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Active Solar Energy

Active solar energy technologies convert sunlight into other forms of energy by using an energy transfer fluid such as water or air. In Canada, these technologies are primarily used for air and water heating. Other applications include air conditioning, detoxification of contaminated water, and thermal-electric power generation.

Within the Canadian Government and in the CANMET Energy Technologies Centre (CETC) at Natural Resources Canada, research and development activities for active solar energy technologies and applications are ongoing within the Active Solar Energy Group. This group works with industry to improve the cost-performance of systems.

System testing is a key component of the group and it is usually undertaken at the National Solar Test Facility (NSTF), which is owned by NRCan and operated by Bodycote-ORTECH International. Activities also include:

  • on-site field monitoring
  • development of analysis software for predicting system performance
  • conducting targeted market studies


Technical support and collaborative work is also undertaken with the Renewable Energy & Electricity Diversification for its core activities, including the Renewable Energy Deployment Initiative (REDI) and with the Canadian Standards Association (CSA). The REDI promotes the use of active solar thermal systems, namely solar hot water and solar air heating, in the commercial, institutional and industrial sectors. The initiative also supports pilot projects in the residential sector. REDI undertakes marketing and infrastructure development activities.

Some of the companies that manufacture and develop technologies belong to the Canadian Solar Industries Association. The Solar Energy Society of Canada (SESCI) promotes the increased use of renewable energies in Canada, through their involvement in education, technical development, and public policy. Climate data (e.g. sunshine) from many sites within Canada can be obtained from Environment Canada / AES.

Research and development is also undertaken in cooperation with other countries through the International Energy Agency’s own Solar Heating and Cooling Programme.


Current activities of the Active Solar Energy Technologies group include:

  • Technology Assessments and Market Studies
  • Solar Domestic Hot Water
  • Solar Air Heating
  • Solar Heating for Residential Swimming Pools
  • Aquaculture Water Heating
  • Solar Detoxification of Contaminated Water


Technology Assessments and Market Studies

When companies are deciding to invest in a renewable energy system, they conduct a feasibility study. If the study shows a positive financial benefit will be achieved, the project goes ahead. In conjunction with REDI, the group provides support for feasibility studies. Examples of recent studies include: solar water heating for car washes, solar water heating for dairy farms, solar energy for NRCan facilities, and coffee drying in key producing regions.


Solar Domestic Hot Water

The market potential for solar water heaters in Canada is very large. Hot-water heating accounts for about 20% of energy use in homes. In a typical year, solar energy can supply about half of this energy. To address this market potential, the active solar energy group has been working with industry to develop low-cost, high-performance systems. Further cost reductions can be achieved by purchasing systems with groups of buyers. The International Energy Agency attempted to create buyer groups through Solar Heating and Cooling Programme, “Active Solar Procurement”. Technical support is also provided for pilot projects which are under the REDI.


Solar Air Heating

The active solar energy group has been a key contributor to the development of the Solarwall, a low-cost, fresh-air heating system. The group has assisted laboratory testing, field monitoring, and support for expansion to international markets. More recent solar air-heating activities include:

Development of SWIFT, a software tool that predicts cost and energy performance of industrial and commercial solar air heating systems. If interested, you can download a free copy of the software at the above link.
Feasibility studies and demonstration of solar crop drying applications through the International Energy Agency Solar Heating and Cooling Programme, “Solar Drying in Agriculture”
Research and development of advanced paint coatings for unglazed solar air heaters which are low-e (emittance) or have lighter colours
Development of an unglazed, residential, solar air-heating system


Solar Heating for Residential Swimming Pools

In Canada, a substantial amount of energy is used to heat residential swimming pools. This is an excellent application of solar heating because there is plenty of solar energy in the summer. To assist the solar pool-heating industry in marketing their systems, the active solar energy group has developed an accurate, user-friendly software package called EnerpoolTM. EnerpoolTM predicts swimming pool temperature and energy use. It also estimates the cost of various heating systems and places special emphasis on solar heating for swimming pools.

A market study into the value of solar pool heating in Canada has been undertaken in collaboration with the REDI. Results were extremely positive showing very short pay-back periods for solar swimming pool heating in some cases.


Aquaculture Water Heating

Fish hatcheries often heat water to achieve faster growth rates and shorten the time to market. A preliminary market study into this application indicated that fish hatcheries might be a niche market for solar water heating. Two field studies were then undertaken to analyze this potential: at the Rosewall Creek salmon hatchery and at the Alma Aquaculture Research Facility, which simulated a trout hatchery. Results for both systems were positive with simple pay-back terms under 5-7 years. Feasibility studies have been completed which examine the cost effectiveness of solar water heating at other aquaculture facilities for trout, salmon, and tilapia facilities.


Solar Detoxification of Contaminated Water

In the coming year, a market study will begin to examine the potential for using Solar Energy in Canada and abroad to destroy contaminants that are in solution in water. The study will examine the use of Advanced Oxidation Processes (AOP). AOPs are highly effective at destroying many chemicals such as dioxins, hydrocarbons, and pesticides. If results from the market study are positive and funds are available, further development will be undertaken to improve the technology and demonstrate it in the field.

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