Cost & Savings – Rebates & Tax Credits

Cost of the System

For residential customers you can estimate your water storage requirement by taking the number of people living in your household and multiply by 20.

Example: 4 residents x 20 gal/person = 80 Gallon System Required

Then for every 2 gallons of heated water, you’ll need at least 1 square foot of solar panel area. So for 80 gallons you’ll need a minimum of 40 square feet of panel area. Cooler and rainy areas will require more collector area.

Solar panels typically are mounted on the roof and face south between 130˚ to 230˚ orientation. Solar panels can be mounted on all types of roofs. When there is minimal sunshine, the system’s electrical backup can be automatically or manually engaged to ensure there is an ample amount of hot water.

Residential Solar Water Heating Systems typically cost $5,000 – $8,000 depending on size, area, and installation difficulty.


Rebates & Tax Credits

The Electric Company offers a rebate for Hawaii ($750), Maui ($750), Oahu ($750), and Kauai ($750).

Also, take advantage of the 35% State Tax Credit for solar water installations (Max of $2,250 for Residential Systems). And a 30% Federal Tax Credit.

Solar systems in Hawaii are very cost-effective with our abundance of energy from the sun. Solar Water systems usually have a return on investment of 1-2 year. There has never been a better time to go Solar.


For more information about residential solar water heating visit these pages…

  1. How Residential Solar Water Heating Systems Work

  2. Cost & Savings - Rebates & Tax Credits

  3. Getting Started