Plug-in-Hybrids in 4 Parts

What's all this talk about Plug-In Hybrid Cars? (Part I)

You may have heard of General Motors' plan to develop a "Plug-In Hybrid Electric Vehicle" (PHEV) as soon as they can (Chevy Volt). Toyota is also working on such a car. This is an important move for all U.S. drivers because it can transfer much of the energy that autos use from oil to electricity, cut toxic air pollution, and reduce global warming. A major automaker has finally recognized the importance of this technology after 4 years of pressure from several grass-roots organizations. Just what are PHEVs and what makes them so important to our future?

You have probably heard of Hybrid Electric Vehicles (HEVs), which have both an engine that burns fuel and an electric motor that draws power from a large battery. This almost doubles the fuel economy of the car (40 to 50 mpg is typical). The engine can run at a more constant speed because the electric motor gives extra power when needed and generates power to store in the battery when slowing down. So what's different about PHEVs? The simple answer is the battery is 5 times bigger and the car can run on battery-only for the first 30 miles or so (called a PHEV-30). The battery must be charged from an ordinary outlet at night, but the typical cost for this first 30 miles is about 35 cents/day. When the battery is discharged the engine takes over and works like a normal hybrid electric car. Many people have a daily commute of less than 30 miles, and with a mix of long and short trips PHEVs get over 100 mpg of gas (plus the cost of recharging the battery at night). You may forget how to pump gas, since a 12 gallon tank would take you 1200 miles. Next time: Why are 100 MPG cars so important to America?



Why are 100 MPG cars so important to America? (Part II)

That wasn't a misprint last week. Plug-in Hybrid Electric Vehicles (PHEVs) can get 100 mpg of gasoline (but you also have to pay for the electricity to recharge them... about 35 cents a day. This car can have a huge impact on building a sustainable energy future! Studies show that gas powered cars are dirtier than present electric power plants... and the electric plants are getting cleaner every day. Every time someone signs up for CT Clean Power, more clean renewable energy is added to the grid. Beyond that, PHEVs helps us reduce our huge volume of imported oil by 4, which drains money from our economy, makes us vulnerable to supply interruptions, pollutes our skies and increases global climate change. We are a particular problem because even though we are only 1/20 of the world's population we use 1/4 of the world's oil. So if we can cut our use by 4, we can have a big impact on all of the problems related to our energy use.

But there is another important reason we must cut our fuel use by 75%: it will enable us to use Biofuels. They are fuels we can make from crops we grow and plant wastes. Last year 1/6 of the US corn crop was converted into ethanol, raising market prices and making farming a viable business. But this year new ethanol plants are being built that don't use food crops, but instead use plant wastes or grasses grown on marginal land. If we can cut our fuel use to 1/4 of what we use now, we have a chance to grow our way to energy independence. But we must reduce our use by 3/4 because there is not enough land in the US to grow enough for the amount we use now. Next time: Can we make a 500 mpg car?


Can we really make 500 mpg Plug-In Hybrid Cars? (Part III)

Last time we talked about these PHEV cars that get 100 mpg in typical use, if you recharge the battery overnight. We also said that we could use ethanol made from crop wastes in such cars and make a car that gets 500 mpg of gasoline. But this biofuel isn't magic; it will not suddenly make Plug-in Hybrids get 500 mpg. But only 15% of the ethanol fuel is gasoline (called E-85); the other 85% is made from U.S.-grown plant material from farm and urban wastes. So the PHEV burning E-85 fuel gets 500 mpg for every gallon of imported gasoline (plus electricity for charging, plus the ethanol fuel). But remember that the money we spend buying ethanol, unlike gasoline, stays in the US economy, providing good jobs in farm communities and more income for farmers.

Won't the burning of any fuel release carbon dioxide, the troublesome greenhouse gas that's changing our climate? That is true, but if we cut our use by 75% through efficiency, we would only emit 25% of today's CO2 amounts. Even more important, the CO2 emitted by biofuels made from plant matter is re-absorbed by the next season's plant growth; they are called "carbon neutral". Unlike oil extraction, the process can continue indefinitely. Moreover, we already have enough electric capacity at night, when electric demand drops off, to charge our car batteries even if 84% of our cars were PHEVs. We don't need a whole new fuel supply system for them. The air would be cleaner and the planet's climate problems could level off and perhaps decline. By the way, prototype PHEVs exist now, usually made by converting hybrid cars like the Toyota Prius. One was made by a battery company right here in Danbury, Connecticut (electroenergy.com). Next Time: It sounds great, so when can I buy one?




When Will We Be Able to Buy 500 mpg Plug-in Hybrid Cars? (Part IV)

So if Plug-in Hybrids (PHEVs) can quadruple auto mileage, dramatically cut oil imports, give us cleaner air, reduce global warming, and enable us to rebuild our economy by growing crops that will fuel our cars, mostly with ethanol, what are we waiting for? When will they be in showrooms? While there are a few dozen prototypes on the road now, none were built by the auto companies. The carmakers are being dragged into the business by grass-root efforts from California and Texas, which have worked tirelessly to explain the benefits and build a broad consensus in favor of the technology. But GM and Toyota won't say when they will go on sale. Why? They feel the batteries are not quite ready. The batteries for PHEVs will have to be light and powerful, and most importantly, durable under daily full-discharge cycles and wide temperature swings.

Right now this means only Lithium Ion batteries (as in your cell phone and laptop PC) can give a 30 or 40 mile electric-only range, but no one is making a battery large enough for this application, and there have been some well-known problems with laptop batteries. So there are some unanswered technical questions. The answer seems to be to build a group of test cars, probably for fleet buyers, and develop a way to insure all parties against the risk of battery failures. There are quite a few companies developing large capacity batteries which are expected to have the safety and durability needed. GM has contracted with two joint-venture producers for delivery later this year, and testing can then begin. It seems likely that the cars could go on sale within the next 3 years. Like the current hybrid cars, PHEVs may take 5 to 10 years for their fuel savings to pay for their extra costs, but they have many other benefits... to our nation's economy, to our air quality and to the global climate. Ultimately we have to make a personal moral decision about what's more important: a sunroof, GPS and leather seats, or a highly efficient drive system that can change the world, the national economy and our local environment.