Charging into the future with electric power systems

 

To reduce annual GHG emissions across the global fleet by at least 50% by 2050, maritime stakeholders are exploring two decarbonized forms of energy: batteries and wind.
 

The first wave of battery-powered ships

As a green shipping solution, electric storage systems (ESS) show promise. Electric-hybrid power systems are becoming increasingly popular, serving as backup power and helping improve energy efficiency. Using battery power also reduces fuel consumption and GHG emissions, particularly for ships traveling with low load levels and large fluctuation in power demand (e.g. offshore service vessels, tugs).

With battery technology evolving quickly, ship owners and managers alike are optimistic about further advances. Research and development are well underway, with experts designing next-generation technology such as lithium-sulfur and solid-state batteries.

But as of today, a purely electrical ocean-going vessel remains out of reach.
 

The limits of electric power

R&D needs to overcome several obstacles in the path of purely electric vessels. The primary technical challenge is improving batteries’ energy density: ships require large amounts of energy to sail even short distances, and today’s batteries cannot accommodate the energy needs of large, seagoing merchant ships. Additionally, shipowners are faced with high CAPEX costs, the limited availability of renewable energy to charge batteries and a lack of battery charging infrastructure.

For the moment, this limits the potential of purely electric ships to short sea ferries, inland navigation vessels and small boats. Still, what works today on a small scale can be considered a trial run for the larger, seagoing ships of tomorrow, especially as new and improved technologies emerge.
 

Steering safely into the future

Bureau Veritas has created a comprehensive regulatory framework to help shipowners develop safe battery-powered and electric-hybrid ships. Our rules consider three modes of operation: power back-up mode, zero-emission mode, and power management mode, which accommodate peak shaving, load smoothing and enhanced dynamic responses.

Bureau Veritas currently offers two notations: ELECTRIC HYBRID for battery-powered vessels and ELECTRIC HYBRID PREPARED for ships intending to install batteries.

Among the vessels that have received our Electric Hybrid notation are two hybrid-electric ferries built by Damen for BC Ferries, and two walk-to-work service operation vessels for the maintenance of offshore wind farms, built by Cemre for Louis Dreyfus Armateurs.

Another noteworthy project is Damen’s two all-electric road ferries for Ontario’s Ministry of Transportation, which are equipped with Schottel electrically-driven propellers. Thanks to their battery-powered systems, these ferries are expected to reduce emissions by about 7 million kg of CO₂ per year. Both ships are slated to receive Bureau Veritas’ BATTERY SYSTEM notation.
 

Ghost ships of the future?

While the image of a ghost ship such as the Flying Dutchman pervades popular culture, the self-sailing – autonomous – ships of the future are likely to be far more practical – and potentially battery-powered. By replacing intricate engine systems with numerous moving parts with electric power systems, owners can greatly reduce ship wear and tear. This, in turn, requires fewer onboard personnel to perform maintenance.

Beyond batteries, wind-assisted propulsion (WAP) is making a comeback, thanks to the efforts of organizations such as the International Windship Association (IWSA). This five-year-old non-profit promotes wind as a viable and economic option for commercial vessels. One WAP solution, for example, combines wind power with an ESS, allowing ships to store and release wind-generated power to meet a ship’s demands. 

Bureau Veritas joined the IWSA in June 2019, offering its industry experience to further develop the wind propulsion sector. As wind-assisted propulsion moves past the research stage, we will continue to facilitate the transition to a decarbonized future, helping industry stakeholders implement this new technology in a safe manner.

Photo Credit: Seaspan