Frequently Asked Questions
About Plug-in Hybrid Electric Vehicles (PHEVs)
Are PHEVs available today?
There are prototypes in operation today, but there are no commercially available PHEVs on the market. DaimlerChrysler has developed and is testing a plug-in Sprinter Van prototype with an all-electric range of 20 miles. There are also many conventional hybrids, from sedans to SUVs, that have been converted to plug-ins. Some are getting up to 60 all-electric miles per charge.
Does plug-in technology work?
Yes. This has been clearly demonstrated by several sedan and SUV conversions at the Hybrid Center at the University of California at Davis.
The California non-profit California Cars modified a Toyota Prius by adding a 2.4 kWh lead-acid pack to prove that it could be done. Then, an R&D company, EnergyCS, replaced the standard 1.3 kWh battery pack with a 9 kWh battery pack. The larger battery pack was sufficient to provide half of the power needed to drive the first 60 miles each day. It’s like having a second small fuel tank, only you fill this one with electricity at an equivalent cost of under $1 per gallon, depending on your car and your electric rate. You refill at home, from an ordinary 120-volt socket, with energy that’s much cleaner and cheaper and not imported.
What’s the problem then?
The cost of the batteries needed to power a PHEV a sufficient distance is considered to be the stumbling block. However, battery technology is advancing rapidly and cost is expected to decrease with mass manufacture.
What distance must a commercially produced PHEV be able to achieve on the battery alone?
According to EPRI (Electric Power Research Institute), half the cars on U.S. roads are driven 25 miles a day or less. Consequently, a plug-in with a 25-mile all electric range could eliminate gasoline use in the daily commute of tens of millions of Americans. Furthermore drivers of PHEVs would only need to fill up with fuel a few times a year, versus the current 24-36 times a year on average.
Won’t PHEVs just replace air pollution from automobiles with air pollution from power plants?
No. In almost every conceivable power generation mix plug-ins reduce greenhouse gases and other pollutants. Additionally, emissions would be concentrated in one location that is often away from critically-endangered air sheds. Also, it is less difficult to control emissions from a relatively few number of smokestacks rather than millions of vehicle tail pipes. And, efforts to clean up coal plants and other emissions will continue. In recent decades, many power plants have been modified to lower emissions while a number of older plants have been retired. This trend has resulted in a 25% decrease in emissions from U.S. power plants over the last 25 years. This trend is continuing so emissions will continue to get cleaner over time, meaning emissions generated from electric transportation will get cleaner over time. Furthermore, an increasing share of America’s electricity is being produced by zero emission sources – wind and solar. There is a synergy between increased use of PHEVs and expanded use of wind energy. Widespread use of PHEVs in an electric system makes it easier for that system to accept more wind energy. This is because most PHEVs will be charging at night, when demand for electricity is at its lowest, and wind energy production tends to be at its highest in many parts of the country. Also, PHEV batteries can act as storage for wind energy produced at off-peak times.
What about performance? Will PHEVs be slow?
No. A Toyota Prius, modified with a larger plug-in battery, has essentially the same accelerating power and speed capability of a current hybrid.
How much more will a PHEV cost versus a comparably sized conventional hybrid?
The Electric Power Research Institute (EPRI) estimates that, with mass production, the cost of a PHEV battery will add $2,000 to $3,000 to the cost of a conventional hybrid. EPRI studies project that after considering the lower costs of fuel and maintenance, a mass-produced PHEV should provide better overall economics than either a conventional hybrid or a conventional vehicle. Battery costs are the primary reason for this incremental cost, and battery prices are likely to fall with increased production. The cost difference can be offset by federal and state tax credits and rebates designed to reward consumers for producing lower emissions and decreasing their consumption of petroleum-based fuels. Today, hybrid electric vehicle owners qualify for a one-time $2,000 Clean-Fuel Vehicle Federal tax deduction.
