Page 46: of Marine News Magazine (May 2019)
There are some minor differences in the systems. First,
VESSEL: 1800HP the total brake horsepower of each system is slightly dif-
LOCKING RIVER TOWBOAT:
Some basic assumptions for the life cycle cost analysis ferent. The mechanical system has 1800 BHP while the include both a 365 day per year operational tempo with a DE/ES has a maximum of 2000 BHP. Another difference is the mechanical-based design has a total of four engines, 40-year vessel life cycle.
with two of those engines being required to be EPA Tier
IV, while the electrical propulsion design utilizes only three
Tier III generators. The DE/ES system used for these cal- culations is a DC bus system. The system uses AC gen- erators and AC propulsion motors. However, the main propulsion bus is DC. This provides for a smaller, more reliable system and cost-effective solution.
A DE/ES system does increase the initial capital costs of the towboat. This increase is equal to about $400k increase in overall construction cost of a typical 1800HP towboat.
Most of that increase is due to the costs of the batteries and associated battery equipment.
OPERATIONAL COSTS (OPEX)
Operational costs are broken down into two categories:
Fuel Costs and Maintenance Costs. For example:
Capital Cost Comparison
May 2019 46 MN