How to Scale Up Wave Power as a Viable Renewable Energy Source

How to Scale Up Wave Power as a Viable Renewable Energy Source

How to Scale Up Wave Power as a Viable Renewable Energy Source

Introduction

As the world grapples with climate change and the need to transition to renewable energy, wave power has emerged as a promising yet underutilized renewable resource. Waves contain a tremendous amount of energy – roughly 2 terawatts globally – that can be harnessed to generate electricity. Wave power could theoretically provide over 4 times the total global energy demand. However, wave energy conversion is still in the early stages of development and faces challenges to becoming commercially viable at scale. This article will provide an in-depth look at the current state of wave power, the primary technologies involved, key challenges, and pathways to scaling up wave energy to make a more meaningful contribution to the world’s renewable energy portfolio.

Overview of Wave Power

Wave power refers to technology used to generate electricity from the kinetic energy of ocean and sea waves. As wind blows over the surface of the ocean, it transfers some of its energy to form waves. The larger the wind speed and duration, the larger the waves become. The motion and gravitational forces of waves near the ocean’s surface contain tremendous pent-up energy that can be captured and converted into electricity by specially designed equipment.

The main advantages of wave power include:

  • Renewable – Waves are continuously regenerated by wind and solar energy. The resource is abundant and will never run out.

  • Predictable – Wave patterns can be forecast accurately several days in advance. This helps grid management and stability.

  • High energy density – Water is ~800 times denser than air, so wave power is extremely concentrated.

  • Proximity to demand – Many wave resources are located near major population centers that require electricity.

  • Low visual impact – Wave conversion equipment has minimal aesthetic impact compared to wind turbines.

Currently, global wave power capacity is just over 30 megawatts (MW). However, estimates suggest the worldwide theoretical potential may exceed 29,500 terawatt-hours (TWh) per year or 1-10 terawatts (TW) of capacity. For context, global electricity production in 2020 was ~27,000 TWh. Even capturing just a small fraction of the available resource could make wave power a meaningful contributor to the world’s renewable energy portfolio.

Primary Wave Energy Conversion Technologies

There are several main types of technologies used to convert the mechanical energy of waves into usable electricity:

Point Absorbers

  • Floating buoy style converters that bob up and down with wave motion. The kinetic energy powers an internal generator.

  • Suitable for almost any water depth. Easy to scale by installing multiple units.

  • Example: PowerBuoy by Ocean Power Technologies.

Oscillating Water Columns

  • Partially submerged structures containing an air column. Waves cause the column to rise and fall, driving air through a turbine.

  • Must be built on the shoreline or nearshore seabed. More limited scalability offshore.

  • Example: LIMPET plant built off the coast of Scotland.

Oscillating Wave Surge Converters

  • Hinged deflectors that oscillate back and forth as waves pass through them. The motion hydraulically powers a generator.

  • Located nearshore or offshore. Good scalability potential via modular installations.

  • Example: WaveRoller devices by AW-Energy.

Overtopping Devices

  • Use wave motion to fill an elevated reservoir, then pass the captured water through low-head hydro turbines.

  • Must be built into shoreline. More limited offshore scalability.

  • Example: Wave Dragon floating overtopping/reservoir device.

Challenges to Scaling Up Wave Power

While wave power holds great promise, there are still major techno-economic hurdles that must be overcome to deploy wave energy farms at scale. The most significant challenges include:

Immature Technology

  • Most wave power devices are still in early development and prototype testing stages. Very few commercial scale projects exist.

  • Survivability – Equipment must withstand harsh open ocean conditions like storms, corrosion, and biofouling.

  • Reliability – Technology needs refinement for robust long-term operation to become bankable.

High Capital Costs

  • Building and installing wave equipment is very capital intensive, with costs ranging from $2 – $6 million per megawatt.

  • Makes it hard to compete with traditional energy sources and more mature renewables like solar/wind.

Interconnection and Transmission

  • Wave power sites are often remote. Undersea cabling is very expensive to connect projects to the grid.

  • Distance from grid also leads to higher transmission losses.

Permitting and Regulations

  • Lengthy processes to lease ocean tracts and obtain project permits/approvals. Unclear regulatory framework.

  • Environmental impact concerns (e.g. to wildlife) must be addressed.

Pathways to Scale Up Wave Power

Despite the challenges, wave power can be scaled up by:

  • Continuing R&D to improve technology performance and survivability.

  • Using wave energy hybrid systems that combine storage to improve reliability.

  • Developing larger scale demonstration projects to spur commercial confidence.

  • Streamlining permitting processes and clarifying regulatory frameworks.

  • Offering additional financial incentives like feed-in tariffs for early stage projects.

  • Building clusters/shared infrastructure to reduce transmission costs.

  • Leveraging economies of scale for mass production to reduce capital costs.

With sufficient investment and policy commitment, wave power could follow similar growth trajectories as wind and solar, and make a meaningful contribution to our renewable energy mix.

Conclusion

Wave energy is an immense, untapped renewable resource that has the potential to meaningfully expand the world’s clean energy portfolio. However, wave power technology remains in early developmental stages. Major investments in R&D, pilot projects, regulatory enabling environments, and financial incentives will be required to spur the innovations needed to deploy wave power farms at scale. If key challenges around technology performance, costs, permitting, and transmission can be overcome, wave power has the opportunity to become a major pillar of our global energy transition. With the proper support, the waves of our oceans could provide clean, predictable energy to millions of people worldwide.