FORCE ESD on a Marine Vessel: A 1,800 kW Case Study

Oct 19

3 min read

Updated: Oct 25

Commercial vessels run on electricity far more than most people expect. On a 1,800 kW class marine vessel, the onboard power system feeds propulsion motors, thrusters, HVAC, pumps, and a long list of auxiliary equipment, often around the clock. This case study looks at how a commercial marine vessel operator approached power efficiency with FORCE ESD — Energy Saving Device by ENPOSS, and what to expect from a no-circuit installation.

How a Vessel Uses Electricity

A ship is a self-contained power plant. Generators supply a main switchboard, and that switchboard distributes power to everything on board. On a vessel in the 1,800 kW range, the largest loads are usually induction motors: propulsion drives, bow and stern thrusters, cargo and ballast pumps, compressors, and ventilation fans.

Alongside the motors sit HVAC and refrigeration for the accommodation and cargo spaces, plus lighting, navigation equipment, and galley loads. Because many of these loads run continuously and vary with sea state, port operations, and weather, the demand profile is rarely flat.

Why Power Costs Climb at Sea

Motor-heavy systems tend to carry inductive load. That pushes the power factor down, which means the generators supply more current than the useful work requires. Higher current means higher losses in cables and transformers, more heat, and more fuel burned per unit of work done.

Harmonics add to the problem. Variable frequency drives and other electronic loads distort the waveform, which can increase heating in motors and switchgear. On a vessel, where space is tight and ventilation is limited, extra heat and wasted current are not just a cost issue. They affect the wear on equipment that is hard to service mid-voyage.

The Installation Approach: No Circuit Changes

The operator wanted to improve power efficiency without an invasive retrofit. The FORCE ESD suited that requirement because it installs in parallel with the existing electrical system. There is no need to cut into or modify the main circuit, so the vessel's wiring and switchboard layout stay as they were.

In practice, a parallel connection at a suitable point on the distribution board keeps the work contained. Installation requires briefly lowering the main breaker, so the electrician and the vessel crew should plan a short outage window. Once installed, the device has no moving parts and does not interrupt supply during normal operation. Planning matters on a vessel, where downtime and schedule changes carry real cost.

Results and What to Expect

ENPOSS reports that FORCE ESD installations typically deliver 5 to 15 percent electricity savings. Results depend on the load profile, the existing power quality, and how the vessel operates, so the actual figure for any ship will vary within or around that range. They apply only to the samples and conditions that were tested and are not guaranteed for every ship.

For a vessel with a large share of motor and HVAC load, the benefit comes from reducing wasted current and improving power quality across the system. Operators can verify the outcome by comparing metered consumption before and after installation under similar operating conditions.

Reliability and Certification in Marine Environments

Marine equipment faces vibration, humidity, salt air, and temperature swings. A passive device with no moving parts is a sensible fit for these conditions, and it needs very little routine maintenance.

Third-party inspections of FORCE ESD on vessels have been witnessed by inspectors, but the analysis of the records is written by ENPOSS, and the results are limited to the vessel, period and conditions inspected. UL is an electrical safety listing and does not evaluate saving performance. Always confirm the certification requirements of your flag state and classification society for your specific vessel before installation.

Talk to ENPOSS About Your Vessel

If you operate commercial vessels and want to understand what a no-circuit energy saving device could mean for your fleet, our team can review your load profile and installation options. Contact our team at enposs.com to start the conversation.