Why not solar hot water?
Solar hot water systems are basic technology, A box sits on a roof with a special black coating. Water is pumped by electricity into the box, gets heated by the sun and then flows into a hot water tank. The homeowners use the hot water until it runs out. They don’t have to pay the cost of using electricity to warm up a heating element until the water in the tank is hot. Instead of paying $1200 per year for hot water, thanks to natural sunlight the homeowner pays $120. The basic technology has been in existence since 1909.
A US Navy study found that a typical residence of 4 people would save 7 barrels of oil per household with solar thermal technology. Estimating that there are now nearly 90,000 units installed in Hawaii thats a savings of 160,000 MW a year enough to power roughly 22,000 homes forever.
One would think that this is such simple technology with such clear benefits that everyone would want to make use of it. This is like getting $1000 in additional income every year. And in the beginning people thought so - a state program offered generous tax credit incentives starting in 1977 and demand soared.
The benefits were considered so positive that in 2008 installing solar hot water was made mandatory in the construction of all new homes in Hawaii. The change was implemented in 2010.
So why did the installation of solar hot water heaters then stall so completely that by 2018 more natural gas hook ups were made to heat hot water than solar hot water tanks were installed?
Politics
Builders complained that hot water heaters added $7,000 in costs for new homes when they could have installed natural gas to heat water for under $500. This was why builders lobbied the state government to allow builders to get a variance or exception made from the existing law. Once the variance law was passed virtually all the exemptions were granted.
But there were other reasons as well
* Developers and managers of rental properties complained of bad experiences with leaky hot water tanks. One installer consistently installed systems and then forgot to turn them on.
* For small households with one or two people a solar thermal system is rather uneconomical.
*Many people just want to use solar panels – even though they are more expensive. Because they have been successfully promoted.
* It was hard to find a reliable contractor to put in solar hot water.
The variance meant that instead of saving fossil fuels Hawaii was encouraging the use of natural gas most of which came from fracking.
However, a successful lawsuit brought by Earthjustice in 2020 against the waiver was successful.
The problems with solar hot water adoption could be reversed if there were new tax incentives committed for it and good promotion.
Today solar hot water heaters are once again required to be used on new homes in Hawaii. And there is no waiver. Unfortunately there is not much enthusiasm either.
