Do you have a reasonable south face? Building owners are not always sure of where 'their' south might be. This is one of the most important first steps in deciding if a site will work well for solar. While dead on, true south is always ideal, the mounting surface can be off south as much as 30º or even more and still work just fine. See "Solar South" below.
Slope If a roof mount is likely, ...is the slope appropriate to maximize your solar gain or will there be some level of compromise? Best slope for Nova Scotia is 45º (matchs our latitude) or 12:12. However, a 30º - 60º range is acceptable. Also, ground mounts can be built to meet almost any requirement providing space and shade are not factors. Snow can also be an issue in some locales.
Shade A major obstacle in many urban settings is shade... from neighbours, trees, even the large condo across the street. Solar efficiencies will be affected but systems can tolerate some shade and still provide major benefits, depending on the application. Plus, some compromise may be possible by adding another collector or bank of tubes.
Application The requirements for various solar applications (pool, air, hot water) will vary, and, while one type of system may not work for your structure, an alternative placement or minor renovation may be all that is required to make solar work for you.
Space Solar panels can be mounted on roofs, ground, or walls. The 'footprint' or space for the solar collectors (the panels that collect the sun's energy) must be large enough to allow for an efficient install wherever they are mounted. For a hot water application, The Canadian Solar Industries Association recommends a minimum space of 4m long X 3m high 12' X 10' (two collectors).
To be sure, use a trained, solar appraiser to determine the suitability of your site.
NOT SURE ABOUT YOUR SITE?
Creative Solar can accurately measure the percentage of sun you will receive for each month of the year at a specific point on your property. Often, with wide open spaces, this is not necessary as the amount of solar gain is obvious. However, in many situations, trees, neighbours, orientation and other factors may seriously affect your solar capture. The only way to be sure is to take a reading with our Solar Pathfinder. Where considered necessary, you will receive a copy of the results as part of our site assessment.
Solar Pathfinder
PATHFINDER READINGS
Here's a year's worth of sun readings from a Halifax home: (in % of total sun available for that month)
Jan 60 Feb 73 Mar 87 Apr 95 May 93 Jun 93 Jul 93 Aug 93 Sept 87 Oct 82 Nov 60 Dec 48
Nov-Jan are on the low side but this home does receive sun during the best part of the day in those months, another factor to consider. This home is fine for a solar install.
An evaluation of a property will consider the solar potential for all months of the year. Use of a 'solar pathfinder' can determine exactly how much sun/month a site will receive.
Solarsheat TwinPak horizontal mount for basement
Solar Side: "Solar noon" can be observed at exactly half way between the hours of sunrise and sunset, regardless of time zone or time of year.
What is true South or 'Solar South'?
That would be...the direction, at any point on the earth that is geographically in the northern hemisphere, facing toward the South Pole of the earth. Essentially, a line extending from the point on the horizon to the highest point that the sun reaches on any day at solar noon in the sky.
To find true south here's a simple method: The sun is always due south at solar noon. A shadow cast by a vertical object at solar noon runs true north-south. So, at solar noon, use the shadow cast by a plumb-bob string or a vertical edge such as a building to determine true south.
Do not rely on your clock's time to find solar noon, since time zones are not completely in sinc with the sun.
Insulation or Insolation?!
The use and application of solar appliances of all types, including photo-voltaic (PV) is now well documented in this province and region. We stand up as well as (and often better) than other areas of Canada as documented by NASA. That esteemed body has compiled data on the insolation values for Canada (see chart below). PLUS, our moderate climate contributes to our ranking of Halifax as 3rd highest in Canada for solar gain.
Insolation is a measure of solar radiation energy received in a given area in a measured amount of time - it can be compiled for any location on the planet. The chart shows how Halifax compares to other, major Canadian centres. Note that Toronto only has a marginal advantage over Halifax and that Ontario is now an active leader in solar PV installations in Canada.
