Abstract: Energy used to create a fluid flow through a passageway, e.g., a municipal water system, is partially recovered downstream, e.g., at a residential location. An example energy system includes a primary passageway receiving a first fluid from an external source. The primary passageway includes a first region having a first cross sectional area and a second region having a second cross sectional area. The second cross sectional area is different than the first cross sectional area. The first fluid moves from the first region to the second region. A secondary passageway extends from the second region. A turbine is disposed in the secondary passageway. The movement of the first fluid through the primary passageway causes a movement of a second fluid in the secondary passageway, and the movement of the second fluid in the secondary passageway drives the turbine to generate energy.