Low-Profile Solar Hot Water

If you can't or won't place a solar hot-water tank on your roof, you can have a low-profile solar hot water system instead. In this type of hot water service, only the solar panels are placed up on the roof. Your insulated hot-water storage tank goes inside the home where neighbors can't see it — unless you invite them in to your place to check it out.

This low-profile solar installation still needs panels on the roof, and they have to face the midday sun. if at all possible. Since the solar hot water panel can usually be bolted directly to the rafters under your roof tiles, the panels do not stick out and catch the eye very much. Most people will see them, for sure, but won't think anything special about it.

In this installation on a two-storey residence in Sydney Australia, the cold water inlet can clearly be seen on the lower left corner of the two solar hot water panels. The outlet for the heated water, warmed naturally by the sun, is on the upper right.

This solar water heater is not a passive system, where the hot water flows upwards by natural convection. (It works because hot water is slightly lighter than cold water. So the water rises, just like hot air rises.)

This type of home installation needs to be an active system. It uses an electric water pump to force the cold water upstairs and into the solar panels on the rooftop. The pressure of this incoming water then forces the warmed-up water out the outlet connection on top of the panels. There a pipe leads it back down and into the insulated hot-water storage tank inside the building.

Even though it is solar, the hot water tank usually has its own water heating system, which may be gas burning or an electric heating element. This heating system will be heavily used during winter, and on rainy or cloudy days when there is little direct sunlight (and heat) striking the hot water solar panels. On warm, sunny days you can even choose to turn the heating element off.

There is no doubt that having solar hot-water panels on your roof will cut your heating bill down ... by quite a lot, as long as you get your fair share of sunshine.