New Plug-in Hybrid Study Begs for More Questions

July 23, 2007 – Vol.12 No.18

NEW PLUG-IN HYBRID STUDY BEGS FOR MORE QUESTIONS, MORE STUDIES.

Now there are at least two major studies on the viability of plug-in hybrids (PHEVs) for the US.

The first, a 2006 study from the Department of Energy said that there’s plenty of excess, unused off-peak power on the nation’s grid to energize a fleet of tens of millions of plug-ins for part of a day’s driving, say 20 miles or so.

Now there’s a second important study, this time from the Electric Power Research Institute (EPRI) and the Natural Resources Defense Council (NRDC).

This one says that there is an abundant supply of electricity for transportation; a 60 percent US market share for plug-ins would use 7 - 8 percent of grid-supplied electricity in 2050.

The grid will be cleaner by then, as well. With cleaner powerplants and more renewable power, plug-ins can improve nationwide air quality by running on less petroleum and utilizing that cleaner power from the grid. Plug-ins, with that 60 percent market share, would reduce petroleum consumption by 3 million to 4 million barrels per day in 2050.

Greenhouse gases would be cut too, more than 450 million metric tons annually in 2050. That’s the same as removing 82.5 million passenger cars from the road.

The two studies bolster support for PHEV’s. Yet there seems to be room for more studies if all automakers and lawmakers are to be convinced to jump full tilt on the plug-in bandwagon. More studies need to answer more questions.

For example:

--- How many vehicle owners/drivers have the facility to plug-in a car at home? To achieve the high fuel economy the vehicles need to plugged into the power grid for an extended period, presumably overnight at home. How many vehicle owners have parking spots (such as a driveway or garage) near their homes where they can plug in? What’s the national census on driveways?

--- If city dwellers wanted plug-ins, how many cities would permit dedicated parking spots in front of people’s homes to allow the installation of recharging equipment? City dwellers, with only on-street parking (who, by the way, would get the best use of plug-ins - driving locally, only short distances on all-electric zero pollution power) might not be able to own plug-ins because of their inability to charge them from their homes. Will municipalities build public use recharging stations in residential areas or allow residents to install their own?

--- And what about apartment or condominium dwellers who park vehicles in parking lots or garages? Will building owners or condominium associations install charging equipment for them?

--- Will batteries be ready? All eyes are now on lithium technology. But what if the cost of lithium batteries can’t be brought down to affordable levels? Can alternative battery chemistry be used in place of lithium? Already Toyota has scrapped plans to use lithium in its next generation Prius and will continue to use nickel metal hydride (NiMH) batteries. Will NiMH batteries be OK for plug-ins?

--- If lithium chemistry does improve, is there enough lithium on the planet to supply batteries for hundreds of millions of cars and trucks?

--- And, jumping back to the battery affordability question, what will a plug-in hybrid with its large battery pack cost? How much more than a conventional hybrid? (The cost of the battery may determine the cost of the vehicle.)

--- And where can biofuels fit in? How much could plug-ins, with their dramatically better fuel economy, stretch existing and planned production of ethanol and biodiesel leading to greater energy independence? It seems as though the plug-ins and biofuels could complement each other. Just how much?

More questions that need more answers, certainly, but the more questions answered the greater the likelihood that automakers will steer in a single direction - rather than the many that they’ve been going in for years.

Links:

The EPRI-NRDC study

http://www.epri-reports.org

The DOE study

http://www.pnl.gov/energy/eed/etd/pdfs/phev_feasibility_analysis_combined.pdf