G99 Application

The process of complying with Engineering Recommendation G99 (EREC G99) for connecting Power Generating Modules to a Distribution Network Operator (DNO) network involves detailed engineering analysis. Regardless of whether the installation is a Type A system or a large-scale Type C or D Power Park Module, the initial application requires precise technical parameters to verify grid stability.

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A substantial part of the procedure is dedicated to collecting accurate data on generating units and transformers. For instance, determining the site's maximum fault current contribution necessitates specifying the peak asymmetrical short circuit current at 10 milliseconds (ip) and the RMS value of the initial symmetrical short circuit current (Ik''). Additionally, evaluations include Active and Reactive power swing requirements during operational transitions, along with critical transformer electrical characteristics such as positive and zero sequence reactance.

Managing a project from the initial submission of the Single Line Diagram (SLD) and layout through to the issuance of the final connection offer requires ongoing, detailed technical communication with DNO engineers. Precise definition of system parameters, including frequency response droop settings and Fast Fault Current Injection K-factors, is essential for structuring the Power Generating Module Document (PGMD) appropriately and advancing toward a compliant network connection.

Feasibility Study

Navigating the UK's electricity network requires rigorous technical due diligence, especially given the current constraints where transmission-level connection dates can stretch into the mid-2030s. A robust feasibility study must dynamically assess multiple voltage levels—ranging from 11kV distribution networks up to 400kV Grid Supply Points (GSPs) —to pinpoint viable capacity.

Our assessment methodology focuses on several critical grid parameters to ensure project viability:

• Regulatory Thresholds: We analyze whether a project's capacity triggers a Statement of Works (SoW) or Project Progression (PP). For instance, distributed generation under 1MW can often bypass complex PP requirements , which can drastically reduce energization timelines to just 1-2 years.

• Reinforcement Triggers: Larger utility-scale assets, such as 150MW to 400MW+ Battery Energy Storage Systems (BESS), are evaluated against existing GSP limits to determine if they will trigger the costly installation of new Super Grid Transformers (SGTs) or necessitate entirely new substations.

• Curtailment Profiling: With unconstrained connections becoming increasingly rare, we deeply evaluate Active Network Management (ANM) and flexible connection schemes. By analyzing half-hourly operational data, we accurately model curtailment impacts—for example, distinguishing between a connection that experiences frequent restriction versus one that merely loses 5% of its total export capacity over a given period.

Ultimately, identifying a feasible connection is a balancing act of mitigating non-contestable upgrade costs, navigating the queue, and managing acceptable curtailment limits to secure a realistic path to energization.

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Connection Point Sourcing

In the context of a constrained electricity network, determining feasible grid connections requires an approach that extends beyond basic capacity assessments to encompass a dynamic, multi-factor feasibility analysis. Our Grid Sourcing methodology implements a quantitative scoring framework to systematically evaluate both electrical and spatial constraints associated with potential Points of Connection (PoCs).

Electrically, the analysis involves examining Embedded Capacity Register (ECR) and Transmission Entry Capacity (TEC) data to assess localized queuing pressures. Upstream Grid Supply Point (GSP) Appendix G data are reviewed to identify whether thermal limits or fault level restrictions necessitate broader transmission reinforcements, such as upgrades to Supergrid Transformers (SGTs) or switchgear. Additionally, the approach considers the probability of export curtailment arising from Active Network Management (ANM) or Load Management Schemes (LMS).

Spatial and planning considerations are equally integrated. Geographic information is overlaid to detect constraints such as Flood Zones 2 and 3, which may require raised platform structures to mitigate flooding risks, Greenbelt areas, and zones of ecological sensitivity. The analysis also accounts for construction challenges like the need for directional drilling where cable routes intersect significant infrastructure, including motorways or rivers. By combining estimates of non-contestable upgrade expenses, energization timelines, and planning uncertainties, this framework identifies connection points that offer optimal feasibility within the limitations of a saturated grid.