Permitting, Interconnection, and Installation (PPI) for Solar Systems

Installation of solar generation systems is growing at a very fast pace for various reasons (Government incentives, possibility of a reduced power bill, and love for the earth). In some states it is nearly doubling every year. These systems may be private, or commercial. In either case, they are bound to have an impact on the surroundings, and the community around may have objections. Also, a connection of the solar project to the grid is always preferable for many reasons. Solar energy is intermittent in nature. When the sun is available, extra energy may be produced. When the sun is down, grid energy will be required. Energy supplied to the grid will be accounted by the utility towards the energy bill of the solar operator. Connection to the grid demands care and protection. The utility, and the local government or state machinery may need to inspect the site and review the plans before they permit. Further, the rates of selling and purchasing, and other conditions must be signed. This whole process is called “permitting, Interconnection, and Installation (PPI)”.


Permitting is the first step towards installing a renewable energy project. Permission is required from the state / local government to install the system. Permission is also required from the utility provider to connect to the grid. The government, as the guardian od public interest, has to ensure that the proposed project does not have any potential to pose a risk to individuals, the community, or the environment.


At the same time, the utility has to ensure that an interconnection to the grid is technically and operationally safe. The utility is bound by law to purchase extra energy from the solar generator if one applies to it. But the utility operator must ensure that the interconnection does not affect the stability of the grid, safety of workmen, and quality of power on the grid.


Thus, both the Authority having Jurisdiction (AHJ) in the area, the utility operating in the area must carefully examine the plans submitted. This may involve one or more visits by them to be able to grant a permission. While the government AHJ will ensure that the public interest is not compromised, the utility representatives will have to ensure that the project is not likely to compromise the grid quality and stability as well as the workmen’s safety. Towards this end, the utility may require the project operator to add requisite equipment or modify the proposed system to some extent.

Going Through PII

PII is a complex process demanding a very responsible action on the part of the utility and the government. It is also a difficult process for the applicant. It affects the applicant in two ways. It adds costs to the project in terms of fees to be paid to both permitting parties. Issues pointed out may necessitate modifications to the plans which will add cost. The utility may demand additional safety and metering equipment, which will also raise the cost. Intangible cost will also be added because the process can take many weeks to complete.

Simplifying the Procedure

Most of the complexity is due to extra caution by the state and local authorities, and different sets of rules and criteria by different states and AHJs. How does the AHJ ensure that no member has any objection. Different states and local authorities have different perceptions of how to protect public interest. A time period is allowed by some to permit affected parties to raise objections. In order to facilitate the citizens, different states are now considering simplifying the procedure. The state of Vermont has evolved a procedure which will allow systems under 15KW to be permitted in only ten days. The process is based on clear definition of requirements (of the local building and wiring codes etc. and the utility interconnection requirements) and a self-certification by the applicant to the Public Service Board (PSB) that his / her project meets all the requirement. If the utility does not object to the proposal within ten working days, a “Certificate of Public Good” is automatically deemed to have been issued. The project stands permitted. This, of course, demands a lot of care and preliminary work on the part of the proposer.

What Should I do?

If you are planning to install a solar system, and you are not familiar with the process, it may be cost effective to obtain specialist help. Whoever is designing or supplying a system is the most likely person to execute the PII process for you. At a fee, of course.
Florian Lewe

Florian Lewe

on 16 Feb 2023

Permitting, Interconnection, and Installation is referred to as PPI twice in this article, whereas later the correct abbreviation used is PII. Also thanks a lot for providing all this free information!

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