Trains rolling through the San Joaquin Valley chug along on diesel power, hauling freight and passengers at speeds that range from a seeming crawl -- especially if you're stuck at a crossing -- to upward of 75 mph.
But the 220-mph passenger trains proposed by the California High-Speed Rail Authority would run on electricity, with overhead power lines providing juice along the 800-mile route connecting San Francisco, Sacramento, Los Angeles and San Diego.
If the system is ever built, it's going to take massive amounts of electricity to make those trains fly, raising questions about the power grid's ability to meet the demand. If you think your electric bill is high -- just be thankful you're not the Rail Authority.
Deep within environmental-impact reports for the system's Valley sections is a tossed salad of kilowatts, megawatts, gigawatts, BTUs and passenger miles. When combined, they form a picture of a train system that could use more than 3 billion kilowatt-hours (kWh) a year by the time it's fully operational statewide.
The average California home uses about 6,960 kWh in a year. At that rate, it would take more than 430,000 households to use what the train system would consume.
The Rail Authority believes actual demand will be less than that, spokeswoman Rachel Wall said.
"The draft EIRs have to analyze the largest possible impacts," Wall said. "That's certainly more than we anticipate using, but it ensures that we account for the most robust needs of the system."
Where will that electricity come from? How much will it cost? And in a state where summer heat forces people to crank up their air conditioners and utilities ask customers to watch their consumption, could the extra demand from trains create power shortages elsewhere?
Huge demand, cost
The 3 billion kWh needed to power California's high-speed trains by 2035 represents a little more than 1% of the state's current total electricity consumption, according to the California Energy Commission.
The trains would get their electricity from power stations plugged into the lines every 30 miles or so, pulling electricity from the same power grid that feeds California's homes, farms, businesses and cities.
The largest share of California's electricity -- about 49% -- comes from power plants that burn natural gas or coal. But in 2008, the California High-Speed Rail Authority set a goal of using 100% renewable energy -- electricity from wind, solar, biomass, small hydroelectric plants or geothermal sources -- to power the trains.
All of those renewable sources combined added up to just under 14% of California's electricity production in 2010.
But they represent about 30 billion kWh a year -- more than enough to juice the trains. And it's a number that's likely to grow as more solar, wind and other projects are developed.
Going green, however, doesn't come cheap. The Rail Authority expects to pay a premium for renewable power.
The agency estimates it will pay 17.5 cents per kilowatt-hour for electricity -- a figure that Wall said includes a surcharge of 3.5 cents for using all-renewable sources.
If the trains reach their full ridership potential and require the maximum 3 billion kWh of electricity, the bill adds up to about $531 million a year. The Rail Authority estimates that electricity will represent nearly 30% of its annual operation and maintenance cost.
The price per kilowatt-hour, Wall said, is based on studies of what several other transportation agencies in the state have paid for electricity in the past couple of years, and allows for rate increases in years to come.
"It looks like we still have a very conservative estimate, and we're optimistic that it will cover our needs in the future," Wall said.
Wall added that the authority believes prices for renewable energy will be more stable than for electricity generated by burning fossil fuels like natural gas, coal or oil.
Straining the grid?
But renewable energy still has to be fed to the trains through the power grid. And each summer, utility companies warn residents to conserve electricity to avoid power shortages.
Powering the trains "represents an electricity usage even larger than that of the more moderately sized public utilities in the state," according to a 2008 consultant's report to the authority.
And the environmental impact reports, which remain open for public comment through Oct. 13, state that "although the authority adopted a goal to power the system with clean, renewable energy, any potential impacts on electrical production [from the high-speed trains] would affect statewide electricity reserves and, to a lesser degree, transmission capacity."
But the authority's consultants say they're confident that the trains won't put undue strain on the grid.
In the summer of 2010, reports suggest that California had electricity reserves of between 18 million and 27 million kilowatts. "The projected peak demand of the [high-speed trains] is not anticipated to exceed these existing reserve amounts," the environmental reports declare.
State energy officials, however, say they don't know yet how the train system might affect statewide power supplies or grid capacity.
"At this time, we have not done any studies or incorporated any additional demand for the high-speed rail in our preliminary energy forecast," said Susanne Garfield-Jones, a spokeswoman for the California Energy Commission. "We are gathering information on high-speed to consider including in further forecasts, but this work is preliminary."