Wave Swell Energy Ltd (WSE) has commissioned CSIRO to provide an independent analysis of the cost-benefit of using its wave energy technology as a reliable supply of renewable energy. Previous studies have suggested that the consistency and reliability of wave power along Australia’s southern coastline can contribute to a significant proportion of Australia’s renewable electricity supply. This report assesses three sites in Victoria and South Australia, focussing on the ability of wave energy to complement the intermittency of wind and the seasonal variability of solar photovoltaic (PV) energy thereby improving grid stability and reducing the cost of guaranteeing electricity supply.
The report uses a dispatchability analysis to determine if wave energy, based on the WSE technology, confers a net economic advantage when combined with battery storage in conjunction with wind and/or solar energy. Dispatchability in this report is defined as the ratio of guaranteed power to average power. The dispatchability analysis uses this definition to compare the costs of supplying dispatchable power for a range of renewable electricity generation modes including solar PV, onshore wind, offshore wind, and wave energy. These generators are assessed as either single mode ‘standalone’ systems, or as ‘hybrid’ combinations of modes.
In this study wave energy utilising the WSE technology required the lowest energy storage for all standalone configurations to meet dispatchability requirements between 0 and 1. Wave energy was also an essential component where the lowest energy storage was required for hybrid systems that had dispatchabilities greater than 0.35. It is worth noting that the Australian Energy Market Operator’s Integrated System Plan report of 2022 implies an approximate dispatchability value of 0.8 for the period 2024 to 2050.
Hybrid configurations that included wave energy required the lowest CAPEX for dispatchabilities above 0.36 and as the CAPEX of the WSE technology reduces further with additional installed capacity, the 0.36 dispatchability threshold that excludes wave energy could be further reduced. This study used redox flow batteries, alternative energy storage modes may increase or decrease the dispatchability threshold.
Energy storage combined with hybrid power generation has the potential to provide much higher levels of cost-effective energy security than any single renewable energy generation mode can provide, particularly those hybrid combinations that include wave energy. For example, if 70 percent of average power generation is to be guaranteed using battery storage, then a hybrid generator of solar, offshore wind and wave energy in the ratio of 1:1:1, could require less than half the CAPEX compared with a hybrid solar and offshore wind farm, and one third the cost of a hybrid solar and onshore wind farm.