by Marvin Somers

Created on: March 14, 2010

Solar water heaters can save you a great deal of money in the long run. They do, however, cost a fair bit to install in the first place. Many are hesitant to do so because of the initial financial outlay, wondering whether it will be really worth it – particularly those that live in temperate climates where, they argue, the sun doesn't shine enough to make this worthwhile.

But solar hot water heaters do not require direct sunlight or hot days. All they require is daylight and they can effectively heat water even when the sky is overcast. It doesn't even have to be warm. Solar heaters in the northern reaches of the US and Canada can still produce 80-90% of your hot water needs.

Cost:

Prices for viable solar hot water systems from large commercial outfits tend to start at around $2,200, while more efficient heaters can cost around $5,000. However, it is possible to buy or build a system for around $1,000 – for example at Build It Solar.

Most developed world countries also run grant schemes that could further reduce the cost. If you are buying or remortgaging a house you can get the solar heater included in the mortgage cost, and in countries in the US you can also get an income tax deduction to offset the cost.

The US Department of energy reckons that you could pay between $13 - $20 a month on your mortgage, with reductions of around $3-$5 from income tax rebate, meaning that if the heater saves you $10-$15 a month then you'll immediately be saving. These costs are also for a commercial water heater of between $2,500 and $4,000 dollars – opt for a D.I.Y. version and you would only need to be saving $5 on your bill.

Savings:

How much you save depends on a number of factors. The two main ones are:

- What is the solar factor of your heater?

- What time of day is your peak hot water consumption?

The solar factor of your heater is a measure of the amount of energy the heater is capable of collecting and converting. This may not be as important however as size and cost when purchasing one as most heaters have a factor of at least two and this is generally sufficient to provide a good proportion of your needs.

The timing of your water consumption could play a bigger factor. If the majority of hot water consumption is after the hours of daylight, there are a couple of adjustments you can make.

Firstly, ensure that you wash and shower during daylight. The same goes for tasks such as the washing up. Secondly, make sure your house is fully insulated. During the winter, when daylight is short, you can minimise your after-daylight consumption by insulating your house so that the (free) solar energy during the day is not lost quickly when the sun sets - meaning you expend less energy after dark keeping the house warm.

It is impossible to provide an accurate figure as to how much a solar water heater will save you - in some cases it is as low as 50%, in others it is as high as 95%. A good rule of thumb is that it will cut 65-70% off your gas bill. If it doesn't, then you should investigate other potential problems in your home - such as insulation or the efficiency of your existing gas boiler.

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