Dangling Rope Marina

Located mid-lake and 45 miles from the nearest road or power line, Dangling Rope Marina serves over 350,000 visitors per year. On busy summer weekends, Dangling Rope pumps over 20,000 gallons of gasoline per day, making it one of the busiest gas stations in Utah.

In 1992 Glen Canyon NRA spent over $140,000 to generate electricity for Dangling Rope Marina at an average cost of $0.38/kilowatt-hour (kWh).

Diesel generators ran 24 hours per day and consumed 65,000 gallons of diesel fuel each year to provide electricity to the marina. Fuel was delivered by barge, 35 deliveries were made annually. The generators created significant air and noise pollution at Dangling Rope Marina and exposed Glen Canyon NRA to the potential risk of a diesel fuel spill in Lake Powell.

A partnership between NPS, the Utah Department of Natural Resources and a consortium of federal, state and private energy interests was created to provide financial resources, technical engineering assistance and project management expertise necessary to install a 115 kilowatt (kW) photovoltaic/propane-hybrid power system at Dangling Rope Marina which began operation in September of 1996. In December of 1998, the array was increased to 160 kW to accommodate increased energy needs due to expanded services and increased visitation.

Project Description

The solar or photovoltaic array is rated at 160 kilowatts and generates approximately 750 kilowatt-hours per day, enough electricity to power approximately 32 Utah homes.

The PV/propane-hybrid system includes a 160 kW photovoltaic array, a 2.4 MWh battery bank, 250 kW inverter, and two 250 kW propane generators.

Installation of $22,000 of energy efficiency improvements including compact fluorescent lamps, and replacement of electric stoves, water heaters, furnaces and clothes dryers with propane-fueled appliances.

Financial participation in the initial $1.45 million project included the state of Utah ($250,000); U.S. Department of Energy -- Office of Utility Technology ($137,500), FEMP ($350,000), and Sandia National Laboratory ($175,000); PacifiCorp ($150,000); National Park Service ($343,000); ARAMARK ($40,000); and EPA ($75,000).

The $306,000 array expansion was funded by the state of Utah ($30,000); U.S. Department of Energy -- State Energy Program ($77,000); and ARAMARK ($199,000).

Results

Energy Generation Data (xls)

Diesel fuel consumption to generate electricity from 1996 to 1998 has been reduced from an estimated 75,500 gallons per year to 37,000 gallons of diesel fuel-equivalent (53,600 gallons of propane).

Generator run-time was reduced from 8,760 hours per year to 2,500 hours. Shorter run-times mean less noise and lower levels of air pollution. Air emissions were reduced by an estimated 590 tons of CO², 9,500 lbs. of NOX, and 3,000 lbs. of SOX annually.

The new 45 kW of array is estimated to save an additional 14,000 gallons of propane per year and reduce generator run time to 1,850 hours. Emissions will be reduced by an estimated 75 tons of CO², and 2,340 lbs. of NOX annually.

Reliability and power service at Dangling Rope has markedly improved. PV system availability was 99.6% during the first year.

The battery bank.	The inside of the 250 kilowatt inverter.