New Electrolyzer Calculator 2026: Hydrogen Cost & Efficiency Tools

TH Köln's 2026 Electrolyzer Calculator Adds Battery Storage and Agri-PV Features

Cologne University of Applied Sciences Updates Its Electrolyzer Calculator

The Cologne University of Applied Sciences (TH Köln) has released an updated version of its Electrolyzer Calculator, a free online tool developed by the Cologne Institute for Renewable Energy (CIRE). The calculator determines full-load hours, hydrogen production costs, and application scenarios for PEM electrolyzers—and now, for the first time, it can also model integrated battery storage systems.

The idea for the tool originated from a lecture discussion on how to support engineering firms and industrial companies in system design. In response, students and researchers at CIRE, led by Prof. Dr.-Ing. Peter Stenzel, developed the calculator, with the first version launched in April 2023. Marvin Benedict Brands oversaw web development for both releases. Designed for users in the early planning stages, the tool enables rough system sizing but does not replace detailed engineering design.

Time-Series Model for Renewable Energy Integration

The calculator is based on a time-series model, using hourly generation profiles for photovoltaics (PV), onshore wind, offshore wind, and hydropower. Users scale these normalized time series according to the installed generator capacity. By combining multiple sources, the tool creates a total generation profile that defines the renewable electricity mix for the electrolyzer.

The default locations represent average German generation sites: - Offshore wind (Norderney): 4,058 full-load hours - Onshore wind (Oldenburg): 2,789 full-load hours - PV (south-facing, 30° tilt, Cologne):987 full-load hours - PV (east-west, 10° tilt, Cologne):940 full-load hours - Hydropower (Iffezheim Rhine hydroelectric plant):7,170 full-load hours

New in the 2026 release is agri-PV (east-west orientation, 90°, 80% bifacial efficiency) with 1,010 full-load hours.

Battery Storage as a New System Component

For the first time, the 2026 update incorporates battery storage into the model. The system operates with: - 90% round-trip efficiency - 90% depth of discharge - 1C charge and discharge rates

Investment costs for battery storage can be adjusted between €5 and €1,500 per kilowatt-hour, reflecting current market trends.

Dispatch Logic Governs Power Use and Operational Limits

The system follows a rule-based dispatch strategy: - Renewable generation powers the PEM electrolyzer up to its rated capacity. - Surplus energy is stored in the battery, within its power and state-of-charge (SOC) limits. - Any remaining excess is considered curtailment.

The electrolyzer only operates if the minimum required power is available from generation or battery discharge.

Two key operational limits apply: 1. Partial-load constraint: The electrolyzer shuts down if renewable generation falls below 10% of rated capacity. 2. Maximum-load constraint: Operation is capped at 100% of rated capacity.

Electricity not used by the electrolyzer due to these constraints remains available for other applications, such as grid feed-in.

The electrolyzer operates with: - 62.5% electrical efficiency - 20% thermal efficiency - 17 kg of water per kilogram of hydrogen - A gravimetric hydrogen-to-oxygen ratio of 1:8.

Three Cost Components Determine Hydrogen Pricing

The tool calculates levelized cost of hydrogen (LCOH) in both gravimetric (€/kg H₂) and energetic terms (€ct/kWh, based on higher heating value). The calculation includes three cost blocks:

Annualized capital costs – Based on adjustable specific investment costs for the PEM electrolyzer (€200 to €10,000 per kW) and an annuity factor of 0.0672.
Maintenance costs – Fixed at €20 per kW.
Operational costs – Comprising electricity and water expenses. The water price is set at €1.66 per cubic meter, while levelized cost of energy (LCOE) can be adjusted per source:
PV:3.12 to 19.72 €ct/kWh
Onshore wind:3.94 to 8.29 €ct/kWh
Offshore wind:7.23 to 12.13 €ct/kWh
Hydropower:~8.50 €ct/kWh

Two system configurations fundamentally alter the cost structure. In direct coupling, all generated electricity is factored in as a cost variable, and any unused power counts as a loss. With grid coupling, only the electricity actually used in the electrolyzer is accounted for—excess power is fed into the grid, though no revenue from this is included in the calculation. Optionally, income from waste heat utilization can be factored in, valued at €25 per megawatt-hour of thermal energy.

Use Cases in Transport, Industry, and Buildings

The calculator presents the computed hydrogen and waste heat quantities across three sectors, without cumulative totals.

Transport: The tool assumes an average passenger car travels 13,700 kilometers per year, consuming 1.0 kilogram of hydrogen per 100 kilometers. For hydrogen fuel cell buses, the figures are 45,000 kilometers annually and 7.5 kilograms of H₂ per 100 kilometers.
Industry: The model bases its calculations on the hydrogen demand of a blast furnace process using direct reduction, requiring 57.1 kilograms of H₂ per ton of crude steel.
Buildings: The model uses a representative German residential building as its reference: 140 square meters in size, with a specific heat demand of 155 kilowatt-hours per square meter per year, weighted according to the distribution of energy efficiency classes in Germany's building stock. Heating is provided by a hydrogen condensing boiler with an efficiency of roughly 105 percent (based on heating value, Hi). Additionally, waste heat from electrolysis can be utilized alongside hydrogen in all sectors.