Blog by Steven Ziolkowski, R&D and Consultant Engineer at Kinewell.
Steven Ziolkowski is a dedicated and creative engineer with extensive knowledge of model-based engineering, data analysis and power systems. He undertakes international consultancy utilising the KLOC software for Kinewell to carry out inter-array cable layout design and electrical loss studies. He has delivered >£52m of value through 7 GW of offshore wind project consultancy across European, Japanese and US markets to date through developing a comprehensive cost model of the offshore wind farm incorporating both CAPEX and OPEX considerations, upon which the cable layout was optimised to deliver substantial cost savings for the project. Steve leads on KLOC software training and support for both clients and staff, as well as state-of-the-art research and development projects making use of machine learning algorithms and python proficiency. Steve demonstrates rigourous testing of new features to ensure quality. Steve has a strong academic record from his master’s degree in Electrical and Electronic Engineering from Newcastle University and practical application from industrial experience with Northern Powergrid and Siemens energy.
The Trump administration’s tariffs sent ripples through global energy infrastructure—offshore wind included. Foundations, towers, cables, and turbines could feel the squeeze of price hikes, reshaping how developers plan and price projects.
For offshore wind developers, this creates a complex and uncertain cost landscape. Materials are getting more expensive. Global supply chains are increasingly politicized. And the long-term viability of projects can be challenged overnight by policy changes, in an uncertain political environment.
So how should developers respond? Stick with their existing design? Absorb the higher costs? Or pivot—rethink, redesign, and reoptimise?
In this blog, we explore those questions using a case study from a 2GW wind farm. We show how advanced design software—specifically our inter-array layout optimiser, KLOC—can dynamically and rapidly reconfigure a project to soften the tariff-induced blow. The goal: make the smartest trade-offs possible between capital cost, operational cost, and energy revenue.
A Case Study: Wind Farm Design Under Tariff Pressure
Our case study wind farm consists of 143 wind turbines and two substations. The turbines are connected in strings via inter-array cables. These cables come in two varieties—both aluminium, but one with a smaller ampacity (supporting up to 3 turbines) and one with a larger ampacity (supporting up to 7).
We feed this configuration into KLOC, which generates a cable layout optimised for lifetime project value. This includes:
- CAPEX: upfront investment costs (dominated by cable length and type)
- OPEX: annual operational costs (including cable maintenance)
- Revenue: energy sold over the lifetime of the farm (which includes the thermal losses)
KLOC uses these inputs to determine the most cost-effective design. But what happens when one of the inputs—cable purchase cost—suddenly increases?
The Tariff Shock: +25% Cable Cost
In our scenario, tariffs increase cable costs by 25%. This affects not just the upfront CAPEX but also a little bit of the ongoing OPEX (e.g., cable replacements).
We compare two paths:
- Keep the original layout, but apply the new (higher) cable prices.
- Re-optimise the layout using KLOC with the new price inputs.
Comparing the Two Outcomes
Let’s break down the numbers.
Design 1 – No Re-Optimisation:
This design uses the original layout but with the 25% price hike applied. Because the layout hasn’t changed, the cable length remains the same. However, total CAPEX rises due to more expensive materials. Some downstream OPEX costs also rise (e.g., cable replacement), and overall, the project takes a value hit of ~£25M relative to the pre-tariff scenario.
Design 2 – Re-Optimised with KLOC:
KLOC responds to the new cable prices by significantly shortening total cable length by about 4km. This reduces capital expenditure—but at a cost. Energy losses rise by 600 MWh per year, translating to a revenue penalty of ~£38k per year.
Broader Implications for Offshore Wind
This case study offers valuable lessons for the offshore wind industry:
- Trade-offs are inevitable. In any optimisation, there’s a balance between competing objectives—like minimising capital expenditure versus reducing electrical losses. A sudden 25% price hike in cable costs can’t be erased, but software can intelligently re-prioritise these objectives to soften the impact.
- Software tools like KLOC enable agile responses
- It’s worth holding some aspects of the design open for longer. Early-stage decisions often rely on assumptions that may shift—especially in volatile markets. By identifying which parts of the design are more sensitive to cost changes, developers can take a more strategic approach: locking in what’s stable, while keeping options open where flexibility could protect value later on.
This isn’t limited to cables. Similar sensitivity analysis and reoptimisation processes can be applied across other major wind farm components—turbines, foundations, export systems—using tools such as KWOTA for turbine placement optimisation or KDOTS when selecting export system technologies under uncertainty. As long as CAPEX/OPEX/revenue impacts can be modelled, this approach supports better decision-making across the entire project lifecycle.
Conclusion: Pause, Pivot, or Push Ahead?
Faced with tariff-driven cost increases, developers can’t control the market—but they can control how they respond. By re-optimising with the latest input data, they not only improve design resilience, but also gain a clearer picture of where risks lie and how sensitive outcomes are to changing assumptions.
Whether it’s aluminium or copper cables, energy prices or interest rates, the principle remains: good design is not static—it’s responsive. Understanding how cost changes ripple through CAPEX, OPEX, and revenue allows stakeholders to make better decisions—not just about design, but about which risks need watching, which can be absorbed, and where flexibility matters most.
Steve held a webinar on this topic, if you’d like to view the recording, or if you’d like to discuss how we can support your project, please get in touch.
