While driving through the countryside, you may see an unusual “crop” in the fields: sprawling displays of metal and silicon panels. Instead of wheat, barley or beans, these farms produce energy in the form of electricity. Mainly found in rural areas where space and sunlight are abundant, solar farms produced 146 billion kilowatt-hours (kWh) of electricity in 2022. (For context, an average home in a mild climate consumes roughly 20 kWh of electrical energy in a day.) Underneath (literally!) these clean energy endeavors, you’ll find custom metal parts, which make up the various substructures used in solar farm installations.
Solar farms have been popping up across the United States for decades and are growing substantially in numbers – currently, there are more than 7,000 solar farm developer businesses in the U.S. intent on establishing more solar fields. The industry is rapidly growing:
- In 2022, solar was the fastest-growing source of electricity in the world – for the 18th year in a row!
- Solar power generation has been rising by 24% year over year, adding enough production to power to meet the electricity demands of South Africa.
- According to the Solar Energy Industries Association (SEIA), the solar energy industry just came off a record-setting first quarter for Q1 2023: Utility-scale (that means any solar installation connected to the power grid) solar installations were up 66% compared to Q1 2022.
Harnessing the Sun’s Power at Scale
A solar farm is technically any collection of several photovoltaic (PV) solar panels in a single location used to generate electricity that’s sent to distribution systems for consumption by people.
Solar farms vary greatly in size, shape, and output. Large solar farms may stretch as far as the eye can see and contain thousands of PV panels. These are known as utility-scale and can generate sufficient electricity to be a key player in an area’s power supply. Others are designed to supply power to a certain location or application, like small communities, businesses or entities. These are referred to as community-scale.
While smaller solar or PV panels are commonly seen on the roofs of homes and commercial buildings, solar farms generally use ground-mounted systems. Instead of affixing the solar apparatus to a structure, the panels are arranged on racking systems that rest on the ground.
Solar farms use a variety of methods to absorb the sun’s energy and involve panels supported by structures made up of metal parts. From the frames to the racking systems, custom metal components – rails, beams, posts, and substructural steel components – are an important part of solar field systems. The parts and components used depend on what type of installation is used: pole-mounted, fixed-tilt, or tracking systems. Let’s look at each type.
Just as their name implies, pole-mount solar panels are affixed to a pole that is solidly planted into the ground. It’s thought by many installers to be the most straightforward method. Pole-mount systems are generally used when roof space is lacking, or such installation is impractical, but they still require sufficient ground space.
However, users are not as limited as they would be with a roof installation – the roof size is considerably smaller than most tracts of land. There are fewer restrictions with pole-mount installations, and they are the easiest to equip with a tracking system that affords optimal sun exposure (and productivity!) This type of installation is used on smaller solar farms, large campuses (healthcare, university, or corporate,) or on rural properties where land is abundant.
Pole-mount installations are a wise choice when:
- Roof mounting isn’t possible or practical.
- There’s plenty of outdoor space.
- Aesthetics aren’t a key concern.
- Zoning regulations are not prohibitive.
- Users are willing to spend more initially for a better long-term ROI.
Fixed-Tilt Racking Systems
Much like their rooftop counterparts, fixed-tilt racking systems are stationary and similar in appearance, except that instead of being attached to a roof, panels are affixed to a metal racking system. The panels are placed where sun absorption will be the most efficient (based on their orientation to the sun) and tilted to a fixed position to further increase their efficiency.
Panels collect solar radiation more efficiently when placed perpendicular to the sun’s rays. With that in mind, the tilt is calculated to work as efficiently as possible with the sun. Geography plays a part in this optimal orientation: in lower latitudes (like Hawaii, for instance), the sun is higher in the sky, so panels don’t require much direct sunlight. But on the Great Plains, for example, the sun is lower in the sky so you’re likely to see panels tilted greatly to receive as much direct sunlight as possible.
Once positioned, the panels remain as such – hence the name “fixed-tilt.” Advantages of this type of installation include ease of design, installation and maintenance, cost-effectiveness, and strength.
Compared to tracking systems, fixed-tilt installation is much easier and less expensive. Installation of these arrays requires fewer tools, reduced man hours, and less expertise than their moving counterparts. Racking is affixed to the soil, which is less involved than working on a rooftop.
