Development and Fabrication

Gaining the appropriate legal and regulatory approval ended up as about a third of the total project effort. By the summer of 2009, we had successfully gained the formal approval required to put a test rig on Lake Erie. Successfully achieving this milestone was nothing short of phenomonal, as much larger organizations with many more resources at their disposal are still tangled up trying to receive such approval.

Commercial buoys are very expensive, and a wind farm system utilizing such buoys would not fit within budget. As it turns out, common trash cans have a comparably tough polyethylene structure as commercial buoys, but are a fraction of the cost. We filled our cans with the same foam that watercraft and commercial buoys often use to ensure buoyancy. According to structural analysis, our design would offer comparable performance for a very large cost savings.

A number of technical challenges were confronted, and mostly addressed through quick and flexible thinking.

The two turbines provided a battery array with up to 1.2 kW of power, and are the sole power source for two independent computer and telemetry systems. Two weather dataloggers also collected data about weather conditions and transmitted results directly to the computers. Computer networking problems could not be addressed within schedule, and as a result, only one computer system could be accessed remotely. Both systems, however, successfully logged and recorded data.

A windlass (a power winch for pulling up the anchor line) was incorporated into the design to drop and pull up the polyester and chain anchor line, rated for 8000 lbs of strength. However, at the last minute, the windlass failed, and required climbing onto the rig and manually dropping anchor. The anchor dropped and held tight in place within 2 feet of the approved location, about 8 miles offshore on Lake Erie from Cleveland, Ohio.

For some reason, the smaller 450 W turbine would not spin and generate power prior to and during the launch. Both turbines were tested on a makeshift dyno (system for testing powers, torque, others) and worked prior to shipping.

Fortunately, this wind farm test rig was designed with considerable redundancy and fault-tolerance (when one thing fails, another thing still works to ensure performance).