This article originally appeared on The Climate Examiner.
British Columbia now has sufficient detailed information about the height, frequency and direction of its coastal waves to start developing and testing wave energy converters in the ocean, according to a new report.
Quantifying the amount of energy contained in waves as they propagate — or more simply, the ‘wave energy transport’ — is more complex and intricate than assessing the energy contained in wind, tidal or solar resources. In general, these energy sources can be described using a single variable; air speed, water speed and incoming solar irradiation, respectively. In contrast, wave energy transport is multi-dimensional and depends on a variety of factors.
As a result, while industry and policy-makers were aware that British Columbia has one of the best wave energy resource potentials in the world, up to now, this understanding had been based on very broad-strokes analyses. Moving beyond the global scale and understanding the spatial distribution of the wave resource, especially near-shore, is a critical step in the development of wave energy converters — the large (up to 120m in length) mechanical devices that transform wave energy into electricity.
Researchers with the University of Victoria’s West Coast Wave Initiative developed a computer model of the B.C. coastline from the Columbia River in the south, up to Haida Gwaii in the north, and combined this with years of data from wave measurement buoys. This two-pronged approach allowed them to develop the most high-resolution wave resource assessment yet available for British Columbia, and to reveal several ideal locations for wave energy development.
Their findings together with a comprehensive plain language introduction to the concept of wave power, how wave-energy converters work, and the opportunities and challenges of this energy resource, are described in a new full-colour Wave Energy Primer recently published by PICS.
Waves arriving on B.C. shores are the result of storms occurring across the vast Pacific Ocean. This makes wave energy highly predictable for power system managers compared to other variable renewable energy sources, such as wind or solar. The West Coast Wave Initiatve has found on average, a four-hour wave forecast features just a 15 per cent margin of error, while wind and solar in the Pacific North West are closer to 77 per cent and 86 per cent, respectively.
This significantly greater forecastability means that while wave energy, like wind and solar, is intermittent, the requirements for grid back-up power source to make up for this intermittency would be significantly lower.
Other advantages uncovered by the University of Victoria team include seasonal timing, whereby the biggest (and most energetic) storms occur in winter when energy demand is highest.
Researchers from the PICS 2060 Integrated Energy Pathways project also found that the integration of a 500 MW wave energy farm has the potential to reduce Vancouver Island’s dependency on annual electrical transmission from the Lower Mainland by up to 11 per cent, and reduce peak winter demand by up to 15 per cent.
The Wave Primer also spells out other challenges facing the industry, including the high cost per unit of energy compared to other renewables, biofouling and operating in a hostile ocean environment.
Image: John Lemieux via Flickr