How to be more efficient with your energy usage

Last time we identified simple ways of removing energy wastage by using devices that help us turn off those things that constantly use energy even when not in use — the Vampires!  

Today we are going to concentrate on the next step which is ‘Increased Efficiency’. There are two areas in our homes and businesses where we can usually make very significant gains in efficiency and those are lighting and water heating. Let’s see what the dictionary has to say on the topic of efficiency?

Efficiency: “The ratio of the energy delivered by a machine to the energy supplied for its operation”.

A lot of the devices in our homes and offices have been around for so long, without significant re-design, that our great grandparents would have no difficulty in recognizing them, let me give you a couple of examples. 

Firstly, the true dinosaur in the room, the incandescent light bulb, it has seen very little change in its overall design since the early 1930’s.

In terms of efficiency it scores very low, over 90 per cent of the energy delivered to it is converted directly to heat, less than 10 per cent is converted to light. 

If you still have incandescent light bulbs in your house or place of business there is every possibility that you may also still own a rotary phone! 

Unscrew them (not when they’re turned on or you will burn your fingers) and throw them away (responsibly, of course), replace them with low cost compact fluorescent lamps (CFL’s). 

Congratulations, you’ve just increased you lighting efficiency by almost 400 per cent. 

LED’s will give even greater efficiency but they are not yet low cost, still have reliability issues  and  do not provide as much light output (lumens) as the CFL’s so seek ‘independent’ professional advice before investing your hard earned money in LED’s.

The next dinosaur to deal with is the traditional electric water heater also known as the immersion heater. 

The origins of this common household appliance date back to the late 1800’s and the work of Thomas Edison. 

The principle is simple, pass a large electric current through a resistance element that is immersed in a tank of water and the by product is heat, a lot of it. 

The heat is transferred from the element directly to the water by virtue of the ‘immersion’. 

Overall, it is a very effective way to heat water as long as you have access to large amounts of inexpensive electricity. 

Unfortunately, as we already know, in Bermuda inexpensive electricity is about as common as the Cahow.

In Bermuda heating water typically accounts for around 25 per cent of the monthly BELCO bill so it is important to do it as efficiently as possible. 

Fortunately, modern technology has brought us some significantly more efficient solutions. 

One of the most interesting and least expensive is the heat pump water heater (HPWH) which extracts ambient heat from the surrounding air and effectively ‘condenses’ the heat into the water. 

It uses a truly renewable resource (warm air) that is available in Bermuda all day, every day and more importantly, unlike solar energy, all night every night! 

A heat pump water heater will reduce the cost of water heating by approximately 70 per cent, which on an $800 bill is worth around $140 per month. 

It also uses a natural resource that will never run out and has a zero carbon footprint. 

Solar thermal water heating is also vastly more efficient than the traditional immersion heater. 

A large thermal panel, mounted on a roof or other structure, is used to heat water using the sun; once the water is hot it is moved to a storage tank and replaced with cool water. 

Once all the water in the storage tank is hot the circulation stops to prevent the water in the tank from overheating. 

In Bermuda’s climate it is possible to produce high volumes of hot water very quickly particularly during the hottest summer months. 

The overall electricity saving, is up to 95 per cent but installation costs are typically higher than HPWH’s! n

Comments and questions to [email protected] Nick Duffy is the divisional manager for Bermuda Alternate Energy (BAE)