Buoyant Air Turbines (BATs)
In the pursuit of sustainable energy generation, inventive approaches have emerged that challenge existing technologies. The Buoyant Air Turbine (BAT), a pioneering project developed by MIT researchers and graduates at Altaeros Energies since the early 2010s, stands out as one such innovation.
Unlike traditional wind turbines, the BAT is designed to float to higher altitudes to harness the stronger and steadier winds found at those heights to produce a more consistent generation of electricity. In this blog post, we dive into the BAT concept and assess its potential impact on the future of renewable energy.
High-Altitude Wind Power: A Paradigm Shift
While traditional wind turbines have become iconic symbols of renewable energy generation, these structures have their limitations. Positioned at ground level, wind turbines can only capture the intermittent and variable winds that sweep close to the Earth’s surface.
The concept of High-Altitude Wind Power (HAWP) represents a paradigm shift, addressing the constraints of surface-level wind by tapping into unobstructed, high-speed winds at significantly higher altitudes. As wind intensity increases at greater heights due to smoother airflow above obstacles such as trees, buildings, and mountains, HAWP technologies such as the BAT strive to harness high-altitude winds to provide a more consistent generation of electricity.
The BAT Design
The BAT’s structure resembles that of a massive helium-filled balloon or blimp. According to the National Science Foundation (NSF), this buoyant element enables the BAT to float up to 2,000 feet above the ground, well beyond the reach of conventional ground-based wind turbines. The use of helium also ensures that the BAT remains aloft with minimal energy consumption.
Contained within the BAT’s helium-filled shell is a wind turbine that, much like its ground-based counterpart, captures the kinetic energy of wind as it flows past, converting it into electricity. To maintain stability at high altitudes, the BAT is engineered with advanced aerodynamics. As reported by MIT, the BAT’s sleek and streamlined design enables it to withstand turbulent winds of up to 100 MPH.
Despite being an airborne structure, the BAT relies on tethers to provide structural support and prevent unwanted drifting or positional loss in response to changing wind conditions. These tethers serve a dual purpose; they not only anchor the BAT, but also act as conduits for transmitting the electricity generated by the turbines down to a ground station and distributed to an electrical grid.
Envisioned Use Cases:
The BAT was not designed as a replacement for conventional wind turbines. Instead, its design was born from the vision of bringing wind-generated power to the most remote and off-grid areas where the installation of traditional turbines proves impractical or economically unfeasible.
As reported by CNN, the rural landscapes of Alaska, where remote communities often rely on expensive fossil fuel generators to meet their energy needs, could instead use BATs to reduce kilowatt hour costs.
The BAT’s versatility extends beyond energy generation, as its airborne structure allows it to carry additional payloads. According to Altaeros Energies Founder Ben Glass, this opens a world of possibilities, from installing weather monitoring and surveillance equipment to being fitted with WiFi capabilities to provide internet access to remote and underserved areas.
BAT Proof Of Concept
According to an MIT News article in 2014, the BAT was to undergo an 18-month long trial to power microgrids at a site south of Fairbanks, Alaska, funded by the Alaska Energy Authority, in 2015. No information could be sourced about the results of this trial.
SOURCES
**(1) https://news.mit.edu/2014/high-flying-turbine-produces-more-power-0515 (2) https://edition.cnn.com/2014/05/12/tech/innovation/big-idea-airborne-wind-turbines/index.html (3) https://new.nsf.gov/news/floating-wind-turbines-bring-electricity-where-its
4 - https://energydigital.com/renewable-energy/flying-wind-turbines-high-energy-potential**