Winds of fortune blow to the east (part one)

Joshua Israelsohn, Editor-in-Chief, Power Systems Design


US: Congress and the wind-power dustbowl

About a decade ago, I started using a simple measure to gauge the health of the trade shows I attend and, by extension, the market segments on which they focus. I call the measure the MTBC (mean time between collisions)—a slight exaggeration in name that produces an approximation inversely related to the trade show's health and vitality. The MTBC works quite simply: I walk down a typical trade-show aisle at what we might term sidewalk pace and time how long I can do so before I must change my course—sidestepping or dodging other attendees to avoid collisions. In heavily attended shows, even the sidestepping and dodging are not always sufficient and I must stop to wait for a break in the traffic, as was often the case, for example, at this year's PCIM Europe exhibition. Twice I've predicted the demise of a trade show based entirely on MTBCs extending out to several minutes, indicating that there were far more exhibitor staff populating booths than attendees populating the aisles. Of course the MTBC is by no means the only assessment I make of a trade show, which is a good thing because if it were, I'd be far less sanguine about the AWEA's (American Wind-Energy Association's) WindPower 2012 exhibition held at Atlanta's World Congress Center. WindPower 2012 drew 920 exhibiting companies to Atlanta this year and, according to the AWEA, "11,000 participants". The word participants, in this case, appears to refer to the sum of exhibitor staff and attendees because it is hard to believe that the latter outnumbered the former by a significant margin. Yet the general mood on the floor was far more positive than the limited acting skills most exhibitors possess could support if judging by attendance numbers alone. In fact, instead of having the run of the floor with few customers with whom to compete for vendors' time, I had to reschedule several meetings because key exhibitor personnel were engaged with customers both on and off the trade-show floor. Here, it's not the number of attendees a show attracts but rather who those attendees are that determines the success of a trade show from the exhibitors' perspective.

The overall impression I received from the majority of vendors I interviewed at the show was that wind power is a healthy, vibrant sector showing impressive growth in many parts of the world. This is particularly true for those parts of the world that are not the United States. Here, reportedly, it will take an act of a Congress decidedly not prone to action to get major wind-power projects moving forward. Even under politically supportive conditions, siting, permitting, constructing, and deploying wind-generation plants is a slow—some might say tedious—process (figure 1). Indeed, if there was one message that echoed through the exhibition's halls, it was that the US Congress's disinterest in or hostility toward (depending on who you talk to) non-hydrocarbon-based energy initiatives is stymieing development of large-scale US-based renewable-generation facilities. This is having the interesting side effect of promoting small-scale generation and finer-grained grid-management schemes, which are certainly not replacements for large-scale installations though they do positively affect energy supply at the local level. It is also having the effect of shipping thousands of jobs and billions of dollars worth of business overseas for large-scale renewables. Thanks US Congress!

By contrast, the British Government appears highly engaged and committed to a significant renewable-generation build out: According to the UKTI (United Kingdom Trade and Investment), a non-ministerial office of Her Majesty's Government, "Renewables' share of electricity generation was 9.5% in 2011. Projections show that the UK is on course to meet its legally binding target for 15% of its energy consumption to come from renewable sources by 2020." UKTI also reports that roughly 25% of the annual growth in the renewable-energy sector derives from wind-power capacity (Reference 1). Offshore wind-generation capacity in the UK has increased from a mere 3.8 MW from two turbines in 2001 to more than 1.5 GW from 487 turbines in 2012 with another 719 offshore turbines under construction (Reference 2). UK employment in offshore wind more than quadrupled from 700 to 3,200 people in the four years from 2007 to 2011. At present, offshore wind provides 1.5% of the UK's electricity. The build out to which the UK government has legislatively bound itself will increase offshore wind generation to 18 GW from as many as 5,000 turbines by 2020. As a share of total UK electricity supply, offshore wind should account for 7% by 2017 and 17% by 2020. This offshore-wind-generation projection alone is ahead of the legally mandated 15% target and there are tide, wave, and on-shore wind projects underway as well. One side effect: the industry trade group, RenewableUK, projects that UK employment due to offshore-wind generation will increase more than 21 fold to 67,700 during the decade from 2011 to 2020. Components for large-scale wind-power generation—either on-shore or off-shore—are not given to easy shipping. This is not a case where logistics problems are resolved with a phone call to Federal Express. Indeed, some of the employment and investment numbers derive from the fact that it is usually easier to construct large components close to the locales in which they will operate than to ship them from, say, overseas. For example, to support the UK build out, Germany-based Siemens Energy, which focuses on large-scale machines in the 1 MW to 1 GW range, is on track to build the UK's first offshore-wind-turbine manufacturing plant by 2014. The new plant will be facilitated by a £60 M pledge from Her Majesty's Government for port upgrades. According to the UKTI, Spain-based Gamesea, which manufactures turbines in the 65 kW to 5 MW range and provides construction, operation, and maintenance services, also plans to open manufacturing and R&D facilities in the UK. The UKTI has identified five classes of opportunity for companies interested in participating in the UK wind-generation build out:

  • Wind turbines and components including gearboxes, bearings, generators, large castings and forgings
  • Blade development and manufacture
  • Wind turbine installation vessels
  • Balance of plant including; supply of foundations, offshore substations, cables and cable laying vessels
  • Operations & Maintenance
With all of the activity in large-scale wind generation, both on- and off-shore, the UK is not ignoring small-scale generation. Small-scale generation growth in 2011 came predominantly from the 10 to 20 kW and 50 to 100 kW market segments. UKTI reports that five of the world's top ten small wind companies are based in the UK. The Carbon Trust reports that "small scale wind energy has the potential to generate 41.3 TWh of electricity annually"—about 12% of the UK's electricity demand.

