ETF project - BV Dairy Ltd

BV Dairy was established in 1958, and is located near the Dorset town of Shaftesbury. The company processes around 35 million litres of milk per year sourced from 35 farms closely located to the site. Their product range includes fresh and cultured dairy products for sale to the UK’s food manufacturers and food service operators.

The proposal was to build an anaerobic digestion plant which would utilise the liquid wastes streams from the dairy's manufacturing processes. These would then provide the site with renewable electricity and heat which would be used within the factory and business premises.

The company's technology partner in this project was Clearfleau, who assisted BV Dairy throughout the project from design, planning, construction, commissioning and monitoring.   Clearfleau’s innovative approach to high-rate liquid digestion handled the entire waste stream, including fats. The plant would cut the effluent treatment charges and also reduce the site’s overall carbon footprint.

This project demonstrated the role which anaerobic digestion could play within the food manufacturing process - providing a means of treating liquid waste where it is produced. The project was keenly supported by DairyUK (representing the UK dairy industry), who have incorporated specific anaerobic digestion targets within the Milk Road Map.

Project Updates

Project build - April 2011

We have satisfactorily gained the ABPR approval and can now move digestate off site.

The main issue overcome this month has been optimising the performance of the CAF units which have been difficult to control.

We need to ascertain the cause of water within the CHP engine and eliminate it. This is causing some serious downtime.

We also intend to install some bench scale AD digesters to allow us to determine the value of material from other dairy companies.

We also need to involve the local councillors in the project and a visit is planned for May, in the hope that we can gain approval to vary our planning permission conditions to allow material to be brought in from other dairy companies.

Project build - February 2011

Our main achievement in February is that Digestate is now being produced and we are sending samples for analysis to calculate the nutrient content.  The CHP engine is running regularly and we have reached 10% generation of our electrical requirement for the company.

We have achieved a steady state condition which has resulted in an increase in biogas production.

Our key focus over the next four weeks is to finish the DEFRA validation process on the digestate and then we can start to move it off site.  We will have the project monitors final visit and sign off the project.

The plant is performing as design with 95% COD removal and 65% methane content in the biogas.

Project build - January 2011

The weather caused a number of problems in January and we were unable to run for a number of days due to frozen pipes. There was some damage which needed repairs.

The digestate press has been commissioned.

Over the next few weeks we will be increasing the loading on the AD plant to test its performance.  We will be going through the DEFRA validation process on the digestate.

We plan to run the plant on a steady state protocol to allow operational conditions to stabilise. 

Project build - December 2010

The weather caused a number of problems in December and we were unable to run for a number of days due to frozen pipes. However when running we did generate electricity. The application to OFGEM for FIT accreditation has been submitted.


Over the next few weeks we will be increasing the loading on the AD plant to test its performance.  The digestate press will be commissioned.

There were some minor issues during commissioning but most of these have been overcome. 


Project Build - October 2010

The construction of the bund commenced to comply with the EA permit but we are waiting for planning permission. The Digester has been successfully commissioned, and the CHP unit has been delivered to site.


The Polymer addition is proving to be problematic but we have now found the correct polymer and the CAF units are operating reasonably successfully. We have started the bunding of the site which is proving to be difficult to do retrospectively.

During November and December we will focus on the commissioning of the CHP unit and sludge press. Once the CHP is running we should be able to rasie the operating temperature of the digester and increase the gas output.

I am still having issues with the FIT and electrical side in that the structure of the electrical industry is very fragmented with parts of the same company not understanding other areas – so how can I?

Project build - July 2010

We have once again been working with the Environment Agency to resolve permitting issues, and they have been helpful in working on our application.

We have no appointed our Knowledge Transfer Partnership (KTP) associate so we are looking forward to working with them on the project.

Previous communication problems have delayed the installation of bunding around the facility, however this now being resolved means that the build of this can commence.

Over the next month or so we are looking to complete all required registrations, install the combined heat and power (CHP) unit and to finally begin to commission the plant.


