Frequently Asked Questions

1. What is a Plug-in Hybrid Electric Vehicle, and how is it different from other cars?
Simply put, a plug-in hybrid electric vehicle (plug-in hybrid or PHEV) is a hybrid vehicle whose battery you can charge by plugging in to a standard 120 volt outlet at home or work. Commercially available hybrids charge their batteries through the running of the engine and brakes. Electric vehicles use batteries that are charged through outlets, but don’t have alternate ways to charge the battery, thus limiting the range they can travel (increasing the size of the battery to increase the distance has its limits, and unlike filling up the gas tank, charging the battery can take at least a few hours, depending on the size of the battery). Plug-in hybrids combine the best of electric vehicle and hybrid vehicle technologies. You get the benefits of short trip zero car emission travel coupled with extended range limited only by the availability of gas stations.

2. What is a flex fuel hybrid car?
Flex fuel hybrids allow you to use alternate fuels (biodiesel or ethanol E-85, for example) as opposed to regular gasoline to power the motor. These alternate fuels produce lower CO2 emissions than regular gasoline.

3. Why is Google.org interested in plug-in hybrids?
The integration of hybrid cars with the electric power grid could reduce gasoline consumption by 85 billion gallons per year. That’s equal to a 27% reduction in total U.S. greenhouse gases, 52% displacement potential of U.S. oil imports, and $270 billion avoided in gasoline expenses (see http://www.pnl.gov/energy/eed/etd/pdfs/phev_feasibility_analysis_combined.pdf).

4. Will plug-in hybrids require the construction of new power plants?
Actually, studies have shown that our current electricity grid could power three quarters of the nation’s 217 million passenger vehicles.

5. Is battery technology capable of powering electrical vehicles?
Today’s batteries have the necessary power and energy density to provide the performance and range requirements for common driving duty cycles. Plus, battery technology continues to improve rapidly while costs decline.

6. Where can I buy a plug-in hybrid?
Plug-in hybrids are not currently commercially available. GM has created a concept car - the Chevrolet Volt, and is taking comments from consumers about plug-in hybrid production on its website. Toyota has also publicly stated they are interested in plug-in hybrid technology.

At this time, the only way to get a plug-in hybrid is to retrofit an existing hybrid vehicle through a conversion company.  To get more information on whether or not this is possible in your area, or to learn more about the conversion companies that exist today, please check out our collaborators page.

7. What is 'the Grid'?
'The Grid'’ is the term used to describe the system of junctions and power lines that enables outlets to draw power. In most cases, this is a system that the utility companies use to deliver power to your home or office. There are some systems which are closed grids that may be fed power via a generator or other device versus the utility company.  

8. What is a Smart Grid?
A 'smart grid' is one that has the capability to send power in multiple directions based on the supply and demand. In most cases, energy flows in one direction – from the power company to an outlet. However, if you have the capability to generate excess power (via a solar panel for example), you can either store it for later use in a battery or you can send it back into the grid. A 'smart grid’ would be a system where energy flows could be managed with multiple sources of power connected to it. So, if the system could tell that it was cheaper or cleaner to get power from a solar panel versus a coal fired power plant and while still meeting energy demands, we would have much smarter grid.  

9. What is Vehicle to Grid (V2G)?
Vehicle to grid is a concept where electricity that is stored or generated from a vehicle could be transmitted to the grid if the vehicle is plugged in.  Similar to what is done with solar panels, excess electricity could be sent back in to the grid.  In cases where this is set up, the utilities will pay for the power they are receiving.  

10. Why is V2G and smart grid technology important?
Think about how a plug-in hybrid can manage its energy to run – it can start by only using the motor powered by its battery. Once it runs out of that energy, it can switch to the regular engine or a combination of that engine and an electric motor that runs from power generated from the operation of the vehicle. Similarly, it’s important that the utilities can do the same type of energy management – start by maxing out all the sources that have the fewest emissions. This can be easy to do during low demand time periods (in the evenings and on weekends), but during peak electricity consumption times (during the day, during the week), they may need to rely on other sources that may have higher greenhouse gas emissions. If you could create a system that had enough cars that were not being used during these peak times, were connected to the grid, and had the capability to send this excess energy back into the grid, or into another source that might use other energy, you would prevent the need to use less clean energy sources.  

11. Why does mileage vary so much between vehicles and between trips?
The Google fleet includes hundreds of drivers who take out the plug-ins under a variety of driving conditions. On some trips, drivers have recorded over 100 miles per gallon, while on other trips, drivers have recorded much lower mileage. Often, low mileage is due to driver error (i.e. plug-in hybrid system switched off or failure to recharge the night before).

Some examples:

(Note: mileages shown are estimates with accuracy of approximately +- 10%, based on fuel usage data reported by the vehicle computer)

12. Why don't some cars show data yet?
Some cars have been added recently to the fleet and have not yet been refueled, so it is not possible to calculate an average miles per gallon. These cars have not yet been included in the fleet average, but will be once refueling data is available. For all cars, individual trip data may sometimes be missing if our experimental data acquisition system failed to transmit data properly to the server. This does not affect the average miles per gallon calculation.

13. How can I learn more about the RechargeIT cars?
Please check out the Our Fleet section of the website, where you will find pictures and data that we have for each vehicle in the fleet. There is also more technical information about how the cars were converted and the systems that were put in place to track the data.  

14. How can I learn more about plug-in hybrids or V2G?
Please check out the Resources section of the website. There you will find reading materials, references, partner lists and other materials that will help you learn more about this subject.

For media inquiries, please email press@google.com.