Farm Solar Applications

Solar photovoltaic systems were once used almost solely for power in remote locations, with the agricultural sector being an early adopter of these off-grid systems. An off-grid solar energy system is not connected to the utility grid, whereas a grid-tied system is connected to the utility grid. The implementation of either an off-grid or grid-tied system will determine how electricity is accessed, what equipment is needed for excess production, what happens when the utility grid goes down, and how electricity will be billed. The basic difference between off-grid and grid-tied systems is illustrated in Figure 28, but the differences in these two systems will be discussed in further detail later in this handbook.

While grid-tied applications became more common at the residential, community, and utility-scales throughout the early 2000’s, the widespread adoption of grid-tied systems remained somewhat limited within agricultural settings due to the high costs. In recent years, energy policy tools, combined with significant reductions in the price of PV solar panels, has made on-farm solar systems more affordable to install across various system sizes and capacities. For the purpose of this handbook, residential systems will be considered as those which are comprised of only a few solar panels with a system capacity typically in the range of 5 to 20 kilowatts (kW). Commercial systems are often built by businesses on rooftops, parking canopies, or at ground level while generally ranging between 10 kilowatts (kW) and 2 megawatts (MW). Utility-scale systems are almost exclusively ground-mounted and have capacities in excess of 2 megawatts (MW). According to the Code of Maryland Regulations (PUC Article § 7-207.2), photovoltaic systems that are 2 megawatts and above must file an application for approval to construct from the Public Service Commission (PSC).

Consideration will now be given to basic types of solar photovoltaic installations in terms rooftop, ground-mounted, and mobile systems (see Figure 29). This handbook will describe rooftop systems as those placed on existing structures though addition. These systems generally provide on-site electricity which reduces the utility load. While the addition of rooftop systems provides limited structural benefit beyond the extension of the roof lifespan, the solar photovoltaics can be integrated into a new construction as part of the building itself. These integrated systems are commonly referred to as Building Integrated Photovoltaics (BIPV). BIPV generally have a strong aesthetic appeal and are architectural rather than simply utilitarian in nature. They provide multi-functional energy improvements for heating, cooling shade and even noise because they're built into the structure themselves.

Ground-mounted systems are another type of photovoltaic implementation which are often more time-intensive to construct because of the mounting system, as well as the connection to a utility. There are two basic types of ground-mounted solar panel systems. Standard ground mounts use metal framing driven into the ground to hold your solar panels up at a fixed angle. Some standard ground-mounted solar panel systems can be manually adjusted a few times a year to account for seasonal shifts of the sun. Pole mounted solar systems support multiple solar panels on a single pole and elevate panels higher off the ground than a standard ground mount. Pole mounted solar often incorporates tracking systems, which automatically tilt the solar panels to capture the optimal amount of sunshine. Single-axis or dual-axis tracking systems can increase the production of your solar panels by 25% or more, but the sophistication of tracking technology comes at a higher cost and maintenance level. Ground-mounted systems are also capable of large utility-scale installations and can be used in brownfields or other uninhabitable sites.

Mobile solar photovoltaics are another implementation option which are designed for portability. These systems are replacing the use of diesel generators in many applications since solar photovoltaics do not require the fuel to be replenished manually as is required with any system using fossil fuel. Micro systems (around 20 to 200 watts) are common with outdoor recreational uses such as charging a mobile phone or GPS device in the field. Larger mobile systems, or deployable solar, are moderately sized systems (around 1 to 3 kilowatts) that are commonly used in construction, military applications, or disaster relief when the grid is down. Inverters are rarely needed with mobile systems since they are often connected to a battery for energy storage.

In addition to the requirements set forth by Maryland’s Renewable Portfolio Standard (RPS), the solar photovoltaic industry in Maryland also employs 4,854 individuals in jobs directly related to project development, manufacturing, installation and sales of solar energy systems (Solar Energy Industry Association, 2020). This represents a 61% increase over 2014 employment levels, with further growth in the solar workforce expected over the coming years. The demand for solar photovoltaics is growing in Maryland for many reasons, including the continued declines in installation costs, as well as a desire to reduce monthly energy bills. Others appreciate an understanding of where their electricity comes from, particularly as it relates of renewable, local, or alternative generating resources. Still, others may value independence or self-sufficiency in their electrical usage.

While solar photovoltaic systems represent significant investments which require up-front capital or financing, long-term savings can be achieved by lowering your electric bills and protecting against rising electric rates. In fact, positive financial returns are possible when the monthly electric bill savings exceed the cost of system installation and maintenance. Financial returns will be greater in those situations with higher per kWh prices or when energy prices are expected to escalate rapidly. For these reasons, solar photovoltaics may be a viable investment choice to make for the energy needs of your home, farm or business. While these savings will typically drop straight to your bottom line (with no material or labor costs eating into them), a good economic analysis must consider all of the associated maintenance costs, insurance, and taxes. If all of this economic criteria is met, then the savings on your electrical bills may help to free up your budget so that you are able to reinvest your finances into different aspects of your farm or business.

