Solar PV systems are a renewable energy source that convert sunlight into usable electricity. This is thanks to the photovoltaic (PV) effect, hence the term Solar PV Energy.
There are many other sources of renewable energy. These include wind, hydro, and biofuel to name a few.
Solar PV systems consist of these basic parts, further explained below:
- Solar array
- Mounting equipment
- Cabling and protective devices
- Energy meter
- Electrical grid
Each of these parts plays a role in generating usable energy from the sun and providing it where needed.
Most people know what this is but don’t know the name. This is the solar modules we see on the rooftop. The array collects the sun’s photonic energy. This energy is converted into electricity that can be used in your home or business. These come in different sizes and power ranges to fit onto different size and styles of rooftops.
A certified mounting system is what connects the array to your home or business. This mounting system is commonly referred to as ‘racking’. Like the array, mounting systems also come in all shapes and sizes. This ensures that a system can be designed specifically for your space.
*Safety Note: This part of the system forms part of the electrical bonding system. This means that the racking grounds the system, and if not handled properly, can cause significant electrical hazards which may cause serious harm. As such, racking should only be installed by journeyman electricians and electrician apprentices.
Inverters are the heart of a Solar PV installation. Electricity generated by the array is sent to the inverter and turned into grid-compliant energy. If your system makes more electricity then you use, it is sent back to the grid. In Alberta, our system is designed so that the electricity generated is used in our homes and businesses before being exported to the electrical grid.
Cabling and Protective Devices
Cabling and protective devices transmit electricity from the array to the inverter, to your electrical panel and out to the electrical grid. Each of these are to be installed in accordance with the Canadian Electrical Code by qualified electricians as stated in the Electrician Trade Regulation. A photovoltaic info sheet is available from the Alberta government highlighting this requirement.
A bidirectional energy meter is required to account for energy imported from and exported to the electrical grid. Your local service provider will install this at no cost to you. Most service providers have already completed all the upgrades needed.
Alberta’s electrical grid connects electrical generation sources to consumers through transmission lines and distribution equipment. Traditionally, this would be a one-way flow of energy. Today, you are allowed to generate and export your own energy thanks to the Microgeneration Regulation Act.
Now that we know what the basics parts are, we need to determine where they’ll all go.
The site assessment is a crucial stage in the development of a Solar PV installation. This allows the installer to gather all the required information to complete proper quote and/or proposal.
Many companies make use of satellite imagery to complete the site assessment, but this has its risks. While quick and easy, they may not always provide a detailed assessment of the roof, its condition, or any obstructions. A visit to site by a trained solar PV installer will provide a higher quality assessment and a much more reliable quote.
During a site visit, it’s a good idea to have a utility bill available for your installer. This will provide some key data for the design process including historical usage, Site ID number, and retailer information.
Grid Dependant and Grid Independent Topology
There are three basic types of Solar PV types:
- Grid Connected or Grid-tie (Grid Dependent)
- Off-Grid (Grid Independent )
- Hybrid (Grid Interdependent)
A grid dependent systems are by far the most common installations. This is due to the limited number of components and quick installation time. The energy you don’t use goes to the grid. When you need more energy, it comes from the grid into your home automatically. These installations require a connection the electrical grid in order to operate.
Independent or off-grid systems do not require a connection to the electrical grid and can operate in a self-sufficient manner. These installations generally require many more components including battery banks and charge controllers. Because of the added parts in this system, it is usually more expensive. Sometimes this is the only option, for example: in a cabin that is too far away from electricity services.
A grid interdependent system (hybrid) connects to the grid, but also has a battery for back-up. This means if the power goes out, you still get some energy from your batteries. These systems are less common due to their high cost, but are becoming more common as battery storage prices decrease.
Now that you’ve covered the basics of a Solar PV installation, contact a certified PV installer to complete your site assessment and see what the sun can do for you!