A system for a recovering energy wheel implementing an energy conservation device comprising: a1) one or more braking turbines located in a housing of the system, which is/are used when the energy conservation device is operated in a braking state; and one or more accelerator turbines located in the housing of the system, which is/are used when the energy conservation device is operated in an acceleration state; or alternatively comprising a2) one turbine, which has turbine blades with a reversed changeable angle and which is used when the energy conservation device is operated in the braking state and in the acceleration state, wherein the angle of the turbine blades is changed depending on the state of the energy conservation device; the energy conservation device further comprising: b) one or more accumulators located in the housing of the system, utilizing compressed gas and liquid; wherein each accumulator has a 3-way valve comprising an accelerator valve and a braking valve, wherein the 3-way valve has 3 states: a neutral state, wherein the accelerator valve and the braking valve are closed; an acceleration state, where the accelerator valve is open and the braking valve is closed; and a braking state, where the accelerator valve is closed and braking valve is open; wherein the one or more braking turbines push the liquid into the accumulator at a braking time when the braking valve is opened, and the accelerator valve is closed; wherein the one or more accelerator turbines are propelled by pressurized liquid coming out of the accumulator at an acceleration time when the braking valve is closed, and the accelerator valve is opened; characterised in that: the system includes a first connector to an original hub and a secondary hub connector for connection to a tire rim in use, the first connector providing an extended wheel axle between the original hub and the secondary hub connector, and wherein the one or more braking turbines and the one or more accelerator turbines in a1) are arranged to sit on the extended wheel axle, or the one turbine in a2) is arranged to sit on the extended wheel axle. a1) one or more braking turbines located in a housing of the system, which is/are used when the energy conservation device is operated in a braking state; and one or more accelerator turbines located in the housing of the system, which is/are used when the energy conservation device is operated in an acceleration state; or alternatively comprising a2) one turbine, which has turbine blades with a reversed changeable angle and which is used when the energy conservation device is operated in the braking state and in the acceleration state, wherein the angle of the turbine blades is changed depending on the state of the energy conservation device; the energy conservation device further comprising: b) one or more accumulators located in the housing of the system, utilizing compressed gas and liquid; wherein each accumulator has a 3-way valve comprising an accelerator valve and a braking valve, wherein the 3-way valve has 3 states: a neutral state, wherein the accelerator valve and the braking valve are closed; an acceleration state, where the accelerator valve is open and the braking valve is closed; and a braking state, where the accelerator valve is closed and braking valve is open; wherein the one or more braking turbines push the liquid into the accumulator at a braking time when the braking valve is opened, and the accelerator valve is closed; wherein the one or more accelerator turbines are propelled by pressurized liquid coming out of the accumulator at an acceleration time when the braking valve is closed, and the accelerator valve is opened; characterised in that: the system includes a first connector to an original hub and a secondary hub connector for connection to a tire rim in use, the first connector providing an extended wheel axle between the original hub and the secondary hub connector, and wherein the one or more braking turbines and the one or more accelerator turbines in a1) are arranged to sit on the extended wheel axle, or the one turbine in a2) is arranged to sit on the extended wheel axle.