Ice For Short-Distance Propulsion: Source Of Clean Energy



Battery-electric propulsion is commonly used for the short-haul maritime vessels in addition to the steam batteries.  But the shorter working life of electro-chemical batteries and high cost-of-replacement makes it little attractive.  Currently, market trends are uniting for the search of efficiency and successful technologies into new builds and existing vessels that would enable the ship-owners to gain an additional competitive advantage.  They are looking for high value-added and environmentally friendly ships and mechanisms.

The propulsive technology is based on ocean thermal energy conversion which utilizes the temperature difference between cooler deep and warmer shallow or surface seawaters to run a heat engine and produce electricity.  However, it has a limiting factor of low efficiency as the temperature differential is small, making it less economic feasible for electricity generation.  This technology can be exploited in the maritime propulsion offering a viable source of renewable energy.  Under this mechanism, a tug pushing a revenue barge and towing an insulated ice barge can reach the port and interchange the ice barges and push a different revenue barge to another port.  A large fleet of ice barges could sustain the operation of a small fleet of tugs that source propulsive power from the surface temperature of seawater.  The energy storage technology has low cost, offers long service life and very low replacement cost, despite offering low propulsive efficiency.

This technology can be used on islands and in developing countries in the tropical regions like India and Hawaii where conditions are conducive to such operations.