Although this has been an complex project for the dairy, we are looking forward to the build phase being complete and for the commissioning phase to begin so that the plant is ready to run when the bespoke permit from the EA has been received.

Project build - June 2010

This month we have been able to complete the Environment Agency (EA) permitting application, and are in the discussion phase with the electricity distribution company regarding the contract for electricity export to the grid.

The EA bespoke permitting application was the biggest hurdle which we got over this month after having a few false starts.


The site in June with the digester awaiting the arrival of the roof structure.

Project build - April 2010

Equipment has been delivered to site and mechanical installation commenced in the last few weeks, over the next month the target is to complete mechanical and electrical installation across the whole site.


Project build - March 2010

All of the tanks have now been constructed and all of the civils work has been complete, and the contract has been signed for the CHP unit.

Over the next month we need to apply for the necessary EA permits under the new permiting scheme and to commence mechanical and electrical installation.


Project Build - February 2010

The civil works have been completed including all the tank bases, building platform and roadway.

We have managed to bring the build back on to schedule, after the initial delays caused by the poor weather over the Winter.

Looking forward to March, the equalisation tanks and sludge tanks will be constructed, as well as the designs being finalised for the electrics.


Project build - January 2010

Despite the weather conditions the base for the equalisation tank  has been laid and the digester walls have been constructed.

Final equipment orders are now being made including discussions with the supplier of the CHP. Animal Health have also confirmed their position on the animal by-products situations.

As with the time of year, our current issue is with the weather, but we are only one week behind schedule and therefore confident we can make up this Tine going forward.

Our focus over the next four weeks is to push forward with the civils work to complete on schedule.


Project build - December 2009

The pilot plant has now been removed from site following a successful trial period.

Construction commenced in mid November, and the base for the digester has now been laid ready for the walls to begin construction in January.

Following on for the results obtained through the pilot plant we are now awaiting  the decision from Animal Health regarding the pasteurisation  processing prior to the waste entering the digester.

We are still looking forward to a September completion date for the build.


Project build - October 2009

The pilot plant continues to improve in performance achieving now over 95% reduction in COD and a methane content of the gas now at 70%.

Planning permission has now been fully obtained, and the Environment Agency has allowed the permitting application to be placed on hold until April 2010 when the new standard rules for AD comes into force.

Construction of the main plant is due to commence in November. 

Project build - September 2009

The pilot plant is now running successfully and is producing a satisfactory gas output with 70% methane content. The pilot plant is also being used to test the chemical content of the waste material previously discarded to the sewers. This is now being out through the pilot plant which is now achieving a 90% reduction in chemical oxygen demand (COD). The flare has also been lit for the first time.

The COD test measures the oxygen demand of biodegradable pollutants plus the oxygen demand of non-biodegradable oxydizable pollutants. BV Dairy are using AD to reduce the amount of chemical and inorganic material entering the waste water system.

The pilot plant is being used to test the odour output of the plant, with odour testing being carried out by a specialist company. As the dairy factory is close by, odour control is paramount to prevent tainting the dairy goods. So far the odours have been negligible, but BV Dairy will be constantly reviewing this, even on the main plant.

Over the next month, Animal Health will be sampling the liquid outputs of the system to check the microbiological quality. The results of these tests will determine the pasteurisation requirements of the site.

Other dairy companies will also be visiting the pilot plant over the next few weeks, as the interest in AD within the dairy industry increases.

Project build - August 2009

The pilot plant has been delivered to the site to begin digesting and testing the waste through a miniature ClearFleau plant.


We are processing the discussions with DEFRA on the pasteurisation requirements for the facility to ensure that the correct regulations are being adhered to.

Over the next month it is hoped that we will be able to instruct contractors to begin the build on site whilst continuing to run the pilot plant, analysing results to achieve optimum outputs.

The project has raised quite an interest throughout the dairy industry with other companies keen to find out more about their project.