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  • Solar PV
    Solar Photovoltaic (PV) Systems convert sunlight into electricity. You can use this electricity to power your home, business or any other building.
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  • Solar
    Hot Water
    Solar Thermal Water Heating Systems use the sun's energy to heat water for use by homes, commercial buildings and swimming pools.
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  • Solar Space
    Heating
    Solar Thermal Space Heating Systems capture the sun's energy to supplement the existing heating system for a home or commercial building.
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  • Small Wind
    Small Wind Energy Systems contain electric generators that convert wind power into clean, emissions-free power.
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  • Geothermal
    Geothermal heat pumps use the earth's energy to provide heating, cooling and hot water for residential and commercial buildings.
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  • Biomass
    & Bio Fuel
    Biomass Heating Systems generate heat from organic materials and residues. The systems are used for space heating and to heat water.
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  • Combined
    Heat & Power
    Micro Combined Heat and Power Systems are highly efficient natural gas systems that produce electricity and heat at the same time.
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Solar Hot Water

Solar Thermal Water Heating Systems use the sun's energy to heat water for use by homes, commercial buildings and swimming pools. While some solar collectors look like solar photovoltaic panels, they are quite different. Solar thermal panels do not generate electricity, but simply absorb sun's heat.

System Components

Solar water-heating systems are designed to provide large quantities of hot water for residential and commercial buildings. A typical system includes several components:

Solar collectors

The solar collectors absorb sunlight to collect heat. There are three types of solar collectors:

Evacuated Tube
Collectors
Flat Plate
Collectors
Parabolic
Collectors
An evacuated-tube collector is a set of many double-walled, glass tubes and reflectors to heat the fluid inside the tubes. A vacuum between the two walls insulates the inner tube, retaining the heat.

The collector consists of a thin, flat, rectangular box with a transparent cover that faces the sun. Small tubes run through the box and carry the fluid — either water or some other fluid, such as an antifreeze solution — to be heated.

The tubes are attached to an absorber plate, which is painted black to absorb the heat. As heat builds up in the collector, it heats the fluid passing through the tubes.

While they look like solar photovoltaic panels, they are very different. Solar collectors do not product electricity, just absorb heat from the sun.

It is the most powerful type of collector which concentrates sunlight at a single, focal point via a parabolic dish made of reflective surface.
More expensive Least expensive Most expensive
Highly efficient Less efficient Most efficient
Well suited to installation in cold, northern climates Well suited to Southern installations with lots of sunlight
Best for installations with high demand for hot water and/or space heating Well suited for applications that require large quantities of hot water and / or space heating
Very durable, but can be damaged by hail Highly durable - less likely to be damaged by hail Very durable
Easy to repair - individual tubes can be replaced
May be installed on a tracker - i.e., follow the sun during the day - to maximize efficiency

Heat exchanger

Used in closed-loop systems to transfer the heat from roof liquid to water without the liquids mixing.

Storage tank

The storage tank holds the hot water. The tank can be a modified water heater, but it is usually larger and very well-insulated. Systems that use fluids other than water usually heat the water by passing it through a coil of tubing in the tank, which is full of hot fluid.

Monitoring system

Used by system owners to measure and track system performance. While installing a monitoring device and service will add to the overall cost of your system, it will almost certainly pay for itself by:

  • Confirming that your system is performing efficiently;
  • Making it possible to quickly identify and correct any performance issues that do arise; and
  • Tracking your performance, especially during the warranty period, to ensure that your results, and investment, are optimized.

Active and Passive Solar Heating Systems

Solar water heating systems can be either active or passive, but the most common are active systems. Active systems rely on pumps to move the liquid between the collector and the storage tank, while passive systems rely on gravity and the tendency for water to naturally circulate as it is heated.

Active systems come in two types:

  • Direct circulation (open loop): water is circulated directly through the solar collectors. This system cannot be used in areas where temperatures drop below freezing.
  • Indirect circulation (closed loop): a non-freezing liquid is circulated through the collectors and heats the water in a tank afterwards via a heat exchanger.

Solar Pool Heating

Swimming pool systems are simpler. The pool's filter pump is used to pump the water through a solar collector, which is usually made of black plastic or rubber. And of course, the pool is used to store the hot water.