Infinitas Design

Renewable Energy System Design & Development


Case Study



Infinitas Design Ltd was engaged by Dundee and Angus College to investigate an inoperative biomass boiler

Case study – Dundee & Angus College

Infinitas Design Ltd was engaged by Dundee and Angus College to investigate an inoperative biomass boiler at its Arbroath campus. The site also used 25 year old gas boilers to generate space heating and hot water.

After assessing the existing heat generation system, we suggested the decommissioning and removal of the existing biomass and gas boilers and the installation of a new biomass boiler system to serve the existing college buildings as well as connecting two other plant rooms on the college campus to provide additional and back up heat. The other plant rooms were also using gas boilers for heat.

The strip out of the old biomass boiler and gas boilers took place over Summer & Autumn 2016 with the new 800kW boilers, 15,000l buffer vessels and pumps being installed in November 2016. The fuel store was also modified to accept a greater amount of wood chip with new trough delivery system. The remote plant rooms were connected to the biomass boiler plant room by roof-mounted external pipework.

3D model of new biomass boiler plane room Dundee & Angus College Scotland - Infinitas-Design

3D model of new biomass boiler plane room

Infinitas Design provided the full detailed design including plant room layout, hydraulic schematics and tender specifications. We also supported the college throughout the installation process with any technical queries and working with suppliers.

We are also undertaking the RHI application now that commissioning has taken place.














Case Study 2 – Rosti Automotive


Infinitas Design Ltd was engaged by Rural Energy to provide the design and development of a new biomass boiler energy centre with gas boiler top-up for the Larkhall site of Rosti Automotive.

Rosti Automotive was looking to reduce their carbon footprint by using wood chip biomass boilers to provide the baseload for space heating, hot water and various process loads within the adjacent factory. The final design comprised 2 x Herz 499kW Firematic boilers, 2 x 10,000l buffer vessels and 2 x 550kW Wolf gas boilers. A short run of preinsulated pipework connected the new energy centre to the factory.

We took responsibility for the boiler house footprint and chip store size, sizing and positioning of all equipment within the energy centre, design specifications and system schematics. We used Onshape 3D CAD to produce the layout models and drawings for build.

Infinitas began the design following initial site visit in January 2017. The boilers are due for commissioning in May 2017. This was a very condensed timeline for design, installation and commissioning, which was achieved through good working relationships between the whole team.



Case Study 3 – Freshfield Energy, Hendwr Farm

Problem – Waste heat recovery and heat pumps

Date – May – October 2017


Infinitas Design become involved with Freshfield Energy and the Hendwr project after being asked to advise on the RHI eligibility for a waste heat recovery heat pump and biogas CHP system. It was planned to utilise some of the waste heat from the slurry discharged from the anaerobic digester on its way to the slurry lagoon within the heat pump. However, the heat was leaving the digester at a temperature greater than can be accepted by the heat pump so could not be used directly. Infinitas Design worked with the client and their M&E contractor to design a heat exchanger that reduced the temperature of the slurry to a level that was acceptable to the heat pump whilst retaining the high efficiencies of the system that were achieved by using a relatively high temperature into the heat pump. By combining this with naturally occurring heat from a ground loop also attached to the heat pump, the system became eligible for non-domestic RHI.

The system was installed during the summer of 2017 alongside a biogas CHP engine, which used the biogas generated by the digester. The heat pump is generating heating for 3 properties on the farm site and displaces the oil boilers, which were previously generating the space heating and domestic hot water. Heat pump efficiencies exceeding 420% are expected due to the intelligent use of waste heat in conjunction with the water from the ground loop.

Infinitas Design has undertaken the RHI applications for the heat pump and the biogas CHP systems, which also includes an IRMA (Independent Metering Report) due to the Multiple metering on the site.



Case Study 4 – Highcliffe Primary School, Leicestershire

Problem – Non-operational biomass boiler and no RHI

Date – March 2015


When your biomass boiler goes wrong or stops working it can be difficult to know where to turn. So, having expert advice can be crucial in making sure that you get the most out of your investment and avoid expensive pitfalls.

Highcliffe Primary School is a small school in Leicester. In 2012, they invested with a company in a biomass boiler to generate the majority of the heat required by the school buildings and its swimming pool. The new system replaced an older oil boiler, which the school decided to keep for back up heating.

Three years after the initial installation of the D’Alessandro boiler the school contacted Infinitas Design as they were having difficulty operating the system correctly and relying heavily on the back up expensive oil boiler – costing the school a lot of money to run.

