FC
Fuel cell
An electrochemical source that converts hydrogen or another fuel directly into DC electricity, usually followed by a converter.
SLD / Schematic
Symbols · ELY
Hydrogen electrolyser
A DC load that splits water into hydrogen and oxygen, supplied through a rectifier as a controllable sink in a microgrid.
In plain English
What does Hydrogen electrolyser mean?
An electrolyser uses DC current to split water into hydrogen and oxygen. In microgrids and renewable hubs it acts as a large controllable load that can absorb surplus solar or wind generation, with the hydrogen stored for later use in a fuel cell or sold off site.
A simple example
On a single-line diagram the electrolyser stack appears as a DC load fed from a transformer-rectifier or an active front-end rectifier. Large units show the rectifier transformer, harmonic filtering and a DC busbar to the stack; smaller units may be drawn as a single block labelled with the stack rating.
What the drawings help you do
Thyristor rectifiers for large electrolysers draw significant harmonic current and reactive power, so filters or compensators may be needed. The symbol does not state ramp rate, minimum load or the gas plant constraints that limit how flexibly the electrolyser can follow generation.
This particular reference
A DC load that splits water into hydrogen and oxygen, supplied through a rectifier as a controllable sink in a microgrid. An electrolyser consumes electricity to make hydrogen; a fuel cell consumes hydrogen to make electricity.
- DC
- Direct current: electricity flowing in one direction.
- Winding
- A coil of conductor inside an electrical machine or transformer.
- Rating
- A value stating the conditions for which equipment is specified.
Read the source: IEC graphical symbols for diagrams · Battery energy storage and power conversion
SLD · ELY
What it represents
An electrolyser uses DC current to split water into hydrogen and oxygen. In microgrids and renewable hubs it acts as a large controllable load that can absorb surplus solar or wind generation, with the hydrogen stored for later use in a fuel cell or sold off site.
On a single-line diagram the electrolyser stack appears as a DC load fed from a transformer-rectifier or an active front-end rectifier. Large units show the rectifier transformer, harmonic filtering and a DC busbar to the stack; smaller units may be drawn as a single block labelled with the stack rating.
Thyristor rectifiers for large electrolysers draw significant harmonic current and reactive power, so filters or compensators may be needed. The symbol does not state ramp rate, minimum load or the gas plant constraints that limit how flexibly the electrolyser can follow generation.
How to read it
- Read the rectifier type to judge harmonic and reactive impact.
- Treat the stack as DC load; its rating is often given in MW of DC input.
Information to show or reference
- State stack DC rating and ramp limits.
- Show rectifier, transformer and filters.
- Reference minimum load and process interlocks.
A distinction that matters
An electrolyser consumes electricity to make hydrogen; a fuel cell consumes hydrogen to make electricity.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
IEC graphical symbols for diagrams
IEC graphical symbol context for loads and conversion elements.
Battery energy storage and power conversion
Public power conversion context for storage-type systems.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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Thyristor phase-controlled rectifier
An AC-to-DC converter using thyristors fired at a controlled angle to set its DC output voltage.
SLD / Schematic
AFE
Active front-end rectifier
An actively switched AC/DC stage using a documented current-control and DC-link regulation arrangement.
Schematic / SLD
LOAD
Generic electrical load
A generic electrical load identifies a documented consuming circuit or aggregate load on an SLD.
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