New Wave Power Technology Cuts Costs

A hand-picked selection of Sweden's best cleantech companies will tour London, Zurich and Boston this year. Sweden has positioned itself as a world leader in environmental innovation and growth of businesses that want to solve the big challenges in the energy and environment sector, and amongst the group is wave energy innovator CorPower Ocean.

CorPower is bringing a new type of compact high efficiency wave energy converter (WEC) to market. The patent pending technology, inspired by the pumping principles of the human heart, can enable harvesting of energy from ocean waves with an energy density five times higher than currently known methods at less than a third of the cost per kWh.

Wave power represents a significant opportunity for clean renewable energy supply. With an economically exploitable resource estimated to 2000-4000TWh, 10-20 percent of the global electricity can be provided by wave power, assuming a reliable and cost effective technology is demonstrated. Wave power offers a fairly predictable output with power levels that can be forecasted 1-2 days in advance and a different timing of intermittency compared wind and solar, which is beneficial for grid balancing. The seasonal load correlates well with the electricity consumption on the northern hemisphere.

Despite several attractive features of the energy resource, there are significant challenges that have so far prevented wave power from becoming a mainstream energy source. The main problem is the harsh ocean environment, with highly fluctuating power levels. Devices have to withstand loads in extreme waves that have 30-40 times higher energy compared to the average waves. In order to survive extreme waves in storms, most WECs have designs that result in the following characteristics:

1. High CAPEX cost compared to the rated power output, due to large and heavy structures
2. Low capacity factors (average/max power ratio) due to poor performance in varying sea states
3. High operation and maintenance cost due to complex off-shore service scheme.

CorPower Ocean’s Wave Energy Converters address the challenges of cost effective electricity generation from ocean waves in a new way. A unique mechanical design, inspired by the pumping principles of the human heart, is combined with advanced control algorithms that make the WEC oscillate in resonance with incoming waves. Active phase control by latching enables 3-4 times increase in power absorption compared to conventional passive wave power buoys, resulting in high power output compared to its physical size and weight. 

It also gives a more stable power output over varying wave heights and periods, resulting in a high capacity factor. The device is designed to be fully submersed in normal operating mode, giving an inherent survivability advantage since the peak loads in storms are not significantly higher than the load from the design sea state that the device has been rated for. The systems are of point absorbed type, with a heaving wave buoy on the surface absorbing energy from ocean waves. 

The wave farm concept is based on combining hundreds to thousands of small WEC units in arrays, with a common grid export cable that connects the offshore wave farm to existing on-land grid. With a WEC rating of 100-300kW per unit this enables wave farms with 10-300MW capacity. The concept allows mass production to drive down cost per unit and an effective maintenance scheme based on replacement of entire units at sea. The service scheme offers significant improvement in farm uptime and operational costs, and is enabled by the small physical size and limited cost per system. CorPower’s team has extensive experience in the energy generation market, system design, manufacturing and marketing of advanced technology products. 

The company is run by CEO Patrik Möller, entrepreneur and technologist with experience from building VC funded startups from first idea to >80 people with multinational operations. The inventor behind the technology is Stig Lundbäck, serial entrepreneur, M.D. and Ph.D. with background in heart mechanics, pumps, turbines and power generation technology.

Additional competence in wave power modeling, testing and benchmarking is provided through partnerships with the Wave-Energy-Center (WavEc) and IST in Lisbon, Marintek in Trondheim and KTH in Stockholm. Johannes Falnes, professor emeritus of NTNU, wave power guru and pioneer within phase control of WECs is a technical advisor to the company. 

CPO’s technology builds upon the principles of latch control developed by Falnes and Budal in Trondheim since the 1970s. The company has been part of the KIC InnoEnergy Highway incubator since 2012, which provides a strong support offering for renewable energy startups, project funding and access to a network of major European industrial players within the field. 

Ocean testing will be performed during 2014-2016 in collaboration with infrastructure partner Iberdrola Engineering (IbE). The project consortia covers the key parts of the value chain with CorPower Ocean as device Supplier and Iberdrola Engineering as infrastructure and farm engineering supplier, jointly having the competence and resources to develop and supply integrated wave farm solutions at an industrial scale.

The company is currently preparing for ocean testing of a scale 1:2 system that will take place during 2014-15 at an established European test site, in a consortium with Iberdrola Engineering, WavEc and additional partners. The aim of the project called “HiWave” is to prove functionality and performance in ocean environment with a system having the highest power density demonstrated (>5kW/ton device) while gathering product data supporting a Cost of energy (LCOE) < 15 EUR/MWh.