comments_image Comments

Postal Service as a Giant Battery? A Plan for Cashing In

The U.S. Postal Service may earn millions by storing and stabilizing some of the nation's energy supply in its trucks.

This postfirst appeared on SolveClimate.

By trading oil for batteries, the struggling U.S. Postal Service could transform its fleet vehicles into overnight moneymakers that deliver much more than the daily mail.

The cash-strapped agency has the potential to earn millions by storing and stabilizing some of the nation’s grid energy in mail trucks during off-peak hours. The idea comes from PJM Interconnection, a regional electricity transmission organization (RTO) that transmits electricity to 13 states and the District of Columbia over 268,5000 squares miles east of the Mississippi River. PJM envisions "borrowing" the batteries of electrified fleets of postal trucks, school buses and trash trucks as cyclical energy sinks for its network.

"Right now, these fleets are just sitting idle at night," explains Kenneth Huber, PJM’s advanced technology manager. "Charging those batteries would allow us to store wind energy and also balance load and generation at the right frequency."

For that to happen, of course, plug-in and hybrid electric vehicles have to advance beyond the boutique stage.

The Obama administration has vowed that 1 million plug-ins of all varieties will be on U.S. roadways by 2015. BMW, Nissan and General Motors -- with their respective Mini E, Leaf and Chevy Volt -- are among 30-plus entrants in this potential "EV evolution." Mitsubishi announced last week that it intends to put an EV on the road for under $30,000. Early adopters in places such as San Francisco and San Jose are already leading the EV charge, and stimulus money is giving momentum to a movement that has traditionally bumbled forward in fits and starts.

On the fleet side, Ford plans to begin selling an electric fleet vehicle, the Transit Connect, late this year that will will run on lithium-ion batteries that can travel 80 miles on a single charge.

The Postal Service already has a small number of electric vehicles in its in fleet. Hypothetically, if it replaced its continental fleet of 144,000 mostly fossil-fueled delivery vehicles with battery-powered plug-ins, it could rake in annual payments between $237 million and $378 million from RTOs across the country. (More on that arithmetic later.)

Putting Wind Power to Use

Currently, plug-in owners in PJM’s service area could charge their batteries for free in the off-peak wee hours of the morning because much of the wind power generated then is going to waste.

Wind producers pump about 3,000 megawatts of clean energy into a PJM market that has a total of 164,895 megawatts of generating capacity. And Huber’s figures indicate wind generation at PJM expanding 15-fold in the not-too-distant future.

"Our storage capacity is at a minimum because we only have access to pumped hydro," explains Huber, an electrical engineer. Very few industries in PJM’s territory have on-site water supplies for that kind of energy storage, so "that’s why we’re looking at compressed air, flywheels and batteries. The idea of these vehicles being available, that would be ideal."

PJM sees potential for propelling its postal plan from paper to parking lot in the near future.

U.S. Rep. Jose Serrano (D-N.Y.) introduced legislation in December that would spur vehicle-to-grid technology and require the Department of Energy to collaborate with the Postal Service to manufacture, test and deliver 20,000 electric drive vehicles for local postal delivery. A study Serrano requested from the Office of the Inspector General last summer suggested that an initial launch of 3,000 electric postal vehicles could save the government $1,500 per vehicle every year in gas alone.

The challenge, the study pointed out, will be the initial funding. The Obama administration may be amenable to some investment, however. Just last week, the president announced that he would double the number of hybrid vehicles in the federal fleet to set an example for the nation.