Modeling California's NEM 3.0 in Aurora

What is in the NEM3 / Net Billing Tariff:

While NEM 3.0 is not finalized, Aurora is closely monitoring the proceedings and this guide is based on the latest structures to this plan proposed November 10, 2022. The next two scheduled CPUC voting meetings are December 15, 2022 and January 12, 2023. If proposed changes pass on December 15, the effective date is April 23, 2023. Read More Details in our Blog.

• Residential customers are required to enroll in Electrification Rates. The currently allowed rates are:

  • PG&E: E-ELEC
  • PG&E: E-ELEC-CARE
  • SCE: TOU-D-PRIME
  • SCE: TOU-D-PRIME-CARE
  • SDG&E: EV-TOU-5
  • SDG&E: EV-TOU-5-CARE
  • We expect more rates to be allowed by the CPUC in the future

What has changed with NEM 3.0 and how to model it with Aurora

Overview

• Behind-the-meter operation is the same as normal. However, excess energy is no longer compensated at retail rate (less non-bypassable charges); instead, the compensation rate is based on the most recent Avoided Cost Calculator (ACC) and has a different rate for each hour.
  • Aurora does not currently support export rates that vary hourly. However, we find that you can approximate the ACC export rates using a percentage reduction.
    • For residential customers:
      • PG&E: Export Rate with an 50% reduction (30% for CARE rate)
      • SCE: Export Rate with a 60% reduction (15% for CARE rate)
      • SDG&E: Export Rate with an 82% reduction (75% for CARE rate)
  • Customers who sign up in the first 5 years receive an adder on top of their ACC-based export
    rate, starting at 1.8 cents for PG&E and 4 cents for SCE non-CARE customers. The adders are applied for the first 9 years after interconnection. The adder is smaller for customers interconnecting in later years.
  • The export rate is only fixed for 9 years, however, there’s no strong indication that future iterations of the ACC will be better or worse for solar.
• True-up period is still annual, and the true-up month is based on the expected PTO of the system. Customers may request a one-time update to their true-up month. We recommend selecting March or April to realize the best savings.
• No changes for NEM-1 and NEM-2 customers. Any customers who install solar before the Net Billing takes effect will be grandfathered into NEM 2.0 for 20 years.

Suggested Approximation for Residential Rates

Aurora Utility Rate Database

Aurora has created 6 rates in the utility rate database, which all include the above rate behaviors. The percentage reductions have been slightly increased to account for the fact that electric rates will escalate in the future, while the ACC-based export rate remains flat. Remember that self-consumed electricity still saves costs at retail rate.

How to Model:

First, your admin user has to find NBT / NEM3 Approximation rates in the utility database section of Aurora, and Duplicate them in by clicking the three dots on the right side of the listed rate. Duplicating a rate creates a "custom" copy which is then able to be selected in your designed.

After the duplicated rate has been favorited, you can search for and select the NBT / NEM3 Approximations as the Post-solar rate. You can also select the NBT approximation rates in Sales Mode.

You should verify that the settings were applied correctly in the Advanced section of the Production / Savings detail drawer.

The details may change in the final decision. The model steps are an approximation of the proposed decision. For any questions, please reach out to our support team by submitting a request. You may also email us at support@aurorasolar.com.