Abstract: An energy harvesting system (100) for harvesting energy from vehicles travelling on a road (102). The system (100) includes a plurality of flexible hoses (104) which are embedded in a road overlay (106). Each hose (104) holds a hydraulic fluid, e.g. water, such that, when a vehicle wheel (108) passes over the hose (104), the fluid is displaced. The system (100) further comprises a plurality of double-acting hydraulic fluid cylinders (109) which are in fluid flow communication with the fluid in the hoses (104) and are configured to convert pressure applied to the fluid into rotary motion which drives an electrical generator. One hose is connected to each end of the cylinder (109) to drive it in opposite directions to induce linear reciprocating motion which is converted to rotary motion by way of a mechanical drivetrain. Due to the double action, it drives at least two drive shafts simultaneously.