Skip to main content

PV Guidance

FINDINGS #8, December 2013


On-Site PV Guidance will prove to be a useful and valuable tool for anyone contemplating a solar energy project.” Kevin Myles, Branch Chief, R7

On-Site PV Guidance Report Offers Valuable Information for Project Implementers

In 2011, GSA contracted with the National Renewable Energy Laboratory (NREL) to collect critical knowledge gained from developing and implementing GSA’s 63 newest on-site photovoltaic (PV) solar energy projects. The study was supported by GSA’s Green Proving Ground (GPG) program with the intent of optimizing how the agency locates, sizes and funds future projects for a maximum return on investment. The resulting lessons learned, best practices and case studies were compiled into a robust resource that also contains guidance on project considerations such as funding, incentives, interconnection and permitting. On-Site PV Guidance aims to help future project teams maximize their projects’ chances for success and minimize the risk of underperformance, and may also be useful to other real estate organizations with interests in PV projects.

What We Did


NREL researched existing literature to identify a broad set of policy challenges and risks involved in on-site PV deployment, then surveyed GSA project teams to collect information on the specific challenges they faced and their respective outcomes. Following review of the survey results, NREL conducted interviews with a subset of the respondents and aggregated the findings and industry research into lessons learned and best practices. GSA supplemented NREL’s research with case studies from its project teams, and both organizations provided additional reference material and links to existing guidance.

What We Evaluated


The survey captured both project-specific and general information on the types of challenges PV project teams experienced in the following categories: project management, site, interconnection, technical, economic, incentives, weather, lack of expertise, procurement, state or local laws and regulations, conflicts with agency or site mission or plans, net metering, and other utility issues. Respondents were asked about the effects of each challenge on their projects; whether there was an action, best practice, or key success factor employed that lessened the impact; and the potential impact on their project if the challenge had not been resolved. The survey also collected data on project location, utility provider and PV system capacity— factors that determine policies, rules, and contractual forms.

Icon for Building Applicability

GSA'S DIVERSE PORTFOLIO OFFERED A BROAD SPECTRUM OF EXPERIENCE  GSA’s substantial portfolio of PV projects, together with its project teams’ collective experience and knowledge, provided a rare opportunity for examining a broad spectrum of challenges and potential solutions. The study yielded wideranging lessons learned and best practices because the projects studied were diverse in terms of location, capacity, and funding source or mechanism — variables that have a potential impact on project considerations including, but not limited to, energy resource, financial strategy, procurement methods, construction type, and approach to operations and maintenance.

Gear Operations Maintenance icon

CHALLENGES WERE NUMEROUS AND UNIVERSAL  The study revealed that PV project developers face many challenges in ensuring that installations are both feasible and operable. No trends were identified based on project location. Most challenges faced by GSA project teams fell within five main categories: project management, site, interconnection, technical, and economic. Project teams were usually able to overcome the issues they encountered, though many of the projects experienced delays or financial impacts.

Tag cost effective icon

MANY PROJECT RISKS CAN BE MITIGATED BY ADVANCE PLANNING AND MANAGEMENT  Project teams can plan for and manage risks to address potential issues before they arise, as well as expedite implementation and improve quality of outcomes. Early discovery of potential challenges often allows for modifications in design and scheduling to be made at minimum cost to the project, so that the project can remain a viable investment. Forming an integrated project team (i.e., with an executive level champion, architect, engineer, lawyer, contracting officer, estimator, energy expert, and facility manager) from the outset can be invaluable for surfacing and addressing potential challenges.


Projects in NREL Study, by System Capacity. Of the 63 projects included, capacity ranges widely

[*Projects in NREL Study, by System Capacity. Of the 63 projects included, capacity ranges widely]

What We Concluded


With more than 9,600 assets and over 354 million square feet of workspace, GSA has enormous potential for implementing renewable energy technologies, including solar PV, to reduce energy use and associated emissions. By learning from the experiences of their predecessors and from the additional guidance provided in On-Site PV Guidance, project teams can maximize their projects’ chances for success while avoiding pitfalls such as schedule delays, adverse financial impacts, and reduced quality. One of the most remarkable findings from this study is the modest effort needed to identify and avoid these pitfalls; sometimes it is only a matter of ensuring early in the project that the right people are on the team and in contact with the appropriate experts.

There are several excellent resources in On-Site PV Guidance that should be explored by federal agencies and others who are contemplating implementing a PV project. Two sections of the report also function as standalone guidance for future PV project implementers: the Photovoltaic (PV) Project Considerations Guide and GSA PV Project Lessons Learned and Best Practices.

For more information, contact Green Proving Ground


Reference above to any specific commercial product, process or service does not constitute or imply its endorsement, recommendation or favoring by the United States Government or any agency thereof.


The Green Proving Ground program leverages GSA’s real estate portfolio to evaluate innovative sustainable building technologies. The program aims to drive innovation in environmental performance in federal buildings and help lead market transformation through deployment of new technologies. 



Thumbnail image for PV Guidance Findings report

Findings: PV
Guidance >


Cover for PV Guidance Report

Guidance >

GPG Technologies findings PV Guidance