I’m gratified Neil Dikeman invited me to contribute to the CleanTech Blog. I may sometimes duplicate what I say at Power, Plugs and People at HybridCars.com.

I thought I’d start with a backgrounder that will bring readers up to speed about plug-in hybrids, the existing-technology solution that has been the subject of much attention in recent months. This is a version of a column published in the Green Car Journal, the quarterly publication that’s read both by consumers and auto industry insiders.

This year, batteries and electric motors are back in the news, spurred by the popularity of gas-electric hybrids and the recognition that fuel-cell cars are electric vehicles. The plug-in hybrid (PHEV), long consigned to a footnote as an interesting but unrealistic idea, may soon enter the mainstream as an automotive option.

Here’s how our organization, The California Cars Initiative (a non-profit group of engineers, environmentalists, entrepreneurs that combines technology development and advocacy), explains how PHEVs work for drivers. “It’s like having a second small fuel tank you always use first. You fill it at home with electricity, at an equivalent cost of under $1/gallon. Your energy is cleaner, cheaper and not imported.”

Now support for PHEVs comes from unexpected places. Neoconservatives seeking rapid reductions in oil dependency. Engineers immersed in online communities. Futurists concerned about a vulnerable centralized power grid. Ethanol advocates discovering feedstock alternatives to corn. Clean-Tech investors are supportive but haven’t yet determined how to participate.

They’ve joined forces with long-time supporters like renewable energy advocates, utilities with cheap off-peak power, fleet owners eager for green cars and component suppliers seeking new markets.

One by one, objections have fallen away:

* The complexity of two systems. Today’s hybrids use advanced technology to remove components and engineer some of our highest quality and customer-value cars.

* The national power grid is too dirty. Argonne National Laboratory and other studies show electric vehicles beat out gasoline vehicles on well-to-wheel greenhouse gases.

* No one is interested. Journalists have jumped on CalCars’ and EDrive’s high-MPG conversion stories. They understand how flex-fuel PHEVs would use almost no gasoline. Admittedly, some reporters haven’t factored in electricity and biofuel costs. But when the bipartisan National Commission on Energy Policy dug into the emissions numbers and looked for achievable strategies, they gave plug-in hybrids the highest grades. Then Orrin Hatch, Barack Obama and other Senators, along with George Shultz, James Woolsey and other former Cabinet Members, hailed the 2-4 cents/ mile cost for local travel as a breakthrough this country needs.

* Car companies won’t build them. DaimlerChrysler is now completing the firstOEM PHEV prototypes. Recent statements from Toyota and Ford indicate they are weighing the concept as well. We hope at least one company will jump on the opportunity to differentiate itself, leapfrogging over current hybrids.

* Batteries cost too much and won’t last. This remains a subject of debate. Even discounting promising materials science advances, batteries are competitive through incremental but substantial technology, production and cost improvements, rising gasoline prices. Soon we’ll have data from DaimlerChrysler Sprinter vans with NiMH and Li-Ion batteries. A forthcoming Electric Power Research Institute (EPRI) study will report no technology impediments and see affordable batteries when produced in volume.

* Overly long payback. This topic is fading as many auto buyers demonstrate their willingness to pay more up front for green cars. They recognize that energy security and global warming are not simply issues of “dollars and cents at the pump”. Meanwhile, EPRI studies project lower lifetime costs for PHEVs than for any other type of car. And growing concern over the danger of further delay in reducing oil consumption led to tax credits that scale by MPG, and prompts companies like Hyperion Solutions and Timberland to subsidize employees’ hybrid purchases.

PHEVs are an extendable platform that welcomes other solutions like engine efficiencies. They can be designed for any fuel type, starting with gasoline and evolving to biodiesel, cellulosic ethanol and even hydrogen. This way, PHEVs solve both the “chicken and the egg” infrastructure dilemma and the uncertainty of predicting future technologies.

CalCars.org and our allies plan to partner with OEMs on demonstration programs. We know the auto industry can deliver. After Pearl Harbor, Detroit switched from cars and trucks to planes and tanks in a year. With PHEVs, we have the opportunity to find out how clean and efficient cars can be right now.