Frequently Asked Questions
Is your question not here? Ask in the chatbox!
+ How fast does a battery charge?
In general, when a battery is charged using single-phase power, you multiply the current (A) times the voltage (V) to derive the power (W). When you multiply the power times 1 hour, you get the energy (Wh) that is 'put into the battery'. For example, a battery with an energy capacity of 100 (Wh) is charged with 100 (V) and 1 (A). It then takes 1 hour (100 W * 1 A = 100 Wh) for the battery to charge.
For three-phase power, you do the same but multiply by the square root of 3, which is roughly 1.7. For example, if you take the same battery and charge it with three-phase power, the power put into the battery is roughly 170 (W). It would then take you about 100/170 = 0.58 hours to charge the battery, or roughly 35 minutes. Let us know in the comments if we overlooked something!
+ How does a hybrid vessel work?
A comparison is made between a diesel-electric vessel and a hybrid vessel. Click here to check out some of our blogs on hybrid vessels and learn more.
Current - Diesel Electric
A typical diesel-electric vessel works as follows. An internal combustion engine directly powers a generator (dynamo), turning mechanical energy into electrical energy. The electrical energy is routed to a switchboard, from which it is diverted to on-board systems that demand power. The power demand is determined by the energy consumers, for instance propulsion or deck equipment. If there is a sudden increase in power demand, the combustion engines will have to quickly provide this energy. There is a limit to how fast energy can be provided by diesel engines, which could result in blackouts on the vessel if power demand is limited by the power management system.
New - Hybrid
A hybrid vessel has the same type of equipment on-board, that is the combustion engines, generators and switchboard. There is however a battery system added, which is connect to the switchboard. The battery system stores electric energy during normal operation. Upon a sudden failure of the diesel engine, or above a certain limit, the battery system can take over some or all power production, ensuring that the vessel can uninterruptedly continue its duty. Battery systems can generally provide virtually instantaneous power, which adds to the flexibility of the energy system in case of an emergency, increasing redundancy.
+ What functions do batteries have on-board vessels?
Generally speaking there are three types of functions a battery system can fulfill on-board a vessel:
Load leveling
Peak shaving
Spinning reserve
Load leveling and peak shaving are similar, as in that they moderate the load to a certain level. Load leveling makes sure the generator load remains constant continuously, while peak shaving only keeps the engine load within certain boundaries. This function potentially reduces the need to start up an additional engine. All functions save fuel, though it is usually the case that for larger vessels with larger generators spinning reserve applications preserve more fuel because one or more generators can be shut down. Running your generators more efficiently and having to use them less results in significant cost and fuel saving benefits.
+ What is the average amount of time a spinning reserve battery needs to cover?
The average time for spinning reserve that most hybrid vessels have is 15-30 minutes. For DNV DYNPOS (E/ER) classification, only the time to startup a second engine (one engine failure) needs to be considered. Of course, it is always dependent on vessel specifics, certification and client wishes.
+ What is a solid-state battery?
A solid-state battery is uses solid electrodes and electrolytes instead of (regular) liquid ones. This makes solid-state batteries more compact, safer to use and could result in faster charging times. Solid-state lithium batteries are currently viewed as one of the 'holy grails' in battery technology. Check it out in this excellent video by QuantumScape:
https://www.mr-sustainability.com/movies/2020/what-are-solid-state-lithium-batteries