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sts.components.contact.mr.placeholder Sebastian Webel
Mr. Sebastian Webel

Editor-in-Chief

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Pictures of the Future
The Magazine for Research and Innovation
 

The Future of Energy

New Ideas: Fueling Wind Power’s Growth

Wind power already accounts for a substantial share of the energy mix in many countries. For example, following its most recent expansion phase, the London Array offshore wind farm, which uses Siemens turbines, among others, generates power for some 750,000 households.

Wind power is a well-established technology. However, to become even more competitive, it must become more cost-efficient. With this in mind, Siemens has established a number of wind power research centers in Europe and the USA. The company is also investing in new production facilities, advanced remote maintenance, and new energy storage concepts.

In its effort to reduce emissions of greenhouse gasses, Germany plans to generate up to 85 percent of its electricity with renewably-generated energy by 2050. However, wind, solar, and other energy sources currently cover only about 30 percent of the country’s electricity needs. In other words, there is still a long way to go. Furthermore, these energy sources must become cheaper if their use is to expand more rapidly, because energy from fossil fuels is still more affordable. With this in mind, Siemens has established energy research and development centers in Aalborg and Brande in Denmark, Keele, UK, and Boulder, Colorado. Each of these locations has its own research focus.

In Boulder, for example, specialists are studying aerodynamic rotor blade design, structural analysis, and wind forecasting technologies. Siemens’ facility, which is located in close proximity to government-owned research centers such as the National Renewable Energy Laboratory (NREL), facilitates cooperation on joint projects. The research center in Brande has special test rigs to test large wind turbine components such as generators, main bearings, and entire nacelles. Siemens also has seven test rigs in Aalborg, where it tests entire rotor blades, including the largest offshore rotor blade now in use, which is 75 meters long. In Keele, the company is developing electrical components such as the Siemens-Netconverter, which converts the electricity generated by wind turbines into 50 hertz alternating current that is compatible with power grids.

Siemens manufactures and tests a large share of its wind turbines in the Danish city of Brande. The turbines are built to withstand many years under the harshest conditions.

Small Step Toward an Eight-Megawatt Giant

The insights gained at these test centers are helping to make associated technologies more efficient and thus to make electricity production from wind power more affordable. One striking example of the benefits of Siemens’ investments in research is its new eight-megawatt wind turbine for offshore applications. The first such turbines will enter service off the west coast of Denmark in the spring of 2017. What’s unusual about this turbine is that it was created by making only minor technical adjustments to Siemens’ seven-megawatt (MW) offshore system. Proven components such as its 75-meter rotor blades and medium-voltage transformers were left unchanged. The supply and logistics chains are also still the same. As a result, little effort was required to create a wind turbine that has 14 percent more output than its 7 MW predecessor. The 8 MW system’s main innovation is the improvement of the magnets in its generator. “The increased output of our direct-drive offshore facilities is a great example of how our developments are making wind power more cost-efficient,” says Michael Hannibal, Head of Offshore at Siemens’ Wind Power and Renewables Division.

The efficiency of the wind power market can also be improved by streamlining logistics and supply chains. For example, Siemens Wind Power is building two large factories in Hull, England, and Cuxhaven, Germany, where wind turbine components are manufactured practically next to these cities’ harbors. In the future, the facility in Hull will produce the 75-meter rotor blades that are needed for wind farms off the English and Scottish coasts. A total of 104 wind turbines will be needed for the East Anglia wind farm in England alone. The factory in Cuxhaven will begin manufacturing nacelles for offshore wind power facilities in mid-2017. Associated potential savings are especially large for offshore wind power, which is more expensive than electricity from onshore facilities. Such savings can be achieved by installing small transformer substations offshore. “We need distributed lightweight transformer substations in order to reduce the costs of offshore wind power to 10 cents per kilowatt-hour by 2020,” says Mirko Düsel, Head of Transmission Solutions at Siemens. Siemens Wind Power believes that even lower prices may be possible. It expects the price to decline from 12.3 cents per kilowatt-hour today to less than eight cents in 2025.

Siemens Wind Power's Remote Diagnostics Center. The center analyzes and monitors operating data from 8,000 wind turbines around the globe.

Remote Monitoring for 8,000 Wind Turbines

However, the price of wind power is determined by more than just construction costs. Maintenance and repairs also contribute significantly to a facility’s costs. With a view to monitoring performance and thus minimizing turbine downtime, Siemens operates a remote diagnostics center in Brande, Denmark. The center receives some 200 gigabytes of data every day from around 8,000 wind turbines worldwide. Using algorithms trained on oceans of data, the facility can detect minuscule anomalies in behavior that can be an early indication of impending damage. Many such problems can be corrected remotely by adjusting operational perameters. In more serious cases technicians can be dispatched to a site.

Replacing Batteries with Gravel

The efficiency of wind power production would be vastly increased if much of the surplus electricity that is generated on windy days or during periods of low demand could be stored. Initial solutions have been based on large battery systems or facilities that use electricity to produce hydrogen. However, experts at Siemens have now developed an energy storage technology that requires no battery chemicals and doesn’t produce any gas. In fact, not much more than gravel is needed. This new technology, which is called “bulk solids storage,” uses excess electricity from wind turbines to produce hot air in a kind of big blow dryer in order to heat the gravel to more than 600 degrees Celsius. The stored heat can be converted back into electricity on days when there is no wind or when demand for electricity is particularly high. The hot gravel heats up the air, which creates steam in a boiler. This steam then runs a turbine in order to generate electricity. Till Barmeier, the head of Siemens’ Energy Storage program, describes the advantages of the bulk solids storage system as follows: “We produce almost no emissions and there is no danger of explosions or fires. The gravel for the storage system can be quarried from local gravel pits in many areas.” A pilot plant that is expected to be able to store heat for one week is currently being set up in Hamburg. If everything goes smoothly, a larger facility will be built by 2019. It will have an output of 30 megawatts — the equivalent of four wind turbines.

Tim Schröder