As modern marine vessels move toward full electrification, ancillary power has become a critical focus beyond propulsion systems. From pumps and winches to HVAC, galley systems, and watermakers, marine ancillary power supports a wide range of essential onboard functions. Effective management and integration of these systems not only enhance efficiency but also reduce emissions and operational costs. With advances in energy optimization and smart load scheduling, vessels can prioritize critical subsystems while maintaining reliable performance. This article explores the role of ancillary power in electrifying boat systems, highlights practical examples of fully electric vessels, and examines innovative strategies for integrating and managing ancillary power systems to create sustainable, high-performing marine environments.
Understanding Marine Ancillary Power: Key Components and Benefits
In modern marine operations, ancillary power plays a pivotal role beyond propulsion, powering critical subsystems that ensure vessel efficiency, safety, and comfort. Whether you’re managing a commercial vessel in United Kingdom’s busy harbor or operating a luxury yacht in regional waters, understanding the key components and benefits of marine ancillary power is essential for optimizing performance and minimizing operational costs.
Key Components of Marine Ancillary Power
Ancillary power encompasses all electrical systems that support the vessel’s non-propulsion functions. The main components typically include:
- Pumps and Winches: Essential for cargo handling, bilge management, and mooring operations. Modern electric pumps are capable of handling high flow rates, improving efficiency compared to traditional diesel-driven alternatives. For example, some electric pump models can deliver up to 700 m³/h, making them suitable for industrial applications requiring high-capacity pumping solutions (Depon Pump product page).
- HVAC Systems: Providing heating, ventilation, and air conditioning. Modern electric HVAC systems for vessels up to 50 meters in length typically consume between 2.6 kW and 10 kW, depending on the unit’s cooling capacity and operational conditions. For instance, a marine air conditioner with a 36,000 BTU/h (approximately 10.6 kW) cooling capacity consumes around 10 kW of power. These systems are designed for efficient energy use, with some models offering energy-saving features to reduce overall consumption (ACI Marine product page).
- Galley Equipment: Electric ovens, refrigeration, and dishwashers reduce fuel dependency and emissions, especially relevant in United Kingdom’s green vessel initiatives.
- Desalination and Watermakers: Modern reverse osmosis units powered by ancillary vessel power can produce 10–50 m³/day, providing freshwater for both crew and passenger needs (MAK Water product page).
- Cranes and Deck Machinery: Electrified cranes can lift up to 100 tons while providing smoother operations and reduced maintenance compared to hydraulic alternatives.
Benefits of Marine Ancillary Power
Integrating ancillary power in your vessel brings measurable advantages:
- Operational Efficiency: Electrically driven subsystems respond faster and require less maintenance than traditional mechanical systems.
- Emission Reduction: Replacing diesel-powered auxiliary systems with hybrid or alternative energy solutions can reduce NOx and CO₂ emissions by up to 30% on mid-size vessels ( Reddit discussion).
- Enhanced Safety: Electric systems offer precise control and automated shutdowns, reducing risks of overheating or flooding.
- Energy Optimization: Smart load scheduling ensures critical subsystems remain powered during peak demand periods, preventing power shortages.
Compliance with Regional Standards: In the UK, maritime regulations promote low-emission vessels, with initiatives like the Maritime Decarbonisation Strategy aiming for zero fuel lifecycle greenhouse gas emissions by 2050. This includes extending the UK Emissions Trading Scheme to maritime from 2026 and introducing measures to reduce emissions from vessels at berth and wider port operations (GOV.UK).
Comparison of Traditional vs Electrified Ancillary Power Systems
| Subsystem | Diesel/Mechanical Power | Electrified Ancillary Power | Benefits |
|---|---|---|---|
| Pumps | Fuel consumption: 150 L/day | Electric: 60 kWh/day | 60% energy saving, lower maintenance |
| HVAC | Heat pumps driven by diesel, 30 kW | Electric, 25 kW | Reduced emissions, precise climate control |
| Watermakers | Diesel-powered RO, 30 m³/day | Electric RO, 30 m³/day | Lower fuel usage, silent operation |
| Deck Cranes | Hydraulic, high maintenance | Electric, automated | Improved safety and operational efficiency |
By understanding the components and benefits of marine ancillary power, you can make informed decisions on retrofitting existing vessels or designing new electric vessels in United Kingdom’s maritime sector. Implementing electrified subsystems enhances operational efficiency, aligns with environmental targets, and provides a scalable foundation for integrating smart energy management and future electric propulsion technologies.
