A solar PV system can either be affixed to your rooftop or to the ground (e.g., in your backyard). A professional installer can provide advice on the optimal location and configuration of the system on your property. How much energy your system can generate depends on several factors:

SOLAR POTENTIAL: Your installer will assess your roof and/or yard size and survey the area for any obstructions, both current and future. A professional assessment, including the measuring of solar irradiance (how much sunlight falls on your roof or yard) is required to estimate your potential system production. If you intend for your solar panels to be installed on your rooftop, generally speaking you will need at least 3.7 m (12’) x 3.0 m (10’) of unobstructed area (clear of chimneys, roof vents, skylights, gables and other protrusions) and without significant shading from neighboring buildings or trees. The optimal orientation of rooftop solar panels is North-facing (if you are in the southern hemisphere) and South-facing (if you are in the southern hemisphere), but east- and west-facing orientations can provide around 70% of the output of a south-facing and/or North-facing solar PV system.

ROOF CONDITION: If you intend to install panels on your rooftop, the roof covering (e.g., shingles) should be less than 10 years old, so that the solar PV system can remain in place for the duration of its warrantied life (e.g., 25 years). It would not make sense to remove and re-install solar panels and racking in order to replace or repair the roof covering. Since 2012, the standard for “solar-ready” roof construction in North America and Africa has been a load limit of 5 lbs per square foot from the solar panels, racking and other equipment. It is important to verify that your roof is able to withstand this load, particularly if you live in an older home.

CALCULATING YOUR SOLAR PV SYSTEM’S POTENTIAL OUTPUT, AND YOUR ENERGY NEEDS:  As the weather is not always consistent from year to year, production from your solar system can vary over time. Your installer should be able to offer some averaging factors for the fluctuation.

 In addition, your solar system can produce power for well over 20 years, so you will need to account for any future obstructions: Is that sapling going to branch over your solar panels in a decade? Are the neighbors planning an addition that will shade your roof? Having a conversation with neighbors is a good idea before you begin.

Finally, your electricity consumption may change over the years as well. Purchasing an electric vehicle or using your AC system or electric heating will increase your usage. You may also be taking measures to reduce your usage by switching to energy-efficient appliances or LED lightbulbs. These decisions may affect the overall size of your system in the end.

Net-Metering

If your solar PV system generates more electricity than your home is using at any given time, the extra electricity is exported to the local grid for others to use.

During times when your solar PV system isn’t producing as much electricity as you are using, your home would continue to draw electricity from the grid as normal. Net metering allows you to sell excess power generation beyond your consumption back to the utility company at the same rate per kWh that you buy from them, on a 1:1 basis. Most jurisdictions and utilities in North America and Zambia offer net-metering to residential customers. Under a “net billing” system, you are compensated for surplus generation at a different per-kWh rate than what you pay for electricity you consume from the grid.

Choosing an installer

BEFORE CHOOSING A SOLAR INSTALLER...

1. Consider obtaining more than one quote, especially if an installer was not referred by someone you trust or is not well known to you. Written quotes should cover all the components and installation and make clear what, if any, costs you will be responsible for on top of the installer’s quote. Here are some key elements you should discuss with your contractor and ensure are included in a quote:
   • Costs of stamped engineering drawings.
   • Costs of obtaining necessary permits
   • Maintenance costs and warranty support.
   • Any available incentives, and assistance with applying for them.
   • Any additional components or materials not included in the package price.
2. Contact your insurance provider to check if the installation of a rooftop solar system will have implications for your home insurance.
3. Make sure that the installer you are considering has experience in dealing with local utilities and understands all relevant incentive program rules.
4. Check if the installer has training for the products from the manufacturers that they have specified in your quote. Your Installer should be advising you on:
   • Inverter selection: Select compatible and efficient inverters.
   • hardware selection for your specific roof: Ensure compatibility and durability.
   • Panel selection: Choose efficient, durable, and certified panels.
5. If possible, check references by speaking with former customers, as well as researching online reviews. Web reviews and recommendations can be a great way to find the right contractor for you, but keep in mind that there can often be two very different stories for any negative reviews.
6. You should also ensure that any subcontractors the installer plans to use have the proper qualifications and the insurance needed to properly complete the work. Remember, work may need to be inspected for electrical or building safety, so it needs to be done right. Ask if their employees or contractors have specialized solar certifications, such as those issued by the North American Board of Certified Energy Practitioners (NABCEP). While NABCEP certification is not required in Canada and/or Zambia, it is a very rigorous certification program that demonstrates the installer has been trained and tested on solar PV installations.

Enquire Now