E-27 — Policy on the use of Electricity Meters in Net Metering Applications

E-27—Policy on the use of Electricity Meters in Net Metering Applications (PDF, 50 KB, 4 pages)

Category: Electricity
Bulletin: E-27
Document (s): Information Bulletin 2007-04-20
Issue Date: 2007-04-20
Effective Date : 2007-07-01
Supersedes :

Table of Contents

1.0 Scope

This document applies to electricity meters used in net metering applications.

2.0 Purpose

The purpose of this bulletin is to establish Measurement Canada's policy on the use of electricity meters for net metering applications, clarify the conditions under which electricity meters can be used for net metering for the purpose of establishing a charge for the sale of electricity, and communicate the date by which only electricity meters approved for net metering will be allowed to be used in net metering installations.

3.0 Authority

3.1 The temporary permission for the use of electro-mechanical meters in net metering applications is granted under the authority of subsection 9(2) of the Electricity and Gas Inspection Act.

3.2 No requirement in this bulletin shall be construed as limiting the powers of the President in his capacity as director under the Electricity and Gas Inspection Act and Regulations.

4.0 References

4.1 Electricity and Gas Inspection Act (R.S. 1985, c. E-4), s. 9, 28.

4.2 Electricity and Gas Inspection Regulations (SOR/86-131), s. 13,14, 18.

4.3 Specification S-E-05: Specifications for Approval of Type of Electronic Meters - Net Metering

5.0 Terminology

Bi-directional meter

A bi-directional meter is a meter that has the capacity to meter delivered energy or received energy and to record them in separate registers.

Delivered Energy

Delivered energy is the energy measured when current flows through the meter from the electricity grid to the load.

Micro-Generator

A micro-generator is typically a residential or small commercial generator that is connected to the electricity grid, and produces their own electricity. The source of the electricity generation could include but is not limited to using renewable energy sources.

Net Metering

Net metering is the ability to measure delivered and received energy and to register the difference (net) between the two. If received energy exceeds delivered energy the net value is negative. If delivered energy exceeds received energy the net value is positive.

Net meter

A net meter is a meter that is used to perform net metering.

Net Register

A net register is a register, which records the difference (net) between the value of the delivered and of the received energy quantities measured by the meter.

Received Energy

Received energy is the energy measured when current flows through the meter from the load side of the service back to the electricity grid.

Registered Contractor

A registered contractor is an organization registered pursuant to Section 6 of the Electricity and Gas Inspection Act.

6.0 Background

The growing application and expansion of micro-generation of electricity by consumers in recent years has raised industry interest in the metering of electricity energy flow from the consumer to the contractor. Consequently, this has raised questions on the accuracy of electricity meters measuring the energy flow in forward and reverse directions. This type of measurement is available on most of the bi-directional electronic meters currently used in the market. However, electricity contractors and micro-generators agree that measuring the difference between the forward and reverse energy flows (i.e. net metering) is often more beneficial or practical for this type of trade transaction. Provincial jurisdictions across Canada have determined a variety of methods for applying net energy measurement (i.e. net metering vs. net billing).

Measurement Canada (MC), in cooperation with National Resources Canada (NRCAN), and electricity industry and micro generator representatives have recently completed a study on the application of net metering in Canada and the restrictions resulting from the federal Electricity and Gas inspection legislation and associated policies. Experiments and studies were also conducted with regard to the accuracy of electro-mechanical meters when placed in net metering situations. Two primary facets emerged that needed to be addressed, namely, the possible use of existing electro-mechanical meter installations for net metering applications, and approval of electricity meters for this purpose.

7.0 Policy on Electricity Meters used for Net Metering

7.1 General

7.1.1 Electricity meters that are used for net metering shall be of a type that is approved by MC for that specific purpose with the exception of the meters referenced in 7.1.2. Meters containing bi-directional and/or net metering functions are acceptable to MC.

7.1.2 Electro-mechanical meters may be used in net metering applications for the purpose of establishing the basis of a charge for electricity on a temporary basis under the conditions prescribed in section 7.2 of this bulletin.

7.2 Temporary Permission to Use of Electro-mechanical Meters for Net Metering Applications

7.2.1 Agreement and/or Contract

7.2.1.1 The micro-generator and contractor shall establish an agreement/contract to use the existing electro-mechanical meter as long as this meter currently complies with MC legal requirements (i.e valid seal). The signing of the agreement/contract by the two informed parties will attest that they understand and acknowledge the use of the existing meter for the intended purpose, and they understand the policies contained in this bulletin.

7.2.1.2 The agreement/contract shall include the following statement(s) or convey the same intent:

  1. In the case of a disagreement between parties where the accuracy of a meter is suspected, the parties will try to resolve their disagreement before requesting a dispute investigation by MC.
  2. All parties named in the agreement/contract shall indicate that they understand the potential inaccuracy of electro-mechanical meters used in reverse direction for the purpose of net metering. MC's ability to successfully conclude a dispute investigation may be limited as a result of this anomaly.

Note: MC has performed a study on the effect of operating electro-mechanical meters in the reverse direction. This study indicated that at low currents, the accuracy trend of electro-mechanical meters taken from a small sample of meters tested shows the errors to be in favour of the contractor. The report included results showing that some errors at low currents may be as high as 8% slow. Details of this study by MC will be made available on MC's website.

7.2.1.3 The contract shall identify each metering site which will be subject to net metering.

7.2.1.4 Each party entering into the agreement/contract shall have reviewed and understand the policy contained in this bulletin.

7.2.1.5 Expiry of Temporary Permission

This temporary permission shall expiry upon replacement of the existing electromechanical meter, but no later than December 31, 2013. After this date or upon meter replacement, any meter used for net metering shall be of a type approved for this purpose, otherwise an applicable bi-directional meter shall be used.

7.3 Compliance Sampling of Electro-mechanical Meters Used For Net Metering

7.3.1 Electro-mechanical meters used for the purpose of net metering shall not be eligible for compliance sampling.

7.3.2 Any electro-mechanical meters used for net metering shall be removed from their compliance sampling group and replaced with approved net metering prior to the date when the meter is required to be reverified. If the meter is due for reverification prior to January 2014, the meter shall be replaced with either a meter approved for the purposes of net metering or with an applicable bi-directional meter.

7.4 Approval of Electronic Meters For Net Metering

7.4.1 Electricity meter approval applicants are encouraged to ask for net metering approval when submitting a meter to MC for type approval unless they know that the meter will not comply with the specifications for net metering approval.

The criteria for type approval of electronic net metering can be found in MC Specification S-E-05: Specifications for Approval of Type of Electronic Meters - Net Metering

7.4.2 The Notice of Approval issued by MC for a meter with net metering function shall indicate that a the meter is approved for this purpose.

7.5 Identification of Meters used for Net Metering

Each meter that is used for net metering shall be physically marked to identify it's use for this purpose. The identification mark may be in the form of a sticker, tag or other suitable material, and shall be easily visible, indelible, and weather resistant. This identifying mark shall be affixed to the meter by the utility or micro-generator.

7.6 Identification of Micro-generators

Each micro-generator shall be identified uniquely within the contractor's billing records and on any correspondence sent to MC. For example, in the case where contractors apply special tariffs for a micro-generator class of customers, identification of this customer class would meet the intent of this requirement.

8.0 Additional Information

For additional information regarding this bulletin, please contact the Senior Program Officer responsible for electricity measurement.

Gilles Vinet
Vice-President
Program Development Directorate