Transmitting wind could permanently change energy rules
The Bulletin|Josh Meyer|January 4, 2008
[P]urchasers of green energy will find that wind energy produced in Pennsylvania is much more expensive than wind produced in, say, Montana. This mainly has to do with the location of wind resources. Montana has more areas with a higher sustained four wind than Pennsylvania. Also, since Montana is less densely populated, there are fewer troubles in siting the windfarms. The drawback, obviously, is that Montana is very far away, and electricity grids lose power over long distances. However, some researchers in Europe claim to have found a solution: DC current.
[P]urchasers of green energy will find that wind energy produced in Pennsylvania is much more expensive than wind produced in, say, Montana. This mainly has to do with the location of wind resources. Montana has more areas with a higher sustained four wind than Pennsylvania. Also, since Montana is less densely populated, there are fewer troubles in siting the windfarms. The drawback, obviously, is that Montana is very far away, and electricity grids lose power over long distances. However, some researchers in Europe claim to have found a solution: DC current.
Large electricity purchasers across the country are opting to pay a premium to purchase the electricity from renewable energy sources. The Commonwealth of Pennsylvania was awarded the Green Power Purchaser award from the Environmental Protection Agency last year for its purchase of nearly 80 million kWh of "green" energy. This equals approximately 8 percent of the total usage of the commonwealth's operational usage, up from 3.5 percent in 2005. Pennsylvania was the first state to voluntarily purchase "green" power.
Pennsylvania was also successful in recruiting the Spanish wind turbine company Gamesa to locate its U.S. headquarters and East Coast development offices in Philadelphia. This is part of an $84 million investment in …
... more [truncated due to possible copyright]Large electricity purchasers across the country are opting to pay a premium to purchase the electricity from renewable energy sources. The Commonwealth of Pennsylvania was awarded the Green Power Purchaser award from the Environmental Protection Agency last year for its purchase of nearly 80 million kWh of "green" energy. This equals approximately 8 percent of the total usage of the commonwealth's operational usage, up from 3.5 percent in 2005. Pennsylvania was the first state to voluntarily purchase "green" power.
Pennsylvania was also successful in recruiting the Spanish wind turbine company Gamesa to locate its U.S. headquarters and East Coast development offices in Philadelphia. This is part of an $84 million investment in facilities in Pennsylvania that includes the construction of 4 wind turbine manufacturing plants in the state. With the wind energy market in a strong upswing, this will certainly help the state's economy.
However, purchasers of green energy will find that wind energy produced in Pennsylvania is much more expensive than wind produced in, say, Montana.
This mainly has to do with the location of wind resources. Montana has more areas with a higher sustained four wind than Pennsylvania. Also, since Montana is less densely populated, there are fewer troubles in siting the windfarms.
The drawback, obviously, is that Montana is very far away, and electricity grids lose power over long distances. However, some researchers in Europe claim to have found a solution: DC current.
Electricity is produced by the movement of electrons. Direct current, or DC, is produced by the continuous flow of electrons in a single direction. The transmission grid in the U.S., as well as the rest of the world, is overwhelmingly AC, or alternating current. AC current is produced by electrons that move back and forth in two directions.
The use of AC current can be traced to the outcome of the "Battle of the Currents" between Thomas Edison, who favored DC, and George Westinghouse and Nikolai Tesla, who favored AC. At that time, AC was considered superior because it was cleaner (in terms of quality) and could travel better over the shorter distances needed at that time.
However, experiments done over a century ago showed that electricity could be transmitted over long distances with minimal losses through the use of high-voltage direct current (HVDC). HVDC showed the capacity to limit loss to 3 percent over 600 miles of transmission. AC current suffers energy losses due to grounding. That is why power lines are so far off the ground. However, studies show that DC power suffers only 1/40th of the loss of AC at clearance of 100 feet above ground.
The Irish wind energy company Airtricity currently owns and operates 13 wind farms with a total capacity of 455 MW throughout North America, Northern Ireland, Republic of Ireland and Scotland. The company is working on a "supergrid" project that will include 10 GW of capacity from 2,000 offshore wind turbines in the North Sea. The electricity will be transmitted via DC current to markets in the U.K., Holland and Germany. This project is designed to provide "base load" energy to markets throughout Europe, easing reliance on fossil fuels and nuclear energy. Since the grid will be interconnected, the absence of wind is not a concern, since studies show that it's always windy somewhere in Europe.
For Pennsylvania, this means that electricity purchasers can purchase inexpensive wind power from farther away. Offshore wind projects can transmit energy more efficiently, and places like Montana can become the "Saudi Arabia" of the electricity markets.
DC current could also be used to transmit electricity from solar sites in the desert to more populated areas.
The ability to transmit energy long distances will increase the United States' capacity to utilize renewable energy sources in areas of low population. This could lead to the redesign of the utility grid to optimize the dispersion of electricity across the country.