Community solar power a hit in Florida
A community carport solar power project developed in that sunniest of locations, Florida, has proven to be a big hit with both the power company, Orlando Utilities Commission, and its customers�"subscriptions to the solar power sold out in less than a w
By Tony Kryzanowski
Homeowners interested in solar power frequently encounter two hurdles-the hardware costs and having enough space to install it. But a community solar power project in Florida, initiated and constructed by developer ESA Renewables, and embraced by the Orlando Utilities Commission (OUC), has shown a way to overcome these hurdles.
The OUC hired ESA Renewables through a Request for Proposals process to construct a 400 kilowatt (kW) solar power installation on a carport canopy on 2.5 acres at its Gardenia campus in Orlando. In turn, OUC offered subscriptions to individual customers for the solar power generated by the installation by providing them with a credit on their electricity bills, or 'virtual net metering.'
Subscriptions to the project were limited to five kWs per customer so that one large customer couldn't purchase all the power, making it possible for many people to subscribe. The subscriptions available to homeowners sold out in less than a week.
The OUC community solar installation cost about $1 million and provides not only solar power, but also protective shade for 151 vehicles, and it has earned high praise from OUC employees. It is the first community solar power project of its kind in Orlando and only the second of its type in Florida.
"There really are not that many community solar farms in the United States that we are aware of," says Lindsay Herold, ESA Renewables chief operating officer.
Despite the obvious interest from consumers, there are two constraints to the development of community solar farms. The first is economic. It is easier to work with a single customer than with many customers. The second is legal. There are legal complications related to the size of solar farm development and ownership in the U.S. Often, two solar farms situated side by side require different owners. The regulations vary from state to state.
Herold says OUC deserves a lot of credit for its willingness to consider the community solar approach and making the effort to develop the virtual net metering system internally. They also hosted a number of community focus groups to gauge the level of interest in subscriptions prior to proceeding with the project.
"OUC really wanted to be green and involved in the community," says Herold. "They went the extra mile to be a little bit flexible with the program and make it work for everyone's needs locally."
After completion, the solar project was purchased by Spear Point Energy, an independent power producer and solar project developer. As part of the sale, it negotiated a 25-year power purchase agreement to sell the generated solar power to OUC. While OUC's subscribers will initially pay a slight premium for the purchase of the solar power, their rate is locked in for 25 years.
"Half of our customers live in multi-family housing and do not have the ability to add solar to their homes," says Byron Knibbs, OUC vice president of customer and sustainable services. "Innovative projects like this allow our customers to purchase solar power without the upfront costs or hassle of installing it-with the added bonus of being able to lock in their power rate."
The location and visibility of the solar power project along a major interstate highway brings attention to OUC and the innovative service it is providing to its customers. Given the level of customer interest in solar power, the utility is seriously considering a Phase 2 community solar project. The solar power industry has also taken notice.
"We have received a lot of questions about the program from people within the renewable industry as well as from other utilities," says Herold.
Javier Latre Gorbe, ESA Renewables co-owner and vice president of technical operations, says this type of community solar power installation and virtual net metering system is commonly practiced in places like Spain. ESA Renewables has a strong connection to this European country as a group of investors from Valencia are also owners of ESA Renewables. The company thought the community solar concept could be adopted from Spain and implemented in Florida.
"We have encountered different difficulties when we have looked at solar projects on rooftops. Sometimes the roof is not big enough, too old, there are interconnection issues, or you have shade issues. The same is true in the residential area," Gorbe says. "With our experience on solar farms in Spain, we thought the community solar and virtual net metering approach was the way to go."
Michael Johnson, president of Spear Point Energy, says what attracted the company to investing in the project was the innovative approach that ESA Renewables took in its selection of construction methods, materials, and equipment, as well as the "smart way" that OUC structured its community solar program.
|ESA Renewables used some different building materials and design approaches on the Orlando Utilities Commission project, which helped to reduce the construction period by about half. It also resulted in an installation that can withstand Florida’s rainy and sometimes violent weather.|
ESA Renewables used some different building materials and design approaches on this project, which helped to reduce the construction period by about half. It also resulted in an installation that can withstand Florida's rainy and sometimes violent weather. Winds can sometimes reach over 140 miles per hour. The carport structure features long span modular engineering design, micro-pile technology versus traditional concrete pilings, and pre-cast concrete pads.
"Here in Florida, we not only have high winds but we have water really close to the surface," says Gorbe. "So when you work with concrete, it is really difficult to dry the construction site out, and you have to wait for two weeks."
Instead, ESA Renewables perforated the ground with a hollow, bolt-like metal device that penetrated the earth for about 30', and the concrete was poured inside the hollow device, "making the micro-pile much more efficient than a concrete footer." This also resulted in the use of about one-tenth the amount of concrete as would normally be used. This was the first time ESA Renewables used this approach in the U.S.
The racking system on the carport was constructed of aluminum instead of steel, making it maintenance-free in this rainy environment.
Using aluminum also had a positive impact on the overall cost of the carport structure.
It took about one-third the time to install the racking system because aluminum is lighter than steel and easier to handle on site.
Gorbe says the combination of this approach to install the footings as well as the use of aluminum is what allowed ESA Renewables to construct the solar project in about half the time and also resulted in significant cost savings. Using traditional building materials and methods, a project of this size would normally take about two-and-a-half months. ESA Renewables was able to construct this project using its methods and materials in less than a month.
Pre-cast concrete pads were used to attach the concrete footers to the float level of the racking system.
ReneSola America supplied the 305 watt, polycrystalline solar panels. The installation required 1308 panels. Schletter Inc. supplied the racking system as well as the micro-pile technology and the precast concrete pads. It has three manufacturing facilities in North America and is headquartered in Shelby, North Carolina.
There were two types of inverters used on the project. The central inverter was provided by Advanced Energy and the string inverters were provided by Chint Power Systems America.
"Our CPS 3-Phase string inverters are ideally suited for use in solar canopy designs," says Jesse Batista, Eastern and Latin American Sales manager for Chint Power Systems America. "This decentralized approach provides reduced installation and balance of system (BOS) costs, lowers operation and maintenance costs, and improves system uptime."
Combiner boxes were provided by San Jose, California-based,
Bentek Corporation. OUC provided a transformer from ABB Group to tie in the solar power installation to the grid.
ESA Renewables was the main project contractor, and its electrical contractor was Winston-Salem, North Carolina-based, Sylvester & Cockrum Inc. Most of the electrical equipment-from the circuit breakers to the main panel-was supplied by Eaton Corporation.
The project was offered as an investment to Spear Point Energy, which is among a pool of investors that ESA Renewables works with regularly to provide third party financing on some of its projects.
"I think there is definitely an interest to do other community solar power sites, not only by OUC, but generally in the Florida market," says Herold. "The biggest challenge is just structuring the program for some of these sites."
A number of interested parties and community organizations-from universities to architects to renewable power groups-have visited the site. Gorbe says there is really no limitation on the size of this type of community solar project, and there is definitely more opportunity in Florida, which would allow companies to extend the value of their parking places beyond just parking.
He also says it is possible to develop more solar projects on existing structures. It is simply a matter of conducting the proper engineering and design studies.
"That's the beauty of solar-it is modular, and you can adapt it to almost every environment and urban area," says Gorbe.