Does Your Solar or Battery Need ComEd Rider POG?

Somewhere in the paperwork for a commercial solar array or battery in ComEd territory, a rider gets named. It is usually Rider POG, or one of its siblings, and the customer signing the project rarely knows what it is or why it is there.

It is worth ten minutes, because what the rider is written about tells you something specific about your own project, and because two things people commonly believe about ComEd and on-site generation turn out not to be in the tariff at all.

What the rider governs

Rider POG covers parallel operation of retail customer generating facilities. Its applicability language is about a customer with an electric generating facility operating in parallel with ComEd's delivery system, and the variants attach to different arrangements, including net metered service.

Read that carefully, because the object of the sentence is doing the work. The rider governs the generating facility and its parallel operation. It is a set of terms for having equipment on your side of the meter that is electrically connected to, and can push into, the utility's system.

It is not a rate on what you consume. Your underlying delivery and supply arrangement continues to be whatever it was.

What follows for a battery that never exports

This is where the distinction becomes practical.

A battery drawing energy to charge is load. It is indistinguishable, at the meter, from a compressor or a chiller. It is billed under your normal rate: energy on the supply side, delivery charges on the delivery side, and it contributes to your demand charge exactly as any other load would, according to when it draws.

That last clause is the whole economics of storage in ComEd territory. Because billed demand is set only during weekday hours between nine and six, a battery charging overnight contributes nothing to the demand determinant, while the same kilowatts drawn at two in the afternoon would set a new peak. The tariff does not treat those two differently because the battery is a battery. It treats them differently because of the clock.

So for a non-exporting battery, the parallel operation question is narrower than it first appears. The equipment still has to be reviewed and interconnected properly, because it is capable of energising and must not do so unsafely. But the rider is written about the export-capable, parallel-operating side of the installation, not about charging.

The two things that are not in ComEd's book

Both of these are worth knowing because both get asserted in sales conversations, and neither is supported by the filed tariff.

There is no commercial standby, supplemental or backup-power rider. Some utilities charge a customer with on-site generation a standby rate for the privilege of having the grid available when the generation is not running. Reading ComEd's ratebook, that construct is not there for commercial customers. If someone tells you your solar array will trigger a standby charge, ask them which sheet it is filed on.

There is no separate energy storage tariff. A commercial battery is not reclassified onto a special rate, and grid-charged energy is not surcharged. It is metered as load, at your existing rate.

Neither absence is a loophole. They are simply features of this tariff book, and they are not universal, which is why a national rule of thumb about storage economics can be badly wrong here in both directions.

What to actually ask, and when

The rider is not the decision. It is a consequence of decisions made in the design, and the useful version of the question is asked of the installer before the application is filed.

Which rider variant is this project going on, and why? The answer should follow from whether the system exports and whether it is net metered. If the answer does not match what you were told about export, something in the design and something in the sales conversation disagree.

Does the design export at all? A non-exporting design has different paperwork, different review, and, under Illinois's supply-only net metering, much less to gain from exporting than a proposal from a few years ago would assume. Whether to export is an economic choice now, not a default.

What review level does the size put us in? That question belongs with ComEd interconnection, and it is where the schedule and cost consequences actually live.

The rider itself is rarely the thing that decides a project. It is a good indicator of whether the people filing your paperwork understand what they are building.