Solar PV 101

By: Smart Zero Home
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A solar installer will usually design the solar PV system based on an individual home's annual energy usage. However, trying to cover your entire roof with PV may not work and may not even be required. Often only a part of the roof can be used effectively, because of roof-fragmentation and orientation. Our ( intelligent design generator gives the design specs for your home, including the best PV size (not the maximum) that should be installed on your roof, so that you get the maximum output from the PV and don't overspend.

Following are the main considerations when planning to install a solar PV system on your roof:

    • Orientation: A south facing system generates the maximum output in the Northern hemisphere (US). However, if south orientation is not a possibility (because of the site, lack of available contiguous roof space, shading etc.) a West facing or a South -West facing system, is an equaly good option. Infact a West facing solar PV can be a better option if the home is set up on time dependent utility pricing.
    • Tilt: A tilt of around 25 degrees is usually recommended for maximizing the solar PV’s performance in North America. However, this varies based on your location, and it is therefore advisable to use a design tool such as PvWatts to determine the best PV system tilt for your home location.
    • No Shading: The solar system should not have any shading on it from nearby trees or buildings, as the sun moves from east to south to the west during the day.

    • System Size: The designed size of the system is driven by the availability of the optimum (roof) space for installation , the budget (and the financing), and the goal. The resident’s goal could be to meet a portion of their energy usage, or all of it (net zero energy). In either case, increasing the energy efficiency of the home is an important first step, as higher the energy efficiency of the home, lower is the required solar PV size to meet the set goal. Learn more here. See our intelligent design generator to get the ideal size of the PV for your home.

Also see our post on solar financing and our pick of the solar companies & products in the market.