Heat controlled Metal Hydrides H2 Storage (HY2 System)


The project aims to create a turnkey hydrogen-based energy storage system suitable for both new and existing buildings. This control unit will optimise energy management by considering local power from PV production, building consumption, and employing adaptive and predictive strategies for efficient operation.

Target technical data

% of recyclable (or reusable) product

>98% of whole system

% of product from recyclable sources

>60% of whole system

Embodied Energy:

~ 80 kWh/kWhel (HY2MINI) / 72 kWh/kWhel (HY2MEDI), - 20/28% of standard solution

Embodied Carbon

~ 85 kg CO2eq/kWhel (HY2MINI) / 75 kg CO2eq/kWhel (HY2MEDI), -20/28% to standard

Efficiency (stored energy to extracted energy)

25% and 35%, depending on the technology and make of hydrogen used

State of the art and main challenges

Existing hydrogen-based energy storage systems are limited to small-scale applications, mostly for single houses. These systems use conventional hydrogen pressure storage, requiring compression by a compressor and extra power input/loss. Typically power-controlled, they operate based on electrical energy demand. Similarly, metal hydride solutions are seen at small and mid-scale demos, featuring basic internal thermal management for self-use.

Innovations and added value

REN+HOMES will offer a turnkey solution applicable to new and existing buildings. It features all essential interfaces (inverters, heat transfer, LAN, modbus) and a dedicated control unit developed with partners. This unit will:

  • adapt to local PV power, building consumption, and predictive management
  • outperforms hydrogen pressurized storage with enhanced metal hydrides, storage density, and efficiency
  • directly store the hydrogen, produced by the electrolizer in metal hydrides, utilizing released heat
  • optimise storage size (120kg H2), electrolyser, and fuel cell

Moreover, waste heat recovery enhances efficiency, and functions include remote access, monitoring, and predictive maintenance. The system can be heat or power controlled, and an underfloor hydrogen installation with innovative safety measures will be implemented.