Solar Water Heaters for Any Budget

Photo: JoePhoto/Flickr

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It is estimated that more energy from sunlight hits the Earth in a single hour than human beings use in an entire year. Sunlight is free and abundant, so it makes sense that we would want to use it as a source of energy. However, while most people only think of solar panels that directly produce electricity, such photovoltaics (PVs) aren't the only way to harness solar energy. For many, there's a more financially and technologically viable option in the process of heating water from sunlight.

In fact, starting in 2010, all new single-family homes built in Hawaii will have to include solar water heaters (unless builders can demonstrate a compelling obstacle, such as underneath forest canopies). Some 90% of homes in Israel already have solar water heaters, and they are common in the Caribbean and on other islands.

So let's explore three options for getting your own solar water heater, so you can take advantage of the sun to offset your own home hot water needs.

Option #1 - Professional Solar Water Heater Install

The average professionally installed solar electric (PV) system will take about 30 years to pay back, even after the great federal and state solar rebates available. Solar hot water systems, on the other hand, can pay for themselves in about 10 years -- or 1/3 the time it takes to recoup the cost of solar electric. Combine that with an efficient, energy-saving tankless water heater, and you can save the cost of a professionally installed system in just a few years.

There are several reasons why you may want to go with a professionally manufactured and installed solar hot water heating system. These include convenience and high quality work, as well as confidence in the system. Note that today's units are much thinner, lighter and lower-maintenance than the giant solar water heaters you might have seen from earlier installs. Most come with 30-year warranties.

Some solar water heaters can operate throughout the winter, a great feature for areas that get sun all year round, but have low nighttime temperatures. As for the two DIY plans below, neither gives you the option of heating all year long in most parts of the world. Of course the advantage is that you can often make them yourself out of stuff from the junk pile.

Approximate cost: $10,000 for parts and installation, not including widely available rebates

A solar water heater "breadbox" design. GreenTerraFirma.com

Option #2 - Build Your Own Solar Breadbox

The most popular form of a passive solar water heater for do-it-yourselfers is the "solar batch hot water heater," or "solar breadbox," which is essentially an insulated, glass-topped box with a black water tank inside. The tank accepts cold water from your main water valve and, after warming it up, sends this pre-heated water into your household hot water tank or on-demand tankless water heater.

Breadbox style water heaters can go on the roof, but can also be placed on the ground without the use of a water pump. This is because the pressure in your household plumbing is what moves water through the unit. As with most hot water systems, you may need to drain out the system in cold months to keep it from freezing.

Approximate cost: $500

Resources to help you build your own batch solar hot water heater:
REUK
GreenTerraFirma
Save Kauai
JC Solar Homes
Build It Solar

A solar shower. Rebecca Sudduth/Flickr

Option #3 - Quick and Easy Outdoor Solar Shower

The fastest and easiest way to get solar heated water is to coil a black water hose around on your roof. Attach the input into your faucet and run the output down to a showerhead (you can even make that a low-flow showerhead). Some creative homeowners will run the hose into the house, but most just use it as an outdoor hot shower -- a perfect place to rinse off before or after a dip in the pool (make that a natural pool!), or after a hard day's work in the garden.

Even a 100-foot long hose will only hold a few gallons of water, which is why many DIY hot water shower builders will incorporate a holding tank (painted black) into the design. Just don't put this directly above your head in the shower area. Instead, set it back a little ways. A 55-gallon drum full of water can weigh about 460 pounds!

Speaking of swimming pools, the hot water inside the hose or tank at the end of the day can also be let out into your pool to warm up the water. Don't worry, you'll get another batch of free hot water tomorrow!

Approximate cost: about $50

Below are some resources to help you build your own solar hot water shower using a coiled black hose or an elevated black holding tank:
Homegrown Evolution
Build It Solar

Everett Sizemore is a full time search marketing manager for Gaiam and operates a directory of farm vacations in his spare time.

Also by Everett Sizemore: Home Solar Panels Reviewed

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