Fixing a major market distortion that disadvantages local renewables
The Clean Coalition, backed by a broad range of organizations, is leading a campaign to remedy an unfair charge on local renewable energy in California.
What are TAC?
Transmission Access Charges (TAC) are fees designed to pay for the state’s transmission system, including operations and maintenance, amortization of capital, and return-on-equity. TAC add about $0.03 per kilowatt-hour (kWh) to the levelized cost of energy over a 20-year contract, which is about 30% of the wholesale value of energy in California. To align costs and benefits, TAC should only apply to energy that is delivered through the transmission system. Therefore, TAC should be calculated based on the metered Transmission Energy Downflow as measured at the transmission substation and distribution substation, where energy down-converts from transmission grid voltages to distribution grid voltages.
TAC are being misapplied
Currently, any California utility that owns part of California’s transmission grid (known as a Participating Transmission Owner or PTO) applies TAC based on the metered load of its customers, or Customer Energy Downflow (CED) — not the utility’s metered Transmission Energy Downflow. As a result, PTOs pay TAC on every kWh delivered at the customer level, even if that energy was not delivered through the transmission system.
The current TAC assessment on every kWh of metered customer electric usage, instead of on metered Transmission Energy Downflow, creates a major market distortion. The transmission cost savings of local distributed generation (DG)* are denied to ratepayers, local generation is denied fair market competition, and communities lose the benefits of local energy development.
Creating a level playing field for local renewable energy
The Clean Coalition’s campaign seeks to change PTOs’ TAC assessment methodology to calculate TAC based on metered Transmission Energy Downflow, aligning charges with cost causation. Through this campaign, we seek to correct the California Independent System Operator (CAISO) tariff language to assess TAC on a utility’s Transmission Energy Downflow. This fix will ensure proper valuation of local renewable generation, including the avoided use of transmission. Local energy should not continue to subsidize transmission infrastructure when these resources are actually reducing the need for future investments into the transmission system.
Leveling the playing field helps WDG win utility procurement bids
PTO utilities evaluate energy project bids through the Least Cost Best Fit (LCBF) analysis. Using LCBF, a project is evaluated by its cost of generation plus the cost of any system losses or upgrades required to deliver the project’s energy to consumers. LCBF does not currently consider TAC because CAISO assesses TAC regardless of whether energy is delivered through the transmission system. As shown in the example below, a local DG* project may have higher generation costs, but lower total delivered cost — if recognized for avoiding use of transmission capacity.
Initially, utility and ratepayer TAC costs remain constant
- No change to the Transmission Revenue Requirement (TRR) used to calculate the TAC rate; the transmission system continues to be fully paid for and used
- Slight decrease in metered transmission usage used to calculate the TAC rate
- Slight increase in TAC rate
- No change to total transmission costs incurred by ratepayers
Ratepayers save over time when less transmission is needed to deliver energy
Eliminating the TAC market distortion will result in increased deployments of local generation, which reduces required investments in new transmission. As a result, TAC will not grow as quickly and can even decline as existing assets depreciate, saving ratepayers enormously: up to $26 billion over 20 years for all California ratepayers. The chart below shows drastically reduced TAC rates over 20 years by eliminating the TAC market distortion. The area between the blue curve and the other curves represents avoided ratepayer transmission costs.
Cost of implementation is negligible compared to benefits
Implementing the Clean Coalition’s proposed TAC fix will require installing revenue-grade meters at substations, at a total cost of less than $20 million: an average meter upgrade cost of less than $10,000 per substation, and fewer than 2000 substations need a meter upgrade. This implementation cost is negligible compared to the tens of billions of dollars in TAC savings for ratepayers over the next 20 years. Furthermore, the communications solutions are already in place for use with the existing non-revenue grade metering hardware.
Want to get involved?
Your support will help ensure CAISO resolves the TAC market distortion by eliminating TAC charges on local renewable generation. To become a TAC Campaign supporter, email your logo to Josh Valentine at firstname.lastname@example.org, and state you authorize the Clean Coaliton to use your logo on its TAC Campaign Supporters web page.
