Solar Thermal (solar water heaters)

In "solar thermal" systems, the sun heats up a fluid. The most common example is a solar water heater.

An estimated 80,000 single family homes, multi-unit dwellings and institutional facilities in Hawaii are served by solar water heaters.

According to an analysis by the National Renewable Energy Laboratory,

"... solar water heating is cost effective at any location in the Hawaiian Islands."

State income tax credits for solar water heating systems of 35 percent of the installed cost (up to stated limits and subject to reductions) are available. See the Hawaii State Tax Credit Fact Sheet.

Federal tax credits are also available: 

• Information on the Federal business investment credit (Form 3468 and instructions) may be found at: http://www.irs.ustreas.gov/formspubs/index.html.
• The residential credit may be taken for systems installed beginning 1/1/06. Information is available from the IRS: http://www.irs.gov/.

Incentives of up to $1000 per system are being offered by Hawaii's electric utilities to their customers who currently have electric water heaters; contact your local electric company for more information.

• Oahu, Maui, Molokai, Lanai, and the Big Island: see the Hawaiian Electric pages at www.heco.com.
  • HECO's list of approved solar water heating contractors
  • MECO's solar water heating program
  • HELCO's list of approved solar water heating contractors
• Residents of Kauai: see the Kauai Island Utility Cooperative (KIUC) pages at www.kiuc.coop or call KIUC at 246-8284, Monday through Friday 8AM - 4 PM.

Presentation on "Solar Water Heaters on the Big Island - Analysis of Sizing, Costs, and Customer Satisfaction" (2002).

 Solar Electric (photovoltaic or concentrating solar power)

In "photovoltaic" (PV) systems, solar cells convert the sun's energy directly into electricity. A common example of PV is a solar cell on a solar-powered calculator.

In "concentrating solar power" (CSP) systems, the energy from the sun is focused by mirrors onto a pipe or a point(receiver), using mirrors.  This heats up a fluid, which is used to run an engine which generates electricity.

State income tax credits for photovoltaic systems of 35 percent of the installed cost (up to stated limits and subject to reductions) are available. See the Department of Taxation Website (http://www.state.hi.us/tax/); the Tax Information Releases, including TIR No. 2007-02 (http://www.state.hi.us/tax/a3_1tir.htm); and the Hawaii State Tax Credit Fact Sheet.

Federal tax credits are also available:

• Information on the Federal business investment credit (Form 3468 and instructions) may be found at: http://www.irs.ustreas.gov/formspubs/index.html.
• The residential credit may be taken for systems installed beginning 1/1/06. Information is available from the IRS: http://www.irs.gov/.

Reports

Solar Maps - Maps of each island, showing solar radiation in cal/sq.cm./day; also, a conversion table from calories per square centimeters to Btu per square foot to peak sun hours per day.  

Complete list of on-line publications
Current; includes reports on renewables in general, and renewable portfolio standards, which include solar.

Links

In My Backyard (http://www.nrel.gov/eis/imby/) is a program that allows a user to understand how a residential commercial photovoltaic (PV) system will work in their area. 

The Solar Prospector (http://mercator.nrel.gov/csp/) is for concentrating solar power (CSP) and allows downloading of the direct normal (10km) irradiance data sets.

The U.S. Department of Energy's "Energy Efficiency and Renewable Energy" website (http://www.eere.energy.gov) has information on solar energy for homeowners, businesses, students, teachers, and the general public, as well as links to national laboratories and financial opportunities.

The "Find Solar" website (http://findsolar.com), co-sponsored by the US Department of Energy, the American Solar Energy Society, and the Solar Electric Power Association, helps residential and business customers to calculate solar system costs and to find solar professionals doing business in Hawaii.

The National Renewable Energy Laboratory website (http://www.nrel.gov/csp) features information about research and development efforts in concentrating solar power technologies, as well as data and resources.