FAQ

The cost of installing solar arrays has fallen dramatically in the past few years, making it a viable resource investment. For the developer, the cost of the array is a combination of initial costs and the operating costs over the projected life of the system, divided by the amount of electricity that the system will produce. Systems in different regions of the country will produce differing amounts of energy, industry experts explain. Size matters and utility-scale solar can take advantage of economies of scale, including stream-lined production, installation, and materials. Utility-scale photovoltaic (PV) systems cost 50 percent less on a dollar per kilowatt (kW) basis than residential systems.

Solar energy is among the cleanest, most abundant renewable energy source available today in the United States. With today’s technology, this resource can be harnessed in several ways, giving the public and commercial entities flexible ways to employ both the light and heat of the sun. While solar is comprised of a diverse suite of technologies, PV is the most common type of solar, according to industry sources. PV panels, which directly produce electricity from sunlight, have no moving parts and use an inverter to change the direct current (DC) power they produce to usable alternating current (AC) power.

According to the Department of Energy, the conversion efficiency of a PV panel is the percentage of sunlight shining on the panel that is converted to electricity. The amount of energy produced by any given PV panel depends on four factors: the PV cell efficiency, the temperature response of the cells, the module layout and the anti-reflective coating. Residential solar arrays should use high-efficiency modules, which allow more power to be installed in a smaller area.

In WFEC’s projects, each panel is about 3 feet by 6 feet, weighing around 55 pounds. At each solar site, panels are arranged in rows and are oriented to west-south-west to maximize output later in the day to reduce summer peak load. The panels for community solar projects are ground-mounted, with a fixed tilt. As for the utility-scale sites, single-axis tracker panels are utilized and these panels will follow the sun.

With regard to reflectivity, solar panels are designed to absorb light as opposed to reflecting light. With regard to temperature, the outer surface of a solar panel does not noticeably increase in temperature. However, the underside does.

PV panels can use direct or indirect sunlight to generate power, though they are most effective in direct sunlight. Solar panels will still work even when the light is reflected or partially blocked by clouds. Rain actually helps to keep the panels operating efficiently by washing away any dust or dirt.

There are no reported issues with bird collisions related to solar PV arrays, according to industry sources. This is more closely tied to large utility-scale solar thermal farms that use mirrors to concentrate the sun’s rays onto large towers that heat liquids and run steam turbines to create electricity. The heat is so intense that birds flying through this type of array literally get scorched. This is not a concern for a standard field-installed PV solar array.

The sound from the inverters will not be heard beyond 10 feet or so.

The outer surface of a solar panel is covered with tempered glass. Typically, they would only break due to vandalism or gunfire. Hail rarely damages solar panels for two primary reasons: tilt and materials. First, most solar panels are tilted to some degree, so hail striking the panels usually hits at an angle, lessening the force of the impact. Second, since the widespread adoption of tempered glass, solar panels have become much more resistant to damage from hail or other projectile impacts. Most are rated for golf ball size hail and designed for 90 miles per hour wind loads in accordance with national and local building codes.

Assuming they’re high-quality modules and properly maintained, the life of a PV system should be 30 years or more. However, the efficiency of the panels will slowly degrade over time. PV modules typically have a warranty for 25 years to 80 percent of the original output. However, they will continue to provide power for many years after that.

The generation of electricity from PV solar panels is safe, effective, and systems don’t have emissions associated with other generation technologies. According to the U.S. Department of Energy, few power-generating technologies have as little environmental impact as PV solar panels. 

For decades, electricity has essentially traveled a one-way street from the power plant to the end-user. That is changing as technological advances are made in the industry. Energy storage and micro-grids are also changing how the grid operates. These changes are driving efforts nationwide to modernize the grid and create a system that is more dynamic and resilient.Feeding the grid large amounts of electricity generated from the sun and wind poses some challenges. Experience shows that increases in solar and other intermittent generation affect power plants that may have to slow or shut down in response to the drop in demand.

There are many different technologies for storing energy, including new residential battery options for adventurous consumers. Not only are the technology and applications for energy storage evolving rapidly, but the costs are also coming down. Overall, this industry is still in the early stages of development.

The current national average of homes powered by a megawatt of solar photovoltaics is 164. The U.S. solar industry is growing at an unprecedented rate. There were 7.3 gigawatts (GW) of photovoltaic capacity installed in 2015, which is 16 percent more than installation levels in 2013, according to the Solar Energy Industries Association. As solar becomes a more significant piece of the U.S. energy generation mix, it is important to understand just how many homes a megawatt of solar capacity can power. The U.S. installed 2,051 MW of solar PV in the second quarter of 2016 to reach 31.6 GW of total installed capacity, enough to power 6.2 million American homes. With more than 1.1 million residential solar installations nationwide and a contracted utility-scale pipeline over 20 GW, the industry is on pace to nearly double in size within a year or so. However, the average number of homes powered per MW of PV varies from state to state due to a number of factors including average sunshine, average household electricity consumption, and temperature and wind.