I think about energy a lot. I’m not sure why this is, but often I see little places where energy is being squandered when it should be reclaimable. In general, any time you have something that’s hot, and you don’t want it to be hot, energy is being lost.

Some of this energy can be hard to spot. Take, for example, the fully-loaded truck at the brake-check pullout before going down a long hill. It’s not moving. Its fuel tanks could be almost empty. But it has energy. Lots of it. The driver is checking the truck’s brakes because the truck is about to turn all that energy into heat. If the driver is not careful, that heat could cause brake failure and a very dangerous situation. The driver will inch down the hill, allowing time for brakes to cool and to use the compression of the engine to slow downward progress as well (heating the exhaust).

All that energy, and we treat it like a bad thing. But energy is expensive, even now when we only pay a fraction of its true cost! What we need is a safe way to reclaim the potential energy of the truck, safely and in a useful form.

Introducing TruckGen. TruckGen is a system that uses the truck to turn a generator as it descends. The generator provides resistance to the truck, but rather than turning the energy into heat, turns at least some of it into electricity. (In fact, the generator would have to be able to provide huge resistance to the motion, but that’s OK — that’s where the electricity comes from.) The truck’s brakes are spared, saving wear and tear and making the descent safer, and as a bonus useful power is reclaimed.

I’ve considered several ideas for exactly how this would work; one of my favorites is a chair-lift-like affair with a cable that runs above the road. Descending trucks would attach to the cable with big clamps, and as they descended they would drive a capstan that turned a generator. The cable would have to be quite strong, of course, but if anything went wrong all the trucks would have nice fresh brakes.

An alternate would be to dispense with the generator and have the uphill trucks attached to the cable as well, and the descending trucks would give them a push. Cutting out the electrical generation makes this system quite efficient. (There would have to be something to prevent some uphill trucks from slacking and forcing other ascending trucks to haul them up as well while they save fuel.) In either case all trucks attached to the cable would move the same speed, improving traffic flow.

If cable strength is a problem (I’m not sure even where to start figuring that out), I imagine an alternate method with a vehicle that latches on to the front of the truck for the descent. It might look something like the tractors that push jets around at an airport, with big tires with good traction (or cogs on a rail?) which would turn a built-in generator. There would be an overhead power line, similar to the ones used to power trains, but in this case they would be receiving the power instead of providing it. The tractors would use some of that electricity to get back to the top of the hill, which cuts into the efficiency of that plan, but the descending trucks would still be a heck of a lot safer.

Next time you see a truck creeping up a steep hill, ask yourself, “what’s going to come of all that work?” With TruckGen, you have the answer.