We were very interested to read a question posted here by Jon Wellinghoff, a commissioner with the Federal Energy Regulatory Commission. Mr. Wellinghoff asks, basically, about plans to equip a production version of the Prius Plug-in Electric Hybrid Vehicle (PHEV), the topic of a previous blog posting here on Open Road, for what’s called Vehicle-to-Grid (V2G) applications.

As you probably know, the V2G concept means that consumers would plug their PHEVs in overnight to get them fully charged, then drive to their destination for the day, plug them in again and allow the PHEV to feed its stored electrical power back into the energy grid.

First of all, we’re very grateful for Mr. Wellinghoff’s interest in Toyota's continuing development of our plug-in hybrid technology, and in the ways in which the Prius PHEV may fit into ideas about V2G applications.

However, we think it’s important to keep in mind that Toyota’s first priority is to continue developing its PHEV technology and then, when the technology is ready, get PHEVs into the hands of our customers. Secondly, our expertise is in building motor vehicles. It’s not in power generation. That’s something that we would prefer to leave to those best equipped to do it.

That said, as you're no doubt aware, Toyota is one of several auto makers who are developing PHEV technology. While our various approaches to solving the many challenges may differ, there is broad agreement on this: Before market-ready PHEVs can be developed, we need to develop advanced batteries that can meet the customer's expectations for performance, durability and cost. Prior to any meaningful exploration of V2G concepts, we must first resolve the very basic battery and product issues that we're addressing today.

Beyond the challenges of developing PHEV technology, electric-energy experts tell us that the hurdles for V2G concepts are significant:

- Battery performance must be 10 times higher than today's best batteries.

- PHEVs are intended to be charged from home, using existing circuitry. The grid contribution from a single car therefore is insignificant when compared to the massive size of regional grids. This means that meaningful V2G contributions will depend upon hundreds of thousands of vehicles plugged into an existing grid, all contributing grid services in some yet-to-be-defined coordinated method.

- We are unaware of any discussions concerning how to pay for the necessary infrastructure to collect the 120 VAC current from each PHEV and step it up to transmission and/or distribution voltage.

- We are also unaware of any concrete plan for insuring the safety of utility workers in light of such a massively distributed system.

- And while there are many concepts for vehicle and account identification and communication, none of these concepts are thoroughly developed.

There’s another important question, as well: In light of the uncertainty of gas prices and perhaps even future gasoline availability, will motorists want to sacrifice overall MPG by trading away their PHEV’s reserve battery power?

The automobile business is changing and will, we feel sure, require strategies, partnerships and alliances we might not even have thought of yet. We don’t even know, for sure, if PHEVs will come to market in the way in which we think they will. Indeed, that’s the point of at least some of the research now being done, using Prius PHEVs, at UC Irvine and UC Berkeley. UC Irvine, with its expertise in the technical side of these issues, is studying that, while researchers at Berkeley take a long, hard look at the human side of the equation from the point of view of the PHEV consumer.

Finally, when we discuss various pricing schemes to make the idea of V2G interesting to consumers, we must make every effort to avoid unintended consequences. We can all learn from the recent problems with the California solar roof program, where, in some cases, time-of-day rates actually increased the overall utility bills of participating customers. This had the consequence of severely reducing program participation by California consumers – the very opposite of the program’s intent.

So while the potential for V2G is another intriguing aspect of hybrid technology, we must not become sidetracked so that we lose sight of the immediate goal. That goal is to produce an affordable, reliable PHEV that can be sold in large quantities, that can be serviced at any dealership, and that will meet the needs of the American motorist.

I assure you, that’s a big enough task.