With the steep declines in solar photovoltaic (PV) system prices over the past 5 years, many developers of remote microgrids – systems not interconnected with a traditional utility grid – have begun to shy away from their previous reliance on wind power to lower the systems’ consumption of polluting and increasingly expensive diesel fuel.
As one long-time observer summed up the situation: “The history of the small wind turbine industry is one littered with failures.” The story of Southwest Windpower is particularly galling. Backed by investments from General Electric, the company’s tiny turbines were pumped out into the market with little regard for long-term performance. As a result, many of these extremely lightweight machines, producing less than 2 kW of power each, have stopped working only after a few years. In some remote island installations, the machines have literally been blown away by hurricanes and other extreme weather events. While some other small wind turbines, such as those of Bergey Wind Power, have had lasting power, many of these typically small, small wind companies have struggled over the past few decades.
Wind in Lonely Turbines
A survey conducted by the Commonwealth Scientific and Industrial Research Organization (CSIRO) of Australia in 2009 claimed that 71% of microgrids included some form of wind capacity. Given that Australia is one of the global leaders in off-grid wind/diesel systems, it is likely these results were skewed by data weighted too heavily toward off-grid applications. A more recent analysis performed by Navigant Research found that of those microgrids that included wind power, 67% were installed in remote microgrids. Interestingly enough, North America is the global leader, due to two states: Alaska and Hawaii.
Remote Microgrid Capacity with Wind Capacity, World Markets: 2Q 2014
(Source: Navigant Research)
Wind has fallen out of favor for at least three reasons:
- Unlike solar PV, small wind turbines historically have required greater operations and maintenance (O&M) investments. In many remote locations, local expertise is hard to find.
- Many remote locations do not benefit from an adequate wind resource assessment. If you’re constructing a 100 MW wind farm, you can justify the expense of a detailed wind resource assessment. This is not the case for just one or two wind turbines in a remote microgrid.
- The variability of wind is immense, requiring a more nimble and sophisticated control system for a microgrid.
Both, Not Either
Despite these negatives, many remote microgrid developers still see value in wind. In many cases, wind power is still half the cost of solar PV. In fact, the ideal scenario is not just solar or just wind as renewable options, but both. The sun shines during the day; the wind often blows at night. Incorporating both of these renewable resources enables the use of a smaller energy storage device – a technology that is currently often viewed as the weak link among hardware choices for a microgrid due to high cost.
Furthermore, there are many wind turbines that now offer direct drives, eliminating the gearbox that is the most common point of failure, which contributes to high O&M costs. If such wind turbines can be installed without a crane, as is the case with Eocycle’s, some of the installation headaches also go away.
Tags: Digital Utility Strategies, Distributed Generation, Microgrids, Remote Microgrids, Smart Energy Program, Wind Power
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