Electrifying Pumps, Winches, and Cranes with Ancillary Power
The electrification of ancillary power systems such as pumps, winches, and cranes marks a major shift in marine engineering. Traditionally, these auxiliary loads have depended on hydraulic or mechanical drives powered by the main engine. However, with the growing transition toward hybrid and fully electric vessels, engineers are recognising that electrifying these subsystems delivers measurable benefits in energy efficiency, maintenance reduction, and environmental performance. As more shipyards and yacht builders in the United Kingdom and Europe push for decarbonisation, electrified ancillary systems are becoming a cornerstone of next-generation vessel design.
Why Electrifying Ancillary Equipment Matters
Unlike propulsion systems that run continuously, pumps and deck equipment operate intermittently — ideal for electric conversion. By drawing power from onboard energy storage or a DC grid, these systems can operate silently and efficiently, reducing both noise and emissions. For instance, electric winches powered by a vessel’s ancillary battery bank consume up to 30% less energy compared to hydraulic equivalents. Furthermore, the ability to regulate torque electronically offers superior control for precision tasks such as mooring, towing, or lifting cargo.
Electric ancillary power systems also eliminate the need for complex hydraulic lines and oil reservoirs, reducing risks of leakage and contamination in marine environments. This simplification not only cuts maintenance costs but also aligns with international environmental standards such as MARPOL Annex I. For operators in coastal and inland waterways, this is particularly critical since electric systems ensure compliance with increasingly strict emission and pollution regulations.
Technical Integration and Energy Distribution
The integration of ancillary loads within a vessel’s electrical network allows engineers to optimise energy distribution dynamically. On hybrid-electric vessels, for example, pumps and winches can run off stored energy when engines are idle, avoiding unnecessary fuel burn. When paired with intelligent load management software, ancillary loads can be scheduled or prioritised based on system demand and battery state of charge. This approach not only improves operational efficiency but also prolongs battery lifespan.
In workboats and offshore vessels, electric cranes represent one of the fastest-growing applications of ancillary power. Electric drive cranes enable energy recovery during lowering operations through regenerative braking, which feeds power back into the vessel’s electrical system. Similar technologies are being applied to capstans, anchor handlers, and deck winches, helping to stabilise power demand peaks and balance onboard energy usage across multiple subsystems.
Performance Benefits for Different Vessel Classes
From small research vessels to large commercial ships, the impact of electrified ancillary systems varies by operational profile. In leisure yachts, electric pumps and winches provide near-silent operation — an important comfort factor for premium vessels. In contrast, offshore support and tug vessels benefit from higher efficiency during repeated heavy-load cycles. For ferries and short-sea transporters, electric pumps for ballast and cooling integrate smoothly with battery-hybrid systems, reducing idle-time fuel consumption and CO₂ emissions by as much as 10% per voyage.
| Drive System | Reported Efficiency Range | Source |
|---|---|---|
| Electric drive winch (marine) | 70% – 85% | ERVO-Group Study (2009) “Comparison study of electric, electro-hydraulic and hydraulic winch drives” |
| Electro-hydraulic drive winch | 45% – 70% | Same source as above |
| Hydraulic drive winch | 35% – 60% | Same source as above |
Challenges and Future Developments
While the benefits are clear, electrifying ancillary power systems requires strategic engineering to handle surge loads and thermal management. High-current draw from simultaneous deck operations can strain smaller battery banks if load prioritisation is not properly configured. Advanced energy management systems (EMS) are therefore essential to synchronise power delivery between propulsion, hotel loads, and auxiliary components. Manufacturers are now experimenting with semi-solid-state battery packs and DC microgrid architectures to further stabilise ancillary load operation.
Looking ahead, the development of modular, pre-certified electric winches and pumps will reduce retrofit complexity for existing vessels. For new builds, shipyards are expected to adopt all-electric ancillary suites integrated directly with propulsion control units — creating unified vessel management systems that monitor both drive and auxiliary energy use in real time.
In summary, electrifying pumps, winches, and cranes using ancillary power transforms how modern vessels manage energy. By shifting from hydraulics to electric drives, operators achieve quieter, cleaner, and more efficient operations while reducing their environmental footprint. As component costs fall and control technologies mature, ancillary electrification will become standard practice across commercial, defence, and leisure fleets worldwide.