Siemens Energy focuses on large-scale turbines in the MW to GW range. Siemens Industry, on the other hand, supplies automation, drive train, and power conversion components to the energy generation industry. The company's Motion-to-Grid concept evolved from an investigation starting about a year and a half ago into the small-scale wind market and similar generation technologies that convert kinetic energy into electrical energy. In addition to wind, these include mini-hydro, bio mass, bio gas, wave, tidal, and geothermal. Siemens Industry manufactures components for these facilities including gearboxes, permanent-magnet and induction generators, and AC-AC power converters. The power converters take variable frequency AC from the generators and output grid-synchronized AC. This design contrasts with the more common practice of direct grid connection with rotor-speed control or AC-DC-AC conversion. The AC-AC converter improves system efficiency, particularly at rotor speeds other than the design nominal, where efficiencies tend to drop off rapidly with increasing speed deviation. This is particularly important during light-wind conditions, under which many generators must disconnect from the grid Siemens comments that ongoing reduction in electronic costs is making inverter-based wind-generation systems ever more attractive and expects that, with this technology, manufacturers will be able to construct fixed-pitch direct-drive turbines without gearboxes, which reduces cost, weight, and maintenance. The company notes that, though GW class generators will probably always dominate the market in terms of sheer dollar investment, there are many locales that small-scale facilities serve better. This is particularly true in rural and suburban regions where loads distribute across large areas. In such environments, small-scale wind exhibits an important advantage simply for operating in a grid system with finer granularity and, as a result, shorter transmission distances from source to load. With this comes lower distribution losses and transformation costs. Small-scale, distributed generation also combines more readily with other alternative energy sources and energy storage than do large-scale wind farms.

Siemens is also collaborating with small-scale wind companies such as Cambridge, Massachusetts-based Eastern Wind Power, which constructed their first vertical-axis wind turbine—a 50 kW machine—adjacent to the Martha's Vineyard airport, also in Massachusetts. For this installation, Siemens provided a 55 kW converter but can fit a 120 kW AC-AC converter in the same form factor. The vertical axis machine brings several advantages including presenting a small footprint, which allows small machine-to-machine spacing, and the ability to operate within a small vertical extent (figure 2). These characteristics make vertical-axis turbines well suited to a variety of sites that are inappropriate for horizontal-axis machines. These include rooftop installations where such machines can significantly trim an office building's or residential tower's draw from the grid. In preparation for such application of their vertical-axis machine, Eastern Wind Power has embarked on a project to gather wind data from 10 high-rise buildings in Boston. They've installed web-based weather stations on two buildings to measure wind speed, gust, and direction and plan to install similar systems on eight more Boston sites by 2013. According to the company, single machines are capable of generating 45 MWh per year—enough to power several homes. They installed their prototype machine, located at the Martha's Vineyard airport, in 2010 and it is currently grid-connected and producing power for the airport.

Siemens isn't the only big player that sees potential in small distributed power generation strategies. Switzerland-based ABB's US organization exhibited a number of services and technologies for small- and moderate-sized plants. For example, ABB offers a full line of wind-turbine converters covering the complete wind market, including small, community, and utility-scale wind farms. ABB also is providing PC simulation models for utility compliance studies and offers test facilities to validate compliance. The company also exhibited three transformer lines: EcoDry dry-type distribution transformers are provide the inherent benefits of a dry-type transformer, including fire safety and environmental friendliness with no potential for fluid leakage and high efficiencies for renewable energy applications. Biotemp transformers contain a complete and sustainable transformer fluid for distribution and power transformers combining environmental friendliness through biodegradability, safety through superior fire resistance, reliability, and efficiency with high overload capacity for many wind applications. ABB's Green-R-Pad distribution transformers combine the benefits of amorphous metal cores for up to 70 percent lower no-load losses, with the benefits of Biotemp environmentally-friendly transformer fluid for wind and other renewable energy applications. ABB's Ventyx subsidiary provides software to global energy, utility, communications, and other asset-intensive businesses for energy operations and energy analytics, among other applications. The company also provides software for planning and forecasting electricity needs, including renewables. At WindPower 2012, Ventyx exhibited their most comprehensive offering of integrated information and operations software for wind. They also demonstrated their DRMS (demand-response management system), which supports commercial and retail utility operations necessary to deliver effective demand response programs, distributed energy management, and resource optimization for successful Smart Grid deployments. Of course ABB's interests extend to large-scale wind generation as well. ABB Vice President Roger Rosenqvist argued for offshore wind and HVDC, drawing on projects the company has engaged around the world in his presentation, Case studies of offshore AC substations and HVDC converter stations. For example, the German North Sea DolWin2 project is an offshore wind farm with 900 MW generating capacity. ABB is supplying two 45 km 320 kV DC submarine cables, two 90 km 320 kV DC land cables, and two 12 km 155 kV AC submarine cables (figure 3). The company also provided HVDC VSCs (voltage source converters) for the project. The company has already installed grid connections for the BorWin1 400-MW offshore wind farm in 2009 and the 800-MW DolWin1 project, scheduled for commercial operation in 2013. DolWin2 should be online in 2015. It's DC cables are rated at 900 MW—among the highest in the industry. They have integrated optical fibers for control-system connectivity. Links ABB Carbon Trust Eastern Wind Power Gamesa RenewableUK Siemens UK Trade and Investment References 1. Duhon, Amanda, Eleanor McBarnet, Mike Rosenfeld, and James Cummings, Wind Power in the United Kingdom, UK Trade and Investment, 2012. 2. Working for a Green Britain, vol 2, UK Renewable Energy Roadmap, RenewableUK