Origin Stories: Wind Farm

The first Wind Farm puzzle was created for the Spring 2008 green issue of Imagine. Similar to the Gerrymandering puzzles originally created for the election issue in 2004, I wanted to create a puzzle that would be interesting on its own, but also draw attention to an important subject. I considered several possible environmental topics at the time: carbon emissionsmelting glaciers and rising sea levelsendangered speciesclimate change. But an indelible memory was fresh in my mind, and it turned my thinking toward my own experiences in sustainable energy.

During the summer of 2007, I was moving from Madison, WI, where I had just completed my graduate studies, to Dayton, OH, where I would be starting my first college professor job. To this day, I still remember driving down I-65 through northwest Indiana and seeing for the first time, with my own eyes, a wind farm. Rows and rows and rows of wind turbines stretching for as far as you could see. Even going 70 mph, it still takes a solid 10 minutes to drive through the Meadow Lake Wind Farm, which has an operational capacity of 500 Megawatts.

Meadow Lake Wind farm (2) 2-3 2010” by Chris Light at en.wikipedia. Licensed under CC BY-SA 3.0 via Commons

Once it had occurred to me to use a wind farm as the basis of an environmental puzzle, I needed to figure out how such a puzzle would really work. The details of the puzzle, like the T-shaped footprint and “windier areas”, are loosely based on how wind farms are actually built. In reality, the windiness across wind farm areas is generally quite consistent at any one time, with altitude and access to the power grid more critical to wind turbine placement.

The solution strategy for these puzzles is based on an incomplete tiling of the T-shaped turbine footprints. You can tesselate these shapes to maximize the number of turbines; however, that regular tessellation (or complete tiling) is disrupted by the irregular footprint meeting the straight boundary of the land. Plus the windier areas give some incentive to shift the pattern around, or break it up entirely, so long as you do not lose too many turbines in the process. Many of the earlier puzzles I wrote maximized the use of the windier areas, so that every turbine could be placed (in only one way) on those areas. Later puzzles shifted away from this line of thinking and towards using the interlocking tessellation itself as a constraint to create a maximum number of turbines that could be placed in windier areas.