A PHEV, like the Hymotion conversion of the Toyota Prius puts a larger battery in the car and you charge-it up from the mains' electricity and drive around mostly on electric charge rather than the gas engine, saving a lot of gas money.
A regular compact gas-powered car, driven 20,000kms (12,500 miles) in a mixed urban and highway commuting cycle, and which gets around 12.7 km/liter (30mpg) for fuel consumption, with gas at $1/litre ($3.79 a US gallon), costs you around $1,580 for gas per year for 1,580 liters of gas. For comparison, a present day technology Toyota Prius hybrid consumes 1019 liters of gas for the same drive cycle, so gas would cost $1,019, thereby saving $661 a year compared to the regular gas-powered compact.
The PHEV Prius only consumes 210 liters of gas and 1,375 kilowatt hours of electricity.
With electric costing around $0.08 per kilowatt-hour, the PHEV Prius will therefore cost about $210 for gas and $110 for electricity saving $1,260 a year compared to a regular gas-powered compact. A fully electric vehicle would cost less than an estimated $200 a year for electricity, and obviously zero dollars for gas and no visits to the gas pump.
Right now, a Hymotion conversion to make a Prius into a PHEV, is around US$10,000 so it would take about 8 years to get your money back unless gas goes up again in which case you will pay off the investment much faster. If gas went up by 50%, then the payback period is only 5 years. However, the biggest plus for switching to a PHEV is that pollution levels will drop a lot, especially if the electrical power comes from a renewable resource, such as hydro, wind or solar.
A compact PHEV, driving a mixed urban and highway commuting cycle of 20,000kms yearly, emits 2 tons less CO2 compared to a compact fossil fueled internal combustion engined compact vehicle, assuming aggregated emissions of around 0.14kg/kWh for the electricity from a Hydro source. The savings are not so good if you get your electricity from coal power stations. A fully electric vehicle would save more than 3.2 tons of CO2 per year. So it really does make sense to get PHEVs and EVs on the road as soon as possible to reduce overall transportation GHG emissions.
There might be another good reason for switching too if you dont like giving your money away to the government, you can deprive them of the gasoline tax money. Using Vancouver, British Columbia as an example, the tax on a $1/liter of gas is around $0.44 per liter. The provincial government loses $571 per annum for every typical regular compact replaced by a PHEV driving 20,000kms a year. BC Hydro would get an estimated $110 extra in electricity sales and some of that money goes back to the government but it doesnt cover the lost revenue in gas taxation.
If we assume a growing market of PHEVs (and electric only vehicles) then the provincial government is going to lose a lot of tax revenue from gas sales. In fact, the total taxation loss to the province of British Columbia in 2020 would be around $18million annually and by 2030 this rises to $95million annually, based on the public starting to buy PHEVs from 2010 onward, just as the Chevy Volt comes to the market.
In the U.S., there are big plans to get PHEVs on the road, including incentives such a new $7,000 tax credit for purchasing advanced PHEV and EV vehicles. The plan is to establish a national low carbon fuel standard, reduce the carbon content of fuel oils by 10% by 2020 and to require 60 billion gallons of advanced biofuels to be used by 2030. Specific PHEV policy objectives include putting 1 million PHEVs (150mpge) on the road by 2015, and make sure they are built in America.
The bottom line is, recycle your old internal combustion engine car and buy a plug-in hybrid when they come on the market in 2010, buy a completely electric vehicle, or get your hybrid converted to a plug-in.