Economic and Social Benefits from Wave Energy Conversion Marine Technology

This paper summarizes the energy resource, the energy conversion technology, and the economic and social benefits of using wave energy technology. The Electric Power Research Institute (EPRI) estimates that the U.S. wave resource potential that could credibly be harnessed is about 6.5% of the 2004 U.S. national electricity energy demand (the total 2004 demand was about 4,000 TWh). Wave energy conversion (WEC) is an emerging technology; ten WEC devices have been tested to date in natural waters worldwide over the past 10 years. The economic opportunities are significant. A relatively minor investment by government in the public good today could stimulate a worldwide industry generating billions of dollars of economic output and employing thousands of people, while using an abundant and clean natural resource to meet our energy needs. Wave energy is potentially more easily assimilated into the grid (compared to wind and solar) because it may be more accurately predictable two to three days ahead and sold as firm power. Given proper care in siting, deployment, operations, maintenance and decommissioning, wave power promises to be one of the most environmentally benign electrical generation technologies. The primary barrier to the development and use of these technologies in the U.S. is the cumbersome regulatory process. We recommend and encourage the development of an effective regulatory system that fosters the application of this environmentally friendly electricity generation technology for our society. north and south. The power in the wave fronts varies in these areas between 30 and 70 kW/ m with peaks to 100kW/m in a few locations. EPRI estimates that the U.S. wave resource potential which could be credibly harnessed is about 6.5% of 2004 U.S. national electricity energy demand (EPRI WP-009-US). The U.S. wave energy potential is about 2,100 TWh/yr (see Figure 2) and composed of four (4) regional wave energy climates, each with their own characteristics. Assuming an extraction of 15% wave to mechanical energy (which includes the effects of device spacing, devices which absorb less than all the available wave energy and sea space constraints), typical power train efficiencies of 90% and a plant availability of 90%, electricity produced is about 260 TWh/yr, which is about equivalent to the total 2004 energy generation of conventional hydro power. In order to effectively use wave energy, the variability over several time scales— namely: wave to wave (seconds), wave group to wave group (minutes), and sea state to sea state (hours to days)—must be understood. The time scale of seconds to minutes is important for continuously “tuning” the plant to changing sea states. The hours to days time scale is important for providing firm power guarantees into the day ahead electrical grid market. Being able to accurately forecast changes in wave energy in response to the FIGURE 1 Worldwide Wave Resource (Thorpe, 1998). T Resource he power of ocean waves is truly awesome. Aside from thrilling surfing enthusiasts and enthralling beachgoers, their destructive potential has long earned the respect of generations of fishermen, boaters, and other mariners who encounter the forces of the sea. Ocean waves can be harnessed into useful energy to reduce our dependence on fossil fuel. Instead of burning depleting fossil fuel reserves, we can obtain energy from a resource as clean, pollution free, and abundant as ocean waves. The technology, though young, exists to convert the power of ocean waves into electricity. The worldwide wave energy resource, stated in kW power per unit meter of wave crest length, estimated by Dr. Tom Thorpe (Thorpe, 1998) is shown in Figure 1. The highest energy waves are concentrated off western coasts in the 40–60 latitude range