Smart Inverter Power Priority Setting Staff Proposal Informal Comments Due

Through the stakeholder calls for the implementation of the Phase 1 requirements, the SIWG has had significant discussion regarding the modification of the Volt/Var function in Electric Tariff Rule 21 (Rule 21) to transition all grid-connected inverters subject to Rule 21 from reactive power priority to real power priority. With this in mind, CPUC Staff has produced a Staff Proposal on how the investor-owned utilities (IOUs) can modify the Rule 21 tariffs to require Volt/Var setting changes to enhance grid function. Please note that this is a staff proposal and not a Commission order. Energy Division is seeking informal comment to inform Commission consideration of this issue.

Stakeholders are strongly encouraged to provide informal feedback on this Staff Proposal. CPUC Staff requests informal written comments on the Staff Proposal by 5 PM PST on Friday, August 11, 2017. Instructions for preparing and submitting comments are provided at the end of this email. At this time, Commission Staff does not see the need for reply comments but will consider allowing reply comments if parties request the opportunity to submit them.

After gauging the degree of consensus on this Staff Proposal, the Energy Division may work with the IOUs to finalize tariff revisions to be submitted to the Commission via advice letters. Alternatively, the Commission may provide another regulatory channel to address this issue. Please note that the utilities have the liberty to submit advice letters on their own motion at any time.

Staff Proposal Summary
CPUC Staff proposes to modify existing Rule 21 tariff language to incorporate reactive power priority through the following text change to Section Hh.2.j. Please see the attached document for the full Staff Proposal.

The Smart Inverter shall be capable of operating dynamically within a power factor range of +/- 0.85 PF for larger (>15 kW) systems, down to 20% of rated power, and +/- 0.9 PF for smaller systems (≤15 kW), down to 20% of rated power, based on available reactive power. This dynamic volt/var capability shall be able to be activated or deactivated in accordance with Distribution Provider requirements.

When activated, the Smart Inverter shall provide reactive power irrespective of the effect on active power. The reactive power provided shall be based on available reactive power, but the maximum reactive power provided to the system shall be as directed by the Distribution Provider.

Distribution Provider refers to the electric utility the customer is connected to, i.e. Pacific Gas and Electric Company (PG&E), San Diego Gas & Electric Company (SDG&E), or Southern California Edison (SCE).

CPUC Staff proposes that new interconnecting generating facilities be required to comply with the modified language by January 1, 2018.

Guidelines for Preparing Comments
CPUC Staff requests stakeholders address the following prompts:

Do you agree that transitioning to reactive power priority will better support voltage regulation and help to reduce distribution upgrade costs associated with high penetrations of DERs, and if so, why? Parties should offer the pros and cons of adopting reactive power priority.
Does the proposed tariff language adequately reflect the goal of the text change, i.e. to ensure reactive power priority, and if not, how can the text be modified?
Is the proposed date optimal and achievable, and if not, what is the preferred date and why? Please be specific in your reasoning. For instance, you may indicate what tasks and lengths of time are necessary to comply.
If the change to reactive power should not be adopted, please give specific reasons why not. Parties may provide any research and/or evidence available to demonstrate from a technical standpoint that real power priority should be kept in favor over transitioning to reactive power priority.

Instructions for Submitting Comments
To submit comments, please send but do not serve comments to Jeffrey Kwan ( of the Energy Division. It is not necessary to submit hard copies or to include certificates of service. Jeff will post submitted comments to the CPUC’s Smart Inverter Working Group webpage. All comments received by 5 PM on August 11, 2017 will be fully considered and posted. Jeff will send notification of the available comments once they are posted.

Event Date: 
Wednesday, August 16, 2017 - 17:00
Focus Area: