmission beam without being physically connected
to each other. Therefore, one transmission beam
may now come from hundreds of smaller panels.
SPOT propels a spacecraft into an optimal geosynchronous
earth orbit by using electronic thrusters
powered by the solar array. SPOT also decreases the
weight of the panel by 67 %, which dramatically reduces
launch costs.
If launch costs continue to drop and investors become
less hesitant about new and expensive technologies,
it is only a matter of time before the benefits of
SBSP are realized, predicts Sage. In order to meet
growing energy demand, governments and investors
will have to take risks. “Many countries now understand
that oil is a depleting resource, and to compete
in the 21st century they have to aggressively look at
all alternative resources”, says Sage.
Reid Smith, Lisa Cohn
Sun & Wind Energy 10/2009