# PEM Electrolyzer

The DISPATCHES PEM Electrolyzer Model represents a simple proton-exchange membrane electrolyzer that operates with a fixed efficiency in converting electricity to hydrogen gas. The outlet state is determined via an H2 property package.

This file here is a synopsis of the PEM system. The full description with arguments and details on the class are available in the renewable case documentation.

## Degrees of Freedom

The PEM Electrolyzer Model has 0 degrees of freedom.

## Model Structure

The PEM Electrolyzer Model consists of a fixed conversion rate between the inlet electricity and the outlet flow rate of hydrogen gas.

## Variables

The PEM Electrolyzer Model Model uses the following variables:

Variable Name

Symbol

Notes

electricity_to_mol

$$\eta$$

electricity

$$I_{t}$$

outlet_state

$$O_{t, *}$$

state variables such as mol flow, temperature, pressure

## Constraints

Outlet flow of hydrogen gas depends on efficiency:

$O_{t, f} = I_{t} \times \eta$