Step-based electricity price adjustment for electrolyzers
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To control costs, the company plans to adjust the load on the electrolysis units based on tiered electricity pricing. Are there any of you currently doing this? If so, could you please share the details of your approach? Thank you
By controlling the electrolyzer current up and down, the relevant process parameters can be properly managed. Many organizations are doing this these days.
Is there a specific procedure? Could you upload it? Thank you
The operation procedure you are referring to is the operating protocol for your electrolyzers; different electrolyzers have varying protocols, and there is no unified standard. Generally, it is operated according to normal load increases and decreases; for example, when increasing the load, the flow rate into the tank must be adjusted first ； When reducing the load, it is necessary to first lower the load and then adjust parameters such as the flow rate into the tank.
Operation plan? Operate according to the data provided by the electrolyzer manufacturer. There are mainly the following aspects regarding the control of current levels: 1. Controlling the rate at which the current level changes; 2. Monitoring changes in the temperature of the electrolyzer cell; 3. Adjusting the flow rates of the anode and cathode, as well as the flow rate of pure water (and the alkali concentration at the cathode), in a timely manner; 4. Controlling the voltage difference across the electrolyzer cell; 5. Regulating the pH values of the saltwater entering and leaving the electrolyzer cell. 6. On-site personnel should check the overflow from the anode and cathode, as well as the voltage of the electrolyzer cell whenever the current level is adjusted (it is advisable to measure the voltage of each individual cell every time the current level is changed, if possible)
Generally, how low does the current drop during the day, and how high does it rise at night? How are these time periods determined?
Asahi Kasei can see current levels reach 4KA during peak hours during the day, and operate at full load at night. Before PVC production started at our company, the 4 electrolyzers operated at 4KA for over three months.
During the day, it’s best to keep it above 5KA; at night, raise the voltage as much as possible (the quality of the secondary brine should be good)
It has been in use for some time, and the results are pretty good: 13.6 during the day and 14.5 at night
There are many papers on this topic; you can look them up online.
Operating with peak-valley electricity pricing takes into account changes in current efficiency and the capacity of the equipment; it is generally not economical, unless it is used in facilities with a very high level of control