Green energy from green water

Wave energy represents a significant untapped energy source. As Professor Jo Hermans from the University of Leiden says: 'Worldwide the economically exploitable amount of wave energy is estimated at 2,000 TWh/year, an average power of 200GW over a year. This is quite a lot: the equivalent of 200 large power stations.' But the challenge is to generate a predictable amount of energy, in a reliable way, at a reasonable cost.