Ancillary Power in HVAC, Heating, and Galley Systems
As marine electrification advances, ancillary power systems such as HVAC, heating, and galley installations are undergoing transformative redesigns. These subsystems—traditionally reliant on diesel-driven generators or mechanical compressors—are now being electrified to reduce emissions, improve comfort, and streamline energy management. By shifting to all-electric auxiliary systems, shipbuilders and yacht owners can enhance onboard sustainability while lowering lifetime operating costs. In the United Kingdom, where maritime regulations increasingly favour low-emission designs, electrifying hotel loads has become a key step in achieving cleaner, more efficient vessels.
HVAC Electrification: Quiet, Efficient Climate Control
Heating, ventilation, and air-conditioning (HVAC) are among the most energy-intensive hotel loads aboard vessels. Conventional systems rely on compressors powered by diesel generators or hydraulic drives.
In contrast, electric HVAC units integrated into a vessel’s ancillary power network—utilising variable-speed drives—can achieve significant energy savings. One study found that switching from fixed-speed compressors to variable-speed control reduced energy consumption by approximately 23.2% in marine air-conditioning systems (Xu et al., 2018 – “The Analysis for Energy Consumption of Marine Air Condition Systems”). Modern electric HVAC systems are also quieter, an important factor for passenger ferries, cruise vessels, and superyachts.
Electric chillers and heat pumps powered by the ancillary power network also allow seamless integration with renewable or hybrid energy sources. When paired with a battery system, HVAC can operate autonomously while the main engines are off, enabling “silent mode” operation. This is increasingly common among luxury yachts and research vessels operating in noise-sensitive environments such as marine reserves or harbours.
Heating Systems: From Diesel Boilers to Smart Electric Heaters
Marine heating has traditionally relied on oil-fired boilers, which contribute to emissions and require regular maintenance. Electrification replaces these systems with resistive or heat-pump-based electric heaters that draw from the vessel’s ancillary electrical grid. Electric heating systems offer modular installation, reduced risk of fuel leakage, and immediate response times.
In practice, fully electric marine heating systems—including cabin and water heaters powered by the vessel’s ancillary power network—can achieve efficiencies up to 99 %, as nearly all input electrical energy is converted into heat. This contrasts sharply with traditional diesel-fired boiler systems, which typically convert around 70-80 % of fuel energy into usable heat.
Switching to electric‐based heaters onboard effectively leverages your vessel’s power infrastructure—eliminating fuel combustion, exhaust emissions, and boiler servicing. With the right energy management integration, these systems help optimise your overall ancillary power usage, enabling quieter, cleaner, and more efficient operations at sea.
Switching to electric‐based heaters onboard effectively leverages your vessel’s power infrastructure—eliminating fuel combustion, exhaust emissions, and boiler servicing. With the right energy management integration, these systems help optimise your overall ancillary power usage, enabling quieter, cleaner, and more efficient operations at sea.
Hybrid systems are also emerging that combine electric heating with waste-heat recovery from propulsion or generator cooling circuits. By routing recovered thermal energy into the HVAC or galley water systems, these designs reduce total electrical demand by 15–20%, lowering the strain on battery banks during extended silent operations. In colder climates or expedition vessels, this integration ensures stable heating performance without compromising endurance.
Galley Electrification: Efficient Culinary Power Management
Galley systems—ranging from induction cooktops to dishwashers—represent another critical application of ancillary power. Historically powered by LPG or direct fuel, marine galleys are now switching to electric appliances for safety and efficiency reasons. Induction cooking units not only eliminate open flames but also deliver energy efficiency rates of up to 90%, compared to roughly 40% for traditional gas burners.
When integrated into the vessel’s DC grid, galley systems can be load-scheduled during low-demand periods, preventing voltage drops or excessive current peaks. On passenger vessels, energy management software can prioritise refrigeration and essential loads over non-critical appliances, optimising power distribution. These strategies are particularly beneficial for all-electric or hybrid yachts, where onboard energy balance is crucial for extending range and operational autonomy.
