Greening the North American Power Grid
From what started back in 1881 by Thomas Edison, the North American electrical power grid has grown from a few copper wires buried underground in lower Manhattan to more than 150,000 miles of transmission lines today. These lines carry power from 5,400 generating plants owned by more than 3,000 utilities in an interconnected grid of 4 regional areas - Quebec, Eastern, Texas, and the Western Interconnection. Most of this electricity comes from burning fossil fuels with only 8 percent coming from hydroelectric, wind, and solar power.
Technology being used in the grid today is the same technology used in the 1960's and the electrical meter on the side of your house is 1920's technology. With demand for electricity skyrocketing, this antiquated technology is unreliable and unable to handle "greener" power supplies in the form of solar or wind energy. We have to build a grid that is "smarter" and more "self-healing" and less prone to failures. It also needs to be able to tolerate fluctuations in power sources such as solar and wind and be able to store energy for later consumption. It seems like we are asking a lot but with having ignored the grid for so long, it is time to revaluate our power grid and bring it into the 21st century. Can we make the grid greener and will this take place in our lifetime?
Using More High-Voltage Power Lines
One thing the grid needs to become greener is to install more high-voltage power lines. Currently, only 2 percent of all power lines are direct current (DC) lines - DC lines lose less power over long distances. Using more high-voltage (DC) lines will allow power to be sent to areas that need more energy from areas that can generate greener energy in the form of wind or solar.
Currently, Edison International is installing 250 miles of high-voltage lines known as the "Tehachapi Renewable Transmission Project" which will connect the Kern County, Texas wind farms to Southern California Edison. West Texas is the Saudi Arabia of wind and the Texas Interconnection cannot handle all of that energy. Another project in the works is the Tres Amigos Superstation (outside of Clovis, NM) that would allow Texas wind and Arizona sun to supply electricity to Chicago and Los Angeles. There is also talk of connecting the West, Texas and Eastern grids by a five-gigawatt capacity superconducting cable loop thus making these three grids into one.
Storing Solar and Wind Energy
Another way to make the grid greener is to be able to store the energy generated by solar, wind or hydroelectric means. Currently, the U.S. can only store about 2 percent of electricity generated from these sources. Because wind and solar power are intermittent, there needs to be a way to store this energy for use at a later date. Fueled by the government's stimulus money, there are a few technologies on the drawing board:
- Compressed Air Stored Underground - An Iowa wind farm plans to pump air into sandstone formations then release the air later to make electricity.
- Sodium-Sulfur Batteries - This technology can store a large amount of energy into a small space.
- Pumped-Storage Hydropower - Water is pumped uphill into a reservoir when demand is low and then released again when demand is high.
Making the Grid Smarter
Lastly, the grid needs to be smarter and more self-healing. The current grid works 99.7 percent of the time and power interruptions cost the American economy about $80 billion each year. A smart grid would be more automated and less prone to failures. It would also be more tolerant to variable power sources, such as wind or solar, and would even out fluctuations by using stored energy.
Also, a smarter grid would use smart meters on homes and businesses. These meters allow a consumer to get more involved in their energy use by letting them view their daily energy usage. They could cut back use when demand is high (and cost more) and use high electricity appliances when demand is low (which costs less). Unfortunately, these meters cost about $200 compared to the $40 mechanical meters with spinning dials so utility companies are not in any hurry to utilize this type of technology.
It may seem like a daunting task, but greening the grid is do-able and we are already moving in that direction. The U.S. is behind Europe in the race to utilize more renewable energy sources, but we are making steps, albeit small steps, forward. Ted Craver of Edison International was quoted as saying, "the power industry faces more change in the next ten years then we've seen in the last hundred".