California Regulators Could Kill Plug-in Hybrid Conversions

While major carmakers have dragged their heels on delivering the next big breakthrough on fuel efficiency, the plug-in hybrid, a small group of California entrepreneurs and innovators have made it possible for consumers to convert existing hybrids into plug-in cars running mostly on electricity. Yet, later this week, the California Air Resources Board (CARB) is expected to adopt new regulations that could put many of those conversion companies out of business.

Converting a conventional hybrid into a plug-in hybrid can approximately double the fuel efficiency of a Toyota Prius—from about 45 mpg to nearly 100 mpg—thus greatly reducing the greenhouse gas emissions from the vehicle. But CARB is concerned about potential increases in smog-related emissions from the converted vehicles.

Air resources board engineers are recommending that plug-in hybrids undergo extensive cold-start emissions and gasoline-evaporation testing. According to agency documents, the tests could cost between $20,000 and $125,000 depending on the number of vehicles that CARB wants each company to test. The board’s staff also wants to require the new companies to provide consumers with warranties for the changes they make to hybrids for up to ten years or 150,000 miles—despite the willingness of consumers to pay for conversions without the warranty.

Speak Up

Submit your views on the new rules directly to CARB before the meeting on Jan. 22 and 23

The new rules, which will be considered at CARB’s next meeting on January 22 and 23, will require small start-up companies offering plug-in conversion services to shoulder the costs of these expensive emissions tests.

A plug-in hybrid car is similar to a conventional hybrid vehicle—both use a gasoline engine as well as an electric motor. However, a plug-in hybrid uses larger battery packs that can be recharged by connecting to common household electricity. Plug-in hybrids can be driven for long distances—from a few miles to as much as 40 miles—without using any gasoline. Depending on the type of battery used, after-market plug-in conversions cost between approximately $7,000 and $10,000. As currently constructed, hybrids rely on the gasoline engine running for emissions-reducing components, such as the catalytic converter, to fully clean up the tailpipe emissions and burn off vapors from unused gasoline in the tank.

Potential Workarounds

Plug-in conversion companies can apply a simple technical fix to the problem: Make sure the Prius’s gasoline engine turns on when you start your car—so the catalytic converter warms up and the evaporation canisters are vented. Nonetheless, CARB wants the emissions tests, which are cost-prohibitive for the conversion companies.

Leading plug-in hybrid advocacy groups, such as CalCars, have also offered administrative solutions, such as waiving full-scale emissions tests for small conversion companies until they have completed a certain number of conversions. Until that time, these companies—many of which have only completed a dozen or so conversions—would be required to submit written documentation about emissions. “It’s simply too early for government regulation of plug-in hybrids,” said Felix Kramer, co-founder of CalCars, in an interview with the weekly East Bay Express. “Acting too soon will shut off innovation and will kill companies that are just getting started.”

Ironically, CalCars and the dozen or so conversion companies around the country demonstrated the potential of plug-in hybrids to major car companies, which have finally swung into action. The 2009 Detroit Auto Show, running through January 25, featured numerous plug-in hybrid and electric vehicles due in the next couple of years. General Motors is banking on its plug-in hybrid, the Chevy Volt, to save the ailing company. And President Obama wants to see 1 million plug-in hybrids on US roads by 2015.

Despite all the media attention about plug-in hybrids, it’s still not yet possible for an individual consumer to buy one from a car dealership. For at least the next two years, the only way to get a plug-in hybrid is to take matters into your own hands by converting an existing hybrid. If CARB passes its new rules, that option may also disappear.

“For California to be on the cutting edge of green-tech, they need to be more of an enabler than a restrictor,” said Paul Guzyk of 3Prong Power, which offers plug-in conversion services in Berkeley, Calif. “For us, the new regulations are a deal breaker.”

Update: On Jan. 23, the California Air Resources Board overruled its own staff and unanimously ordered the agency to work out a compromise with plug-in hybrid companies. The board, led by its president, Mary Nichols, ordered the air resources agency staff to devise new regulations ensuring that small startups can continue to provide conversion services. While the board refused to adopt the new regulations on aftermarket companies, it did approve emission testing rules on new car manufacturers that plan to begin selling plug-in hybrids in the next year or two.

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  • John McMillen

    CARB helped kill the electric car and now wants to kill the plug in car. Oh yeah, Dick Cheney and GW Bush just joined the panel so that’s probably why ( Wink )

  • Boom Boom

    This seems a little short-sighted. I can’t see how, with plug in technology, the overall emissions of the car would suffer. If the same engine is running for less time or working less (which is the only way it could get higher mpg), the emissions would always be lower for a given trip. There is no way that this could increase pollution.

  • Anonymous

    Yes, there is a way for a hybrid to emit higher emissions. The most emissions are durring start up of the engine. If the engine if constantly starting and stopping like the Toyota Prius, a higher (co) emission is possible. I own a Prius and the car starts and stops all the time. Whenever the car has less than 65% battery power it starts. Or when starting from a dead stop and creating more than 45% of the cars allotted torque. Even if the foot pedal is pressed down more than 75% of the full through. The answer to your comment is yes hybrids do emit higher amounts of (co) than other vehicles that only start up once a trip.