| Subsystem | Traditional System | Electric Equivalent | Efficiency Gain (%) |
|---|---|---|---|
| HVAC (Cooling) | Diesel-powered compressor | DC variable-speed electric compressor | 30–50% |
| Cabin/Water Heating | Diesel boiler | Electric resistance or heat pump heater | 15–25% |
| Galley Cooking | Gas or diesel stove | Electric induction cooktop | 40–50% |
| Refrigeration | Mechanical compressor | DC inverter electric compressor | 25–35% |
Integration and Control of Ancillary Loads
To ensure optimal operation, the integration of HVAC, heating, and galley systems into the ancillary power network must include intelligent energy management. Advanced Vessel Power Management Systems (VPMS) now allow for predictive load scheduling, thermal balancing, and real-time diagnostics. For example, ABB’s Onboard Microgrid technology enables simultaneous operation of propulsion and hotel loads without compromising stability. These systems can dynamically allocate surplus renewable energy—such as from solar panels or regenerative braking—to support hotel functions, thereby maximising system utilisation.
Towards Fully Electric Hotel Operations
Electrifying HVAC, heating, and galley systems represents a crucial step in the full transition to zero-emission marine operations. These subsystems, powered through ancillary power networks, contribute significantly to operational efficiency and onboard comfort. With efficiency gains averaging between 20–50%, reduced maintenance requirements, and enhanced safety, electric hotel loads are now a realistic standard for new builds and retrofits alike. As shipyards continue adopting modular DC grids and high-capacity battery architectures, fully electric vessel environments—silent, clean, and efficient—are fast becoming the industry benchmark across the United Kingdom and beyond.
Watermakers and Desalination Systems Powered by Ancillary Power
Integrating ancillary power into your vessel’s water production and desalination equipment marks a critical step toward a more efficient and sustainable marine design. Watermakers and desalination systems typically draw high electrical loads due to the high-pressure pumps required for reverse osmosis (RO) and filtration processes. By aligning these loads with an optimized auxiliary electrical grid, you can reduce fuel consumption, lower emissions, and enhance operational flexibility—especially in the United Kingdom’s evolving maritime regulatory environment.
Efficiency Gains from Electrified Desalination
Contemporary RO systems equipped with energy-recovery modules demonstrate power consumption in the region of 4–4.5 Wh per litre of fresh water produced. By contrast, conventional watermakers without energy recovery demand up to 8–12 Wh per litre under similar conditions (OS Watermakers, 2024). This means that linking watermaker loads to your vessel’s ancillary grid can halve the electrical consumption of these systems and make them viable for battery-hybrid or fully electric vessels.
In practice, a watermaker setup producing 100 litres per day would require roughly 400–450 Wh of energy in the advanced equipment scenario—versus 800–1,200 Wh in the older model. On a voyage where the generator is off, this translates into considerable savings in terms of battery draw or diesel usage.
Managing Load Integration into the Vessel Grid
Ancillary electrical networks allow you to synchronise watermaker activity with low-demand periods. Because RO units typically operate intermittently (e.g., during anchorage or while engines are idle), you can prioritise watermaker power draw when propulsion or heavy hotel loads are minimised. This enables your system to draw from batteries or shore power effectively, improving the overall efficacy of your ancillary power strategy.
Moreover, watermakers can be paired with energy-recovery technology—such as pressure exchangers—that capture brine after the high-pressure membrane and reuse its energy. This not only reduces electrical consumption, but also lowers heat rejection into the system, making the setup more compatible with thermal management solutions coupled to your auxiliary network.
Application Across Vessel Types
From superyachts to commercial workboats, the benefits of electrified watermakers through the ancillary grid are clear. In luxury vessels where silent operation is valued, a DC-powered RO unit can run during standby without the generator noise or vibration. On commercial craft such as research vessels or fishing boats, integrating watermaker loads into the auxiliary grid helps balance peak electrical demand and reduces generator runtime—leading to lower fuel burn and maintenance.
| System Type | Energy Consumption (Wh per Litre) | Key Feature | Suitability for Ancillary Power Integration |
|---|---|---|---|
| RO with energy-recovery pump | 4.0 – 4.5 Wh/L | High-efficiency Clark pump, brine energy recovery | High – ideal for ancillary grid |
| Conventional RO (no recovery) | 8.0 – 12.0 Wh/L | Fixed-pressure pump, no recovery | Lower – larger battery/generator footprint |
Source: OS Watermakers
Best Practices for Integration with Ancillary Power
To maximise the efficiency of your electrified desalination system, consider the following operational strategies:
- Schedule runs during low-load periods – activate the watermaker during anchor time or when propulsion loads are minimal, reducing interference with other high-power systems.
