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DNOs — Distribution Network Operators

H‑Infinity provides specialist engineering support for UK Distribution Network Operators — connection agreements, impact studies, protection coordination, and compliance with DNO standards.

Working with UK Distribution Network Operators requires deep understanding of Grid Codes, Engineering Recommendations (G99, G100, SNIAD), and individual DNO Technical Conditions. Our team has extensive experience preparing technical submissions, conducting impact studies, and designing protection schemes that meet DNO requirements for both generation and load connections. Whether you are a DNO needing specialist study support, or a developer seeking connection to the distribution network, we deliver technically robust solutions that facilitate timely and compliant connections.

Connection Agreements & Applications

Complete technical submissions for DNO connection agreements — G99/G100 applications, impact studies, protection requirements, and compliance documentation for new connections.

Impact & Compliance Studies

Detailed impact studies for generation and load connections to DNO networks — fault level contribution, voltage rise, harmonic distortion, and flicker assessment.

Protection Coordination

Protection scheme design and coordination for customer connections to DNO networks — overcurrent, earth fault, differential protection, and tripping curve coordination.

Grid Code & G99 Compliance

Ensuring compliance with UK Grid Codes, Engineering Recommendation G99/G100, and DNO Technical Conditions for generation and load connections across all voltage levels.

Distributed Generation & BESS

Electrical design and studies for distributed generation, battery energy storage systems, and CHP connections — from small-scale solar to multi-MW industrial installations.

Load Connection Design

Electrical design for large commercial and industrial load connections — MV substations, protection schemes, and metering arrangements per DNO requirements.

Substation Design & Testing

Pre-packaged substations (PPS), pole-mounted and pad-mounted units, including design, testing, commissioning, and DNO inspection and certification.

Asset Transfer & Verification

Verification and testing of existing electrical assets for transfer to DNO ownership — compliance assessment, defect identification, and remediation design.

Ready to discuss your project?

Our team of power systems engineers is ready to provide expert guidance, detailed studies, and robust solutions tailored to your specific requirements.