Joachim Espvik, Project Manager at Cloudberry Clean Energy, provides essential insights into these differences. His analysis highlights the operational, technological, and environmental distinctions and emphasizes the strategic implications, guiding a balanced and informed approach to optimizing both types of wind farms to meet the world's growing energy needs effectively.
Comparing onshore and offshore wind power
Joachim Espvik, Project Manager, Cloudberry Clean Energy.The conversation with Espvik begins with a fundamental question about the differences between offshore and onshore wind power. Espvik explains, "Offshore wind projects typically involve larger and more numerous turbines, a decision driven by the ample space and sophisticated engineering capabilities that marine environments provide. These larger turbines take advantage of the higher and more consistent wind speeds found offshore, which significantly enhance power output, reliability, and volume."
He contrasts this with onshore wind farms, where the variability in wind speed is more prominent and can impact performance. According to Espvik, offshore allows for larger-scale projects, which are less feasible on land due to competing land uses and environmental constraints. "The recent shift towards offshore wind power is largely motivated by the potential for higher and more consistent production capacities," Espvik asserts.
Technological advancements and grid integration
Over the past decade, the technological evolution of wind turbines has been marked by significant trends and developments. "The scale of wind turbines has grown remarkably," Espvik explains, noting that the standard size for onshore turbines has increased from around 2 megawatts (MW) a decade ago to approximately 7 MW today. This trend extends to offshore turbines as well, with current models in Asia reaching 16 MW. These larger turbines can generate substantially more power, enhancing the overall output of wind farms.
Espvik, leveraging his electrical engineering expertise, also highlights critical advancements in power electronics that have transformed wind turbines. He states, "Modern turbines are not just more efficient at converting wind into energy; they also interact more flexibly with the electrical grid. " This flexibility is key to their ability to provide a dynamic response to changes within the grid, thus maintaining grid stability. Espvik elaborates on the importance of this feature by adding, "They adjust to fluctuations in frequency and voltage, and they can remain connected during faults in the grid, capabilities that older models lacked."
These technological improvements have collectively contributed to creating more efficient, reliable, and powerful wind energy systems.
Insights on developing wind farms
Drawing from his extensive experience, Espvik shares behind-the-scenes details on getting wind farm projects off the ground and the technicalities involved in ensuring their efficient connection to the electrical grid. Espvik begins by outlining the initial stages of a wind farm project, which typically involve securing land rights and navigating the complex permitting process. "Next on the agenda is selecting turbine manufacturers that comply with the permit criteria and managing the construction of essential infrastructure," he explains.
As the development of wind farms requires coordination among the myriad activities and parties involved, Espvik emphasizes the importance of ensuring that suppliers and contractors align seamlessly with project timelines, budgets, and technical specifications.
Discussing technical specifications, Espvik expresses a preference for turbines equipped with full-scale converters, which offer high adaptability to dynamic grid conditions and meet rigorous European standards. Turning to grid connections, Espvik explains that onshore developments are typically constrained by the need to build internal collection grids along internal roads in the wind farm, leading to potential energy losses and suboptimal electrical designs. Offshore projects, on the other hand, benefit from greater flexibility in turbine placement and internal grid optimization. This flexibility allows for more effective strategies to minimize losses and enhance reliability in the energy supply.
The availability of vast open spaces at sea makes offshore projects particularly valuable for generating the large amounts of renewable energy needed to meet climate targets and replace fossil fuels.
Onshore wind projects versus offshore complexities
Onshore and offshore wind projects are often pitted against each other, yet it's difficult to declare a definitive winner. Espvik, leveraging his extensive experience and a personal preference for offshore solutions, highlights their significant advantages. He also offers insight into the substantial challenges faced by onshore wind projects. Moreover, he points out that in offshore environments, logistical and environmental complexities dominate.
"One of the main reasons to go offshore is the potential for higher revenues," he notes, explaining that offshore wind farms can utilize larger scales and bigger turbines to generate more power and enhance profitability despite higher upfront costs. He adds, "The availability of vast open spaces at sea makes offshore projects particularly valuable for generating the large amounts of renewable energy needed to meet climate targets and replace fossil fuels."
