Grid Interconnection Standards

Spain just updated its grid-connection technical requirements (Orden TED/82/2026). A lot of projects won’t notice what changed until commissioning, and that’s when it turns into schedule and warranty pain. The update modifies TED/749/2020 and hits three areas hard: small generators, storage, and self-consumption. Here’s the practical view Type A generators (<100 kW): • Voltage dip ride-through aligned with Type B for both balanced and unbalanced faults (e.g., balanced: 0.05 pu for 200 ms) • Power-electronics blocking allowed during faults (1) Blocking if V < 0.2 pu (balanced) (2) Must unblock within 100 ms once V > 0.2 pu   • Active power recovery required after faults (but no mandatory fast current injection) Storage (BESS): • Until a dedicated storage code exists, BESS must meet generation requirements in both export and import modes • Temporary exemption from submitting NTS certificates in the operational notification process • The sleeper detail: blocking/unblocking and recovery behaviour now becomes a commissioning pass/fail item if your model doesn’t match the plant response The sleeper detail: Blocking/unblocking timing and post-fault recovery are now commissioning pass/fail items. If the plant response doesn’t match the accepted model, it becomes a site problem, not a study problem. Small generators connected to distribution in TNP (islands): • LVRT aligned with PO 12.2 SENP (including 0 pu for 500 ms for balanced faults) • Blocking logic per PO 12.2 (0.1 pu balanced/0.55 pu two-phase-to-ground) • RoCoF requirement: 2 Hz/s (750 ms moving window) • Frequency withstand: 47.0–47.5 Hz (3 s) | 47.5–48.0 (1 h) | 48.0–51.0 (unlimited) | 51.0–52.0 (1 h) • 9-month transitional exemption on NTS certificate requirements Self-consumption: The old technical exemption (DT3ª RD 647/2020) is now removed; full compliance required from 12 May 2026 Why this actually matters? These aren’t paperwork changes. They affect controller firmware, protection settings, fault ride-through logic, and EMT/RMS compliance models. Discovered late, they trigger redesign, retesting, and COD delay. And practically, they will separate projects that commission cleanly from projects that slip because the plant’s real fault behaviour no longer matches the model that was approved. For those active in Spain: 👉 If you discovered a gap at commissioning, would you rather (1) re-tune controls and re-test on site, or (2) accept a temporary export cap until firmware/models are updated? #GridCode #Spain #Renewables #BESS #PV #Inverters #PowerSystemStability #GridConnection

In a significant step towards advancing renewable energy integration, the International Renewable Energy Agency (IRENA) has released a comprehensive report titled “Grid Codes for Renewable Powered Systems.” The publication offers an in-depth analysis and a set of recommendations aimed at developing and implementing grid connection codes essential for power systems with high shares of variable renewable energy (VRE), such as solar photovoltaic (PV) and wind power. Grid codes play a crucial role in maintaining the stability, reliability, and efficiency of power systems, particularly as they increasingly incorporate renewable energy sources. The report underscores the importance of international cooperation and the harmonization of grid codes across regions to facilitate cross-border power trade and the sharing of technical knowledge. Examples from the European Union, North America, and other regions illustrate the benefits of coordinated efforts in developing robust grid codes. “Grid Codes for Renewable Powered Systems” provides a valuable resource for understanding the critical role of grid codes in the transition to renewable energy. By following the recommendations outlined in the report, policymakers and industry stakeholders can ensure the effective and reliable integration of VRE into power systems, thereby supporting the global shift towards sustainable energy sources. https://lnkd.in/ewe2qNPh

New white paper for T&D engineers: Modeling Tools & Study Methods for BESS & DER Grid Interconnections Most interconnection risk doesn’t come from MW. It comes from controls, time scales, and local grid strength (SCR). This paper is a practical guide for planners, protection, and power quality engineers who need to decide what studies to run, which tools to use, and when to escalate to EMT. What’s inside: - Screening → Deep Dive workflow: power flow/ICA, short-circuit, protection coordination, harmonics & flicker, RMS dynamics, and EMT. - When RMS is enough vs. when EMT is required: low SCR, grid-forming controls, reclosing/protection interactions, resonance risk. - Tool map with use-cases: CYME/OpenDSS, ASPEN/ETAP, - DIgSILENT/PowerWorld/PSSE/PSLF, PSCAD/EMTP, RTDS. - Acceptance criteria you can audit: ANSI C84.1 voltage, IEEE 519 harmonics, IEEE 1453 flicker, IEEE 1547/2800 ride-through. - Data request checklist: settings and plant controller details that prevent rework. - Worked examples: 12.47-kV BESS, weak-grid 115-kV PV+BESS, and an industrial CHP+BESS loop. Who should read - Utility T&D planners, protection engineers, PQ teams, and interconnection reviewers. - Developers and EPCs who need to understand utility study expectations. #BESS #DER #TandD #PowerSystems #ProtectionEngineering #PowerQuality #Harmonics #EMT #PSCAD #PSSGEs #GridIntegration #UtilityEngineering