    Mind you, this is not accounting for total emissions. If one were to look on the new EPA postings on vehicles they display two sets of emissions: carbon (co) and the other is carbon byproducts.

  • Dom

    Hmm… not so fond of CARB anymore now are we… now that they’re going after a hybrid tech… this short-sightedness is what diesel fans have been facing for years now… micro-managing a promising technology that represents such a small fraction of emissions compared to the vehicle fleet as a whole…

  • Boom Boom

    If it were true that most of the (co) emissions in a Prius come from the starting, then why are the Prius (co) emissions 4.0 compared to a Yaris at 5.8? (Same size engine……)

    I’m not a engineer and don’t understand engines too well, but I’m just looking at the hard numbers.

  • Andreas

    the problem is temperature. a cold engine does not burn fuel the same as a hot one. I’m not an engineer who understands these processes too well, but basically it is true cold engines burn fuel dirtier and use more fuel for the same distance than a hot one. So there may be some truth in the statement, that cooling the engine faster or more than originally designed could increase CO2 emissions.


    Yes, this is a pretty significant development. For more background and a draft of CalCars’ testimony, see URGENT: What You Need to Know about California’s Plans to Regulate PHEV Conversions at

    – Felix Kramer, Founder, The California Cars Initiative

  • Grolf

    If we are talking about co then yes, they would emit more. But the thing that is going to sink us (literally for us low coastal folks) is CO2. That is the big issue & CARB, per their mandate, is focussing on all the emissions. & bnot giving CO2 the importance it requires. It seems to me that a plug in hybrid that starts & warms its engine once after 40 miles of electric drive is very similar to a plain hybrid that starts up as soon as you push hard on the gas. After that point, they should emit about the same since they are then operating in the same way. Even though those 40 miles of plug power may come from a coal burning power plant, they are still less carbon intense than a gasoline engine. I’m sure there is something I’m missing.

  • ex-EV1 driver

    Unfortunately, CARB, like any other bureaucracy, is stuck in the ’70’s and unable to change their mindset. They are singularly on reducing smog so they end up being a huge impediment to clean emissions. In addition to being a thorn (knife?) in the side of the PHEV folks, they have essentially killed the CNG conversion industry.

  • mike_paul

    I hope CARB is not acting on behalf of the oil companies and car manufactures as it has in the past. If so it should be replaced by a more unbiased body who will actually be concerned about air quality and the reduction of vehicle emissions.

  • RKRB

    Thanks for the useful link to the CARB website.

    I am wondering if the number of vehicles CARB wants to test would be adequate for a statistical sampling anyway. This does not seem to do much for their image — wonder how they explain such things to their kids??

  • AP

    CARB can’t act on CO2 because it doesn’t have the authority, nor should it. Why was California given special permission to create more stringent emissions laws? Because they had a (local) smog problem – not so they could try to solve global warming (which they couldn’t do anyway)!

    Global warming is a much larger problem than California, so it needs to be addressed in a different arena (the Federal level only). If Californians want to set an example and do extra to save the world, they should raise their gas tax by a dollar. California residents would then buy the more efficient vehicles CA wants to mandate, there would be no new regulations needed, and they might be able to balance their budget also.

  • RKRB

    FYI I just received an email from Dan Greenwood at 3Prongpower, which I hope was legitimate.

    ***It said the CARB voted unanimously to scrap the referenced proposal for the time being, despite the recommendations of its engineers.

    THIS IS A VICTORY FOR THE AFTERMARKET CONVERTERS and 3Prongpower, which said they could not be happier with the result.***

    So for those who took the time and energy (?) to push some electrons to the email site you listed, it looks like your efforts helped. The email said CARB received over 100 letters and emails, which is actually not very many. Those who want to eliminate the aftermarket plug-in conversions still have room for maneuvering, so keep us posted with similar info — that’s one reason we visit the hybridCars website.

  • Bruce

    It astounds me that most proponents of plug-in electric and plug-in electric hydrid cars fail to intelligently discuss the source of all of the so called “clean” electricity. The reality is that the vast majority of electricity in the USA is produced in coal fired plants. These plants are (relatively) inefficent, and produce very large amounts of CO2 for the energy delivered. Also these plants are significant sources of other serious pollutants such as SO2, NOx, VOCs and particulates. In effect by using this technology we are simply displacing tail pipe CO2 emissions with emissions of CO2 and other pollutants to the location of these plants …. and inefficently at that! When are we/you going to start to take a wider perspective on these issues so that we can properly assess the OVERALL effects of implementing this type of technology.

  • Anonymous

    I own a Prius and the car starts and stops all the time. Whenever the car has less than 65% battery power it starts. Or when starting from a dead stop and creating more than 45% of the cars allotted torque.
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  • how to become taller

    I own a Prius and the car starts and stops all the time. Whenever the car has less than 65% battery power it starts. Or when starting from a dead stop and creating more than 45% of the cars allotted torque.