Linear Generators combine the efficiency of fuel cells with the power density and durability of conventional packaged generator solutions to deliver clean, dependable and cost-effective power. Libertine’s scaleable and modular technology can form the basis of lightweight products delivering just a few kilowatts to multi-megawatt containerised systems.

Linear Generator products can generate clean power from renewable gas fuels such as hydrogen, biogas and syngas, and from renewable liquid biofuels and synthetic fuels such as methanol and ethanol. They also provide the flexibility to use conventional fuels, mixed gas streams and renewable fuel blends without compromising efficiency.

Recent advances in power electronics and control technologies have enabled the creation of Linear Generator products in which each cylinder’s compression ratio is controlled by linear electrical
machines that govern free piston motion whilst also generating electrical power directly.

Without the cost, complexity and constraints of a crankshaft and other mechanical powertrain components, far more power generation cylinders can be packed into a given volume than is possible with
conventional engine technology.

Real-time compression ratio control provides the flexibility to make better use of variable composition fuels such as biogas, supports advanced low-temperature combustion methods, and enables clean cold start and transient performance – even with renewable alcohol fuels.

Libertine’s intelliGEN and HEXAGEN linear e-machine and control technology platforms have been created through over a decade of customer-facing programmes to provide a basis for rapid Linear Generator product development, reducing OEM product development programme time, cost and risk.

We provide design and development services to help customers incorporate Libertine’s technology platforms into their new product developments. We enable high efficiency linear power generation using a battery-like architecture that combines individual Cells into Modules and Packs.

The intelliGEN Hybrid Power System (iHPS) is a factory-configurable, containerised power generation product concept integrating battery packs for energy storage and Linear Generator packs for power delivery 

Up to 3 MWe of dispatchable power output with up to 2 MWh battery storage integrated in 1 container

Much like battery packs, a Linear Generator pack unit is a packaged set of modules formed of individual cells. A pack unit is designed to be the primary unit for factory configuration of hybrid power systems, and as the swap-out unit for maintenance and end-of-life. Pack units include shared auxiliary systems necessary for combustion, cooling and control to enable a pack unit to generate DC electrical power, on demand.

Libertine’s intelliGEN platform technology enables the creation of high power density pack units. For example, Libertine’s iPU500 pack unit concept could generate up to 0.5MWe DC electrical power from three two-cylinder modules arranged vertically in a compact ‘slab’ form factor that fits comfortably within the width and height of a standard 20’ ISO container.

The unique packaging format of Linear Generator modules within the intelliGEN Pack Unit (iPU) provides a breakthrough in power density and product configuration flexibility. iPUs are ideally suited to use in Linear Generator products for on-site dispatchable power generation serving data centres, EV charging locations and industrial sites.

Pack units can also be incorporated into heavy duty on- and off-highway hybrid powertrains as well as marine, rail and other high power applications.

Libertine’s Linear Generator modules incorporate one or two Linear Power System cells together with power electronics and micro-controllers necessary and operate and synchronise individual free piston movers in a cell, phase-link the operation of a pair of cells, and generate electrical power. Close-coupled combustion auxiliary systems such as the fuel rail, ignition system and charge compressor are also integrated into the module.

An individual cell only produces power when the pistons are moving, and so output drops to zero at the end of each stroke. Two-cell modules can produce near-constant electrical power output thanks to Libertine’s precise phase-linking control software that ensures one cell in a pair is producing maximum power when its neighbour is producing none.

Our range of linear generator prototype modules enables customers to develop linear generator products for a wide range of onsite, commercial, dispatchable and renewable power generation

The building block of all linear generator solutions, the Linear Power System (LPS) cell is a single cylinder combination of a Linear Electro-Mechanical System (LEMS) and a fuel-flexible Internal Combustion System (ICS).

Libertine makes linear electrical machines that are closely integrated with linear bearings, bounce chambers, cooling and mechanical housing components so that the electrical machine mover can also act as a piston to expand, compress or move a working fluid.

Our Linear Power System cells provide class-leading motion control authority and power conversion efficiency for the most demanding linear power and motion applications.

The most important metric for piston motion control is ‘specific force’ – the electro- magnetic force that can be applied to the free piston mover assembly per unit of moving mass.

Libertine’s approach to Linear Power Systems design focuses on specific force. Through optimised electrical machine design, closely integrating the LEMS and ICS to reduce the mass of the free piston mover assembly that oscillates within both of these systems, and use of advanced engineering materials and manufacturing methods, Libertine’s Linear Power Systems are capable of delivering twice the specific force of many other linear electrical machines and free piston systems.

As far back as 2009, Libertine’s Linear Power Systems
architecture has been developed with a path to high
volume, cost effective manufacture of Linear Generator products in mind.

The simple axial geometry of Linear Power Systems lends itself to low cost, low waste manufacturing methods such as extrusion and metallic powder-pressing. The 3D complexity of conventional engines often requires sand-cast engine block and head components with extensive secondary machining operations to achieve each component’s required net shape and geometric tolerances. In contrast, the off-tool form of extrusions and pressed metal components can be used with minimal secondary process operations.

More recent advances in component manufacturing methods such as spin casting, high-pressure die-casting, metal injection moulding (‘thixomolding’) and additive manufacturing techniques provide additional paths to LEMS cost optimisation alongside continuing performance improvements in our technology roadmap.

Libertine uses sophisticated component-level cost analysis tools to inform our platform technology roadmap, which in turn provides insight to each customer’s business case for Linear Generator product development.

Our location in Sheffield is just a short distance from the Advanced Manufacturing Park and Sheffield University’s Advanced Manufacturing Research Centre providing access to world-leading manufacturing technology and expertise.

Through our proprietary Linear Power Systems architecture and manufacturing methods, and our position at the heart of the UK’s world-leading advanced manufacturing cluster, we can support new
product introduction programmes from pilot demonstrations through to product certification and launch of high volume, cost-competitive Linear Generator products.

Libertine seeks to become a strategic technology partner to our OEM customers, build confidence in the business case for Linear Generator new product introductions, and accelerate customer Time to Market (TTM) and Time in Market (TIM) – essential metrics for commercial success.

Motion control software and toolchain for Linear Generator product development productivity

Our integrated toolchain comprises power and motion control software; executable tools for operating parameter library generation and ‘Hardware-in-Loop’ validation; real-time testing user interface and KPI visualisation tools; detailed analytical tools for postprocessing and test data; secure cloud-based repositories and API interfaces for accessing, reviewing and utilising test data, and; simulation model blocks for system design and configuration.

Libertine’s control software can be configured to interface with third party engine control units (ECUs). Our developer tools are designed to complement a wide range of simulation and analytical tools. We provide engineering support through the product development cycle to accelerate our customer development and commercialisation of highly differentiated Linear Generator products.


OpenFPE research engine datasheet


intelliGEN platform datasheet


HEXAGEN platform datasheet


intelliGEN micro-scale 1-10kWe concept datasheet


See our YouTube channel for Linear power systems