Welcome to the Energy Blog

  • The Energy Blog is where all topics relating to The Energy Revolution are presented. Increasingly, expensive oil, coal and global warming are causing an energy revolution by requiring fossil fuels to be supplemented by alternative energy sources and by requiring changes in lifestyle. Please contact me with your comments and questions. Further Information about me can be found HERE.



After Gutenberg

Clean Break

The Oil Drum


Blog powered by Typepad

« BRI Announces Plans for Two Ethanol Plants | Main | New, Inexpensive Process Converts Sugars to Hydrogen »

May 12, 2006



I have read a number of articles on this site relating to plug-in hybrids, and the apparent support for the concept among the various readers of this blog.
My question is: what is the efficiency of these vehicles in plug-in mode? I.e., what is the distance travelled per KWh used? It is only on that basis that you can assess the cost effectiveness, and the environmental desireability of this innovation.
There have been some past comments that referred to the use of cheap power at night, in the 2 cent range, for example. But if there were wholesale adoption of plug-in hybrids, there would also be significant impacts on the electricity system, and the stability of that night time price should not be assumed. Moreover, the US gets more than 50% of its electricity from low efficiency and very dirty coal-fired plants. Running these more to produce incremental power for plug-in hybrids is not necessarily environmentally efficient.
I don't know the answers to these questions, but it seems to me that answers would help clarify the issues.


The Prius uses roughly 200 watt-hours per mile.

Plug-ins are a perfect match for wind power, which needs storage. Wind power is already providing 40% of new generation in the US.


As with anything, this may not be the perfect solution - but is a step in the right direction. Perhaps (I know - I am a dreamer!) the roof of these "Plug-ins" could be covered with PV cells and the batteries could be partially charged by the sun. I take Pelino's comments seriously - gasoline burning cars are really no worse than "electric" cars, if the electricity is created using even more damaging generation techniques.

Wind power and solar are part of the solution.


Here is the economics of a home based solar/wind system charging a plugin.

The typical electric power consumption is 10,000 kwh per year per home.

Cut that in half for a super insulated, smaller home that features solar/wind heating/cooling and the latest flat screen tv/computer technology, mini-flourescent lighting, and energy efficient appliances.

Typical gasoline consumption for a very efficient car is around 8 gallons per week. Figure 500 gallons per year to be safe. A conservative estimate of 7.5 kwh, in a plugin vehicle, equal to one gallon of gas in a gas powered car means that around 4000 kwh would more than do it.

That original 10,000 kwh per year would power this system. A rooftop and parking area solar system that produces electric power and heat, combined with a home sized wind system could produce enough power to do this in many locations. And actually produce enough extra to sell into the grid to offset remote charging of the plugin car too.

Wind, water, and solar power on a larger scale could power the homes, buildings, and vehicles not covered by their own systems. These larger installations could also power industrial and commercial applications.

Only a fraction of a percent of land and sea area would be needed to do the job. It's a shame that the capital needed to acomplish this is squandered on oil wars, wasting energy, and the greenhouse gas destruction of life as we know it here on spaceship earth.

Were even the subsidies to the oil industry alone given to homeowners instead, to install these systems and purchase plugins, the capital needed would naturally flow to meet the demand created.

The resulting mass production would bring costs down impelling a frenzy of investment.

Like the former booms created by techological advances, but powered by renewable energy, providing a sustainable growth curve rather than the boom and bust of former economic cycles based on less substantial footing.


From my research, a battery electric vehicle or plug-in hybrid running in EV mode using Lithium-ion batteries* are 525% more efficient than a comperable size (and performance) gasoline powered ICE. Thus, an EV or PHEV in EV mode would get 115.5 miles per gallon of gasoline equivalent (i.e. 115.5 miles per 115,500 Btu (LHV)) while an equivalent gasoline ICE would get only 22 mpg. In short, EVs and HEVs are five times more efficient than ICEs.

*Note: Nickel-metal hydride batteries are much less efficient than Lithium-ion batteries. NiMH bats have a coulombic efficiency of only around 66%. That means that for every 100 units of energy you put in the battery, only 66 units of useful energy come back out. Li-ion bats in contrast have a 99+% coulombic efficiency - i.e. (nearly) everything you put in comes back out again. This means that a comperable EV with NiMH instead of Li-ion batteries would get only about 3.25 times the fuel economy of an equivalent gasoline ICE. Certainly good, but not as good as Li-ion.

Harvey D.

This is good news, if Ford has real plans to build a PHEV demonstration fleet with the latest most efficient electrical energy storage units (high performance batteries + super-caps). If sucessful, other major car manufacturers will certainly follow.

Wind and Sun energies are by nature intermittent. PHEV owners will not want to wait after the Sun nor the Wind to recharge their batteries. Massive storage units will be required for a good portion of the Sun and Wind energy produced. Home/domestic storage could be a solution but most of us may not be able to afford it.

Existing and future large Hydro plants with their huge water reservoirs are ideal to store energy. Untapped, combination Hydro-Wind potential exist in many areas of Canada and could replace most of the energy expected from the Tar Sands without the associated pollution. The capital investment required may be higher (2X?) than the $75 to $100 billions being used for Tar Sands activities but both countries would win in the long run with sustainable clean power to run our PHEVs for generations to come.

The comments to this entry are closed.

. .

Batteries/Hybrid Vehicles