Interconnection of renewable energy projects to the grid is generally one of the toughest parts of developing a successful renewable energy project -- second only perhaps to obtaining a power purchase agreement.

California, generally a leader in interconnection matters, has reformed its interconnection procedures in recent years, solving some problems, but potentially exacerbating others. I’ll focus here on the positive.

The Federal Energy Regulatory Commission is currently considering a petition from the Solar Energy Industries Association (SEIA) to adopt some of the key reforms in California’s interconnection procedures so they apply to all states. We should be seeing some major improvements throughout the country as a consequence. For now, these improvements will only impact smaller utility-scale projects, generally 5 megawatts and below.

In California, there are two parallel interconnection choices/procedures: the state-jurisdictional Rule 21 process and the FERC-jurisdictional WDAT/WDT process. Both have been reformed in recent years, but the Rule 21 process has been reformed more significantly and beneficially.

Two key changes to Rule 21 have been very helpful for developers so far:

  • A pre-application report from the utility now answers a number of crucial questions for developers about the proposed point of interconnection; the idea is that developers can get a decent idea about the suitability of the proposed location before they actually apply for an expensive interconnection process.
  • A new screen that allows Fast Track projects (3 megawatts and below) to interconnect at a penetration level two or more times higher than was previously allowed.


Pre-application report

The Rule 21 pre-application report (PAR) costs a developer $300 as a flat fee to the utility. It is to be provided within ten business days from request and furnishes the following answers about the proposed point of interconnection and project, but only if such data is “readily available” to the utility staff:

  • Total Capacity (in megawatts) of substation/area bus or bank and circuit likely to serve proposed site
  • Allocated Capacity (in megawatts) of substation/area bus or bank and circuit likely to serve proposed site
  • Queued Capacity (in megawatts) of substation/area bus or bank and circuit likely to serve proposed site
  • Available Capacity (in megawatts) of substation/area bus or bank and circuit most likely to serve proposed site
  • Substation nominal distribution voltage or transmission nominal voltage if applicable
  • Nominal distribution circuit voltage at the proposed site
  • Approximate circuit distance between the proposed site and the substation
  • Relevant Line Section(s) peak load estimate, and minimum load data, when available
  • Number of protective devices and number of voltage regulating devices between the proposed site and the substation/area
  • Whether three-phase power is available at the site
  • Limiting conductor rating from proposed Point of Interconnection to distribution substation
  • Based on proposed Point of Interconnection, existing or known constraints such as, but not limited to, electrical dependencies at that location, short circuit interrupting capacity issues, power quality or stability issues on the circuit, capacity constraints, or secondary networks.


In combination, this information is very valuable for deciding whether a proposed project site is viable. And for a $300 fee, it’s a steal.

Interconnecting at higher penetration levels

The previous rule limited Fast Track interconnection to projects that represented 15 percent or less of the circuit or line section’s peak load. In practice, due to the loading and capacity of most circuits in California, this meant that only projects approximately 1.5 megawatts and below could pass Fast Track. For example, many circuits in California have about a 10-megawatt to 12-megawatt peak load. This means that a 1.5- to 1.6-megawatt project could in theory pass Fast Track. The actual success rate for Fast Track projects was, before recent reforms, extremely low, for a variety of reasons, regardless of size.

More projects are passing Fast Track now -- dramatically more for some utilities, particularly Southern California Edison. Just as importantly, projects can now successfully pass through Fast Track if, in supplemental review, they are found to represent 100 percent or less of the minimum load on the circuit or line section. As a rule of thumb, minimum load is about half of peak load, so this translates to about 50 percent of peak load. This is up to three times the capacity (in megawatts) allowed under the former Fast Track, so larger projects are now passing Fast Track.

In California, there is still a limit of 3 megawatts, in most cases, on Fast Track, regardless of the 100 percent minimum load rule, but this may be changing soon, due to a petition pending at FERC.

FERC’s new ruling

FERC is about to finalize a new rule under the Small Generator Interconnection Procedure (SGIP), which, when finalized, will apply to all states. One of the key changes is to allow projects up to 5 megawatts to pass through Fast Track, under certain criteria. Once this change filters down to the states, there should be a major new tool for quickly interconnecting projects up to 5 megawatts in some situations. Currently, such projects would have to go through the much more expensive cluster study process or Independent Study Process, if eligible.

As an example of how big an advantage Fast Track can be, see the following table. It’s like night and day.

Interconnection doesn’t have to be such a pain, or so expensive, particularly for projects 5 megawatts and below.


Tam Hunt is owner of Community Renewable Solutions, a consultancy and law firm specializing in community-scale renewables. The firm specializes in Fast Track interconnection, which is becoming available to projects up to 5 megawatts in many circumstances, due to pending FERC reforms, though it is generally limited to 3 megawatts and below even under the new rules. We work with the utility to get projects through with the least hassle and in as short a time as possible.