Since these panels don’t track (meaning they don’t move to follow the sun) there are fewer moving parts, which keeps mechanical maintenance to a minimum. An annual inspection and maintenance are usually sufficient to ensure optimal output.
Fixed-tilt systems are also incredibly durable and strong, with the ability to endure harsh environments and all that Mother Nature throws at them: extreme temperatures, heavy snow, high winds, and driving rain.
While not as efficient as tracking solar arrays from an energy production standpoint, fixed-tilt arrays are still suitable in many instances. Large facilities and small-to-medium farms can benefit from a fixed-tilt system, due to significant cost savings in terms of assembly time and the fact that fewer posts are required since the fixed panels don’t need as much support as their mobile counterparts. Further, the availability of various frame options and module arrangements ensures a cost-effective selection of materials that can be tailored to the desired configuration and environment.
The aptly named solar tracking systems offer increased energy production because they incorporate technology that adjusts the position of the panels to follow the changing positions between the earth and the sun over time. This is done to harness as much solar power as possible by adjusting the panels continually for the most effective placement to maintain the smallest angle of incidence – the angle at which the sun hits the panel – possible. Sometimes GPS is used to aid with maintaining alignment but moving the panels in the opposite direction of the earth’s rotation also helps keep them in line.
Trackers fall into two categories: passive and active. Passive trackers are powered by (you guessed it!) the sun. Compressed fluid is warmed by the sun and moves within the apparatus, causing the panels to tilt in the other direction. Active trackers use gears powered by motors and thus require electricity, which adds substantially to the complexity and cost of installation. However, extreme temperatures can cause passive trackers to malfunction so a case can be made for either type depending on location, environment, and weather patterns.
There are also two types of tracking systems, single-axis and double-axis.
- Single-Axis trackers tilt on a single axis, following the sun from east to west each day. Using this type of tracking can boost energy production by up to a third when compared to a fixed system. By working with the sun in this manner, the amount of energy produced can be increased without needing more land or panels. But snow and rain can cause issues, so weather is a major consideration when choosing a system. In the right conditions (mild climate, flat land, and properly working components) installation and equipment costs of single-axis systems can be quickly recouped due to increased electricity production.
- Double-Axis use two axes, primary and secondary. One helps the tracker move from east to west much like a single-axis tracker does. But this type of installation has a second axis that helps the tracker move from north to south. Since they can move in all directions, double-axis trackers are versatile, flexible, and powerful. They can generate 40% more electricity than static systems and seven to 10% more than single-axis arrays. Increased mobility means a double-axis system can operate in less space while still harnessing the sun’s power efficiently. They’re particularly well-suited to places where it’s tough to get adequate solar energy, like uneven terrain or protrusions such as cliffs or stone outcroppings. Again, the initial costs are easily offset by the increased production. But double-axis systems, efficient as they may be, come with caveats. If it’s cloudy, they will not function as expected. Maintenance can also be cumbersome as there are more mechanical parts (many of which have short lifespans) and installation is best left to the professionals due to the complexity involved.
Deciding which type of system is best depends on your desired output, available land, environment, and how much you want to invest initially. No matter what type of installation you choose, it must be made with high-quality components that are suited to this application and the environment where the system will be placed. PV panels are made primarily of silicon wafers arranged in a metal frame; the supporting frames and substructures are also made of metal. As one might imagine, the metal components need to be both durable and strong since they’ll be exposed to the elements. Some components require custom metalwork to obtain the required shapes and specifications. It’s essential to support your array with proper materials.
Solar farms are an integral part of a growing industry, increasing our use of clean energy and moving toward a more sustainable infrastructure. The growing numbers are not expected to slow anytime soon given the advantages of solar energy. In addition to being an environmentally friendly, clean source of energy, solar farms offer other perks such as lower energy costs, sustainability, diverse applications, minimal maintenance requirements, and less noise pollution than other means of generating electricity.
If solar panel racking structures are in your future, an experienced custom metal manufacturer like CMI is your go-to source for the right materials for the project. Specialized applications such as solar panel structures often require custom parts and we have over 100 years of experience supplying custom solutions for a variety of industries. We are pleased to have added components for solar farm applications to our offerings. If you’d like to learn more about our unique capabilities or the different metal types we offer, we’d be happy to help. Give us a call today.