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Case Studies
Greencycle Systems have worked on a wide array of projects, over the years. Here are some of our previous projects.


Apsley Farms
GCS has supported Apsley Farms in a large bespoke AD development. The plant now exports 115GWh biomethane, generates 1.6 MW of electricity, and sells 10,000 t/a food-grade CO2.
GCS supported:
- Project financial modelling and options analysis as required to define the project, justify its viability and to allow Apsley farms to secure capital finance to deliver the project.
- High level design of the entire plant and process encompassing several innovative features, lagoon-style digesters 18,000m³ capacity, 250m³ hydrolysis stage, with retention times up to 150 days
- Specification of key equipment, management of tender processes and vendor selection for key equipment such as feeders, above ground tanks, separation systems, upgrading and gas to grid equipment, CO2 liquefaction and dry ice manufacture.
- Deployment management, design of integration systems and design of lagoon digesters, deployment of site electrical and control system allowing precise control and monitoring of all systems.
- Gas to grid connection management including GNO liaison, grid entry agreements, injection system specifications and commissioning oversight.
- Government support scheme application, administration and ongoing optimisation of revenue opportunities through green gas certifications and sales.
After 11 years of successful operation, Apsley farms continues to innovate, supported by GCS. They have recently added dry ice production and sales, they also innovate within the farm operations employing ag bags to store feedstocks avoiding waste and maximising utilisation of field storage.
GCS supported:
- Project financial modelling and options analysis as required to define the project, justify its viability and to allow Apsley farms to secure capital finance to deliver the project.
- High level design of the entire plant and process encompassing several innovative features, lagoon-style digesters 18,000m³ capacity, 250m³ hydrolysis stage, with retention times up to 150 days
- Specification of key equipment, management of tender processes and vendor selection for key equipment such as feeders, above ground tanks, separation systems, upgrading and gas to grid equipment, CO2 liquefaction and dry ice manufacture.
- Deployment management, design of integration systems and design of lagoon digesters, deployment of site electrical and control system allowing precise control and monitoring of all systems.
- Gas to grid connection management including GNO liaison, grid entry agreements, injection system specifications and commissioning oversight.
- Government support scheme application, administration and ongoing optimisation of revenue opportunities through green gas certifications and sales.
After 11 years of successful operation, Apsley farms continues to innovate, supported by GCS. They have recently added dry ice production and sales, they also innovate within the farm operations employing ag bags to store feedstocks avoiding waste and maximising utilisation of field storage.


STL Energy, from CHP to biomethane
GCS have supported STL Energy to convert their plant from CHP only to a combined CHP and Biomethane plant.
The plant now produces around 40GWh of green gas per year, recovers CO2 as a value stream and feeds electricity into the gas grid at 70Bar. Heat generated is also used for intensive farming operations. The gas to grid expansion first injected biomethane in in 2016.
GCS supported:
- Technical integration strategy to maximize plant performance and operability while utilizing existing hardware
- Technical specification of key vendor work-packages with support for vendor selection and management
- Site layout and systems integration design
- Deployment site management including construction oversight and problem-solving
- Gas to grid connection management including GNO liaison, grid entry agreements, injection system specifications, and commissioning oversight
After 9 years of successful operation. GCS are supporting STL energy with a further expansion of this plant.
The plant now produces around 40GWh of green gas per year, recovers CO2 as a value stream and feeds electricity into the gas grid at 70Bar. Heat generated is also used for intensive farming operations. The gas to grid expansion first injected biomethane in in 2016.
GCS supported:
- Technical integration strategy to maximize plant performance and operability while utilizing existing hardware
- Technical specification of key vendor work-packages with support for vendor selection and management
- Site layout and systems integration design
- Deployment site management including construction oversight and problem-solving
- Gas to grid connection management including GNO liaison, grid entry agreements, injection system specifications, and commissioning oversight
After 9 years of successful operation. GCS are supporting STL energy with a further expansion of this plant.


CCm, Organic fertiliser pelleting plant
GCS provided embedded support to client building a new production facility manufacturing carbon neutral fertilisers. GCS supported the design phase of the project in Q2 2025 through to site installation to allow start of production in Q4 2025
GCS supported:
- Specification of key equipment such as air handling system, additives receipt and dosing system, compressed air system, and bag filling systems.
- Control system design, release of controls documentation & specification of all equipment control integration.
- Vendor bid management, air handling system, additives receipt and dosing system, compressed air system, control system & electrical install.
- Site layout & systems integration.
- Managing sub contractors and vendors to design & deliver compatible process and transfer equipment.
GCS supported:
- Specification of key equipment such as air handling system, additives receipt and dosing system, compressed air system, and bag filling systems.
- Control system design, release of controls documentation & specification of all equipment control integration.
- Vendor bid management, air handling system, additives receipt and dosing system, compressed air system, control system & electrical install.
- Site layout & systems integration.
- Managing sub contractors and vendors to design & deliver compatible process and transfer equipment.


Enhanced digestate management
Digestate management becomes ever more critical to AD operations. GCS have experience in several specification and deployments of advanced de-watering technology to allow optimal phosphate extraction and therefore reduction and avoidance of digestate transport costs.
GCS have supported:
- Equipment technical specification including site trials
- Technology integration: Site pipework, P&ID, control design, Mechanical integration
GCS have supported:
- Equipment technical specification including site trials
- Technology integration: Site pipework, P&ID, control design, Mechanical integration


Composting plant, airborne emissions management
Having built several composting plants previously, GCS recently supported a composting facility that had experienced corrosion in their duct system and required additional biofilter area due to changes in the usage of buildings within the facility.
GCS Supported:
- Appraisal of existing equipment through inspection and measurement of achieved flow and pressure.
- Assessment of extraction flow requirements
- Identification of optimal revised ductwork design to achieve the required extraction flow while maximising the utilisation of the remaining ductwork in serviceable condition
- Design of a new biofilter to meet the site’s airflow and space requirements utilising plastic crate system for cost and speed of deployment
- Specification of blower system, design of ductwork and valve system for blowers, blower tender process
GCS Supported:
- Appraisal of existing equipment through inspection and measurement of achieved flow and pressure.
- Assessment of extraction flow requirements
- Identification of optimal revised ductwork design to achieve the required extraction flow while maximising the utilisation of the remaining ductwork in serviceable condition
- Design of a new biofilter to meet the site’s airflow and space requirements utilising plastic crate system for cost and speed of deployment
- Specification of blower system, design of ductwork and valve system for blowers, blower tender process
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