Solar panels, campfires, fuel cells and personal batteries are the main resources anyone can turn to when they need to generate and store energy away from the comfort of home. But some projects demand much more power, and that's when creativity and budget have to reach their full potential. A good example is this portable cinema, which uses the energy supplied by volunteer cyclists to feed a projector.
Want to go to the movies but can't stand noisy crowds or the high ticket price? The solution is to build your own cinema and take it anywhere. That might sound absurd, but a lot of people think that way, and thanks to them we can watch projects like this bicycle converted into a generator to power a mobile cinema evolve. Granted, making a generator from a bicycle is one of the oldest tricks in the book, but the key lies in how you use that generator. The theory is simple, but the final design is highly complex, not to mention packed with high technology.
The hardware behind the show
The chosen projector is an Optoma ML750, which can run on 19 volts. No specific bike is required, but it's recommended to use a 24-volt, 200-watt motor (with a modified skateboard wheel as the friction element), commonly found in scooters. Buffering is handled by two Goal Zero Sherpa 100 lithium-ion batteries, but they can be replaced by other types depending on the user's needs. A voltage regulator is also critical, one that can tolerate wide voltage fluctuations and charge the batteries. The creators say that at some events they arrived with 50% charge and left with full batteries, indicating a good level of efficiency throughout the generator cycle.
The cost of going portable
The biggest barrier any DIY enthusiast will face when trying to build something similar is the budget. Using this model's specs as a reference, there's already over a thousand dollars tied up in batteries and the voltage regulator. If you want that exact projector, add another $600, and that's without speakers or the motor. Still, when money is tight, the mind usually finds a way to succeed. If you have the chance to build a cinema like this, go for it.
