The National Park Service added a fourth grid-tied PV system to its maintenance building with money from green tag sales and incentives. (Photo by National Park Service)

How times change. Diesel-powered ferries once carried prisoners to a fearsome maximum security prison on Alcatraz Island in San Francisco Bay. Now, visitors ride those ferries to the Rock, and soon, wind and sun will fuel the ferries.

The National Park Service recently awarded the 10-year ferry contract to a company that committed to build two hybrid-electric passenger vessels for Alcatraz tours. Hornblower Cruises & Events, who will operate the contract as Alcatraz Cruises, proposes to put the first vessel into service within two years and the second by five years.

Designed by the Australian company SolarSailor, the hybrid ferries will be fitted with a large, rigid wing covered in solar panels. Like a hybrid car, large batteries on board will store electricity from the array and from backup diesel generators. The vessels can also be plugged into shore power to regenerate the batteries.  While loading and unloading passengers, the diesel engines will be turned off, and the vessel will run on electricity for zero emissions at the wharf. 

DOE, DOI, private businesses partner

The Alcatraz ferry contract is only one strategy in "Green Energy Parks: Making the National Parks a Showcase for a Sustainable Energy Future."

The joint program launched by the Department of Energy and Department of the Interior in 1999 promotes energy efficiency and renewable energy technologies in national parks. In the program's first year, NPS and DOE invested more than $1.5 million in 60 clean-energy projects focused on improving transportation, facilities and visitor education at parks across the country.

Americans expect their national parks to be "green," observed Steve Butterworth, energy program coordinator for NPS's Pacific West Regional Office. "Sustainability and energy go hand in hand. Energy is an umbrella term for power, fuel and water," he added.

Concessionaires, like Hornblower and other private companies that run snack bars, transportation services and in-park lodgings, are major partners in increasing the sustainability of park operations. The 1998 concession reform law required concessionaires to make substantial sustainability efforts as part of their contracts with NPS, according to Golden Gate National Recreation Area Public Affairs Officer Rich Weideman. "That can mean anything from healthy snacks, to energy-efficient systems in lodgings to recycling," he said.

Alternative transportation a greener choice

It also means alternative-fuel vehicles, currently used for concessions and park operations in 29 parks. A fleet of biodiesel-powered ships serve Channel Islands National Park, and compressed natural gas vehicles have been used in the park since 1996.

The diesel passenger shuttle at Scotts Bluff National Monument runs on B-20, a 20-percent biodiesel/80-percent petroleum diesel blend.  At Point Reyes National Seashore in Northern California, park staff drive around the park in electric vehicles.

Even where vehicles use fossil fuel, parks have found ways to reduce the impact of transportation on the environment. Weideman pointed out that the Alcatraz ferries already have diesel engines that are 80 to 90 percent more efficient than average vessels.

 Zion National Park in southwest Utah unveiled its own transit system in 2000. At the time, more than 2,000 cars and buses arrived at the park on any given day and competed for only 400 parking spaces. The park partnered with the near-by community of Springdale to use existing infrastructure, cutting down on the need for new construction. Now, visitors can take propane-powered shuttle buses from Springdale to a new state-of-the-art, energy-efficient Visitor Transit Center and then through Zion Canyon.

Facilities retrofitted for efficiency

Zion's Visitor Transit Center is a showcase for energy-efficient, climate-sensitive building technology. Daylighting through clerestory windows, natural ventilation, evaporative cooling and a thermal storage wall that supplies radiant heat in colder months save the National Park Service around $14,000 in annual energy costs.

Scotts Bluff National Monument has shown that high-tech building material doesn't have to be at odds with natural surroundings. The tables, benches and trash receptacles in the park's picnic area are made of simulated wood fabricated from recycled plastic.

The parks in Butterworth's territory benefited from a $1.5 million investment from Bonneville Power Administration. Parks that are served by utilities that get all their power from BPA receive money to upgrade lighting, thermostats and control systems in offices and private concession facilities. "Some of the savings from those measures are reinvested in energy efficiency," said Butterworth.

At Point Reyes, the park reused and restored historic structures with sustainable materials such as linoleum, waterless urinals and innovative paving materials. Solar panels provide power for the campgrounds and the Education Center.

Creative solutions increase renewables use

The use of renewable energy at park facilities may be Green Energy Parks' biggest success. From a 2-kW array in the Everglades to a solar hot water system at Mount Rushmore to photovoltaic pumps in Yosemite, NPS generated more than 250,000 kilowatthours of  renewable energy in the first six months of 2006 and is always on the lookout for more opportunities.

Development, however, must be balanced against the NPS's mission to preserve the beauty and integrity of America's parks and landmarks. On San Juan Island, Wash., building a solar array big enough to capture the Puget Sound sunlight would have meant encroaching on the park's cultural scenes. NPS asked Orcas Power & Light Cooperative, the park's utility, for a good site to net meter, recalled Butterworth. "We ended up building the system in its utility yard," he said. "It offsets around 10 percent of San Juan Island's power needs, with no extra work load for park staff and no intrusion onto the historic landscape."

NPS applied similar out-of-the-box thinking to get the most out of project funding. Whitman Mission National Historic Site in Walla Walla, Wash., sells green tags from its 12-kW solar system to Pacific Power. Combined with incentives from Washington’s new energy incentive program, the income financed the installation of additional panels that increased the project size by 25 percent—without using any additional funds.

Pacific Gas & Electric incentives helped Point Reyes get five PV systems with the money for four. "We reinvested part of the rebate in another system," said Butterworth. "You can make magic happen by being creative, while still being legal," he joked.

On a serious note, the energy program coordinator added, "Americans want their national parks to succeed, and sustainability is part of that success. We can be sustainable with the right combination of creativity, innovation and great partners."