The Tribune

By JOSHUA KEY

According to the US Department of Energy, 35 per cent of the average home’s electric bill is from water heating. Today, we will discuss how to reduce that: Make the Bahamas a little greener, and save money.

Why does water heating cost so much money? Regular water heaters are simply inefficient because they must heat water over and over again. Whether you are paying for Bahamas Power and Light (BPL) electricity or gas, the process is the same. Imagine you want a hot breakfast tomorrow. Would you heat the food 10 or 15 times today? It does not make sense, but we essentially do that all the time just so we can enjoy a hot shower in the morning. That is how traditional water heaters work.

When clients come into my showroom and ask about saving money on water heating, their first thought is usually to go solar. What many do not realise is that solar water heating is different from solar PV systems that you may put on your roof for electricity.

Solar PV (which stands for Photovoltaic) panels convert the sun’s light (not heat) into electricity. This is then wired into your home. However, the panels placed on your property for solar water heating are solar thermal panels. Much like a hose left in the sun heats the water within it for free, solar thermal panels in the sun automatically transfer heat to the liquid pumped through them. This is then pumped to your sinks, and showers, so that you can enjoy hot water in your home. This, by the way, is often a far more efficient way to heat water than by turning the sun’s light into electricity, only to turn it back into heat to warm water.

If you are thinking about getting solar water heating for your home or business, you will have to decide whether you want to invest in an open-loop or closed-loop system. What is the difference? In an open-loop system, it is actually your water (from your well or from the Water and Sewerage Corporation) that flows up to the solar thermal panels on your roof. It gets hot there, then flows back to a storage tank where it stays hot until you are ready to use it.

However, in a closed loop system, your water never actually flows to the thermal panels. Instead, a liquid solution (normally glycol) is pumped up to the panels, where it is heated. This then gets pumped down into the storage tank (or heat exchange tank) where the water (from your well or Water and Sewerage) is. There, the glycol flows in its own pipes, so it never mixes with the water, and back up to the roof. However, as the hot glycol solution passes through, it heats the water. As a result, you have piping hot water stored and ready to go, just like in the open-loop system.

Which system should you pick? Well, open-loop systems are normally less expensive. However, closed-loop systems are more resistant to damage from hard water. Since most clients want their solar water heater to last them decades, I normally advise closed-loop systems.

Though solar water heaters are not the only way to cut your electric bill, they deserve strong consideration. Solar water heating is a tried and true technology that has been in use for decades. In the tropical Bahamas, the sun comes up every day, and solar heaters produce warm water - even during winter.

Imagine taking up to 35 per cent of your electric bill and making it virtually disappear. There are green options to make that a reality. Find a qualified professional to help you stop wasting money on inefficient heating today.

• NB: Joshua Key is general manager for SuperGreen Solutions Bahamas, located on Wulff Road next to FYP. SuperGreen Solutions is one of the premier advisors, suppliers and installers of domestic and commercial energy efficient solutions.