About Solar | Siting & Location | Municipal Permits | Solar Pool Heating | Solar Air Heating

Locating and installation information

This section contains things to know when considering a solar energy installation, such as:

• Solar Collector / PV Panel Orientation
• Solar Collectors / PV Panels and Shade
• Solar Collectors / PV Panels and Roof Structure
• Solar Collectors / PV Panels in Winter
• Solar Collector / PV Panel Maintenance
• Access to Home’s Utilities

Solar Collector / PV Panel Orientation
The installed location of solar water heater collectors and solar photovoltaic panels is of prime importance if the systems are to work to their maximum efficiency and productivity. In Ontario, solar collectors and PV panels should face due south, the surface face oriented at about 45 degrees from horizontal to capture the maximum possible heat and light energy from the sun. Solar collectors and PV panels are either mounted flat against on a south facing sloped roof or on a light weight but sturdy mounting system made for flat roofs. Some systems can even be mounted on a south facing wall of a building.

Solar Collectors / PV Panels and Shade
Shade from obstructing objects – throughout all seasons – must be taken into consideration when siting the placement of solar collectors or PV panels. Any shadow or shade falling on solar collectors or PV panels throughout the times of peak energy production (approximately 9 am to 4 pm) will decrease the efficiency and energy production of the solar collectors or PV panels. There should be no shading from trees, chimneys, neighbouring tall buildings, etc. on the solar collectors or PV panels during this time period. Observe and track the sun and any resulting shadows over the course of a few months to determine the optimum location for solar collectors or PV panels.

Solar Collectors / PV Panels and Roof Structure
Manufactures’ warranties for most solar energy systems average 20-25 years. If the surface of the sloped or flat roof being considered for the installation of solar collectors or PV panels is coming to the end of its life expectancy, it is recommended that you replace and update the roofing envelope (new roofing paper and shingles for a sloped roof, new surface for flat roof). Also make sure the underlying building structure of the roof – plywood sheathing, rafters, load bearing walls, etc. – is in good repair. The roof needs to be structurally and materially sound in order to support the weight of the solar collectors, PV panels and related mounting hardware. Weights range from approximately 2.5 lbs./ft² for PV panels to 85 lbs./ft² for solar collectors. Assess the condition of the entire roof in addition to the specific location where the collectors or panels will be mounted.

Solar Collectors / PV Panels in Winter
As the sun descends closer to the horizon in winter and days get shorter, solar radiant energy begins to decrease. However, on bright, clear winter days, sufficient energy is still available to create a sizable amount of hot water from a solar water heater or electricity from a PV system. Trees have lost their leaves, allowing solar collectors and PV panels access to low slanting solar energy. Snow will form on the solar collectors and PV panels during winter, however since the solar collectors and PV panels generate a small amount of surface heat because of their dark colour and are covered with tempered glass, the snow will either slide off or melt very quickly. There is no need to clean the snow off the solar collectors or PV panels. In southern Ontario, the average homeowner can expect approximately 65% of hot water to come from the solar water heater in the summer time; about 35% being produced in the winter months.

Solar Collector / PV Panel Maintenance
Solar water heaters will require some maintenance as many designs will include pumps and heat exchange units. Heat transfer fluid such as glycol may need to be replaced or replenished about every 3-5 years.

Solar PV systems are virtually maintenance free as there are no moving parts, motors or system ‘wear and tear’. The efficiency of the silicon in PV panels does degrade slightly over a long period of time, but will not be noticeable over the life-time warranty of a system which is typically 20-25 years.

Solar collectors or PV panels do not need to be regularly cleaned as exposure to wind and rain along with the inclined angle and surface material of the solar collectors or PV panels keep the surface free of dust and dirt.

Hail or damage from animals will not typically affect the structure or performance of solar collectors or PV panels.

Access to Home’s Utilities
The solar water heater or PV system will need to be connected to the residential utilities that they will work with: municipal water system and current residential hot water tank for a solar water heater; municipal electricity grid, inverter and the home’s electricity breaker panel for a PV system. Insulated water pipes or an electricity cable will usually be mounted running down the side of the residence; entering through the foundation above grade. The pipes or cable then connect into their respective utility systems.

For more information and an example of a Solar Assessment Checklist, see:
OurPower’s West Toronto Initiative for Solar Energy Do-It-Yourself Solar Self-Assessment checklist (Word .doc).