Wind energy prices have dropped substantially over the past five years and wind power prices are now regularly in the $0.02-$0.035 per kilowatt hour range ($20-$35/MWh). As turbines improve performance and manufacturers reduce costs, utilities are beginning to naturally and voluntarily prefer wind power as an energy resource, even in states where wind power was previously considered infeasible. Researchers and manufacturers are hard at work to ensure wind turbine performance and costs continue to drop in the near future. Here are just a few innovations the wind industry is testing and preparing for primetime.
DRONES – Wind turbines are regularly inspected to ensure peak performance. Instead of having people climb the tall towers, and rappel down blades for blade inspections, some companies are now looking into using drones for basic blade inspections. UpWind Solutions recently achieved key approvals from the Federal Aviation Administration to operate small drones that will help inspect wind turbines.
BLADE EXTENSIONS – General Electric has a new product, a 10 meter blade extension, where a turbine’s blade is cut in half and then extended to expand the rotor swept area. Rotor swept area is a key metric in determining how much kinetic wind power a turbine can transform into electric power. Longer blades collect more wind power, which boosts performance, and can reduce costs. Wind turbine technology is advancing so quickly it may make sense to do some upgrades to older turbines to boost performance and reduce costs.
INNOVATIVE HUBS – As turbine blades become longer, the base of the blades needs to increase in size to ensure structural stability and integrity (so the blades don’t break off). But the big bases of some blades aren’t aerodynamic and don’t help boost turbine performance – that means some part of the blades aren’t capturing wind and turning it into power. General Electric has developed a new product, the ecoROTR, that is designed to shuttle hub winds towards the effective parts of the turbine blades. It could boost turbine output by about 3%.
SPACE FRAME TOWERS – Turbine towers are becoming so large, it can be difficult to transport the large-diameter tower sections. Specialty trucks are required and those can be expensive. Also, if a tower section is too large, a country road may not bear the load or a short bridge may prohibit transport. Turbine manufacturers, including General Electric and Siemens are developing “space frame towers.” These new towers are modular like a giant erector set, enabling easier transport on standard trucks. Space frame towers could reach higher heights and better wind speeds, which would improve turbine performance and reduce costs. Space frame towers could also use fewer materials and rely on cheaper, common transportation trucks.
MODULAR BLADES – Like turbine towers, as turbine blades become longer, specialty trucks are required for transportation. And, sometimes blades cannot fit under highway overpasses. Blade Dynamics, a wind turbine blade manufacturer in New Orleans, has developed a modular blade. Their modular blade can be split into separate sections, which can then fit on standard trucks and under overpasses.
DIRECT DRIVE TURBINES – The standard wind turbine includes a generator and a gearbox. The gearbox increases the rotations per minute (RPM’s) from the slow turning blades into a high-spinning generator to generate electricity. Direct drive wind turbine generators eliminate the need for a gearbox by increasing the generator’s size. Direct drive turbine generators are commercially available today, and some of the benefits of these generators is that they tend to be quieter (since there are no moving gears) and lighter. Lighter generators mean that turbine towers can be lighter and foundations do not need to be as big, thus there are cost savings associated with fewer materials installed.
SUPER CONDUCTORS – One limitation to direct drive turbines is their heavy reliance on so-called “rare earth elements,” which tend to be fairly expensive. Scientists have been studying superconducting materials to help reduce reliance on rare earth minerals, but also boost turbine generator size. Scientists believe that superconducting wind turbine generators can reach 20 megawatts in capacity (land-based turbines are typically 2 megawatts, and offshore turbines are usually 5 megawatts or bigger, today), potentially without a linear increase in weight. In essence, a wind farm with superconducting generators would need fewer turbines to generate substantial quantities of power. That means fewer towers and foundations and quicker installation times.
CARBON FIBERS – Today, wind turbine blades are largely made up of fiberglass and in some cases, balsa wood. As a lighter and stiffer alternative, some blade manufacturers are increasingly incorporating advanced materials, such as carbon fibers. Carbon fibers are lighter, and stronger than fiberglass. Lighter blades are easier to install since super-heavy cranes aren’t as essential. Also, lighter blades should be able to overcome inertia easier, meaning that turbines could begin generating power in lower wind speeds.
DATA PROCESSING – General Electric recently introduced the “Digital Wind Farm” – which is their effort to optimize wind turbines for specific sites prior to and after construction. By better utilizing data, General Electric estimates their Digital Wind Farm should be able to boost performance by 10%.
LASERS – Prior to construction, wind farm developers rely on data collected onsite to determine wind speeds. For wind speeds, developers may install an anemometer (or meteorological tower) to collect data; however, these towers are frequently shorter than wind turbines and may not properly reflect a wind regime at turbine hub height. Without proper wind speed data, wind developers, equity investors and even utilities are faced with risk associated with wind turbine output. Taller anemometers are available, but they can become quite expensive to erect. Instead of installing towers, some wind developers are turning to lasers to measure wind speeds. Light detection and ranging systems (LiDAR) are usually fairly small boxes that can measure wind speeds at various heights, even at heights to the top of a turbine blade (up past 600 feet). After construction, LiDAR can be installed on the top of wind turbines to get horizontal projections for winds heading towards a wind turbine. As such, turbines can adapt to the winds heading toward them, before the winds arrive. LiDAR can also be used to track birds and bats, and potentially reduce avian mortality by turning turbines off if large flocks of birds approach.
These are just a few of the amazing innovations that the wind industry is developing to keep reducing ratepayer costs and improving wind turbine performance. Truly, the future is now.