There's a lot of water constantly moving through the municipal pipelines of most major cities. While the water itself is already destined for various uses, why not harness its flow to produce hydroelectric power? Well, that's exactly what Lucid Energy's LucidPipe Power System does, and Portland, Oregon has just become the latest city to adopt it.

LucidPipe simply replaces a stretch of existing gravity-fed conventional pipeline, that's used for transporting potable water. As the water flows through, it spins four 42-inch (107-cm) turbines, each one of which is hooked up to a generator on the outside of the pipe. The presence of the turbines reportedly doesn't slow the water's flow rate significantly, so there's virtually no impact on pipeline efficiency.

The 200-kW Portland system was privately financed by Harbourton Alternative Energy, and its installation was completed late last December. It's now undergoing reliability and efficiency testing, which includes checking that its sensors and smart control system are working properly. It's scheduled to begin full capacity power generation by March.