There are typically three factors that should be addressed when considering which type of solar installation is best for your needs, 1) mounting style and location, 2) interconnection type (how the electricity is going to be used) and, 3) solar technology. Both the cost and the overall reliability of the system can be significantly affected by any combination of these choices.
The first thing to consider is the location and style of the solar array. Are you going to be positioning the solar array on the rooftop of your structure, or will the array be ground-mounted somewhere on your property? Will the system be ballasted or require penetrations? Your installer should perform a site evaluation prior to presenting you with any job quotes. During the evaluation the installer will assess the structural integrity of location, the possible shading conflicts and the amount of available space. Based in part on this information, the installer will make a recommendation for the location and style of the array that best meets your needs.
The most common type of solar array installation is the rooftop mount. Your rooftop’s load capacity, the location of chimney units and vents, as well as nearby objects that could cause shading issues must all be considered when assessing a rooftop location.
Ground-mounted solar arrays are customarily used where an expanse of land, clear of vegetation, is readily available on the owner’s property. These installations can be easier to install, aesthetically pleasing and allow for better maintenance access. However, they may need to be cleaned more often.
Although rooftop and ground-mounted installations are the primary installation types, many people have worked with their installers to come up with mounting solutions that suit their specific needs. For example, solar modules make excellent awnings and can be seamlesslyintegrated into covered parking structures.
The low-profile array is fixed in place by either it’s own weight (self-ballasted), small cement blocks, or some combination of the two. Eliminating the need for penetrations in the structure helps to safeguard against possible leaks. However, many residential rooftops are not properly engineered to accommodate a ballasted array.
Most residential solar arrays are mounted directly to the home’s framework. A small number of penetrations are made in the existing rooftop in order to secure the system in place. Any penetrations made are properly sealed against moisture using traditional roofing methods. This style of mounting is clean, secure and lightweight.
Trackers are an exciting development in the world of solar. Tracking units allow the modules to follow the path of the sun throughout the day, increasing system energy production by 20%. Due to the higher cost of installation and necessary preventative maintenance, we currently only recommend this technology on large (<100kW) installations.
The decision about whether to build a grid-tied (connected to utility), or off-grid (no connection to utility) solar array has a considerable impact on the design and cost of your system. You should be prepared to discuss your energy needs with your installer prior to the performance of your site evaluation. The location and the size of the array will need to be adjusted based on the type of interconnection you choose.
Grid-tied solar systems are the most common type of installation. In this case, energy from the solar array is converted from DC power to AC power by the inverter and then fed into the home’s electrical panel. The power generated by the array is allocated to the home first. Any excess power is fed into the Utility’s grid and credited to the owner’s account for future use. Grid-tied installations are the least expensive to install and simplest to maintain.
Those who are serious about declaring their energy independence, or are simply too far from a utility grid should consider installing an off-grid system. Energy produced by the array is stored in a series of batteries. The building’s load is then serviced from the batteries. This installation type has considerably more cost and requires more preventive maintenance than grid-tied, but can be the best solution for some.
The two most common types of solar technology are silicon cell based and thin film based panels. Silicon cell based panels, more commonly referred to as flat plate modules, are the most widely used type of solar technology. Thin film is an exciting technology that has allows manufacturers to create solar modules without the added cost of silicon.
These are the most commonly used type of modules in residential solar installations. Flat-plate modules produce the most energy while utilizing the least amount of space. They come in a variety of sizes and are now available in sleek all-black designs.
This thrilling technology is still in its infancy. Currently, thin film modules require significantly more space to generate the same amount of energy as a standard flat-plate module. However, these modules can be integrated beautifully into some standing seam rooftops without any penetrations and can be a cost-effective option for those with plenty of space to spare.
