Your Personal Energy Independence

San Diego Charging Pattern.JPG

Everyone knows that gasoline is made from oil, and how much a gallon of the stuff costs at the pump, but most people would be hard pressed to accurately explain what a kilowatt-hour is, let alone what one costs, or how it was made.  Thankfully, research suggests that when people plug in their cars, they start to think differently about their energy sources and choices.  If you choose to drive on electricity, you’ll be driving free of oil, as less than one percent of our nation’s electricity is derived from petroleum.  Driving an electric car on the average U.S. electricity mix also emits only half the amount of global warming pollution as does the average new passenger vehicle.  In California, where the grid is cleaner, an electric car emits only a quarter as much.  However, many drivers are motivated to go even further and drive emission-free, often on homemade energy.  Thirty-nine percent of the first wave of California’s electric car adopters have solar on their roofs, and an additional 17 percent say they will install solar within a year.

Plugging Vehicles into Clean Energy,” a paper jointly authored by myself, Ed Pike, and Andreas Klugescheid, explores these themes.  The paper reviews research demonstrating the consumer demand for linking electric cars to clean energy, explores five voluntary pathways to connect the two, and argues that doing so would help accelerate the markets for both clean transportation and clean energy.

Researchers from the University of California at Davis and Simon Fraser University found that providing conventional car buyers participating in a design exercise the option to buy green energy caused them to buy electric cars 23 percent more frequently.[1]  Automakers are taking note.  Ford and Nissan have partnered with SunPower, and BMW has partnered with Real Goods Solar to offer their electric car customers an opportunity to install rooftop solar.  However, rooftop solar is only one of the five pathways to link plug-in cars to clean energy described in our paper.  The four others are:

1) Energy Efficiency - The cleanest and cheapest electricity is the electricity you don’t use.  Energy efficiency upgrades in both the residential and commercial contexts have the potential to completely offset the electricity required to charge a car.[2]  This type of clean energy also pays for itself, providing a steady stream of reduced utility bills.  If you’re going to buy an electric car or install a rooftop solar system, consider a home energy audit.  Energy efficiency upgrades could offset any bill increases that could result from charging your car, and allow you to install a smaller solar system than would otherwise be necessary.  If your water bucket is leaking, plug the holes before you go back to the well.

2) Off-Site Local Renewable Energy Projects – Some utilities, such as the Sacramento Municipal Utility District, offer their customers the opportunity to buy a share of the renewable electricity generated at a local facility.  This is a good option for those who wish to install their own generation, but are unable to do so.  Utilities that already offer customers this option should consider targeting electric car customers, and utilities that do not currently offer such programs may wish to do so to meet the growing demand amongst electric car customers.

 3) Renewable Energy Certificates – When the sun shines on a solar panel or the wind spins a turbine, two products are generated: 1) electrical energy; and 2) the green attributes of that energy.  If you want to buy the latter, you buy a Renewable Energy Certificate, or a “REC,” which grants you the exclusive right to make claims about the green nature of the associated electricity.  The sale of RECs provides an additional revenue stream to renewable facilities that compete against fossil generation.  If you’d like to buy RECs sufficient to match your electric car’s consumption, look for “Green-e” certified RECs.  Twenty dollars will likely buy you more than enough to offset a year’s worth of driving.  If you are the customer of a utility that offers “green pricing,” you can opt to have your electricity provider purchase RECs on your behalf for all your electricity needs.  Or, if you happen to be a BMW “Electronaut,” you can opt to have Green Mountain Energy provide you with wind energy RECs sufficient for all the driving you’re likely to do during your two-year ActiveE lease.  In sum, RECs provide a widely available, affordable, and scalable solution to connect vehicles to clean energy.

4) Facilitating the Integration of Variable Renewables – To keep the electrical grid stable at 60 Hertz, grid operators must match supply and demand continuously, exactly, and instantaneously.  The variability inherent in wind and solar generation makes that job a bit more challenging, but electric vehicles can help.  Cars are parked for the vast majority of the day, which means there’s a large window during which the charging necessary for daily driving needs can be accomplished, shifting demand to meet supply.  Time-of-use utility rates provide drivers with a financial incentive to charge during late evening and nighttime hours, when wind facilities typically are at peak production.  This is already happening in San Diego, where time-of-use utility rates combined with effective customer education and outreach have pushed 80% of vehicle charging to the hours between midnight and 5:00 AM, when electricity is cheap:


Shifting charging to off-peak hours also minimizes adverse grid impacts, mitigates the need for otherwise unnecessary investments in generation capacity, and can be accomplished with the simple timers that come in today’s electric cars.  With a little more technology, charging can also be actively managed remotely to match real-time renewable production, and in the longer term, energy from vehicle batteries could flow back into the grid to help meet peak system demand.

Bringing it all together, imagine living in a super-efficient home, driving a super-efficient, super-sexy car, both of which are fueled with cost-effective renewable electricity.  No oil, no coal, no sweat.  Now imagine that both your car and your clean energy were made here.  That’s no stretch.  Electricity is almost entirely domestically produced and electric cars are helping America reclaim its leadership in global automotive innovation.  The Chevy Volt was named the 2011 North American Car of the Year as well as the 2012 European Car of the Year, and the Tesla Model S was named 2013 Automobile of the Year by Automobile Magazine, and 2013 Car of the Year by Motortrend, whose authors conclude the Model S is proof “America can still make things. Great things.”  How can you make a great thing even better?  Plug it into clean energy.


[1] K.S. Kurani, J. Axsen, N. Caperello, K. Bedir, and J. Tyree Hagerman, Consumers, Plug-in Electric Vehicles, and Green Electricity, presented at “Plug-in Electric Vehicles and Clean Energy in California,” Sacramento, California, October 24, 2012.

[2] See references and calculations on page two of “Plugging Vehicles into Clean Energy.”

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