Play! for Keeps?

Alternative energy is super awesome. But it only works when it works. And when it's working isn't always convenient. Battery technology hasn't advanced to make the best use of alternative energy, but what if extra energy could be kept for future use? Recent developments in compressed air technologies look promising. Also, people love playing. It's fun. Folding that tech into playable structures and energy-collecting landscape elements–Compressed Air Play-Energy Reservoirs (CAPERs)–would be super cool. Can playing produce usable energy? Play! for Keeps? explores the potential to fill batteries with play energy, keeping it around for later. Using models to explore form that bounds energy, and transplanting that form onto landscape to hold CAPERs, we get Play! for Keeps?