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What is solar energy?

Solar energy comes from the sun, whose energy is converted into thermal or electrical energy. There are several types of solar energy technology, the most common being the following:
 

How is solar energy produced?

Solar photovoltaic (PV)

Solar photovoltaic technology converts sunlight (called photons) into electricity. The solar panels are made from semi-conductor material. When the sun’s energy is absorbed by a semi-conductor, it releases electrons, thereby generating an electrical current. You may have seen solar panels on rooftops, in fields, and probably in your calculator!

Solar thermal

Solar thermal technology absorbs the heat of the sun and uses it to heat the air or water. Solar collectors are placed on the southern walls of buildings, which get the most sun, to collect as much heat as possible. Air or water circulates through the solar collector, warming up and helping to heat the building.

Concentrated solar power

Most large power plants rely on coal or natural gas. But you can also use solar energy! Concentrated solar power plants use mirrors to capture and concentrate massive amounts of heat from the sun. The heat of the sun warms the water, which is then powers a turbine that then produces electrical energy.
 

What are the pros and cons of this energy?

Good for the environment

Solar power does not produce any atmospheric pollution or greenhouse gas, which helps fight climate change and improve local air quality. Of all the energy production options, solar power has one of the lowest emission rates over its life cycle.

Money-saving opportunity

The cost of solar energy is dropping fast, but its ability to compete with the grid depends on where you live! In provinces like Ontario, solar power might be a better financial choice, as it might be for places like remote communities that depend on costly fuels such as diesel. The good news is that its cost gets lower by the day!

Energy independence

Installing solar panels helps you get off the grid. In some regions, you can even resell your solar power to the grid and earn money! Decentralized electricity production is the way of the future and, as demand on power plants increases, so will distribution and transmission costs. Having solar panels gives you independence, and protects you from higher energy prices.
 

Interesting facts

The following are examples of ways in which solar power can be used:

Residential solar PV

Some homeowners choose to install photovoltaic solar panels on their roofs to generate their own electricity.

Solar heating for pools

You can reduce the cost of heating the pool by installing a solar heater. The cost is competitive compared to natural gas heating, and is the most economical in many climates.

Solar ventilation air preheating

Solar ventilation air preheating uses solar power to heat ventilation air in industrial buildings. This technology uses a plenum consisting of perforated metallic absorbers, generally painted a dark colour to capture the heat. This technology does not involve any moving parts other than the ventilation fan, which requires very little maintenance.
 

Where does solar energy come from?

1. The solar panels capture the sunlight.
2. The sun’s energy is absorbed by a semi-conductor, which releases electrons, creating an electric current. An inverter transforms that alternating electric current.
3. The current is carried through the system’s lines or stored in batteries.

Exciting developments

SolarWall® technology

The SolarWall® technology is an example of the use of solar power. It is a means of heating the air in the ventilation systems of industrial buildings through solar power. The system consists of perforated metallic panels attached to the southernmost wall of the building, where the panels absorb the heat of the sun and then heat the space between the panels and building’s wall. The heated air is then sucked by a fan into the building’s ventilation or HVAC system, generating savings on heating costs and reducing fuel consumption [3].

SolarWall® technology directly addresses one of the main sources of energy consumption in buildings: indoor heating and ventilation.There are several examples of applications of SolarWall® heating technology in Canada. Hôpital universitaire de Sherbrooke au Québec is one of them. The hospital underwent major energy renovations including a solar wall providing 149 MWh of renewable energy and an annual 40 tonne reduction in GHG emissions!

Sources :

¹ Solar, wind and nuclear have ‘amazingly low’ carbon footprints, study finds (carbonbrief.org)
² REC – Aperçu du marché : Les systèmes solaires résidentiels : rentables dans certains territoires et provinces, non rentables dans d’autres (cer-rec.gc.ca)