Published on April 2nd, 2012 | by Tina Casey6
Wind Farm in the Sky Created by Donut-Shaped Blimp
From a distance it looks like an escaped party balloon in the shape of a donut, but that new thing up in the skies over Limestone, Maine this winter was in fact the 35-foot prototype for a new helium blimp capable of harvesting wind energy at high altitudes, built by the company Altaeros. High-altitude winds are generally stronger and steadier than those near the surface, making them a more efficient feedstock for wind turbines than the low lying winds harvested by conventional wind farms.
How not to harvest wind energy at high altitudes
Building taller wind turbine towers is not a particularly cost effective way to grab high-altitude winds, due to additional expenses for site acquisition (larger towers generally require a larger footprint), manufacturing and transporting the components, constructing the tower, and performing routine inspections as well as maintenance and repair.
The benefits of blimp-lofted wind farms
Altaeros Energies, which calls its new blimp the Airborne Wind Turbine, is one of several companies working around the problem by sailing a turbine into the air (other attempts include hookups between wind turbines and kites).
Along with the benefits of gaining high altitudes without the need for a tower, the dock for the new blimp fits on a trailer for easy portability. The blimp’s tether doubles as a power transmission line and in case of severe weather, the blimp could be grounded by remote control.
Altaeros’s Airborne Wind Turbine
In the test this winter, the Airborne Wind Turbine prototype was lofted 350 feet high, carrying within its donut hole a popular Skystream model turbine from the firm Southwest Windpower. As anticipated, the blimp-mounted turbine generated more than twice the power than it would have if attached to a tower at a more conventional height.
Initially, the company’s goal was to attain a working height of up to 2,000 feet (by comparison, the Empire State Building is 1,250 feet high) and to develop a production model that could be transported in a standard shipping container and installed in just a few days.
So far tests indicate that a height of only 1,000 feet would be sufficient to gain a significant savings over conventional wind power. Within that parameter, Altaeros estimates that the energy produced by its turbine would cost up to 65 percent less than a comparable ground-sited wind turbine.
Many uses for a blimp-wind turbine hookup
Aside from cost benefits, Altaeros also anticipates that its blimp turbine could be used to help remote industrial and military facilities reduce or eliminate their reliance on diesel generators. Its portability would make it especially practical investments for temporary worksites and forward military bases.
Industrial worksites could include oil and gas drilling sites and test wells, which would explain the interest of oil giant ConocoPhillips in the technology. Just a year after its founding in 2010, Altaeros won the fourth annual ConocoPhillips Energy Prize, co-sponsored by Penn State University.
The Airborne Wind Turbine has also received funding from the U.S. Department of Agriculture, which is interested in the technology for its potential for bringing clean, low cost energy to underserved rural areas. In a project statement for USDA, the company noted that “85 percent of rural communities cannot utilize wind power today due to community concerns or poor wind resources at ground level that make projects uneconomical.”
Old technology roots for a new wind power solution
The Altaeros team is on solid ground in terms of the device’s technological roots. In addition to deploying a proven, commercially available turbine, the team boasts foundational research from the Massachusetts Institute of Technology. The blimp itself is adapted from conventional aerostat technology that has been used for decades to send heavy pieces of radar equipment into the air.
A few bumps on the road to low cost wind power
In terms of developing a commercial-scale model for rural communities, the main problem to resolve is testing the Airborne Wind Turbine for durability under maximum wind speeds in its target regions.
Given the extreme weather events experienced in parts of the U.S. within the past two years, that goal could prove more elusive than it would have been in the past.
Another obstacle looming ahead is the helium supply issue. Although one of the most abundant elements in the universe, helium is extremely rare on Earth. It is a component of natural gas, but it usually occurs in such small proportions that it is not worth recovering.
Natural gas deposits in parts of the U.S. are some of the world’s most helium-rich and for this reason the U.S. dominates the global market, but despite the country’s current natural gas drilling boom helium is in short supply.
A massive U.S. helium stockpile from the early 20th century was sold off in the 1990’s, lowering its prices and leading to a massive boom in the party balloon business, contributing to a “squandering” attitude that some analysts blame for the shortage.
Helium is also widely used in medical diagnostics and research. An article last month in The Guardian reported the gas is becoming “worryingly scarce” for some purchasers in these fields.
Helium cannot be synthesized (at least, not so far) and the only currently available substitute is hydrogen. Hydrogen is flammable and has not been used in commercial blimps since the Hindenburg passenger blimp disaster of 1937, which resulted in 36 deaths.
Also of concern is the current majority party in the U.S. House of Representatives, which has been using federal funding for alternative energy as an election-year issue with which to bash the Obama Administration.
One recent target has been last August’s $102 million Department of Energy loan guarantee for the Record Hill wind farm in Maine, which was partly owned by a current Independent candidate for U.S. Senate, Angus King.
On the plus side, wind energy is here to stay and all of the political posturing will probably be water under the bridge by the time Altaeros has a full scale Airborne Wind Turbine ready for testing.
Follow Tina Casey on Twitter: @TinaMCasey.