According to the U.S. Department of Energy (DOE), ocean waves are a renewable energy resource with the potential to power more than 100 million US homes -- yet they are completely underutilized in today’s energy market. Wave energy has many advantages compared to other renewable energy sources (e.g. wind and solar): greater predictability, steady day- and nighttime availability, and significantly higher energy density (with an average of ~30 kW per meter coastline). As part of their effort to advance and accelerate the development of feasible and cost-efficient wave energy conversion technologies, the DOE sponsored a multi-year Wave Energy Prize, a public technology competition with over $2 million USD in prize money. A diverse group of organizations competed to build the best Wave Energy Converter (WEC) in terms of both wave absorption efficiency and cost-effective design.

Our team at CalWave Power Technologies, a startup coming out of the University of California at Berkeley, entered the Wave Energy Prize competition with a vision to develop a novel, scalable solution to wave energy conversion. Our solution was inspired by the ability of a muddy seafloor to completely absorb the energy of passing waves within only a few wavelengths. Waves seem to “disappear” when travelling over a muddy seafloor because the wave energy is dissipated, as the mud moves with and resists the motion of the wave. Our patented WEC solution features an optimized absorber body, to mimic the muddy sea floor, connected to a grid of controllable power takeoff units, consisting of double-acting dampers to extract the wave’s energy. Unlike many of our peers’ technology that extract wave energy at the ocean surface, our system operates fully submerged and out of sight. This unique approach enables several improved operating abilities: it can survive stormy seas; it causes no visual pollution; and it allows for precise control of structural loads because it does not have to manage the broad spectrum of wave loads typical of the ocean’s choppy surface.

The stakes were high and the timeline was tight. To achieve our goals, we would have to move quickly -- and we could not afford to make any mistakes. We decided to seek sponsorship and guidance from industry experts who could accelerate our development and help reduce our risk of failure. We turned to JKI because of their expertise in using LabVIEW to help scientists and engineers get innovative technology to market quickly and reliably.

LabVIEW, NI Hardware, and the JKI State Machine: A Winning Combination

In just a few days, JKI’s engineers were able to understand our system requirements and provide us with a powerful LabVIEW template for our system software based on the JKI State Machine. The JKI State Machine is an easy-to-use yet powerful state machine template for LabVIEW that their team of experts has spent years refining. JKI also helped us select the best NI data acquisition hardware for the rapid development of our control and data acquisition system.

JKI engineers aren’t just experts in programming, they are very connected to the real world and how the code they develop will function in practical applications, which enabled us to exceed the boundaries of current state of the art technologies

Nigel Kojimoto - CTO at CalWave Power Technologies

We selected the NI cDAQ 9184 modular Ethernet chassis for our data acquisition system to allow our signal conditioning to be very close to the sensors, while still allowing our user interface software to communicate over the network. We selected the NI 9205 analog input module for acquiring our load sensor signals (force) and used the NI 9401 bidirectional digital I/O module for acquiring encoder signals from our linear position sensors (displacement, i.e. velocity), enabling us to continuously measure the power extracted from the waves via the power takeoff units (force times velocity). Finally, we selected the NI 9263 output module to provide analog closed-loop control of the system to optimize our power conversion performance.