Pages with tag California Rule 21
Chilicon/Intertek Certifies the CP-250E Micro-Inverter as UL 1741 SA Smart Inverter:
California Rule 21 phase 1 requirements took effect in September 2017, meaning that solar inverter makers are required to achieve UL1741SA certification to continue selling inverters in California. The phase 1 requirements, a.k.a. the autonomous functions, mean that the inverter can automatically, without any intervention by a human, take actions to support the grid in case local grid conditions go wrong. Those functions are as described by Chilicon in the press release below. What's interesting is they could implement the update without changing the control board -- it's just a software change.
Over the next year or two further requirements, phases 2 and 3, will kick in requiring communication across the Internet with cloud systems for command/control of inverter capabilities. The goal is even more support of electricity grid reliability as well as orchestrating energy production and energy storage systems to time-shift electricity produced from renewable resources to other times of the day.
Entire Ginlong Solis 4G Inverter Line Now Available with the UL 1741 SA Certification:
California's plan to reshape the electricity grid is taking a big step forward as solar inverter makers, like Ginlong Technologies, adopt UL1741SA. The plan hinges on smart inverters, with the UL 1741SA standard being the first concrete step. Previous inverters would, if grid conditions go wonky, disconnect from the grid. Power systems engineers thinking about the problem recognized that inverters could help prop up the grid, to remedy certain wonky grid conditions.
The increasing rate of installing solar inverters gave California an opportunity to field a different kind of solar inverter. California Rule 21 governs the methods of interconnecting solar power systems to the electricity grid. Over the last 3-4 years, the Smart Inverter Working Group convened by the California Public Utilities Commission worked on redesigning solar inverters to provide grid support functions. The content of UL1741SA, which was ratified in September 2016, is the first concrete result and describes the sort of grid support functions required of solar inverters.
UL1741SA contains what is called the "Rule 21 Phase 1 autonomous functions", meaning these functions automatically kick in whenever the electricity grid frequency, voltage, power factor and similar measures are out of line with grid stability requirements. If the grid strays beyond certain parameters, the inverter will still disconnect itself from the grid, but so long as the grid stays within those parameters the inverter will assist with keeping the grid stable. This may seem like a small thing, but it is the first step of a cooperatively managed electricity grid.
Over time Rule 21 Phases 2 and 3 will be standardized and be required features of future inverters. Those phases add communications ability so that smart inverters can be proactively managed from a central cloud-based service. It's thought that over time the electricity grid will morph from a system of large centralized electricity generation resources, to a distributed set of electrical grid resources of many types and sizes. A distributed management system will orchestrate electricity inflows and outflows to balance electricity demand throughout the day, and also take care of the intermittency issue.
Newest Products from Enphase Energy Meet the Needs of the California and Hawaii Markets
In California and Hawaii, policy changes are underway requiring "smart inverters" for solar power systems. Requirements going into effect in September call for what's called "Phase 1" functions, comprising a set of "autonomous" actions providing "grid support" functions like voltage or frequency support. That is, these functions happen automatically without any explicit control, and act in reaction to grid conditions. For example the voltage or frequency might go out of bounds, and rather than disconnect from the grid the inverter instead shifts into a mode of helping to correct the problem.
The industry developed a supplemental standard, UL1741SA (Supplement A), defining those autonomous functions. Shortly Enphase, and the other solar inverter manufacturers, will be unable to sell inverters in California that lack this feature.