The large, low-sloping and shade-free surfaces are an excellent way to generate supplemental revenue and offset the costs associated with landfill maintenance.
In addition to making money from otherwise unusable property, an added incentive that landfills offer is that many sites have gas to energy systems already equipped with the electrical infrastructure - further reducing the overall installation costs.
Behind the Process: Regulatory Concerns
There are several major factors to take into account before solar can be considered. The ideal landfill would be large, relatively flat with little to no shading from adjacent buildings or foliage, and located near an existing power grid.
Once location is determined, it is necessary to work with city agencies to find out what local permits are required - an important step that will result in well-informed bid documents.
The typical permitting process for landfill solar projects, in most cases, includes obtaining a permit for use of the landfill from an overseeing solid waste state agency, local permits and approvals from various boards and agencies such as the planning, zoning boards and conservation commissions, as well as an interconnection permit with the local utility.
The reason for such an arduous approval process is to address the most common concern of the regulatory agencies-- how the construction and operation of the solar energy system is going to impact the integrity and functionality of the landfill's cap?
In order to protect the landfill cap and minimize the risk of penetrating the protective membrane, the solar power installation should be designed to sit on the landfill's surface. This is known as a ballasted installation and requires no excavation or disturbance of the landfill's cap or protective membrane.
Through the various design steps, modifications can be made to the system's racking design in order to best meet any requirements, as well as the overall goal to maximize energy production and savings.
Addressing Issues around Operations
Typical concerns for municipalities where large-scale solar ground mount systems are proposed include limiting site accessibility from the public for safety, lighting impacts, prevention of soil erosion during construction, impacts to 100 year flood zones, the amount of forest clearing needed, impacts to wetlands and other natural resources, as well as the disturbance to traffic and noise during construction.
There are many options to address these issues, such as preventing access by fencing in ground mounted arrays. In the case of lighting issues, for most installations no lighting is necessary, installing it only if specifically requested by the host customer.
Soil erosion and other construction impacts are most often managed through government permits and at the local level through storm water pollution prevention plans and mitigation measures which are designed to protect sensitive areas such as wetlands or surface water bodies.
Often times when an ordinance is required to submit a special permit to the city's planning board for review, a public meeting is also called. The meeting provides a platform for the community to show their support and, in turn, have any of their concerns addressed.
Once the array is connected, the system owner will operate and maintain the installation, and they will be responsible for maintaining vegetation in and around the array, which covers and protects the majority of the landfill cap.
Getting the project financed
The last action item is to research what incentives the solar energy system qualifies for, and what other financing options like a Power Purchase Agreement (PPA) or a municipal bond are available.
Some states even offer upfront cash rebates based on the size or cost of the system, while others spread rebates out over an extended-period (performance based incentive), and are based on the system's actual energy production. Depending on the state, municipality, and utility territory the project is in, incentives can cover more than 50% of the total system costs.
Through a PPA, a third-party investor takes on all finance, design, installation and maintenance costs, and the municipality or landfill owner agrees to buy the clean power the solar energy system produces at a fixed, below-the-grid rate.
With this, municipalities can enjoy immediate cost-savings and environmental benefits, without paying anything upfront, while third-party investors take on all financial risk associated with the system's construction and long term performance. At the end of the contract the municipality has the opportunity to renew their contract or purchase their system outright at fair market value.
Municipal interest rates are at an all-time low, and in many cases, the cost of borrowing money is so cheap, that customers are able to use the energy savings from the solar project to offset or eliminate the loan payments. This is another way for municipalities to see savings on day one, and own the asset that will monetize greater savings.
For any municipality or private landfill, it's worth looking at the options available and discussing them further with a trustworthy solar professional.
By building a solar power installation and saving thousands on operation costs, these projects are a testament to how renewable energy can create a sustainable asset from a previously untapped resource.
Amy McDonough is a project developer with Borrego Solar.
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