A method and system used to identify an optimal hybrid vehicle operating mode based on a variety of potential factors, and then recommend the optimal operating mode to the driver so that they can make an informed decision regarding their operating mode selection. An hydraulic coupler includes a master piston, a slave piston, and a coupler volume formed in-between, the coupler volume being connected to a compensating chamber via a throttle. Another application of wind farms with wind driven pumps is for the creation of variable hydraulic flow of fixed pressure as function wind power availability which may be used for water elevation as well as for the desalination of salt water solutions by reverse osmosis.