🔌 Understanding G99 – The UK Grid Code for DER Interconnection 🇬🇧 As Distributed Energy Resources (DERs) continue to transform the energy landscape, G99 plays a critical role in governing their integration into the UK grid. Issued by the Energy Networks Association (ENA), G99 outlines the technical and operational requirements for safely and reliably connecting generation assets. 🔍 Key Anti-Islanding Requirements: ⚡ DERs must disconnect within 1 second upon detecting unintentional islanding. ⚡ Supports ROCOF and Vector Shift as methods for Loss of Mains (LoM) protection. ⚡ Localized settings may be enforced by grid operators based on network conditions. 📊 G99 Classification by DER Capacity: Type A: 0.8 – 1 MW Type B: 1 – 10 MW Type C: 10 – 50 MW Type D: >50 MW 🛠️ What This Means for Developers & Engineers: ✅ All DER units must undergo witness testing and compliance validation. ✅ LoM schemes must avoid nuisance tripping and maintain grid stability. G99 is not just a compliance checkbox—it's a foundation for a more resilient, decarbonized power system. #GridCode #G99 #DERIntegration #LossOfMains #ROCOF #VectorShift #Renewables #PowerSystemProtection #UKGrid #EnergyTransition #ComplianceEngineering #SmartGrid

Grid Interconnection, Inverters and Grid Codes This is the fifth in a series of posts to build a bridge between the "expert V2G world" and the "non-V2G-expert world" and educate and address head-on the critical issues often raised with V2G. Question: “Is the EV/EVSE pair interoperable with the electric grid?” My last post focused on the interoperability between the EV and the EVSE using the same version of the ISO 15118-20 protocol. To achieve interoperability between an EV/EVSE pair and the electric grid, we must also look at what it takes to be allowed to inject power into the grid. In 2030, there will be millions of Distributed Energy Resources (DER) - EVs, Rooftop solar, Home batteries,..) connected to the grids. If these DERs act independently without living up to some pre-defined interconnection requirements, they risk making the whole grid unstable and unmanageable. In short, the DERs must become certified “Good Citizens of the Grid” before being connected to the grid. The term: Good Citizens.." was coined by David Hochschild and Patricia Monahan, California Energy Commission. It is also known under the rather technical name of Interconnection Rule 21 in California. For a DER (EV/EVSE pair) to be allowed to interconnect to the grid, it must support a set of technical requirements known as Grid Codes. An analogy is to think of an EVSE/EV pair needing a unique key to open the door (lock code) to the grid. Most DERs, injecting power into the grid, are changing DC power into grid AC power.  This is done by power electronics known as Inverters.   So, fulfilling the requirements to interconnect to the grid mainly falls upon the Inverter, whether in the EVSE (DC) or the EV (AC). Therefore, California has defined a Common Smart Inverter Profile (CSIP) that DERs must support to be connected to the distribution grid. Some examples of grid code support: 1.     If the grid frequency falls or rises for a shorter period due to a temporary disturbance. The DER must not disconnect from the grid immediately since this could further aggravate the event. They are supposed to – for a given time – continue operating. This is known as Frequency-ride-through. 2.     The same applies to high/low voltage (Voltage-ride-through). So, to be truly interoperable, the EV and the EVSE must: A. Be able to talk and understand each other using the same protocol and B. The EV/EVSE pair must be able to support the grid codes of the distribution grid. This is precisely what the new International Energy Agency Task 53 aims to achieve worldwide (www.Task53.org) by gathering a consortium of EV/EVSE/DSOs/Aggregators that collectively support fully interoperable bidirectional charging solutions. A follow-up post from @Marco Piffaretti will detail the first concrete step to ask experts for input on Gaps & Bugs in ISO15118-20 or Grid Codes hindering V2G interoperability. Note: The 11kW inverter pictured is from Watt & Wells. #Task53 #V2G #Bidirectional #IEA

When an #EV feeds power back to the grid, it stops being a consumer and becomes a generator, which means it needs to obey certain #gridcodes. The grid operator says: when frequency drops, ramp up discharge. When voltage rises, absorb reactive power. When the grid is in emergency, trip off. But how do those rules actually travel from a grid operator's control room to the inverter inside your car? That's what my latest article answers. And as far as I know, it's the FIRST time someone has documented in a clear, digestible way how #OCPP 2.1 and #ISO15118-20 (including its upcoming Amendment 1) work in concert to carry grid code parameters all the way to the EV inverter. Here's what you'll learn: → How grid code parameters travel from a grid operator to your EV's on-board inverter, via a three-layer protocol stack → What OCPP 2.1's two #V2G sections do: Section Q for #bidirectional power orchestration, Section R for grid #compliance parameters, and how they relate → What ISO 15118-20 offers for bidirectional charging: DC and AC power transfer services, message flows, and the difference between #scheduled and #dynamic control → Why bidirectional power control alone isn't sufficient for grid code compliance, and what #ISO15118-20 Amendment 1 adds to close the gap (new services AC_DER_SAE, AC_DER_IEC) → How the European and US approaches diverge, and what #IEC61851, #IEEE1547, and #SAEJ3072 each represent → Where the certification landscape stands in 2026 This was BY FAR the most challenging article I've written for my Current Affairs newsletter. It meant digesting material spread across hundreds of pages of these two standards and distilling it into something that actually makes sense. I hope I managed it well — and I genuinely welcome any feedback. Your input drives my news articles, and if you like what I'm putting together, then please share with your peers. The more people in the EV charging industry that understand the complexities behind V2G, the quicker we get to mass adoption. Link in the article, as always.