Scottish ports face grid barriers to industrial expansion

Electricity connection constraints and delays in securing network capacity could hold back further industrial development at Scotland’s ports, according to research commissioned by Scottish Renewables. The report identifies a growing mismatch between port investment programmes and the electrical infrastructure required for offshore wind manufacturing, industrial electrification and the supply of electricity to ships at berth.

Prepared by grid connections consultancy Roadnight Taylor and published on 12 October, Port Power – Electricity Demand in Scotland draws on confidential interviews with representatives of 12 Scottish ports and harbours, supplemented by publicly available information. The findings show substantial differences between locations, with some seeking relatively modest increases in electricity capacity and others planning developments that could require much larger connections.

The greatest prospective demand often comes from industrial businesses seeking to locate manufacturing and assembly operations at ports, rather than from the electrification of existing port equipment alone. Offshore wind development is encouraging investment in quays, heavy-lift facilities and manufacturing space, creating opportunities for businesses whose electrical requirements may be considerably greater than those of the port’s established operations.

A fabrication or assembly facility can impose a sustained electricity load through welding equipment, production machinery, ventilation and other industrial systems. Additional tenants may need dedicated transformers and electrical distribution infrastructure, while the aggregate demand across several facilities can exceed the capacity available through a port’s existing connection.

The size and location of these new loads determine whether additional electricity can be supplied through an existing network or whether upstream reinforcement is necessary. A development requiring substantial additional power may need new high-voltage equipment or an increased connection capacity, potentially involving works beyond the boundaries of the port itself.

Planning those upgrades is complicated by the sequence of commercial decisions involved. Ports may need credible access to electricity before a prospective manufacturer will commit to a new facility, yet a network operator may require detailed evidence of future demand before investing in reinforcement. The report identifies this uncertainty as a barrier to attracting tenants and securing finance for industrial developments.

Connection requirements also differ between individual ports. Their existing electrical infrastructure, proximity to available network capacity and proposed industrial activities influence the scale of additional investment required. Roadnight Taylor found that the 12 ports interviewed could not reasonably be treated as a single category with a uniform electricity demand profile.

The timing of requirements adds another complication. A port may invest in infrastructure to attract offshore wind developers while the generating projects themselves are still progressing through consenting or commercial decisions. Delays affecting the wind farm can influence when associated manufacturing activity is required, making it harder to establish the appropriate date for network reinforcement.

The report warns that some ports have already committed substantial capital to facilities intended to serve the offshore wind sector. If electricity connections cannot be delivered in time, those investments may be underused even where the physical port infrastructure is ready to accommodate new activity.

Shore power creates a different pattern of demand because electricity is supplied to vessels while they are berthed, allowing compatible ships to reduce reliance on onboard auxiliary engines. The power required depends on vessel type, onboard electrical systems and the number of ships connected simultaneously. Shore-side equipment may include transformers, switchgear, connection systems and frequency conversion where vessels require a different electrical supply configuration.

Such installations can require substantial upfront investment, but their commercial performance depends on how often the equipment is used. Ports may be reluctant to commit to expensive network upgrades and shore connections without a sufficiently reliable forecast of demand from visiting vessels. Electricity prices also influence whether shore power offers a financially attractive alternative to onboard generation.

The research identifies constrained network capacity, connection costs and uncertainty about future vessel use as barriers to wider adoption. These factors need to be assessed alongside the potential reduction in local emissions, noise and vibration achieved when ships use electricity from shore instead of operating auxiliary engines.

Scottish Renewables wants future port electricity requirements to inform the Strategic Spatial Energy Plan and Regional Energy Strategic Plans, with network investment coordinated more closely with prospective industrial developments. The organisation is also seeking clearer connection application routes, better access to queue information and greater transparency over the costs associated with new capacity.

Flexible connection arrangements could provide an interim option in some circumstances, allowing a customer to use available capacity subject to agreed operating restrictions. Their suitability depends on the electrical demand involved. An activity that can shift electricity consumption to different hours may be more capable of accepting constraints than an industrial process requiring continuous high-power operation.

Montrose Port illustrates the wider investment activity associated with offshore wind. In September, it announced plans to host SSE Renewables’ Berwick Bank B operations base and a £5m manufacturing facility for Subsea Micropiles. Developments of this kind can introduce new electrical requirements alongside the port’s existing cargo-handling and operational demands.

Roadnight Taylor’s findings provide an initial evidence base rather than a definitive national electricity demand forecast. The interviews identify recurring barriers and substantial variation between locations, but they do not establish a single megawatt figure for future demand across Scotland’s ports or the network reinforcement required to meet it.

The next steps recommended by Scottish Renewables concern the integration of port requirements into network planning and the coordination of investment decisions. Converting those requirements into deliverable projects will depend on more detailed demand forecasts, connection studies and agreement over the timing and financing of the electrical infrastructure needed at each location.