New Directions in Transmission
2010 - Salvatore Salamone - Energybiz insider
around the world, there is a growing need to move what is expected to be significant
amounts of wind, solar and hydro-generated electricity from sparsely populated
remote regions to the cities where demand is great.
This has ignited a
quest for new high-voltage and ultra-high-voltage transmission systems that can
carry more electricity longer distances. And to be sure these systems work properly,
there is a growing need for test facilities to evaluate and certify the new transmission
products and technologies.
Certainly, the idea of ultra-high-voltage transmission
systems is not new. There have been many notable deployments in Russia and Japan,
and experimental systems are being tried in several countries.
is now added urgency to deploying such systems. "Our electricity is going to be
generated farther away from its use," said Bill Babcock, director of the utilities
practice at the consulting firm LECG. "You have losses moving power long distances,
so if you are putting in a new system, use the best or most efficient transmission
That's the reason for the new interest in new ultra-high-voltage
transmission systems. Their desirable properties are a good match for anticipated
new generation scenarios. AC and DC ultra-high-voltage transmission systems have
rated voltages of 1,000 kilovolts alternating current, 800 kilovolts direct current
or more. And the higher voltage systems can carry more power longer distances
with less loss than their lower voltage counterparts.
nicely complement new generation worldwide. Countries such as China and India
are expected to vastly increase power generation of all sorts. Europe, Africa,
and the Americas are expected to add significant renewable capacity to meet mandates
that, in many countries, demand that 20 percent of the power come from renewable
sources. In the United States, it's not just getting solar from the southwest
to New England or wind energy from the Dakotas to New Jersey, there is also a
desire to get hydro power from Quebec to Boston and wind power from sparsely populated
Hawaiian Islands to the population centers.
In China, vast hydroelectric
power resources in the west and coal plants in the northwest are expected to help
meet the country's booming demand for electricity. That demand is and will be
primarily in urban areas in the east and south. Ultra-high-voltage transmission
systems offer lower power loss over great distances, thus making a great fit for
"China's explosive load growth is a classic case of generation
in one region, load center in another," said Wade Malcolm, transmission and smart
grids director, utilities industry group at Accenture.
address this issue, the State Grid Corporation of China plans to invest more than
$14 billion in the next three to four years to build and expand an ultra-high-voltage
network. Longer-term, the country anticipates investing about $88 billion in ultra-high-voltage
development between now and 2020.
Through the work of the State Grid, currently
one ultra-high-voltage transmission circuit is operational and three more are
To support the higher voltage transmissions requires
new switchgear. To that end, about three years ago the State Grid Corporation
of China set out to demonstrate the feasibility of AC power transmissions at ultra-high
Over a two-year period, switchgear provider ABB, working with
Chinese technology partner Xian Shiky High Voltage Electric, designed, tested,
and commissioned gas-insulated switchgear for the project. Pushing the envelope
further, ABB more recently commissioned switchgear rated to handle more than 1
million volts. According to ABB, "The equipment has a switching capability of
6,900 megawatts, which means it can turn power equivalent to the average electrical
consumption of Switzerland, a country with more than 7 million inhabitants, on
or off within milliseconds."
One point that has emerged in this work is
the need for testing and certification to keep pace with the new products and
technologies. "The move to higher voltage transmission impacts transformers, breakers,
and other transmission and distribution equipment," said Mike Bahrman, ABB's high-voltage
and ultra-high-voltage transmission expert. "As we go to higher frequencies, there
are all sorts of new standards, testing standards, and test requirements."
pointed out that testing is really a people business, meaning technicians must
be competent, possess special skills and know the certification process.
help meet the demand for the testing and certification, KEMA opened a new lab
in the Netherlands last year. At the lab's opening, Peter Bus, managing director
of KEMA's transmission and distribution testing services, said, "We expect the
lab to play a major role in helping companies worldwide make strategic decisions
about infrastructure development."
The new facility will function as an
independent laboratory for testing and certification of high- and medium-voltage
components used in electrical infrastructure. From the lab, KEMA will issue type
test certificates and reports for tests on cables, cable accessories, insulators,
power transformers, instrument transformers, switchgear, gas-insulated switchgear
Although the move to high-voltage and ultra-high-voltage transmission
seems to be a sure thing, other scenarios might or should be considered. For one,
alternative technologies might play a role. For example, several transmission
system demonstrations and trials are going on around the world using superconducting
cables. Such cables offer very low loss and very high capacity. They are likely
to find use in urban settings such as New York City, where they would carry electricity
shorter distances than the ultra-high-voltage circuits.
And, although they
are not a major factor now, conservation and energy efficiency efforts could help
reduce power demands. However, few think the reductions would be significant enough
to negate the need for the new ultra-high-voltage systems.