Marine power: An overview of superyacht generators
Written by Yachting Pages
Last updated: 15/02/2019
It’s amazing, and a little worrying almost, to think about how much we rely on electricity in our modern-day society; from switching on the bedside lamp in the morning, to watching TV, browsing the web, and everything in between.
Life is no different aboard a superyacht, with these impressive vessels equipped with extravagant entertainment and AV systems and other sophisticated digital systems, with enough power still required to maintain the simultaneous smooth running of the yacht’s operational equipment.
Sure, shore power sources do the job, but what good is a superyacht if it has to be berthed to fully enjoy its amenities? Thankfully, marine generators have evolved over the years to serve all kinds of applications where large amounts of power are required without a static power source.
As such, Yachting Pages asks and answers some key questions about marine generators, and provides key facts to get to the bottom of common marine power queries.
Key information about marine generators
What is a marine generator, and how does one work?
In theory, a marine generator is much the same as any other generator, and can be found on board just about any large boat or yacht to power its running equipment and various electrical appliances. Of course, a marine generator is specialised to the marine environment; designed with weight and space saving in mind, and equipped to survive the damp and salty sea air.
Put simply, marine generators output electricity (or electrical energy) by taking 'ordinary' energy, like that generated by combusting fuels such as diesel and gasoline, and converting it into electrical energy. The energy created by burning this fuel drives mechanics inside the generator that spin a coil of wire inside magnets of opposite charges. This forces electrons through the wire and creates a current. Soon, electricity flows, and the outlets on the generator have power.
Why do I need a marine generator?
Although you probably have a range of batteries and inverters which could be used to create power on board your yacht, it’s likely that with the size and purpose of a superyacht you’ll be running air conditioners, lighting and refrigerators around the clock, before the crew wakes up and fires up the galley and host of cleaning and entertainment systems. As such you’ll need a marine generator of appropriate size to meet the yacht’s demands without putting additional strain on the boat’s batteries.
Key facts about marine generators
A marine generator’s operating speed matters
Electronic equipment, whether it's at land or sea, is designed to use power with a fixed frequency, or hertz (Hz). Whilst it would be lovely if the entire world ran on the same frequency that unfortunately is not the case: The USA and Canada use 60Hz power, whilst Europe, Australia, and much of Asia use 50Hz.
On world-roaming superyachts, this can be tricky. Generators that run at the same frequency as the regions you’re likely to spend the most time in are therefore the best choice for minimal hassle, but it’s good to know that many AC-powered devices these days aren't too sensitive to whether they're receiving 50Hz or 60Hz power – but, bear in mind that an AC-powered motor that's designed for 50Hz power in Europe would run 20% faster if you powered it at 60Hz from shore power in the USA. This could therefore cause potential problems with refrigerators or air-conditioning systems if they were to be powered incorrectly.
These sorts of issues typically have solutions these days, which can be advised by suppliers – but it's a worthwhile point to understand, as you may need to make advance preparations before visiting different regions to ensure your power needs are taken care of safely at all times.
Superyacht generators typically log 2 to 3x more running hours than the engine
A superyacht generator is a hard worker, typically logging more than double the amount of time running than the main engine. As such they typically come in as the second most expensive piece of operational equipment on board – only behind the engine itself. This makes choosing the right generators essential to operating a superyacht – and its plethora of electrical equipment such as lifts, powered doors, entertainment solutions, and large AC installations – successfully with minimal issues.
It’s typically best to have a load-analysis performed before fitting any new generator in your yacht, to ensure whatever is installed has enough power to run everything on your vessel.
Turning on appliances that utilise electric motors produces what’s known as inrush current. This can cause frequency and voltage dips, and lights to dim. Depending on the motor being started and its quality and size, sometimes it can take up to ten times the normal running wattage to start the appliance.
Similarly, having a yacht generator that’s constantly running significantly under load is also not ideal. This causes very inefficient fuel combustion and will reduce the life of the engine due to carbon build-up. For a diesel superyacht generator, it’s often said running it at 35 to 70% of its load is ideal. Multiple generators are often used where the electrical load on board may vary regularly, so one or more generators can be switched off or on dependant on the specific requirements at the time.
Having a dealer or specialist assess your electrical needs before installing generators is essential to the seamless operation and enjoyment of a superyacht. It’s also important to assess any foreseeable future needs, such as equipment upgrades (a larger refrigerator, for example), as this will also affect the decision.
A specialist generator supplier can help assess your needs
Understanding this key information about how generators work in the superyacht world is great knowledge to have for any seafarer – but luckily, the experts are out there to help in selecting and choosing the best power solution for a superyacht based on a vessel’s bespoke power requirements.
Protecting and maintaining superyacht generators
With all this responsibility, how do superyacht engineers protect and maintain the operating power of their superyacht generators?
We’ve created a guide detailing some basic yacht generator maintenance checklists recommended for yacht crew, with engineering best practices. Read our article on protecting your superyacht generator here.