Cost has been perhaps the most prevalent technology gap holding wind energy back. In order to be economically competitive, wind-generated electricity must cost as little as conventionally generated electricity, what is referred to as “grid parity”. The U.S. Department of Energy (DOE) Energy Efficiency and Renewable Energy (EERE) Wind Energy Program seeks to reduce the cost of electricity generated by large wind systems to 3.6 cents per kilowatt-hour (kWh) by 2012. [1]
To reach the right Cost of Energy (COE), seven areas are targeted:
DOE’s National Renewable Energy Laboratory (NREL) is conducting wind turbine R&D into areas such as blades, components, computer modeling, control systems, drivetrains, dynamometer testing, and towers[3]
. In order to reach the U.S. goal of 20% wind energy by 2030, R&D is needed in improving wind energy system reliability, operability, and manufacturing processes. Other research areas include transmission and grid integration issues, siting and environmental issues, and expanding the wind energy market. In addition, EERE is investigating other applications such as the use of wind energy to produce hydrogen, to clean and move water, and to work in synergy with hydropower to provide a stable electricity supply. [4]Sandia National Laboratories is conducting research aimed at improving wind turbine performance, reliability, and reducing the cost of energy. While specializing in all aspects of wind-turbine blade design, manufacturing, and system reliability, Sandia focuses on materials, structurally efficient airfoil designs, active-flow aerodynamic control, and sensors.[5]
While not specific to wind energy, there are inadequacies in the current U.S. electric transmission infrastructure that limit renewable energy development. The American Wind Energy Association (AWEA) is working to pass legislation to support construction of Green Power Superhighways that would address current transmission infrastructure inadequacies.[6]
A more specific issue for wind energy has been gearbox failures. In those cases in which the failure is due to the bearings, it can be difficult to pinpoint whether the problem lies with the bearings themselves, or whether there is something more fundamentally wrong with the turbine design such that undue stress is placed on the system, which then shows up in the bearings. Turbine manufacturers, gearbox manufacturers, and bearing suppliers have been working together to untangle this issue.[7]
Energy losses in generator windings, power electronics, gears and bearings, and other electrical devices are individually quite small, but together these losses add up to significant numbers. Improvements that remove or reduce losses during low power generation could increase capacity and reduce cost. Technologies that could help include innovative power-electronic architectures and large-scale use of permanent-magnet generators.[8]
*The learning curve results from the NREL report (Cohen and Schweizer et al. 2008) are adjusted from 3.0 doublings in the reference to the 4.6 doublings in the 20% Wind Scenario
