Grid-connected solar photovoltaic systems
Solar photovoltaic (PV) panels installed on roof-tops or mounted on the ground convert the sun’s rays into electricity. Your home or business will use the electricity produced by your solar PV system, and when more energy is generated than you are using, it can be sold to us through net billing.
To eliminate the need for grid connection you would need to invest in a very efficient home, a larger PV system, a large battery storage capacity and/or a large backup generator (usually fuel-fired) which would be very costly. Retaining grid connection provides the lowest cost method of installing a solar PV system today.
Connection to the Manitoba Hydro grid ensures a reliable supply of electricity when your solar PV system does not generate enough for your needs. Grid-connected solar PV systems can significantly reduce the amount of electricity you buy during daylight hours. How much electricity you buy and sell will depend on several factors including:
- PV system kW size and panel orientation;
- season, time of day, and cloud cover and shading;
- electrical loads currently operating.
For example, on a sunny day a home with a 5-kW system would likely be selling electricity to us when only the lights and refrigerator are operating. However, on a sunny day when a 20-kW electric furnace or a 5-kW electric dryer are operating you would begin purchasing power until the furnace or dryer shuts off. Cloudy, rainy, or snowy days would also require you to purchase power from the grid.
Solar PV electricity production changes throughout the day and reduces dramatically from summer to winter. Electric heat customers need most of their energy in winter when solar PV production is at its lowest due to the short days and the low angle of the winter sun. When solar production is at its highest during long summer days your energy requirements are much lower, resulting in more excess energy being sold to Manitoba Hydro at the excess energy price.
Panel system options
Fixed panel systems facing due south at 40° to 50° inclination achieve better energy output. This is easier to do by using a ground system. A rooftop system is often limited to the direction the roof faces, which is not often due south, and the roof slope, which is generally lower than the ideal inclination. Most ground systems installed in Manitoba to date have been lower cost fixed rack systems.
Solar tracker racks are automated systems that move to track the sun. They can produce up to 25% more energy but cost much more to install and may have ongoing maintenance expenses due to the moving parts. Snow and ice getting into the drive mechanisms could be a challenge in Manitoba.
If you are thinking about installing a grid-connected solar PV system in Manitoba, remember:
- generating your own electricity generally does not mean you will eliminate your electric bill;
- the direction the solar panels face and their angle of inclination will impact performance;
- shade from trees or buildings, snow cover, and dirt will reduce energy production;
- fixed ground systems are generally easier to keep clean/clear of snow and maintain compared to rooftop systems due to better accessibility;
- your system is required to shut down during power outages to ensure the safety of our crews working on power lines;
- solar PV has a greater lifecycle carbon footprint (per unit of energy) than Manitoba’s hydroelectricity, which makes up 98% of Manitoba’s generation.
All solar panel installations need an electrical permit and usually a building permit from your municipality. All electrical work must be done by a licensed electrical contractor and meet the Manitoba Electrical Code.
The payback period of a solar PV system depends on:
- the total install cost including financing costs;
- ongoing operating and maintenance expenses;
- system performance, which can be impacted by dust, snow, dirt and shading;
- quantity of energy used to offset load versus excess sold to us;
- your site’s annual energy needs relative to the size of system you are installing;
- future electricity rates in Manitoba and the excess energy price.
The Canada Energy Regulator completed a review of solar cost effectiveness, including information specific to Manitoba. Most Manitobans will not find solar energy cheaper than our low-cost and renewable hydroelectric power. View the Canada Energy Regulator’s Economics of Solar Power in Canada report.
PVWatts® is a solar production calculator developed by the National Renewable Energy Laboratory (NREL) that can be used to estimate your annual energy production. Advanced settings including additional system losses due to soiling, snow cover, and panel degradation can be programmed to provide a realistic estimate for your project. Note: Using all of the default settings in PVWatts could overstate energy production estimates by 10 to 20%.
Calculate your payback period
Step 1: Determine your costs
Once you have a quote from your contractor, subtract the value of any federal/provincial grants and rebates from the total cost of your solar PV system. We recommend getting at least 2 or 3 quotes and to be wary of estimates that promise quick paybacks.
Step 2: Determine your annual cost savings
Calculate your annual financial benefits including your avoided electricity usage at the current electricity rates and add any additional benefits including any excess energy sold to us.
Assumptions to help you calculate your annual savings:
- ground systems will typically produce 1200 kWh per installed KW of solar capacity per year;
- rooftop systems will typically produce 1000 kWh per installed KW of solar capacity per year.
Assuming that your system is sized to produce as much electricity annually as your home consumes you can assume that between 40 and 60% of the annual solar energy produced will be sold back to us. Generally smaller systems will sell less and larger will sell more.
Annual cost savings formula:
(solar energy produced x percent of energy used in home x current electricity rate) + (solar energy produced x percent of energy exported x excess energy price)
Step 3: Calculate the payback period
Divide the total cost of your solar system by your annual financial benefits to calculate the number of years it will take for you to achieve your payback.
Average solar installations in Manitoba
Questions to ask your contractor
- Does the estimate include taxes, permit costs, a bi-directional meter, electrical service upgrades, and ongoing maintenance?
- What kinds of warranties are provided on labour and product?
- What projected electricity rates are being assumed to calculate any potential payback, including the price paid for excess electricity?
Follow our tips for hiring a contractor to ensure you feel confident in finding a supplier that best fits your project’s needs.
Qualifying homeowners may be eligible for financing to assist with the cost of installation through our Home Energy Efficiency Loan.
Learn about the Canada Greener Homes Grant
Homeowners may qualify for the Natural Resources Canada Greener Homes Grant when installing a solar PV system.
For more information about grid-connected solar PV systems, email us.