The Parker Ranch solar / wind hybrid power plant in Hawaii is the world’s largest hybrid solar energy project. Renewable energy projects in the state include five windfarms, a combined photovoltaic, wind and diesel plant, as well as a combined solar and wind power plant.

The US’s Pacific state of Hawaii has been the scene of many small-scale energy projects harnessing the archipelago’s potential for alternative power generation. The Hawaiian Islands are well-suited to both solar and wind power because of their climate and geographical location. Alternative power generation facilities tend to have a small power output as photovoltaic arrays or wind turbines are still fairly small in scale.

Parker Ranch solar / wind power plant

Parker Ranch and PowerLight Corporation teamed up in August 1999 to develop the world’s largest hybrid solar energy project. During the life of the project, it will save Hawaii from the effects of burning 30,000 barrels of oil and emitting 20,000t of CO₂.

Parker Ranch is using the PowerTracker system manufactured by PowerLight Corporation. Power Tracker is a tracking photovoltaic (PV) structure that provides up to 30% more energy than fixed PV structures, providing energy to either stand-alone or grid-connected systems.

Parker Ranch’s PV system can produce up to 209kW under peak sun conditions. The system array is made up of 476 photovoltaic modules, arranged in 17 rows of 28, and rotates on a single axis to track the motion of the sun. This tracking allows the system to produce up to 29% more energy than a stationary array of the same size.

The system was built in five months. According to the company, the solar panels will pay for themselves in ten years, thereafter providing free electricity for up to two decades, while saving 70,000 barrels of oil. Parker Ranch is saving $10,000 a month on a $20,000 power bill.

Upolu Point and Kahua Rach windfarms

In early 2001, the Hawaii Electric Light Company signed an agreement to buy power from a wind farm on Upolu Point. Site Constructors, a Californian company, built the 3MW, $8 million wind farm.

“During the life of the project, it will save Hawaii from the effects of burning 30,000 barrels of oil and emitting 20,000t of CO₂.”

Kahua Power Partners and Zond Pacific Inc were also behind a wind project planned for the Kahua Ranch site. Zond Pacific was a subsidiary of Enron Wind Turbines, and the project was delayed when Enron was bankrupted (Wind Energy assumed the assets of Zond Pacific). Each of the turbines was to generate 750kW. According to the contract between Zond and Hawaii Electric Light Company, the wind energy would cost the utility 5c/kWh. In December 2003, the project was terminated.

The same site already has a small power plant that is not connected to the grid. This existing project has three 10kW Bergey wind turbines, a 10kWPV array, and a 30kW diesel generator, in conjunction with a battery bank and a pumped hydro system. It supplies power to a greenhouse and eleven homes and shops on the ranch.

McGregor Point and Kauai windfarms

Zond Pacific built 27 wind turbines at McGregor Point. Each turbine has a footprint of about 9 acres. They are all mounted on 50ft (15m) tall towers. Each of these turbines generates 750kW, so the overall output will be more than 20MW. The turbines are in Kaheawa Pastures, a remote Conservation District area. The project was postponed after Enron’s bankruptcy but has since been resumed, essentially unchanged.

Kaua’i Electric Company and an Idaho firm, Pacific Winds Inc, are developing the Kaua’i Wind Project. The purchase of Kauai Electric by the Kauai Island Utility Cooperative has been completed. When constructed, the 10MW plant will be the island’s biggest renewable energy source. The project will operate under a 20-year power contract. Pacific Winds is working on onsite development and permitting activities. This project is expected to be online in 2005, but more time may be required.

Lalamilo and South Point wind power plants

Hawaiian Electric Industries’ Lalamilo Wind Farm is located in Waikoloa on the Island of Hawaii. It has an output of about 2.3MW. The plant uses Jacobs power turbines for this. 26 of the turbines have a capacity of 17.5kW. The rest of the output comes from 55 20kW turbines. The plant normally runs around 60 turbines, which is significantly below its nominal capacity.

The South Point wind power plant belongs to Apollo Energy. It has 37 Mitsubishi 250kW wind machines. Currently, about 24 of the machines are operating, although some of these may be repowered.

Related Projects