Renewable Energy Sources

Solar Energy

Hawaii is a National Leader in Solar Power

Rooftop Solar

Solar power provides a huge boost to Hawaii's efforts to build a clean energy future. The year 2010 was a banner year for customer-sited solar electric installations on Oahu, Hawaii Island and Maui County, more than doubling the number in 2009, and the trend in 2011 is to more than double installations in 2010.

Hawaiian Electric Company was again named one of the nation's Top 10 electric utilities for solar power added to its system per customer in 2010 in the Utility Solar Rankings published annually by the Solar Electric Power Association. Of 230 utilities participating, Hawaiian Electric ranked third nationally in added solar watts-per-customer.

In total solar watts per customer, Kauai Island Utility Co-op ranked second. Hawaii Electric Light Company was fourth and Maui Electric Company placed fifth, just barely behind Hawaii Electric Light Company. Hawaiian Electric Company was ninth in the nation (up from 12th in 2009) for cumulative solar power per customer. 

As of fall 2011, the Hawaiian Electric companies recorded over 43 MW of net energy metered solar installations on customer sites compared to 24 MW at the end of 2010. NEM agreements allow customers to receive full retail credit on their electric bills for excess electricity sent to the utility grid from customer-owned renewable energy systems.

In addition, the companies recorded 10 MW of solar photovoltaic in standard interconnection agreements that let customers generate power solely for on-site use and do not feed electricity into the grid.

With only the two smallest tiers of the Feed-in Tariff program in place for less than a year, FIT solar projects added another 1.2 MW and projects totaling over 36 MW are in line to join the FIT program. The third tier, for projects up to five megawatts, is before the Hawaii Public Utilities Commission for approval. The Feed-in Tariff which offers pre-established rates and standardized contract terms to make it easier for individuals, businesses, governmental entities and renewable energy developers to sell power to the utilities.

Hawaiian Electric is also pursuing utility-scale solar power. Already, Keahole Solar Power on the Hawaii Island currently operates a 500 kW concentrated solar power system (see below) and Castle & Cooke operates a photovoltaic system on Lanai currently able to produce 600 kilowatts, with the potential to expand to 1.2 megawatts once its battery system is in place.

Hawaiian Electric has signed contracts for utility-scale solar projects on Oahu with SolarPower, IC Sunshine and Kapolei Sustainable Energy Park and more are in the pipeline. For example, the utility is negotiating with Castle & Cooke and others to purchase power from four (4) five-megawatt PV installations planned for Mililani in Central Oahu.

Finally, the solar water heating program in Hawaii continues to be a resounding success. For 13 years the promotion, inspection and rebate program to encourage Hawaii homeowners to put solar water heaters on their roofs was administered by the Hawaiian Electric companies. In 2009, administration of those programs transferred to Hawaii Energy, a subsidiary of SAIC Corporation, working under contract for the Hawaii Public Utilities Commission. Hawaii continues to lead the nation in per capita solar water heaters. Today, about one in four single-family homes in Hawaii use the sun to heat all or most of the water that residents use, offsetting a significant amount of electric demand. Learn more below.

Solar Water Heating

With our clear, sunny skies, Hawaii has the most successful solar water heating program in the country. An energy efficiency rebate in addition to state and federal tax credits make solar water heating one of the smartest ways to improve a home.

Some quick facts about solar water heating in Hawaii.

  • More than an estimated 85,000 residential solar water heating systems are in operation statewide.
  • One in four single-family homes in Hawaii has solar water heating.

Homeowners who install solar water heating systems can get help with cash rebates provided by the Hawaii Energy Efficiency Program. The rebates, along with state and federal tax credits, can dramatically lower costs.

The typical household can save nearly $15 per person per month (or $600 per year for a family of four) on the home electric bill after installing solar water heating. The typical installation cost can be recovered in three to four years. After that, the savings all go right to the family budget.

Solar Photovoltaic Electricity

Photovoltaic (PV) or solar electric systems use cells made from semi-conducting silicon material to turn sunlight directly into electricity. With federal and state tax credits, decreasing costs for the PV panels and high conventional electricity costs, PV is increasingly becoming an economical option.

For more information on photovoltaic energy, contact:

Hawaii Solar Energy Association
P.O. Box 37070
Honolulu, Hawaii 96837
Tel: (808) 521 9085
Fax: (808) 847 4938

Or click here.

Concentrating Solar Power

Concentrating solar technologies are in various stages of development. CSP uses sunlight focused by a parabolic trough or dish and central receiver to produce heat or electricity. Parabolic troughs focus the sun's energy through long rectangular, curved mirrors. The mirrors move to follow the sun, focusing sunlight on a pipe running down the center of the trough. Through the pipe flows an easily heated fluid. The heated fluid becomes steam that can be used to turn a turbine to produce electricity, air conditioning or drinking water from sea water. Parabolic trough systems have been reliably operating in the U.S. for over a quarter of a century.

Concentrating photovoltaic systems use lenses to focus sunlight on high efficiency photovoltaic cells to produce electricity, thus gaining higher efficiencies than standard PV panels.

Parabolic dish systems use reflectors arranged in a dish-type pattern to focus concentrated sunlight onto a receiver located at the focal point of the dish. The sunlight heats a working fluid such as hydrogen or helium in a reciprocating engine to produce mechanical power which is then converted to electricity by a generator.

Central receiver systems, or power towers, use hundreds of mirrors called heliostats to track the sun and focus concentrated solar energy on a tower-mounted heat exchanger. The concentrated solar radiation heats water, or a molten salt that transfers heat to water, to produce steam for a conventional steam turbine cycle. Two central receiver systems were operated in the U.S. in the late 1980s and 1990s.

For more information on concentrating solar power, click here or here

Solar Research Projects Makes More Renewable Power Possible

Hawaiian Electric, Hawaii Electric Light and Maui Electric continue to initiate and support many renewable energy research and development projects to help develop these technologies and to address some of the barriers to using them.