Using photovoltaic systems to power your home
PV panels convert sunlight into electricity. Safe and reliable PV systems produce no pollution or emissions, incur few operating costs and are easy to install and maintain in most Canadian homes. But how can you know if a PV system is right for you? To help you make a more informed decision, here are some tips from Canada Mortgage and Housing Corporation (CMHC) on how to choose and install a photovoltaic system in your home:
• PV systems fall into two main categories – off-grid and grid-connected. The “grid” refers to the local electric utility’s infrastructure that supplies electricity to homes and businesses. Off-grid systems are installed in remote locations where there is no utility grid available.
• In off-grid PV system applications, the PV array and associated battery banks must be carefully sized to be able to meet the load demands through periods with the lowest solar availability. In grid-connected applications, the presence of the grid eliminates the need to closely match the system size with the year-round electrical loads, and also eliminates the need for batteries, unless desired as a back-up power source during power outages.
• In grid-connected applications, the PV systems are designed to sense a power outage and automatically disconnect all power going to the utility meter and into the grid as a safety requirement to protect utility service employees that may be working on the power lines. In most cases, this would also prevent your PV system from providing you with electricity during power outages. However, special inverters are available that can switch from grid-supplied electricity to a back-up electricity source (such as batteries) that can supply electricity to an emergency electrical panel so that you can continue to power essential equipment and appliances.
• PV systems are modular, and can be expanded as energy needs grow or as budgets allow. It is wise to anticipate future needs by installing over-sized wires, breakers, and inverters so that these components will not have to be replaced to accommodate a larger PV system.
• If you are in the process of designing a new house or doing major renovations but don’t have the resources to install a PV system right away, you may want to consider preparing your house to be “PV ready”. Simple preparations such as installing and labeling a conduit to run future PV wires and leaving space around your electrical panel for future equipment can substantially reduce costs and help increase system performance.
• Whether or not you choose to install a PV system, reducing unnecessary electrical loads can be an excellent way to cut down on energy use in your home. This can include switching to more energy-efficient lighting and appliances, avoiding instant-on features and installing controls to turn heat, lights or other equipment down or off when not needed.
• If you’re considering photovoltaic power for your home, consult an experienced PV professional. In addition to answering your questions, an expert in the design, installation and operation of PV systems can also help maximize your home’s energy efficiency and cost-effectiveness for years to come, as well as guide you to possible incentive programs that can help defray part of the PV system costs.
For more information visit www.cmhc.ca or call CMHC at 1-800-668-2642