- Link to battery-hybrid or DC grid – feed the RO unit from your ancillary distribution so it can run independent of generator operation.
- Monitor membrane and brine pressure – efficient energy-recovery systems maintain lower differential pressure and ensure sustainable performance.
- Automate flushing and standby mode – reduce idle energy consumption and ensure longevity of the membranes, aiding the overall ancillary power profile.
Through these measures, the role of ancillary power becomes central not just for comfort and manoeuvring systems, but for life-sustaining functions such as water production. In vessels operating under the future-focused maritime regulations of the United Kingdom, such integration supports sustainability goals while enhancing onboard resilience.
In summary, when you incorporate high-efficiency watermakers and desalination systems into your vessel’s ancillary power architecture, you step closer to truly zero-emission and fully electric operations. As technology evolves and energy-density improves, the coupling of fresh-water generation with your auxiliary electrical grid will remain a pivotal element of marine electrification—not just for propulsion, but for every system onboard.
Integrating Ancillary Power: Load Scheduling and Prioritization
When electrifying your vessel’s systems—especially those connected via ancillary power—you must plan for intelligent energy management rather than simply adding more electrical loads. Effective scheduling and prioritisation of these loads is critical to ensure balanced performance, operational safety, and optimal use of your vessel’s battery or hybrid-grid infrastructure. In the United Kingdom, where emission targets and offshore constraints are tightening, making sure your auxiliary systems are aligned with intelligent load control is essential.
Why Load Scheduling Matters for Ancillary Power
Auxiliary systems such as galley appliances, HVAC, watermakers and deck machinery can create peaks and dips in your vessel’s power demand. Without a proper energy management strategy, these loads risk causing over-draws, voltage drops or forcing your main engine to restart. Studies show that optimised scheduling can reduce fuel consumption by up to 8–12% and reduce generator runtime by more than 10 times compared to unscheduled operation (Jaurola M., 2019). By coordinating your marine electrification strategy with load prioritisation, you ensure that your ancillary systems contribute to, rather than compete for, the overall energy budget.
Load Prioritisation Techniques for Hybrid-Electric Maritime Systems
On a fully electric or hybrid vessel architecture, you must clearly classify loads into categories: essential, shiftable and non-critical. Essential loads (e.g., navigation systems, fire pumps) must always be powered. Shiftable loads (e.g., galley equipment, laundry) can be scheduled when battery state-of-charge is high or when shore power is available. Non-critical loads can wait. The use of a dedicated Vessel Power Management System (VPMS) enables real-time load control, tracking battery SOC (state-of-charge), demand profiling and predictive scheduling. For example, a battery-DC grid architecture integrating electric marine systems reduced peak load by 15% in real operations according to the INOMANSHIP project (INOMANSHIP Project, 2025).
Scheduling Ancillary Loads to Optimise Energy Use
For your vessel, implementing smart scheduling of ancillary loads ensures you maximise the benefits of your electrified systems. Consider the following strategies: when the main engine is idling or batteries are at high charge, schedule your watermaker or desalination system. During low-demand periods, run your galley appliances, laundry or HVAC maintenance cycles. On the other hand, during peak operations or manoeuvring, defer non-critical loads. By doing this, you enhance overall efficiency and reduce generator start-stop cycles—improving the lifespan of both propulsion and ancillary systems.
| Load Category | Typical Subsystems | Scheduling Approach | Impact on Ancillary Power & Hybrid Grid |
|---|---|---|---|
| Essential Loads | Navigation, lighting, fire/flood pumps | Continuous supply via battery/shore grid | Must be first priority on ancillary power network |
| Shiftable Loads | Galley appliances, laundry, watermaker | Run during low-demand or high-SOC periods | Reduces generator runtime and fuel burn |
| Non-Critical Loads | Visitor services, non-urgent HVAC maintenance | Deferred or scheduled for shore power | Minimises peak load stress on hybrid-grid |
Source: Jaurola M., 2019; INOMANSHIP Project, 2025.
Implementing Prioritisation in the UK Market Context
With the UK advancing its decarbonisation targets under the Clean Maritime Plan, vessels operating in UK waters face tighter emissions rules and port infrastructure constraints. By designing your naval architecture around load scheduling and prioritising ancillary loads, you create a vessel ready for future regulations and port-side demands. Intelligent scheduling of your marine electrification systems not only enhances operational efficiency but reduces maintenance overheads and aligns with the UK’s zero-emission harbour frameworks.
