Car rental companies have spent the past several months trying to one-up each other’s environmental initiatives, and now Hertz just announced that it plans to install solar power systems at 16 of its car rental facilities by this fall, with the intention of eventually expanding further.

Sixteen of the company’s facilities will be retrofitted with a total of over 2.3 MW of solar photovoltaic systems to begin with. The solar project was initially piloted in December at the Denver International Airport. A 1,018 panel, 235 kW system was placed there and Hertz said it is expected to produce 342,766 Kwh of AC output and will offset approximately 650,000 pounds of CO2 annually.

Currently, Hertz has 8,400 locations in 146 countries worldwide, and also operates the Advantage car rental brand at 26 U.S. airports.

The other stations being worked on are in Arizona, California, Colorado, Georgia, Maryland, Massachusetts, New Jersey, New York, and Pennsylvania.

“Hertz leads the industry in sustainable practices,” said Richard Broome, Senior Vice President of Hertz. “From our commitment to electric vehicles and other low emission vehicles to our implementation of reduced water usage and now our solar program, we are at the forefront of integrating sound environmental practices with pro-consumer service, efficiency and growth strategies.”

Earlier this year, Hertz said that it would start renting out the Chevrolet Volt extended-range electric vehicle to its customers. The company will also offer the Nissan Leaf this year at select rental locations in the U.S. and Europe, while it will start renting out the all electric Coda EV sedan in California in 2012.

It currently offers a “Green Collection” in its U.S. fleet, including the Smart ForTwo, the Toyota Prius and the Nissan Altima hybrid, CNET reports.

Not to be outdone, Enterprise, which operates Alamo Rent A Car, Enterprise Rent-A-Car, and National Car Rental brands, said it would reduce both energy use and costs by 20 percent over the next five years to 2015. The company plans to invest $150 million in that time frame to meet its goals. Enterprise has also begun to rent the Chevrolet Volt, and will be offering the Nissan LEAF and Coda EV when they become available.

As we’ve said in the past, EVs and plug-in hybrid electric vehicles fit well with car rental companies because it gives customers an opportunity to experiment with the new technology before they decide to purchase it. It also helps them learn more about charging infrastructure and the different options available to plug-in cars. Besides, most people who rent cars, use them for shorter trips, eliminating range anxiety.