Your Complete Timeline Guide to California Rule 21 Compliance

California Rule 21 is the state’s first regulatory mandate to require the use of smart inverters in solar projects. If you’re in the Distributed Energy Resources (DER) industry in the state of California, Rule 21 most likely affects you. To learn more about what California Rule 21 is, who is affected and why it’s being required, see this blog post.

Requirements for California Rule 21

As a reminder, California Rule 21 is being rolled out in three phases to allow the industry to meet compliance in stages. These phases are:

  • Phase 1: This phase, which rolled out in September 2017, requires that new solar projects use a smart inverter and comply with testing protocol UL 1741-SA.
  • Phase 2: This current phase establishes communication requirements for inverters using the IEEE 2030.5-2018 networking and security standard, which becomes effective with a compliance deadline of August 22, 2019.
  • Phase 3: Parts of the third phase, which requires the use of advanced inverter functions, become effective on August 22, 2019, and we anticipate that this phase will become fully effective in January 2020.

Steps to California Rule 21 with SunSpec Alliance

If you are a solar and storage systems manufacturer subject to California Rule 21, it is important that you understand the need to engage with SunSpec and Kyrio to set up your certificate infrastructure as soon as possible. Setup and process integration of digital certificates can take several weeks, so it is crucial to start that process as early as possible.

To start getting your products Rule 21 compliant by the August 22, 2019 deadline:

  1. Join SunSpec Alliance. SunSpec Alliance is an information standards and certification organization for the DER industry. This organization is entrusted to enforce California Rule 21 communication requirements for all solar inverters and energy storage systems.SunSpec Alliance has worked extensively to create the IEEE 2030.5 CSIP certification program and the SunSpec official PKI to help members meet state (California Rule 21) and federal (IEEE 1547-2018) cybersecurity requirements for DER products and services. Kyrio is the official SunSpec PKI provider, as well as a SunSpec Authorized Test Lab (ATL) to get your device certified and Rule 21 compliant.
  2. Access the SunSpec Certification and PKI Product Development Kit.
  3. Get test PKI certificates. Test certificates allow for proper testing and evaluation prior to certification testing with a SunSpec ATL.
  4. Begin enrollment for SunSpec 2030.5 Manufacturer’s Issuing CA (MICA). In parallel with testing, we recommend that you start the enrollment process for your SunSpec 2030.5 MICA because it can take about 4 weeks to complete the setup.
  5. Test your product at SunSpec ATL and get SunSpec certified. Submit your product to a SunSpec ATL for certification testing. Kyrio offers discount pricing when you choose us for both your testing and security needs.
  6. Get production PKI certificates with Kyrio. Once your products are SunSpec certified, you are authorized to purchase and request SunSpec production certificates. If you started the MICA setup process in parallel with your certification testing as described above, you should be ready to go.
  7. Ship your CA Rule 21–compliant product!

PKI Process Overview Diagram

Expected Timeline for SunSpec Alliance

California Rule 21 timeline with SunSpec Alliance

Your Partner for California Rule 21 Compliance

SunSpec Alliance’s decision to work with Kyrio as its exclusive PKI device security partner means that its members now have the fastest path to bringing secure products to market. When you work with Kyrio for your security and testing needs for SunSpec certification, you’ll benefit from our expertise in security in networked environments, obtain discounted pricing and gain a partner who understands your hardware and manufacturing needs.

Visit the SunSpec Alliance website to learn more and to become a member. If you’re ready to jump into the process, we recommend you obtain your test PKI certificates now. When you’re ready to get your production PKI certificates, please reach out to me directly. Have a question about the process? Don’t hesitate to reach out to us with your questions.

Get Your PKI Test Certificates Now


For manufacturers and service providers, Kyrio accelerates and deploys new network innovations into the ecosystem. Backed by the power of CableLabs, Kyrio sets technology on a path to commercialization, enabling not just today but tomorrow’s communication.

Privacy Preference Center

    Strictly Necessary

    Cookies that are necessary for the site to function properly.

    __cfduid,hubspotutk, PHPSESSID


    These are used to track user interaction and detect potential problems. These help us improve our services by providing analytical data on how users use this site.

    _ga, _gat, _gid, _hjIncludedInSample, mailmunch_second_pageview


    These cookies are used to (1) deliver advertisements more relevant to you and your interests; (2) limit the number of times you see an advertisement; (3) help measure the effectiveness of the advertising campaign; and (4) understand people’s behavior after they view an advertisement.

    __hssc, __hssrc, __hstc