The demand for solar photovoltaic systems has increased in recent years due to the falling costs of installation, as well as the technology itself. Installation costs can be further reduced using the Investment Tax Credit (ITC) which currently allows you to recover 26% of the system’s cost back within the first year. Farms and other businesses can further recover installation costs by taking advantage of 100% accelerated depreciation, as well as various grants including the USDA REAP Grant. Additional economic and financial details will be further explored in Module 6 of this handbook.

As discussed earlier in this module, Maryland’s electricity comes from a wide array of power plants including those which burn fossil fuels. The burning of these fossil fuels contributes to increased levels of air pollution and greenhouse gases emissions such as carbon dioxide. Solar photovoltaics can reduce the need for electricity production from fossils fuels and thereby decrease greenhouse gas emissions. Many businesses have imposed operational goals on themselves to reduce their emissions and carbon footprint. Solar photovoltaic and other renewable energy systems are often acquired by these businesses in order to meet such environmental goals. The associated impacts on climate change can be mitigated by solar photovoltaics since no carbon dioxide emissions or air pollutants are produced by the systems. Businesses may further benefit from the potential marketing and awareness that green energy initiatives like solar photovoltaics can present to the public.

Solar photovoltaics may also help farms and businesses become more energy independent or self-sufficient as they produce their own power. The energy resilience that can be achieved through the installation of a solar photovoltaic system can help farms and other businesses in the state continue with their operations even when the utility grid goes down. Others may install solar photovoltaic systems because they are far from the power grid. In any case, battery storage would be required to become completely independent of the grid. Off-grid systems will require battery storage for nighttime and inclement weather, while grid-tied systems will not function during an electricity outage due to safety regulations. If you need backup electricity, you should look into not only solar photovoltaics, but other backup options to see which is best for your farm or business.

Solar photovoltaics are often compatible with agricultural operations since farmers generally have high electricity demands, as well as access to open land or roof space to host a solar installation. Solar photovoltaics are also a set-and-forget solution with no moving parts and minimal maintenance. As such, solar photovoltaics can reduce the volatility of future energy costs, particularly when the initial investment is recovered. Considering the free fuel resource (i.e., sunlight), low maintenance costs, and positive environmental attributes, many farms in Maryland are installing solar PV systems with an average projected breakeven timeframe between 6.7 to 8.1 years. According to the 2009 On-Farm Renewable Energy Production Survey, solar projects are the most prominent way to produce on-farm renewable energy, as they are present in 93% of farms with on—farm renewable energy production (U.S. Department of Agriculture, 2011). With that said, solar photovoltaic systems often come with their own share of challenges.

Solar photovoltaics will generate electricity as long as the sun is shining, but your system will produce little to no power on cloudy days or at night since photovoltaic technology requires sunlight for its operation. During periods of low solar radiation, electricity is pulled from the grid rather than the solar panels themselves. It should be noted that the installation of a rapid shut down component is required by law for any grid-tied system in order to keep any electricity from back-feeding into the grid. This safety regulation protects those who are working on the electric lines. While a grid-tied system will shut down whenever the electric grid goes down, an off-grid system (or a system that is temporarily operated during grid outages) will require the additional expense and upkeep of a battery storage system to provide power.

Depending on the type of installation, available roof space or open space on the ground is required to install a solar photovoltaic system. While solar photovoltaic systems may utilize unused roof space or unused areas of your property for ground-mounted systems, local ordinances and building restrictions may further restrict the design and installation of your system. Although solar photovoltaic systems may utilize less land that residential and retail development, solar may still be developed on significant amounts farmland, typically in the range of five to eight acres of solar panels to generate one megawatt of electricity. Depending on the placement, type of panels used, and quality of the installation, solar systems can favorably or unfavorably impact curb appeal.

In terms of environmental and wildlife concerns, most solar installations typically undergo rigorous reviews and permitting from federal, state, and local authorities. Extensive planning and studies are required through this process. While the solar panels themselves are generally warranted for 25-years, their useful lifespan may last much longer before they are decommissioned at their end-of-life. Solar panels can be recycled or landfilled, at which point, the land can be restored to its original use. With this mind, some farmers and landowners in the state are considering leasing their land for solar development – as opposed to the land being permanently lost to commercial or residential development. This arrangement can serve as an important cash crop with lease payments helping farmers to retain their ownership, and the long-term usability, of their land.

While the many benefits and challenges will need to be weighed out on an individual and local basis, the continued expansion of on-farm solar photovoltaics in Maryland is expected to continue due to the continued decline in solar photovoltaic costs, as well as the potential rise in electricity costs.