6 - Considerations
Bringing an energy project to completion is a team effort, and it's important to plan ahead.
Permitting & Interconnection
The tail that wags the dog on many solar PV projects, the process of permitting with the local Authority Having Jurisdiction (AHJ), conducting Geotechnical Analysis (Geotech) and interconnection with your local utility should be started as soon in the planning process as possible to ensure timely operation following installation of the system.
Renewable energy projects in California are subject to local building codes and the regulations of that county. Additional key code documents include the California Fire Solar Photovoltaic Installation Guidelines and the National Electrical Code. In the case of schools and state essential buildings, the Division of the State Architect Interpretation of Regulations (IR) 16-8 provides solar PV requirements.
The solar installer selected for the project (the EPC - Engineering, Procurement and Construction contractor) typically handles most permitting requirements, with the exception of the California Environmental Quality Act (CEQA). Your project manager and/or third-party energy consultant should also provide oversight to avoid costly delays in permitting.
With regard to CEQA, Public Resource Code Section 21080.35 was amended to make solar installations on rooftops and in existing parking lots statutorily exempt from environmental review. Ground mounted systems are not included in the exemption and therefore require further effort with regard to CEQA.
Electric cars are increasingly popular, especially in California, where the state provides up to $7000 in rebates for the lease or purchase of an electric vehicle on top of the $7500 federal tax credit. There are both federal tax incentives and state and local incentives and loan programs for the installation of charging stations. Many public agencies and private businesses are providing EV charging for their customers, guests and employees.
The construction of solar canopies in a parking lot is a prime opportunity to include EV charging stations, and many solar vendors will incorporate charging stations into a Design-Build or Design-Build-Operate contract. Even if your organization isn't ready to install EV charging stations, specifying room in the electrical conduit for future installations will make it less expensive and easier to install them at a later date.
Shading and Soiling
Shading even small areas of a single panel can dramatically reduce the output of PV systems. A shading analysis of proposed siting areas must be performed to determine any potential shading issues throughout the year. If shading is unavoidable, micro- or string inverters or optimizers can be used to reduce shading effects.
Because of lower PV module costs, recent trades in solar PV system design have allowed for greater shading in winter months in return for a larger overall system size to maximize annual output.
If vegetation can shade the PV arrays, then vegetation management must be included in ongoing maintenance of the systems. It is important to keep in mind that many PV systems require the removal of large trees on a given site, even when care is taken to design a system to minimize tree removal.
Soiling (dirt) on PV modules also reduces system output. Soiling is dependent on local environment and very site specific. To manage soiling losses, the production/insolation ratio and local weather trends should be monitored as part of the O&M contract with panel washing triggered by unacceptably low production.
Operations and Maintenance
PV systems require maintenance to perform adequately. Most public and private entities do not have the staff or expertise to provide the O&M required for a PV system, and therefore require a separate O&M contract with the installation vendor, or a competent O&M company.
In the case of a Power Purchase Agreement (PPA), O&M is provided by the PPA provider. The O&M contract should specify incident response, monthly and annual reporting and panel washing. O&M contracts are typically a minimum of 10-years with options to extend, termination for convenience clauses, and payments on an annual basis to reduce risk of loss if the O&M contractor does not perform or goes out of business.
Additionally, O&M financial planning should include two inverter replacements in the 25-year lifetime of the system. Some entities opt to purchase extended warranties through their O&M plan to have a known budget for planning purposes. Extended warranties must be weighed against the strength of the company offering the warranty.
Decommissioning - All Good Things Must End
Typical solar PV projects have a design life of 25 years. In reality, solar PV systems are anticipated to function for more than 30 years, but they eventually need to be decommissioned. For direct ownership, decommissioning should be planned for and a decommissioning reserve fund should be set aside. There are currently no solar PV recyclers in California, but components utilize materials found in typical construction and e-waste and can be recycled and disposed of through those channels. The structural elements may be left in place after PV modules are removed to continue to provide shade for the parking areas. Given that the glass, silicon, metals (steel, aluminum, copper) and e-waste will have some value to offset labor and site restoration costs, and based on case studies, a value of $75 per kW based on current PV recycling costs is typically used for decommissioning costs.