Esb Networks Nc7 Mini Generation Connection Application Guide

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Key Takeaways

• Mini-generation applies to inverter installations between 6 kVA to 17 kVA on single-phase connections and 11 kVA to 50 kVA on three-phase supplies.
• The Maximum Export Capacity (MEC) is not permitted to be greater than the Maximum Import Capacity (MIC) for the premises.
• An application is only deemed complete when the associated application fee invoice has been paid within 30 days payment terms.
• Technical review and connection offer issuance average 8 to 10 weeks from payment of the application fee.
• Inverters must hold accredited type test certification proving compliance with standard EN 50549-1:2019.
• Following installation, the confirmation certificate must be submitted no longer than twelve months from the offer issue date.

What is Mini-Generation under ESB Networks Rules?

In the Irish electricity distribution system, mini generation is the term for when an electricity customer installs inverter connected generation, within the range covered in the definition below, at a premises, to produce electricity. These systems bridge the gap between domestic micro-generation and large commercial generation plants. As ESB Networks specifies, these generators are generally installed to produce clean electricity, targeting high on-site self-consumption to displace commercial retail purchases.

Statutory capacity ranges for mini-generation are defined as follows:

• Single-Phase Connections: 25 amperes (6kVA) to 72 amperes (17kVA), when the connection is single-phase.
• Three-Phase Connections: 16 amperes (11kVA) to 72 amperes (50kVA), when the connection is three-phase.

All installations must adhere to the technical document, Conditions governing connection operation mini-generation. Systems incorporating dynamic export curtailment must additionally satisfy Conditions Governing the Connection and Operation of Export Limiting Scheme at LV and MV.

Sizing Rules: MEC and MIC Interlocking

Commercial premises in Ireland must navigate strict capacity interlocking when sizing solar PV arrays:

• Capacity Ceiling: For Mini-generation connections, the Maximum Export Capacity (MEC) is not permitted to be greater than the Maximum Import Capacity (MIC).
• Statutory Definition: The Maximum Export Capacity (MEC) is defined as the maximum power, expressed in kVA, that is permitted by ESB Networks to transfer from the Customer’s Point of Connection to the Distribution System Operator (DSO) Network.
• MIC Adjustment: If a commercial business requires an export capacity higher than its existing import capacity, an MIC increase application must be processed in parallel.

Application Workflow and Technical Documentation

Connecting mini-generation requires formal engineering review via Form NC7 rather than the informal inform-and-fit process used for residential solar:

1. Submission Requirements: Applicants submit the NC7 form accompanied by an equipment block diagram, manufacturer datasheets, and type test certificates proving equipment is compliant with standard EN 50549-1:2019. Hand-drawn SLD's will not be accepted.
2. Fee Invoicing and Payment Terms: The application is reviewed commercially and a non-refundable invoice (inclusive of VAT at 23%) will issue within 10 business days. Crucially, an application is only deemed complete when the associated application fee invoice has been paid. If payment is not received within the 30 days payment terms, your application will be deemed withdrawn and you will need to reapply.
3. Assessment Turnaround: On receipt of payment, ESB Networks conducts a distribution network study. The average timeframe for the connection offer documents to issue is 8 to 10 weeks from payment of the application fee.

Commissioning, Confirmation, and Islanding Safety

Once the connection offer is accepted and solar equipment installed:

• Post-Installation Certificate: The customer must submit the mini-generation installation confirmation certificate as soon as the generator is connected and no longer than twelve months from the issue date on the connection offer documentation.
• Islanding and Outage Protection: Mini-generators are engineered to automatically switch off during power cuts. For facilities requiring backup power during outages, this is a safety requirement under the NSAI Wiring Regulations and requires a changeover switch to isolate internal circuits from the distribution grid.