The Three Types of Solar Power Installation

With a low cost that gets lower every year, combined with increasing efficiency, solar energy is currently the big winner in the race to develop renewable energy infrastructure and decarbonize energy. In 20 years, solar power has gone from a curiosity for survivalists and eco-nuts to a major part of the global energy industry. According to the US Department of Energy, the cost of photovoltaic panels has fallen 70 percent since 2014 and one in seven American homes will have rooftop solar installations by 2030.

The solar industry is currently divided into three main segments, each with their own needs: residential, commercial (or commercial and industrial) and utility. Residential and commercial systems are mainly photovoltaic, with familiar solar panels that use the photovoltaic effect, where sunlight striking the panels generates an electric charge. Utility installations also frequently use photovoltaics, but sometimes they also use concentrated solar power, where an array of mirrors reflects light on a container of fluid, boiling it and causing it to move a turbine, generating power. 

If you live in a city, you’re probably most familiar with residential solar. As the name implies, these are usually home installations, often exclusively on rooftops. Many states and even the federal government have encouraged the adoption of residential solar by offering tax breaks and subsidies, according to the Solar Energy Industries Association. They can also result in the local utility buying electricity from the homeowner. Utilities often like people getting residential solar, since it can reduce peak loads on power grids.

A residential installation often starts with an analysis of local sunlight and shadows. Things like the direction of the roof, the type of the roof and nearby trees or tall buildings can affect performance. Ideally, energy savings, combined with incentives, result in the installation paying for itself over the years. Many companies lease the systems to homeowners, with the net metering paying for the installation. The panels are mostly installed on the roof, but ground-based panels can also be an option.

Residential solar can also take the form of community solar, where a group of neighbors gets together to pool their resources for a solar installation.

In addition to the PV panels themselves, an installation requires a solar inverter that turns the DC electricity produced by the panels into usable AC electricity. In addition, some people choose to have batteries as part of their system rather than connecting it to the local grid. 

Commercial and industrial installations are in between residential scale and utility scale systems. They make use of commercial or industrial properties and much larger PV panels to generate more power. Self-storage facilities, factory roofs and parking lots are popular for installations. One type of site that’s increasing in popularity is the use of agricultural fields, which can generate extra income for farmers when crop prices are too low. There have also been interesting experiments putting panels on reservoirs, which not only generate power but reduce the amount of water lost to evaporation.  

Utility scale solar can cover dozens, or even hundreds of acres. These require sites with high solar potential and few competitors for the land. Deserts are very popular for them, with their clear weather and lack of competing land use. Utility scale installations are also the main users of concentrated solar power.