Solar Energy

Manitoba receives abundant solar energy. Direct solar radiation received in Manitoba is equal to almost 2 billion terajoules of energy per year. If only 1% of this energy was converted into electricity, it would be equal to almost 200 times the annual output of all the hydroelectric dams in Manitoba. Solar heating and photovoltaic systems are clean and non-polluting energy sources, which can reduce our dependence on non-renewable energy resources. Harnessing the Sun's Energy The sun generates an enormous amount of energy each second, by converting hydrogen to helium. Called solar radiation, this energy radiates into space and reaches the earth as: sunlight (47%) ultraviolet rays (7%), and infrared radiation or heat (46%). The components used by solar energy systems are sunlight and infrared radiation. Converting Solar Radiation into Electricity Photovoltaic (PV) cells produce electricity directly from sunlight. PV cells are also called:

Quick Facts Solar electric (photovoltaic) systems convert the light from the sun into electricity. In Canada, photovoltaic systems are often used in remote areas to provide electricity for cottages, telecommunications equipment, water pumping and electric fencing on farms, and navigational aids. Solar energy can also heat water for homes and swimming pools. These systems are located on the roofs of homes or structures facing south. Incentives Natural Resources Canada offers an incentive to businesses and institutions who install biomass combustion systems for space and water heating (more info)

• solar cells
• photovoltaic cells
• photocells, or
• photoelectric cells.

When light strikes the junction between certain materials, a small voltage is produced. This is called a photovoltaic effect.

A typical PV cell contains two very thin layers of silicon with a wire attached to each layer. Each PV cell measures from 8 to 15 centimetres (3 - 6 inches) in diameter with the thickness of a human hair.

When very small bundles of light energy from the sun called Photons strike the cell, they cause electrons to flow from the bottom layer of the cell to the top layer.

Freed electrons are forced to flow through the wire, and any electrical load connected to it, towards the bottom layer producing an electric current. The current will continue as long as sunlight falls on the PV cell.

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Information and statistics excerpted from:
Photovoltaic Systems in Manitoba
download the pdf (1.5 MB) english | french

Solar Heating Systems

Solar radiation can be 'captured' and converted into useful energy. The simplest systems convert solar energy into low-grade heat (temperatures below the boiling point) for space and water heating.

A solar heating system consists of collectors, a storage unit, a circulation system and controls.

The key element is the solar collector. Its absorbs the maximum incoming solar energy and transfers this energy to the heat transfer medium with a minimum of loss due to reflection, conduction and re-radiation.

Currently, the most popular form of heat transfer medium for solar heating systems is a water and antifreeze mixture, although water and air are also commonly used.

When the medium is a liquid, the storage unit can be a tank that stands alone, or is connected to an existing conventional gas or electric hot water tank. When the medium is air, the storage unit consists of an enclosed container full of rocks or other suitable material to absorb heat.

All but the most simple types of solar heating systems have a circulation system to keep the heat-transfer continually moving from collector to storage unit.

Unless the flow is by natural convection, a pump or fan is needed to force the heat-transfer medium on its way. A control unit, with a temperature sensor, turns the pump or fan on and off as required to maintain temperatures in the system.

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Information and statistics excerpted from:
Solar Heating Systems in Manitoba
download the pdf (1.5 MB) english | french

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