Summary of in-stream energy production devices

Renewable energy is more important as the time advances. The need to replace fossil fuels such as coal and oil is a big concern in the European union which has established goals of 20% of share of energy from renewable sources in whole European union. The importance of small energy production devices increases when we think of this goal, so energy can reach every citizen, even in a remote village which is kilometers away from the main power source. In-stream devices are optimal for remote sources, which almost always have a water source in the proximities. In-stream turbines can generate enough power to a common house and because it does not require any sort of head nor dam it is easy to mount. Its efficiency is around 40% for most recent in-stream turbines. The most recent technology in this area, the vortex induced vibration devices are still in development reaching 20-30% efficiency when a single device is working, reaching up to 40% when arrayed in some exact positions.