He believes that the mature technology for large-scale offshore wind farms supports substantial installations, capable of generating significant electricity volumes.
Moving on to the limitations of onshore wind farms, Espvik remarks, "The most formidable barrier in developing onshore wind projects is the slow-moving permitting process." He attributes these delays primarily to bureaucratic and regulatory hurdles rather than technical difficulties, which significantly slow the deployment of renewable energy projects crucial for the energy transition. Furthermore, he identifies grid capacity as a significant infrastructural hurdle. "Even with all necessary permissions, the limited capacity of the existing electrical grid can render new onshore projects unfeasible," he adds.
In the context of offshore wind projects, Espvik outlines increased complexity. "Offshore wind projects are inherently more complex to build and maintain due to the marine environment's challenges," Espvik elucidates. "This complexity involves transporting all personnel, equipment, and materials out to sea, which necessitates extensive planning and coordination. The installation of offshore wind turbines requires specialized vessels, and maintenance may also require ships and helicopters. These modes of transportation are not only more expensive but pose greater logistical challenges than onshore operations, where sites are typically accessible by road," Espvik details.
On the other hand, onshore wind farms are generally easier and cheaper to access for maintenance and operations since they can be reached by conventional road transport, reducing the logistical burden and associated costs.
Espvik, however, emphasizes the need for a holistic approach. "While offshore wind farms are crucial, they are not the sole solution. A comprehensive strategy that includes enhancing energy efficiency, smarter energy use, and exploring alternative fuel sources for non-electric applications is essential."
The evolution of grid integration technologies
As we look towards the next decade, the integration of renewable energy sources, particularly wind farms, into electrical grids presents growing challenges and opportunities. Espvik discusses the evolving role of High Voltage Direct Current (HVDC) technology in addressing these challenges, especially in connecting remote wind farms to the main electrical grid.
Espvik highlights, "HVDC stands out for its transmission efficiency over long distances, which is particularly crucial for offshore wind farms." Unlike Alternating Current (AC), which suffers from higher losses in underwater and long-distance applications, HVDC ensures more efficient power transmission with reduced infrastructure needs. "This efficiency comes from not needing intermediate substations along the transmission route, significantly lowering both cost and environmental impact at longer distances," Espvik adds.
However, Espvik also points out the vulnerabilities, such as the risk of a single point of failure which could disconnect the entire wind farm from the grid if the HVDC link fails.
Looking at the technological and regulatory needs, Espvik accentuates the importance of advancements in HVDC technology. "We need continuous improvements in semiconductors, power electronics, control systems, and converter technology. Innovations like HVDC circuit breakers are also critical for managing and protecting the grid," he states. Furthermore, with HVDC systems often connecting multiple countries, there is a pressing need for international regulatory alignment on infrastructure financing and operational practices to facilitate cross-border energy trade and ensure grid stability.
The rise of hybrid wind farms and beyond
As the renewable energy sector continues to innovate, hybrid wind farms are poised to play a pivotal role in the future energy landscape. Espvik discusses how integrating different technologies with wind energy can enhance performance and versatility, ensuring a more robust and consistent power supply.
"Integrating wind and solar capitalizes on their complementary generation profiles," he explains. This synergy allows for more stable energy output, as the wind can blow during periods of less sunlight and vice versa, smoothing out the variability inherent in each source alone.
Furthermore, the integration of wind farms with energy storage solutions is gaining attention. Espvik notes the current use of batteries for grid services like short-term balancing but acknowledges the challenges of scaling storage to accommodate long-term energy needs. "The vision is there, but the practicality of implementing large-scale battery storage remains a hurdle," he states.
Looking forward, Espvik is optimistic about the trend toward hybrid systems that combine various renewable energy forms with advanced storage and conversion technologies. "These hybrid configurations are likely to become more prevalent," he forecasts.
Espvik's narrative highlights that choosing between onshore and offshore wind technologies involves more than technical assessments—it's a strategic decision influenced by geography, community attitudes, and economic factors. As we look to the future, collective efforts will be crucial in navigating the intricate balance of enhancing energy capacities, adhering to regulatory frameworks, and integrating diverse energy solutions, ultimately steering us toward a sustainable and empowered global community.