Alkaline electrolyzers can have an efficiency of 43–69% for hydrogen production, depending on various factors:

 Alkaline electrolyzers can have an efficiency of 43–69% for hydrogen production, depending on various factors: 

Current density

A high current density is required for economical production, but it reduces efficiency by about 10%. 

Temperature

The maximum efficiency point moves with the variation of temperature. 

Power electronics

Transformer, rectifier, and power electronics for DC voltage adjustment have losses of a few percent. 

Other loads

Fans for ventilation and cooling towers, and pumps for supply water, filtration, and cooling water can add a few percent to the electrolyzer power consumption. 

Hydrogen compression

Hydrogen compression can add a significant load to the electrolyzer system. 

Alkaline electrolyzers have several advantages, including low capital costs, long life spans, and availability of large plant sizes. However, they also have disadvantages, such as low current density and high maintenance costs.