Elevating solar power
Vermont cattle operation Maple Ridge Meats wanted to diversify its business and decided to install a solar power operation. With the help of RBI Solar and the Green Lantern Group, their cattle now graze contentedly, sheltered from the sun and rain, under
By Tony Kryzanowski
Vermont-based solar power developer Green Lantern Group has found a way to minimize the footprint of a solar array on pastureland by elevating the support structure.
In fact, raising the height of the solar array improves the comfort level of grazing animals as they now have shelter from both sun and rain, while still being able to graze the surrounding area.
Keeping the solar power site in agricultural production was an important pre-condition for Maple Ridge Meats when it agreed to Green Lantern Group's $1.8 million, 500-kilowatt, ground-mounted solar project on 4.5 acres of pasture near Benson, Vermont. The company had to design the array in such a way that the cattle producer and commercial slaughterhouse business could still graze cattle on the site.
Green Lantern Group has been engaged in renewable energy development exclusively in Vermont since 2011, having completed about 50 projects ranging from 40-kW rooftop projects to 2.2-megawatt ground—mounted systems, with the majority being 500-kW projects. They own some projects outright and own portions of some projects through their involvement in an investment fund, while contracting their services for project development and construction to other investors. They also have operations and maintenance agreements on many projects they have developed. That is the case with the Maple Ridge Meats array, which they sold to other investors.
The solar panels for the Maple Ridge Meats solar array, which was constructed and came online in June 2016, are mounted so that their lowest edge is 8' above ground.
According to Sam Carlson, project development manager at Green Lantern Group, among the biggest challenges was installing sturdy enough support posts above and below ground to support the array at that height, taking the influence of greater wind load into consideration. The posts are driven 10' to 12' into the ground—about 25 percent deeper than a conventional array—with the same height extended above ground. The heavy clay soil provided an excellent medium to support the posts and made a cost-effective, single-post support system possible. The overall design of the array was constructed with stronger steel, and support brackets were placed behind each solar panel.
Overall, Green Lantern Group was very pleased with the post and racking design solution provided by manufacturer RBI Solar, because it satisfied the landowner and only added about $80,000 to the overall project cost. RBI Solar project manager Jeff Cooley says it was a fairly simple fix to overcome this challenge.
"We basically just used some really large posts and manufactured our typical racking system to be way up high in the air," says Cooley. "The system in general is very robust. From an installation standpoint, it was tricky because typically workers can work off four or six foot ladders. On this project, we had to use matting under the array because it was spring when construction took place, and then four-wheel drive scissor lifts on that matting to work at that height."
Both he and Carlson agree that this design has significant market potential to open doors to more solar development on pastureland with good soil support, where landowners can still graze a portion of the land while benefiting from the rent paid by developers—and gaining shelter from the solar array for their animals.
Also assisting with the construction of the Maple Ridge Meats solar array were electrical contractor E&S Electric; civil engineer Krebs & Lansing Consulting Engineers; procurement, planning, and electrical design consultants Solar Power Engineering Co.; environmental consultants Arrowwood Environmental; and landscape architect T. J. Boyle Associates. The 2,300 solar modules were purchased from Canadian Solar. Chint supplied the inverters.
Maple Ridge Meats is situated on the Hathaway Farm, which had operated as a dairy farm until current owner, Greg Hathaway, decided to raise beef cattle and establish a commercial slaughterhouse instead. The farm raises about 250 head of beef cattle on 650 acres, processing their own beef, as well as cattle from producers throughout New England.
Hathaway says he thought that generating renewable power was a good way to provide a second revenue source for the business. The farm benefits from the rent paid by Green Lantern Group to occupy the land, but not from the power generated by the solar array. Through a system of virtual net metering, the power produced by Green Lantern Group is transmitted to Vermont utility Green Mountain Power and is sold through a system of net metering credits to a business called Cabot Agri-Mark Cheese and Dairy Company. In addition to renewable power development, finding off-take customers for the generated power is part of Green Lantern Group's business model. The developer has a 20-year land lease agreement with Maple Ridge Meats for the solar array and a 20-year purchase agreement with Cabot Agri-Mark for the net metering credits.