In summary, integrating load scheduling and prioritisation into your electrified system architecture is pivotal to unlocking full value from ancillary power. Whether you are refitting an existing vessel or designing a new build, a well-structured approach to scheduling ensures your electric pumps, HVAC, galley, and other auxiliary systems work in harmony—contributing to reduced fuel use, lower emissions and streamlined operations. Properly managing these loads makes your vessel smarter, greener and future-ready.
Case Studies of Fully Electric Boats Using Ancillary Power
Nothing demonstrates the maturity of ancillary power better than real vessels that already run their hotel loads, deck machinery, and mission systems from batteries rather than from auxiliary diesels. The case studies below—spanning passenger ferries, a harbour tug, and a UK-built electric RIB—show how integrating ancillary power with propulsion creates quieter, cleaner, and more reliable operations while simplifying maintenance and compliance.
E-Ferry “Ellen” (Denmark): High-Capacity Battery with Fully Electric Hotel Loads
“Ellen” is a 100% electric Ro-Pax ferry designed for a 22-nautical-mile round trip. Its battery system was specified at 4.3 MWh, providing ample margin not only for propulsion but also for hotel loads such as HVAC and auxiliaries—demonstrating the viability of large-scale ancillary power on a scheduled route. The EU project documentation details the energy sizing and redundancy strategy used to keep onboard systems stable without diesel gensets. (European Commission E-Ferry deliverable (battery sizing); Ship-Technology profile)
Maid of the Mist (USA): Tourist Ferries with Battery-Only Ancillary Systems
Niagara Falls’ “James V. Glynn” and “Nikola Tesla” became the first fully electric passenger vessels built in the U.S., operating with no auxiliary diesel. Each catamaran carries 316 kWh of batteries across twin hulls for redundancy, supporting propulsion and ancillary power (lighting, communications, and passenger services). The shore power is supplied by nearby hydropower, enabling zero-emission turnarounds and silent sightseeing. (ABB technical overview; EESI case article)
Damen RSD-E “Sparky” (New Zealand): Harbour Tug with Electrified Deck Systems
Harbour tugs are energy-intensive, not just for bollard pull but also for winches, deck cranes, and cooling pumps. “Sparky” shows how ancillary power can be fully electrified alongside propulsion: eight battery racks (2,240 cells) provide 2,784 kWh, enough for multiple towage assignments between fast charges. Damen reports substantial CO₂ savings and significantly lower operating costs versus a diesel tug—while electric winches and auxiliaries benefit from instant torque and precise control. (Damen case study; Damen technical overview)
Artemis EF-24 Passenger Ferry (UK): Foiling Efficiency and Measured Hotel-Load Share
Developed in Belfast, the foiling EF-24 demonstrates how reducing hull drag frees energy for ancillary power. Public materials indicate a substantial battery installation (reported as ~2.8 MWh) and explicitly quantify hotel loads—HVAC and other services—at around ~18.7% of daily demand, informing realistic energy budgets for fully electric service. (Electric & Hybrid Marine Technology – Artemis EF-24 case study; Artemis presentation deck (hotel-load share))
RS Electric Boats Pulse 63 (UK): Small-Craft Integration of Hotel Loads
On smaller craft, integrating ancillary power is about dependable, quiet “hotel” functionality—navigation electronics, lighting, comms, and compact HVAC—alongside propulsion. The UK-built Pulse 63 electric RIB reaches up to 23 knots and publishes real-time range data; its clean-sheet hull and battery architecture make space and stability for electronics and auxiliary DC loads without resorting to a petrol genset. (RS Electric Boats – Pulse 63; Powerboat & RIB review)
| Vessel | Battery Capacity | Ancillary Power Examples | Route/Use |
|---|---|---|---|
| E-Ferry “Ellen” (DK) | ~4.3 MWh | HVAC, hotel loads, auxiliaries fully electric | 22 nm round trip, Ro-Pax |
| Maid of the Mist (US) | ~316 kWh per vessel | Lighting, comms, passenger hotel loads on battery | Short shuttle tours |
| Damen “Sparky” Tug (NZ) | ~2.78 MWh | Deck winches, pumps, auxiliaries electrified | Harbour towage, multiple assists |
| Artemis EF-24 (UK) | ~2.82 MWh reported | Hotel loads ~18.7% incl. HVAC | High-speed foiling commuter ferry |
| RS Pulse 63 (UK) | OEM battery pack (spec published) | Electronics, nav, comms, compact HVAC | RIB duties, patrol/training |
Across these deployments, the through-line is clear: by sizing batteries to cover realistic hotel and auxiliary demand, operators eliminate genset idling, slash maintenance, and gain precision control over HVAC, winches, pumps, lighting, and passenger services. For UK builders and operators, this approach to ancillary power also aligns with port-side zero-emission goals and unlocks night-time “silent running” in sensitive waterways.
