Solar water heaters are now required on all new single-family homes constructed in Hawaii.

Starting January 1, 2010, building permits on all single-family new home construction in Hawaii may not be issued if the home does not include a solar water heating system. 

This legislation, SB644, was enacted in June of 2009; however, the state energy resources coordinator may be able to provide a variance for this requirement if:

• Installation is impracticable due to poor solar resource
• Installation is cost-prohibitive based upon a life cycle cost-benefit analysis that incorporates the average residential utility bill and the cost of the new solar water heating system with a life cycle that does not exceed 15 years
• A renewable energy technology system is substituted for use as the primary energy source for heating water; or
• A demand water heater device approved by UL is installed; provided that at least one other gas appliance is installed in the dwelling. (A "demand water heater" means a gas-tankless instantaneous water heater that provides hot water only as it is needed.)

While the legislation is already in effect, the Hawaii Public Utilities Commission must still adopt specifications for the required performance, materials, components, durability, longevity, proper sizing, installation and quality of solar water heaters.

Already, even before the impact of this new legislation is felt, there are over 65,000 solar water heaters in use in Hawaii today, including thousands on the Big Island. In fact, Hawaii ranks number one in the nation when it comes to using energy from the sun to heat water.

With an eye toward the future, Hawaii law makers understand that conventional water heaters are typically the largest electricity consumer in the average household, gobbling up nearly 40% of consumption. Hawaii's move to force solar heating is a big step for a state that relies heavily on imported fossil fuels for 90% of its supply. This bill has been a long time coming - when the legislation was first introduced five years ago, a barrel of oil cost just $40. Since then, the price has more than tripled.

Overall, solar water heating may save about $6 to $12 or more per person per month when replacing a standard electric resistance water heater. The savings, of course, will vary by household based in part on each person's hot water usage.

Using solar water heating can help keep electric rates down by also reducing electricity demand during the peak evening times from 5 p.m. to 9 p.m. when people often use hot water for washing dishes, taking showers, and so forth. To meet this evening peak demand, less efficient electricity generation units must be brought on-line by the power companies. These less efficient units cost more to run and this increase in cost is passed on to consumers.

Not surprisingly, builders and developers were against the new bill, saying it would add too much to the cost of new home constructions. Another surprising opponent was the Hawaii Solar Energy Association. Ron Richmond, with the association, said in an interview with the Star Bulletin, the new legislation would cost home buyers about $2,100 more to have the solar water heaters installed. The average solar water heater, according to the article, currently costs about $5,250, before incentives and rebates.

The length of time required to recoup your original investment (payback) will vary widely and depend on whether the purchase is paid for outright or financed and how much energy (electricity, gas, etc.) is saved. Simple payback is the length of time required to recover your investment through reduced or avoided costs. You can expect a shorter payback in areas that have higher energy costs, where the family uses a moderate to large amount of hot water per person, and for homes with more occupants. Finance charges will also lengthen the payback period.

While this new program may make some new homeowners balk at first, there are additional benefits when the cost of a solar water heating system is included in the mortgage for a home purchase. The interest rates are usually lower than on a short-term loan. In addition, the small additional increase in the monthly mortgage payment may be more than made up for in reduced energy costs (electricity or gas).

In the short run, those purchasing new homes in Hawaii may feel a pinch in their wallet upfront in having to install a solar hot water heater; however, over a short period of time, these new homeowners will easily recoup their investment. And, more importantly, by diversifying the State of Hawaii's mix of energy resources by using more renewable energy, such as solar, helps to make Hawaii less dependent on non-renewable energy sources and, in my opinion, a Greener place to live.