Plug-in hybrid electric vehicles (PHEVs) can operate on an electric charge like a pure electric vehicle or under engine power like a hybrid vehicle. A PHEV’s batteries can be recharged simply by plugging the vehicle in to a standard electrical outlet. When the batteries’ charge runs low on stored energy, the vehicle's internal combustion engine takes over to either charge the batteries or directly power the vehicle.

There are two types of PHEVs:

1. parallel hybrids and;
2. series hybrids which also are known as Extended Range Electric Vehicles or EREVs.

Depending on the size of the battery, light PHEVs can recharge in five to eight hours from a conventional 120-volt AC power outlet. Vehicles with larger batteries likely will offer “quick charge” options which would recharge in less time using a 240-volt AC power supply.

PHEV technology promises benefits in fuel efficiency and economy, environmental responsibility and increased energy security.

All technologies needed to support commercial deployment of PHEVs exist today. The outstanding questions are not technical but economical. For example, further research and development is needed to reduce both the initial investment and operating costs of the batteries – typically lithium ion – currently being used.

PHEVs at AEP

AEP has integrated several PHEVs into its automotive fleet to gain first-hand experience with the vehicle's performance and their impact on AEP's own facilities and operations.

AEP's PHEVs

• AEP has converted two Toyota Prius hybrid vehicles to PHEVs and is gaining first-hand experience with the technology. The vehicles are equipped with data monitoring systems and electric meters to capture valuable information such as electrical load and fuel efficiency over varying operating conditions.
• AEP has deployed a PHEV bucket truck for line crew use in Columbus, Ohio.

In addition, AEP is working with the automotive and energy industries to bring to market a PHEV that serves the personal transportation needs of many Americans economically and with sustainable environmental responsibility.

According to the US Department of Energy, PHEVs promise benefits for customers, fleets and the nation. Advanced vehicles may have the potential to:

• Reduce fuel use and costs
• Increase energy security
• Protect public health and the environment
• Enhance the electrical system