For your next new-build or retrofit, these case studies offer a pragmatic blueprint: specify battery capacity with ancillary power in mind; quantify hotel-load shares; and adopt DC distribution with smart energy management. The result is a vessel that is quieter, cleaner, and operationally simpler—beyond propulsion alone.
Conclusion
As the maritime industry accelerates toward full electrification, ancillary power has become the defining element separating conventional hybrid designs from truly all-electric vessels. From electric HVAC systems and galley equipment to watermakers, winches, and control systems, every subsystem now contributes to a cleaner and more efficient operational profile. The case studies explored—ranging from the E-Ferry Ellen to Artemis EF-24 and RS Pulse 63—prove that fully electric solutions are not only viable but commercially and environmentally advantageous.
By integrating intelligent load scheduling, modular battery architecture, and unified energy management, operators can extend battery endurance, minimise fuel use, and meet tightening UK and international emission targets. The path forward for sustainable maritime design lies beyond propulsion: it depends on the successful electrification of all supporting systems. When you view ancillary power as an integrated ecosystem rather than a secondary feature, you unlock the potential for quieter, safer, and zero-emission operations—setting the course for the next generation of clean marine innovation.
Frequently Asked Questions (FAQs):
🚢What is marine ancillary power and why is it important?
Marine ancillary power refers to the electrical energy used to run non-propulsion systems onboard—such as pumps, winches, HVAC, and galley systems. It plays a critical role in improving vessel efficiency, reducing fuel consumption, and supporting zero-emission operations.
🚢How does ancillary power improve vessel efficiency?
By electrifying auxiliary systems and integrating them into a shared energy management grid, ancillary power reduces generator runtime and optimises load distribution. This approach can improve total vessel efficiency by 10–20% while lowering maintenance needs.
🚢Can ancillary power systems work on hybrid boats?
Yes. In hybrid boats, ancillary power systems can operate on battery energy when propulsion engines are idle, maintaining comfort and operational systems without diesel use. They can also recharge from shore power or renewable sources like solar or wind.
🚢Which systems can be powered by marine ancillary power?
Ancillary power can support HVAC, lighting, watermakers, cranes, winches, desalination units, and electronic controls. Modern electric boats integrate these subsystems through a DC or hybrid-AC distribution system for seamless power sharing.
🚢What are examples of boats using full ancillary electrification?
Vessels like the E-Ferry “Ellen”, Damen’s electric tug “Sparky”, and Artemis EF-24 ferry use fully electrified ancillary systems—covering everything from HVAC to winches—showcasing how advanced marine ancillary power improves sustainability and performance.
References:
- ABB Marine & Ports. (2020). Maid of the Mist: Fully electric sightseeing boats at Niagara Falls.
- Artemis Technologies. (2024). Smart Mobility presentation deck: EF-24 electric foiling ferry (hotel-load share).
- Damen Shipyards Group. (2022). The Damen RSD-E Tug: A sustainable towing force.
- Damen Shipyards Group. (2023). Damen RSD-E tug “Sparky” on TIME’s Best Inventions list.
- Electric & Hybrid Marine Technology. (2023). Case study: Artemis Technologies’ electric foiling ferry.
- European Commission. (2019). E-Ferry project deliverable: Battery sizing and system architecture for “Ellen”.
- Jaurola, M. (2019). Optimising design and power management in energy systems for vessels. Journal of Marine Engineering & Technology, 18(1), 25–37.
- OS Watermakers. (2024). Energy consumption of watermakers for boats & yachts.
- Xu, Y., Zhang, Y., & Li, H. (2018). The analysis for energy consumption of marine air-condition systems. E3S Web of Conferences, 53, 04012.
- Lambert, M., & co-authors. (2020). Energy savings in HVAC systems on board ships. ResearchGate.
- Environmental and Energy Study Institute (EESI). (2020). Maid of the Mist: Making waves for electrification.
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