Rethinking Standards Development For the Grid-Edge

My article published in the December 2023 Newsletter of the Global Smart Energy Federation.

I have participated in international/national standards committees related to power systems. I still do in smart grid and energy related areas. While it works well for the most part, the standard-setting process is slow in relation to grid-edge innovations. We need to rethink this to avoid playing continuous catchup, else the consumers will have products that utilities find not grid-code compliant or safe.

?The electric power industry draws its strength from its legacy over the past century. Its business models and regulatory construct all evolve from this legacy. Its hallmark is its standards, collectively contributed by thousands of global experts. International Standards Development Organizations (SDO) such as ISO, IEC, CEN, CENELEC, IEEE, and national SDOs such as BS, IS, ANSI, facilitate this massive effort. Below these national standards are several application codes prescribed by Trades/Safety Authorities/Councils (electrical, plumbing), Municipalities (fire safety), Building Councils (building codes), etc. These codes apply within specific state or district to meet local requirements and often override parts of the national/international standards.

?The fast-developing grid-edge (EVs, inverters, energy storage, PV) is causing standards to play catchup to the technology. Often products get sold while standards are absent or evolving, leading to safety issues or substandard features. The typical SDO process begins with identify collective needs (system, equipment, other). International SDO efforts call for national “mirror” committees. It takes several years before a standard is adopted (due to iterative reviews and balloting). Many national, regional, and local nuances create a “healthy tension” amongst stakeholders, especially as it relates to operating conditions, affordability and/or technological prowess.

?The SDO process in power systems has delivered well over the past 60 years (1950s to early 2000s). This was due to the efforts of (then) vertically integrated utilities, multinationals, OEMs and large R&D labs, in the USA, UK, France, Germany, Sweden, Japan & Italy. Substantial investments in people, time and testing were made by these organizations (technical papers, meetings, conferences, R&D and field trials).

?Distributed, discretized, asynchronous and digital energy systems since the early 2000s (wind, PV, fuel cells, EVs, energy storage, smart-inverters, distributed controls, etc.) pose a challenge to yesterday’s SDO processes. The painful transition to a Smart Grid and now to Smart Energy is causing industry fatigue in standards-setting. Several factors contribute to this fatigue, (a) smaller deregulated utilities with limited focus and resources; (b) fragmented OEMs along sub-technology lines; (c) growing SMEs/Startups ?and small third-party system builders who have little resources; (d) decline of large government labs; and (e) rapid pace of technology development. The grid-edge technologies fall into this category.

?Since the early 2000s, all SDO efforts has been challenging due to lack of government funding (hosting, travel) and participation cutbacks from utilities, OEMs, SMEs, and industrial users. It is discouraging to see committee participation limited to retirees, academia and SDO staff. Very few OEMs partake in such meetings. Currently, the standards-setting pace is not commensurate with the rapid development in grid-edge technologies. One can see this in areas like hybrid inverters, battery energy storage and rooftop PV where the standards are lagging the market or have been augmented a few times over the last 10 years, resulting in a short shelf-life.

?Standards for grid-edge products and systems need to evolve much quicker keeping pace with (or even leading) technology development. In addition, the SDO process needs to attract passionate participation from the very stakeholders that stand to benefit from its adoption. My initial thoughts are indicated below and are by no means substantive (at best inputs for a healthy discussion):

?1.????? Be Bold to Anchor Standards in the Future: This is required in a fast development area. The IT, chipset and automation industries often take this approach both from an architecture and a requirements perspective. This approach has served it well. The power sector too has done this (albeit limited). In a recent LVDC (low voltage DC) example (where I was involved), the SDO process pegged the voltage at 48V even when existing systems were at 12V and 24V. In a short span of a few years, most battery systems are offered at 48V for stationary applications.

?2.????? Standardize Key Global Ambient Conditions: This area is fraught with misinterpretations in applying de-rating, operating and general safety factors. Mapping key regional or national ambient conditions (temperature, humidity, rain, floods, windspeed, snow/ice) will help operational appropriateness of equipment in such regions. Standardized derating factors will help in this environmental mapping. For example, PV panels are rated at 20 °C (little relevance to Asia, Middle East, and Africa). This also applies to battery energy storage systems for their effective cooling and fire prevention. A standardized baseline will provide clarity to the OEMs, will help developing countries and likely eliminate multiple certifications.

?3.????? Recognize Plug-and-Play in Grid-Edge: Akin to IT and automation standards, embed plug-and-play concepts in grid-edge standards development. Distributed, discretized, asynchronous and digital energy standards will require more emphasis on “black-box” system performance, standardized interfaces and testing rather than traditional equipment specifications. For example, performance requirements for hybrid inverters to maintain behind-the-meter power factor at > 0.9 and ± 10% nominal voltage at the PCC (point-of-common-coupling), eliminates VAR and voltage management for utilities. Also, interfaces should support adopted protocols (DNP3, Modbus, 61850). The industry must ensure its support for the grid code.

?4.????? Ensure Limits Through Direct Thermal Measurements: Often electrical parameters (Amps, KW, KVA) are used as temperature proxies due to the intrusiveness of RTDs and thermocouples. However, today, optical fiber temperature sensing systems has now become mainstay providing thousands of time-stamped, real-time, digital temperature measurements. This allows for dynamic operating thermal limits (pre thermal status with temperature rise due to projected load/ambient). With high penetration of renewables, ESS and climate change swings, this dynamic limit is warranted.

?5.????? Embed Self-Checking Features: Often protection systems only cover major incidents such as short-circuits and/or fires, but not real-time operating conditions (transient overloads) that could lead to cumulative degradation. Most grid-edge systems are unattended and it is important that transient overloads, thermal limits, etc. are also included in self-checking features. For example, battery energy storage thermal runaways are often caused by internal cell overheating due to overload rather than a major mechanical incident. Such real-time self-checking features must automatically regulate output or shutdown rather than merely alarm.

?6.???? Prescribe Dynamic Performance: Often standards prescribe static operating limits, but rarely prescribe dynamic performance within such limits. These are left to the OEM’s own simulations and testing. This leads to performance issues later after the grid-edge equipment is connected. For example, a hybrid inverter’s dynamic response to varying supply and load fluctuations must be specified in the standards as a performance requirement. A second example would be that a load ramp must trigger commensurate increase in cooling to prevent overheating, else it should be prevented from meeting such load ramps.

?The above are a few of my thoughts to elucidate discussion and whether their adoption into standards-setting processes, will speed up things and also ensure the standard’s useful shelf life (relative to the technology pace). Smart energy will warrant customer choices and the SDOs need to be ready for this.

?The sooner we rethink this fundamentally, the better would be our future as a viable power industry.