RICHLAND, Wash. – If all the cars and light trucks in the nation switched from oil to electrons, idle capacity in the existing electric power system could generate most of the electricity consumed by plug-in hybrid electric vehicles. A new study for the Department of Energy finds that
Researchers at DOE's Pacific Northwest National Laboratory also evaluated the impact of plug-in hybrid electric vehicles, or PHEVs, on foreign oil imports, the environment, electric utilities and the consumer.
"This is the first review of what the impacts would be of very high market penetrations of PHEVs, said Eric Lightner, of DOE's Office of Electric Delivery and Energy Reliability. "It's important to have this baseline knowledge as consumers are looking for more efficient vehicles, automakers are evaluating the market for PHEVs and battery manufacturers are working to improve battery life and performance."
The average commuting trip in the United States is 33 miles per day.
Current batteries for these cars can easily store the energy for driving the national average commute - about 33 miles round trip a day, so the study presumes that drivers would charge up overnight when demand for electricity is much lower.
Daily recharging would get old real fast. Every time you come home the need to plug the car into an electric socket would become an annoying chore. Plus,. some people do not live in places where this is practical. Say you live in an apartment building and park on the street or in a big lot. You may have no practical way to plug in your car. Even if you can plug in your car is that always practical? What about running an electric cable out to the car when it is raining? Works okay if you keep it in a garage. But most park their cars outside - including most who have car garages.
The areas which get their power from hydroelectric will need to build more coal or nuclear plants. Natural gas? North American production can't keep up with demand. More electric demand means more coal with smaller amounts of other types.
Researchers found, in the Midwest and East, there is sufficient off-peak generation, transmission and distribution capacity to provide for all of today's vehicles if they ran on batteries. However, in the West, and specifically the Pacific Northwest, there is limited extra electricity because of the large amount of hydroelectric generation that is already heavily utilized. Since more rain and snow can't be ordered, it's difficult to increase electricity production from the hydroelectric plants.
They didn't include nuclear plants because those operate around the clock supplying base electric demand.
"We were very conservative in looking at the idle capacity of power generation assets," said PNNL scientist Michael Kintner-Meyer. "The estimates didn't include hydro, renewables or nuclear plants. It also didn't include plants designed to meet peak demand because they don't operate continuously. We still found that across the country 84 percent of the additional electricity demand created by PHEVs could be met by idle generation capacity."
I suspect the power plants that are shut down at night have higher electric generation costs. So a shift toward using those power plants at night might raise electric costs for all purposes on average.
The coal-fired plants would emit more. But the reduction in gasoline burning might lead to a net reduction in carbon dioxide. However, a big decrease in US demand for oil would lower world prices and therefore lead to a greater demand for oil for other purposes. So I'm not as optimistic when looking at this path from a global level.
The study also looked at the impact on the environment of an all-out move to PHEVs. The added electricity would come from a combination of coal-fired and natural gas-fired plants. Even with today's power plants emitting greenhouse gases, the overall levels would be reduced because the entire process of moving a car one mile is more efficient using electricity than producing gasoline and burning it in a car's engine.
More coal burning means more sulfur emissions. It also means more mercur, particulates, and other pollutants.
Total sulfur dioxide emissions would increase in the near term due to sulfur content in coal. However, urban air quality would actually improve since the pollutants are emitted from power plants that are generally located outside cities. In the long run, according to the report, the steady demand for electricity is likely to result in investments in much cleaner power plants, even if coal remains the dominant fuel for our electricity production.
Newer electric plants could be built to tougher emissions requirements if the political will exists to make that happen. More stringent requirements on emissions from coal fired plants will push more new construction toward nuclear power plants. Tougher emissions regulations would raise the cost per kilowatt-hour of electricity.
"With cars charging overnight, the utilities would get a new market for their product. PHEVs would increase residential consumption of electricity by about 30 - 40 percent. The increased generation could lead to replacing aging coal-fired plants sooner with newer, more environmentally friendly versions," said Kintner-Meyer.
"The potential for lowering greenhouse gases further is quite substantial because it is far less expensive to capture emissions at the smokestack than the tailpipe. Vehicles are one of the most intractable problems facing policymakers seeking to reduce greenhouse gas emissions," said Pratt.
Big power plants can have big emissions control equipment and highly skilled technical staff to manage the equipment. The capture and management of sulfur, mercury, particulates, carbon dioxide, and other pollutants is far easier than with cars running on gasoline.
If utilities were to change their rate structures to charge more during periods of high demand and less during periods of low demand (aka dynamic pricing) then pluggable hybrids would pay off more quickly and people would move toward them more quickly.
Finally, the study looked at the economic impact on consumers. Since, PHEVs are expected to cost about $6,000 to $10,000 more than existing vehicles - mostly due to the cost of batteries -- researchers evaluated how long it might take owners to break even on fuel costs. Depending on the price of gas and the cost of electricity, estimates range from five to eight years - about the current lifespan of a battery. Pratt notes that utilities could offer a lower price per kilowatt hour on off-peak power, making PHEVs even more attractive to consumers.
The pluggable hybrids could be connected to electric sockets with smart electronic switches that waited till electric prices dropped below some settable minimum before starting to charge.
Dynamic pricing combined with pluggable hybrids that can easily respond to pricing changes will do something else too: They will create more growth potential for energy sources that are not reliable. Wind and solar photovoltaics will both become more useful if a large portion of the demand for electricity was highly responsive to pricing changes. Pluggable hybrids will provide such a use for electric power.
To make pluggable hybrids most effective we need better batteries. Venture capital start-ups and established companies are chasing that goal. I'm confident the battery advances will come. The growing demand for hybrid vehicles has provided the financial incentive to invest in better battery technology.
We also need regulatory reform in the electric power market to make dynamic pricing a reality. Here I'm less optimistic. Government regulators and electric utilities don't have much incentive to push through a shift to dynamic pricing and I do not expect the public to be excited about it.
Update: A large increase in the demand for over night electricity would tend to cause a phase out of electric generator plants that provide peak power (notably natural gas burners) in favor of base line electric power generators (mostly coal and nuclear). Why? Because the base load suppliers are cheaper per kwh but only if they can run constantly. Coal and especially nuclear plants cost more to build but use cheaper fuel. They need to operate constantly to pay for their higher capital costs.
The exact mix of coal versus nuclear is going to depend on the regulatory environment and on technological advances. Tougher emissions regulations will favor nuclear. Technological advances might lower the costs of one more than the other. My guess is that nuclear has a greater potential for cost declines from technological advances. But when will those technological advances come?
|Share |||Randall Parker, 2006 December 11 08:53 PM Energy Electric Cars|