Offset Tariff: Frequently Asked Questions

The offset tariff encompasses General Rule 20.2.1(B)(7), on Leaf 157, which covers single-account offset arrangements, and General Rule 20.2.1(B)(8), on Leaves 157.1-157.5, which covers multiple-account offset arrangements.

We designed this tariff for customers who want to connect a generator with a nameplate rating over 2 MW to Con Edison’s high-tension system. The generator can supply electricity from that generator to multiple accounts on the customer’s premises.

Under General Rule 20.2.1(B)(8), premises is defined as:
“A parcel of land; or more than one building and/or parcel of land proximate to each other if there is common use, whether or not such buildings or parcels are separated by public or private roads.”

This tariff is intended to apply to campus-style settings with accounts in a single customer’s name. This is consistent with the definition applicable to line extensions in General Rule 5.1 of PSC No. 10 tariff (Leaf 33).

There are some campuses within the city that cross public streets. Typically, they will also have physical interconnections — such as tunnels below the street — and have agreements in place with city agencies to utilize that space for services such as steam lines or chilled-water lines. Such interconnections would fall under “common use” and would thus make connected buildings eligible for this tariff.

NYSERDA currently requires cogeneration projects to be able to provide emergency backup supply, so please check with NYSERDA regarding your particular interconnection arrangement.

If you are taking Standby Service under General Rule 20.2.1(B)(7) or General Rule 20.2.1(B) (8), Con Edison has the final authority to approve or modify the Contract Demand. This will be handled through the interconnection application process and done in collaboration with you as the project is being designed.

No, the Contract Demand on each Standby Service account will be based on your maximum potential demand on Con Edison’s system inclusive of the delivery of the generator’s output to that account. Because the generator’s output does not reduce your use of local facilities, such output will not be netted against your peak demand as registered by your standby service meters. On the other hand, the generator output will be allocated and netted against the as-used demand of each account, as explained below.

As described in General Rule 20.4.3 of the tariff, you can reset your Contract Demand downward once every 12 months if you can show a permanent load reduction. See tariff leaves 164 and 165 for further detail.

A customer that is a Qualifying Facility may take service under SC 11 if the kWhr export of the generation facility exceeds the total kWhr usage registered on the Standby Service accounts. A Qualifying Facility is a cogeneration or a small power production facility that meets the requirements for qualification under Part 292 of Title 18 of the Code of Federal Regulations or a "cogeneration facility," "alternate energy production facility," or "small hydro facility," as defined in Section 2 of the New York Public Service Law.

For an account that is billed under Standby Service rates, As-Used Daily Demand charges are determined for each weekday in the billing period when service is taken from Con Edison to supplement or replace generator output. As-Used Daily Demand charges are based on applying a daily demand delivery charge to the daily peak demand during each time period, net of the kW allocated generator demand (Monday–Friday 8 a.m.– 6 p.m. and 8 a.m.–10 p.m. during the months of June through Sept. and Monday–Friday 8 a.m.–10 p.m. during all other months). As-Used Daily Demand charges for the billing period are equal to the sum of the As-Used Daily Demand charges for the time periods.

Interval metering is required for all accounts billed under Standby Service rates. Each account is then billed separately for daily As-Used Demand charges based on each account’s specific daily peak demand during the time periods specified above. Each account will be allocated a share of the generator demand based on the account‘s registered demand multiplied by the ratio of the generator demand to the sum of demands registered on the meters of all accounts supplied by the generator. Allocated As-Used Generator Demand will be determined for each 15-minute interval.

The Standby Service charge recovers some of the customer-related costs that Con Edison incurs to serve each account, independent of how much energy is used and when. Examples include costs associated with the service line required to connect each account to the distribution system (if you’re taking service at voltages below 138 kV) and costs associated with your accounting (e.g., customer call center, and credit and collections).

There are incremental costs for billing customers under the offset arrangement, as billing under the offset tariff is manually prepared, rather than going through the automated billing system. The charges are per account because billing complexity scales with the number of offsetting accounts associated with a generator.

Currently, there’s no mechanism for Con Edison to purchase VARs. Customers with on-site generation may qualify to sell VARs to the NYISO. Customers with on-site synchronous generation are able to control the generator’s VAR output.

The customer is in the best position to assure equipment under its control is operating properly. And delays in meter-data collection can result in estimated bills, which are unworkable for allocating generator output across multiple accounts.

Metering used for billing purposes must be revenue-grade per New York State Public Service Commission requirements. Meters contain interval data for approximately two months, so we would be able to retrieve data directly from meters once communications have been re-established or by having a Con Edison employee obtain a reading at the premises (at a cost to the customer as specified in General Rule 16.4).