A gust of energy

Places that relied overly on wind have often regretted the same. Sudden drops in wind have resulted in blackouts. Like in the spring of 2008 the Texas power utility operators struggled to keep the lights on due to a rise in demand and drop in wind.

Wind power, like most renewables is still considered fickle. To increase the efficiency, the generators must run on a single speed which is often not possible. To compensate, engineers design turbine hardware to have adjustable blade angles to shed surplus wind energy or to capture more.

Wind turbines often also employ a transmission to gear the shaft speed up or down to the required spot. But both mechanisms add weight, complexity and cost.

Critics point to the hidden costs and such technical challenges in the construction of expensive transmission lines and lack of a storage system.

ExRo Technologies in Vancouver is working on a generator that operates efficiently over a wide speed range. Retrofitted wind turbines could produce as much as 50 percent more power over time, the company claims.

Here, fast-acting electronic switches can engage individual generator coils as needed to harvest energy effectively at different wind speeds. An intelligent controller turns on only a few coils at low speed and connects more at higher velocities.

ExRo has successfully tested a prototype generator. It expects to start side-by-side trials of turbines with and without the new generators soon and plans to commercialize their product by the end of 2009.

In the final analysis, it is a combination of renewables with suitable storage options that will provide the answer. Costs can be high even for storage systems like fuel cells, thermal mass, batteries, etc but that is no reason to drop it. Especially as more crunching evidence comes in of global warming, the latest from NASA on thinning Arctic ice.

The largest contributor to emissions is fossil fuel based power plants. There are over 50,000 such plants globally and an average plant of 500 MW emits 10,000 metric tons of carbon dioxide daily! The world's emissions of carbon dioxide are predicted to rise over 50 percent to more than 42 billion tonnes per year from 2005 to 2030.

Any stronger reason why we need to take the less-trodden path now?