Offshore wind farms have the potential to generate more electricity at a steadier rate than those constructed onshore, and with global demand for renewable energy always on the rise, the industry is increasingly investing in offshore wind energy. The catch, however, is the much higher costs associated with offshore construction and operations.

According to 2019 data, the average cost of a wind turbine is $1.3 million per megawatt (MW) of electricity-producing capacity. Offshore wind farms will typically build larger wind turbines due to the high cost of installing them and transporting the electricity, which would not be lucrative for smaller turbines. There is also the additional benefit of more consistent faster wind speeds, making larger capacity turbines a more worthwhile investment. Offshore wind farm turbines will usually have a capacity between 6-8 MW, so their estimated cost will be between $7-11 million.

A GlobalData 2019 wind turbine market report states that the development of offshore wind farms is significantly more expensive than onshore wind farms, with estimated costs being 25–30% higher. The cost of offshore turbines makes up 30–50% of the total project cost, with the remaining 50–70% consisting of construction costs at 15–25%, grid connection at 15–30%, and other costs at 8–30%, which include development and engineering costs. For onshore wind farms, turbine costs account for 64–84% of the total cost.

Standard operations and scheduled maintenance checks add up to an additional $42,000-$48,000 per year according to an IHS Markit report, with potential replacement or repair of turbines being a much bigger expenditure, especially as offshore fleet sizes increase. David Letterman, head of business development, North America for Nokia Digital Automation Cloud, estimates the total repair bill for a single failed gearbox of an onshore turbine to be in excess of $200,000, including the cost of the crane roll, labour, and lost energy due to downtime. The GlobalData report estimates that advancing technology such as IoT will lower maintenance costs in the future.

Embracing digitalisation and predictive maintenance is a key method to reducing annual expenditures. Digital transformation and wireless broadband allow for remote monitoring and control of sites and equipment by integrating comprehensive Internet of Things (IoT) systems comprising cameras, sensors and analytic software. Nokia Wind Farm Analytics is an automated workforce optimisation tool that uses machine learning to adjust asset maintenance programmes in real-time based on data collected via wireless broadband from wind farm IoT systems, including failure time predictions and maintenance records, as well energy demand and weather forecasts. Optimising connectivity, productivity and uptime is essential to ensuring that profits are maximised. Nokia’s optimised private LTE connectivity capabilities have been demonstrated during Nokia Digital Automation Cloud platform deployment at the Port of Zeebrugge, where the wireless technology will be used to collect data from quay sensors, tugboats, air pollution detectors and security cameras.

Approximately 23 kilometres from port, Norther offshore wind farm recently officially transitioned to the operational phase as it reached technical completion. Since initial early operations in the spring of 2019, the offshore wind farm has been reporting good operational performance, despite the impact of the COVID-19 pandemic. Successful construction and effective communication has been aided by 5G-ready connectivity provided by nCentric, in partnership with Nokia. nCentric provides wireless solutions to simplify daily routines for the offshore industry, and has worked with many Belgian and Dutch offshore wind farms to deliver 5G/LTE connectivity. From Norther to Mermaid offshore wind farm, the company claims to offer greater bandwidth at a lower cost than two-way satellites.

Private Long-Term Evolution (pLTE) wireless networks connect devices reliably and flexibly, and deliver significant cost savings compared to vSAT solutions. While vSAT will remain in use for some offshore operations, communication can be expensive, so many wind farms and marine vessels are adding 4G/5G connectivity, providing a low-cost, high-speed connectivity alternative.

Nokia Digital Automation Cloud (DAC) is an easy-to-use platform that offers 4G/5G connectivity with wide coverage and low latency, enabling group communication with push-to-talk (PTT) and push-to-video (PTV) features. The DAC platform (with its add-on applications such as video analytics and location tracking) is available through pay-as-you-grow, “plug and play” agreements, so offshore wind farms can expand or reduce the size of operations much more easily and cost-effectively.