|The Maple Ridge Meats solar project design has significant market potential to open doors to more solar development on pastureland with good soil support, where landowners can still graze a portion of the land while benefiting from the rent paid by developers-with the solar array providing shelter for their animals.|
One issue that had to be resolved before Hathaway agreed to the project was the solar array's footprint and the problem that fencing the project would cause the land to be agriculturally non-productive. Raising the panels and allowing cattle to continue to graze the area has solved that problem. Hathaway adds that there are plans to use the land for cows during calving season because it is close to the barn and provides shelter in a fresh air environment. Once calving is complete, the area will be grazed by yearlings, which are smaller members of the herd. The area also serves as a paddock for cattle arriving for slaughter from other beef cattle farms.
But Carlson says more solar projects like this probably won't be built again in Vermont any time soon without some change in site regulations.
He says that Vermont was making huge strides toward achieving its goal of being 90 percent renewable in energy, transportation, and heating by 2050, with major development taking place between 2012 and 2016 and more than 17,000 workers employed. This represents the most jobs in the renewable energy industry per capita in the country. The state's energy compensation rate for solar power was a major attraction, but that ultimately had a negative influence on traditional utility profitability.
"The solar incentive included some measures that made the value of the net metering credit greater than the retail cost of electricity," says Carlson. The utilities were starting to lose money because of the expansion of solar power generation.
Carlson says that the utilities were great to work with during the early rollout of investment in renewable power in Vermont because it reduced their transmission costs, and they were also able to sell Renewable Energy Credits (RECs) to utilities still generating power from fossil fuels in neighboring states. However, that relationship has soured somewhat over the past few years as it became obvious that the solar tax credit program was having a negative impact on the utilities' profits.
|Keeping the solar power site in agricultural production was an important pre-condition for Maple Ridge Meats when it agreed to a 500-kilowatt, ground-mounted solar project on 4.5 acres of pasture near Benson, Vermont.|
"In 2016 and so far in 2017, utilities have become much more difficult to work with because they increasingly perceive net metering as a threat to their revenue, and as a consequence, they threatened to increase electricity rates on all ratepayers because of solar net metering," says Carlson.
Recently, Vermont altered its energy payment structure for new solar projects, which significantly reduces the value of the solar net metering credit. Carlson says that it represents about a 23 percent drop in the per kilowatt revenue of a 500 kW solar net metering project.
The new state initiative also encourages developers to pursue smaller solar projects on disturbed sites like reclaimed gravel pits, capped landfills, parking lots, or brownfield sites instead of farmland, while incentivizing companies not to sell RECs outside the state.
"By the end of 2018, there will be very few reclaimed gravel pits, landfills, and quarries left that have potential for solar development, and at that point, I think solar development is really going to decline," says Carlson, adding that it could be argued that one of the state's goals with these new net metering rules has been to dampen the pace of solar net metering development.
The Maple Ridge Meats solar project was a resounding success, benefiting from Vermont's previous solar incentive program, the 30 percent federal investment tax credit, a $77,000 'Rural Energy for America' grant from the United States Department of Agriculture to help pay for the elevated structure and racking design, and no disincentives for selling RECs outside the state. But Vermont's Public Utility Commission will no longer issue 'Certificates for the Public Good' for 500-kW solar projects like this one on agricultural land without two levels of local and regional government endorsing the project as a preferred site, which Carlson says they seem reluctant to do so far.
In addition to slowing solar development, the new state program is also cutting off a potential new farm income source for many struggling Vermont dairy farmers.
"There are many farm fields in Vermont that can be developed for solar, and there are many farmers who are having a very tough go of it in part because milk prices are so low," says Carlson. "There are many dairy farmers in Vermont that see leasing their land for solar as a real opportunity to maintain the financial viability of their farms by being able to generate a guaranteed amount of revenue for 20 years that was about four times what they could earn on that same four acres by growing hay or grazing their dairy cattle."
While some people criticize the loss of agricultural land due to solar development, leasing land for solar activity helps farmers keep the rest of their land in agricultural production.
Green Lantern Group is actively investigating the entire region around Vermont to see where this elevated array concept might have more business potential, and they are also investigating business opportunities in solar power energy storage development within the state.