Timeline of key events
- September 2016: Clean Coalition, UCLA, SolarCity, and Sierra Club join forces to deliver a webinar discussing how a simple fix will benefit local renewables, ratepayers, and the environment by eliminating the TAC market distortion. Subsequently, CAISO canceled the TAC Wholesale Billing Determinant initiative, and buried the TAC billing determinant issue within a future, broader stakeholder initiative that won’t start until CAISO resolves issues related to CAISO’s proposed expansion. The rationale for the cancellation is not consistent with the facts as supported by evidence from CAISO staff or stakeholders, and California ratepayers can’t afford the delay. The Clean Coalition continues to advocate for a timely resolution to the TAC market distortion by working with the CPUC and state legislators, as well as with CAISO.
- June 2016: Stakeholders submitted comments to CAISO about the issue paper on June 30, including the Clean Coalition.
- June 2016: CAISO releases a TAC issue paper to serve as the basis for a new, TAC-focused stakeholder initiative, the TAC Wholesale Billing Determinant initiative. Stakeholders submitted comments to CAISO about the issue paper on June 30.
- May 2016: CAISO announces it will open a separate TAC-focused stakeholder initiative because, “…TAC billing determinant changes will be of interest and importance to many stakeholders… who might inadvertently miss this important topic due to its reduced visibility within ESDER 2.”
- April 2016: the Clean Coalition files in ESDER a detailed proposal for changing PTOs’ TAC assessment methodology.
- March 2016: CAISO announces it will address the TAC issue in Phase 2 of its Energy Storage and Distributed Energy Resources (ESDER) stakeholder initiative.
- November 2015: Clean Coalition submits a filing to CAISO about the TAC market distortion.
Clean Coalition documents
- Two-page TAC overview
- TAC Campaign Q&A
- Briefing for CAISO Market Surveillance Committee on Transmission Access Charges Wholesale Billing Determinant Initiative
Clean Coalition webinars
- Local renewables are being robbed: Simple fix to massive market distortion caused by erroneous treatment of Transmission Access Charges (September 1, 2016)
Clean Coalition regulatory filings
- September 29, 2016 comments in CAISO’s 2017 catalog of initiatives: updating CAISO’s review of the TAC wholesale billing determinant and ensuring stakeholders are aware of the expanded scope and opportunity to participate in 2017
- August 25, 2016 comments in CAISO’s TAC Options initiative: reviewing the working group proposals on how to assess TAC for new transmission projects under an expanded CAISO jurisdiction
- June 30, 2016 comments in CAISO’s TAC billing determinant initiative: detailing the Clean Coalition’s proposal to fix the TAC market distortion by changing the billing determinant and responding to initial questions from CAISO staff
- June 10, 2016 comments in CAISO’s TAC Options initiative: explaining how the Clean Coalition’s proposed TAC fix might apply in an expanded CAISO jurisdiction
- June 9, 2016 comments in CAISO’s ESDER initiative: reacting to the creation of a separate stakeholder initiative and requesting a prompt review of the Clean Coalition proposal
- April 18, 2016 comments in CAISO’s ESDER initiative: detailing the Clean Coalition’s proposal to fix the TAC market distortion by changing the TAC billing determinant
- February 10, 2016 comments in CAISO’s TAC Options initiative: proposing a change in TAC billing determinant to resolve both the existing market distortion for distributed energy resources and assessing TAC in an expanded CAISO jurisdiction
- November 20, 2015 comments in CAISO’s TAC Options initiative: identifying the distortive market impact of the current TAC assessment process on DER and highlighting ratepayer savings if the problem is fixed
- September 24, 2015 comments to the California Energy Commission: raising awareness of the TAC market distortion
- CAISO Ignores Massive Market Distortion that Harms Local Renewables | California Current (October 13, 2016)
- Finding Equal Footing for Small Renewable Wholesalers | California Current (September 8, 2016)
- California local renewables are getting robbed, but CAISO can help | Utility Dive (June 16, 2016)
- The Perils of Wholesale Distributed Generation: Can California Live Up to Its Promise? | Greentech Media (March 9, 2016)
- Transmission Charges Penalize Local Clean Power in California | Microgrid Media (November 25, 2015)
- In California, a Campaign to Take Transmission Charges Out of Distributed Energy | Greentech Media (November 17, 2015)
*DG includes (i) wholesale DG, or small energy resources that interconnect to the distribution grid to serve local load, and (ii) BTM generation exports to the distribution grid, for example NEM customer exports.