Free Foundation

Energy-Saving Technologies

What rotor sails, air lubrication, energy-saving devices, waste-heat recovery and shore power actually do to a ship's energy bill, and how to read a vendor's savings claim before you sign for the retrofit.

Lessons
8
Quiz questions
64
Time
About 53 min
Who it's for
Technical superintendents, performance analysts and operators who are handed efficiency proposals and have to decide which ones deserve budget.
Assumed knowledge
None. Our course Ship Resistance Fundamentals is a helpful warm-up on the physics; this course stands on its own.
Taught by

Christos Papandreou

CEO & Founder, Blue Autonomy

  • Naval architect and marine engineer, National Technical University of Athens
  • 15 years of experience in fleet performance and operational data
  • Chief Scientist, NEMO — previously DeepSea Technologies, StormGeo, Athenian Sea Carriers, PwC

Part of the Maritime Decarbonisation & Compliance specialisation.

What you will be able to do

By the end of the course. Each outcome names the lessons that deliver it, and each lesson's quiz checks it.

  1. Sort any proposed efficiency measure into one of the five families (operational, hull and propulsion, machinery and waste heat, energy harvesting, shore power) and interrogate its savings claim for baseline, measurement method (CFD prediction versus trial versus normalised service data) and net-versus-gross honesty. Lesson 1
  2. Distinguish rotor sails, rigid wingsails, suction wings and kites by their working mechanism (all lift devices, each with its own parasitic load and deck constraints), and judge a wind-assist savings claim by the route's wind climate and the ship's speed profile — naming the ITTC trial procedure that validates it and the EEXI and FuelEU reward factors (0.95 at ≥15% wind share) that sit beside the physical saving. Lessons 2, 3
  3. Compute an air-lubrication net saving after compressor power (e.g. 8% gross − 3% compressor = 5% net), and state which hull forms, draughts and sea conditions preserve or erode the air layer. Lesson 4
  4. Match each propeller and hull energy-saving device — pre-swirl ducts and stators, boss cap fins, rudder bulbs — to the specific loss it recovers, and sanity-check a claimed gain against the honest 1–5% per-device band and the ship's hull form and propeller loading. Lesson 5
  5. Trace where fuel energy leaves the ship (roughly half never reaches the propeller; the exhaust is the largest recoverable stream) and select machinery measures — shaft generator, exhaust-gas economiser and power turbine or ORC, variable-speed drives on the pump and fan laws — plus shore power where the trading pattern, equipped berths and the IEC/IEEE 80005 interface standards make the retrofit pay. Lessons 6, 7
  6. Build a defensible retrofit shortlist: exhaust operational measures first, multiply rather than add stacked savings (two independent 10% measures ≈ 19%), account for device interactions (wind assist unloading the propeller shrinks ESD gains), price paybacks with fuel and carbon together, and commit to a pre-installation baseline with normalised after-measurement. Lesson 8

Somewhere in your inbox is a brochure promising double-digit fuel savings from a device you had not heard of a year ago. The market for efficiency hardware is crowded, the percentages are confident, and the physics behind them is rarely on the page. This course puts it back.

We start with a map: the five families of efficiency measures, and the three questions that expose what any savings claim is actually made of. Then the deep dives, two lessons on wind-assisted propulsion, from the Magnus effect to the sea-trial procedure that checks a rotor sail's predicted savings; air lubrication and the compressor arithmetic vendors prefer to skip; the ducts, fins and bulbs that recover the propeller's wasted swirl; the machinery room, where half the fuel's energy never reaches the propeller at all; and shore power, the one measure that works while the ship stands still.

The final lesson is the one the brochures never include: why savings multiply instead of adding, how carbon prices change the payback, and what it takes to verify, not hope, that a measure delivered. By the end you should be able to take any efficiency proposal apart and price what is left.

What the course covers

  1. The Measures Landscape: Five Families and a Sceptic's Checklist 7 min
  2. Wind-Assisted Propulsion I: The Technologies 7 min
  3. Wind-Assisted Propulsion II: Performance and Proof 7 min
  4. Air Lubrication: Buying Back Friction 6 min
  5. Ducts, Fins and Bulbs: Propeller and Hull ESDs 7 min
  6. Machinery Measures and Waste-Heat Recovery 6 min
  7. Shore Power: Switching Off at the Berth 6 min
  8. Choosing and Stacking: Savings That Survive Addition 7 min

Start the first lesson →

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