Solar Domestic Hot Water (SDHW) Systems

  

System Costs, Attributes and Incentives  FAQ  Next Steps for Homeowners

 

System Costs, Attributes and Incentives

A portion of your home's hot water supply can be heated by solar energy using a variety of technologies. The two main solar collector technologies are flat-plate solar panels and evacuated tube solar collectors (which are also arranged in a panel). Both methods heat the water in your hot water tank indirectly, by heat transfer from the liquid in the solar collectors. There are two different technologies to prevent the liquid in the collectors from freezing. One is a glycol closed-loop system, which uses a mixture of glycol and water to prevent freezing. The other is a drainback system, which generally uses distilled water draining back into a small tank not located on the roof. Either anti-freezing technology can be used with either type of solar collector.

System Cost

  • Cost $3,000-$8,500 for a family of 2-3 (one 4’x8’ panel), $6,000-$9,500 for a family of 4- 5 (two 4’x8’ panels). There are additional costs if the panels cannot be mounted flush to the roof

System Attributes

System size depends on your family’s needs: 2-3 people will need 1 solar collector, 4-5 people will need 2 solar collectors.

A typical SDHW installation includes:

  • 1 or 2 solar collectors
  • Size depends on type of collector
  • Additional water storage tank next to your existing tank
  • A heat-transfer medium, generally distilled water or glycol

It is also possible to connect an SDHW system to an on-demand water heating system and/or geothermal hot water pre-heater.

Incentives and Rebates

Lower Fuel Costs

  • In solar hot water systems, sunlight reduces the amount of electricity or gas required to heat your hot water supply, so it cuts your fuel bills. Residential buildings benefit most where hot water demand is highest e.g. a large family or a big laundry load. Commercial or industrial solar water heating systems are most cost effective in facilities with water heating systems that are expensive to operate, or in operations such as laundries or kitchens that require large quantities of hot water. A solar system can replace most of your hot water needs during the summer but much less in the winter.

ecoENERGY Retrofit — Homes Grant

  • $1250 from the Federal Government when you install a solar domestic hot water system with solar collectors that meets the CAN/CSA F378.87 standard and provide a minimum energy contribution of 6,000 megajoules per year.
  • For a list of eligible solar collectors, visit www.ecoaction.gc.ca/heat.
  • Only homeowners who booked a pre-retrofit evaluation by March 31, 2010, can receive an ecoENERGY Retrofit – Homes Grant.

Ontario Home Energy Savings Program Grant

  • $1250 from the Provincial Government when you install a solar domestic hot water system with solar collectors that meets the CAN/CSA F378.87 standard and provide a minimum energy contribution of 6,000 megajoules per year. For a list of eligible solar collectors, visit www.ecoaction.gc.ca/heat.
  • This program is scheduled to end on March 31, 2011. To qualify for this rebate, you need to first complete a Home Energy Audit with a certified energy advisor. After this audit, you make the upgrades of your choice based on your energy auditor's recommendations. After doing the work you need a post-retrofit audit, which must be completed by March 31, 2011.

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FAQ

Do I require a building permit to install a SDHW system?

  • Yes.  A building permit is your guarantee that your system is being installed properly, is safe and that it will not cause any structural damage to your home. It is required for roofload saftey and also to protect the municipal water supply (if you live in an urban area).

What is "backflow prevention" and how does it apply to my SDHW project?

  • Backflow prevention refers to technology or systems installed with a SDHW system which prevent water in the SDHW system from moving backwards and contaminating the public water lines. Backflow prevention is an issue in urban area with a civil water service and usually can be ignored for private well-based water systems. CSA B64 standards comprise the minimum standard for backflow prevention, however some municipalities maintain more strict standards, above and beyond the mandated B64 which stipulate that double walled heat exchangers and negative pressure regulation technology be installed as a minimum. Examples of additional measures, above and beyond b64, include annual system testing and certification, both required and overseen by the municipal authorities.

Can I have both a solar photovoltaic system and a solar domestic hot water system installed on my roof?

  • Absolutely. The two systems can sit side-by-side with no issues other than total weight load on the roof. There are even vendors who provide "hybrid" systems which will both generate heat and electricity with a single system.

What is the difference between glazed panels and unglazed panels?

  • Glazing refers to the different types of transparent coatings which can be applied to the energy collecting surface of the solar panel. Some glazes strengthen the glass sheet, other glazes filter out unneeded wavelengths of light radiation or filter out wavelengths which could be potentially damaging to seals and overall lifespan of the panel. Some glazes actually enhance the conversion of light into usable thermal energy.

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Next Steps for Homeowners

Learn about what’s possible for you:

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