An initial site survey showed simple changes to the system would allow the school to be able to use the boiler correctly producing the savings they required and had made the initial investment for.

We identified the wrong heat meter had been installed and needed to be replaced. The biomass boiler had also been commissioned to operate on wood chip whereas the RHI compliance certificate stated it needed to operate on wood pellet.

Working with the school we went through the fuel conversion process, which included a replacement fuel hopper installed by a third party.

We were then able to initiate the RHI application process, which entailed a second site visit to gather information on the boilers, heat meters, buried heat main between the buildings and non-eligible heat sources. Due to the period of time between the initial installation and the RHI application being undertaken, there were numerous queries from Ofgem, which we took care of on behalf of the school.

The RHI application was approved in May 2015 and the school received their first payment in August of the same year.

If you find your biomass boiler isn’t working as it should or you want a quick review, then contact Infinitas Design.




Case Study 5 – Moat Farm Biomass Boilers, Shropshire

Problem – RHI not approved and no payments made for biomass boiler

Date – August 2017


Keeping track of the RHI process can be tricky especially if you are busy trying to run a business as well. Infinitas Design is pleased to provide support and assistance with part-completed non-domestic RHI applications. We are regularly contacted by clients who are stuck with their applications or have been given poor advice and are struggling to get the applications completed.

In July 2017, Infinitas Design was contacted by Mr S of Moat Farm who had two log-burning biomass boilers installed in 2014. Mr S was under the impression that his applications had not been completed and he had yet to receive any RHI payments. He was understandably upset and did not know what to do next. He had been given our contact details by a colleague who we had completed work for previously.

After accessing the RHI application online and setting ourselves up as Additional Users, we were able to review the application contents and establish the current status. It turned out that the RHI applications had been approved late 2016 but the client had not been informed by the applicants and had missed the advisory email from Ofgem.

This was good news but it was also apparent that no heat meter readings had been recorded or submitted to Ofgem. This was the reason for the lack of RHI payments.

Infinitas Design has now forwarded the most recent heat meter readings on to Ofgem who will advise on backdating the meter readings for the missing periods. We will complete this work up to the point that the client receives payment and is satisfied with the outcome.

So, don’t miss out on payments that are rightfully yours. Using years of experience completing RHI applications, Infinitas Design can help with all aspects of the process.

  • Are you just starting out on your RHI application and don’t know where to start?
  • Halfway through an application and need help with certain aspects such as heat loss assessments?
  • Are you yet to receive any payments?
  • Had some queries back from Ofgem on your application that you don’t understand?

Contact us today to get your application back on track and start receiving the payments you deserve.


Call Infinitas-Design on 07813 069940 



Case Study 6 – The Hurst, Craven Arms, Shropshire.

GSHP and Solar Thermal Retrospective RHI Applications

July 2016


The Hurst is a writers’ retreat located in the beautiful Shropshire countryside. As the building is not attached to the gas grid, the team had installed a ground source heat pump in conjunction with a small solar thermal array. Infinitas Design was approached to undertake the RHI application for both systems as neither had been attempted during the original installs. Infinitas Design worked closely with The Hurst team and the original installers to retrospectively gather photographs and documentation enabling successful approval on to the scheme. Gabriella Blandy, Associate Director for Arvon, said: 

“Laura has carried out two RHI applications for a Solar Thermal and Ground Source Heat Pump system for Arvon. Her dedication to the task has been commendable. She is prompt to answer emails, efficient and very positive. Throughout the process I have always felt that the claim was in safe hands. I would certainly recommend Laura to anyone wishing to submit a RHI application.” – Gabriela Blandy – Assistant Centre



Case Study 7

North Warwickshire Borough Council (NWBC)

HNDU Feasibility Study


The heat mapping, energy master planning and feasibility study for the NWBC HNDU project was carried out in Q1 2015. The heat mapping and master planning part of the process identified 16 possible schemes, which were then worked up to different extents in order to assess the best schemes in terms of technical, financial, risk, environmental and economic and social criteria. The work carried out enabled each scheme to be ranked against these criteria resulting in 5 schemes that would enable competitive heat prices to be offered to residents, tenants and businesses.

The NWBC area encompasses a number of towns and villages to the east of Birmingham. Key towns include Atherstone, Coleshill, Shustoke and Arley.

Figure 1 The NWBC area []

Infinitas Design Ltd worked alongside Down to Zero as part of a consortium. Together, we undertook site surveys of the main areas identified in the mapping and planning stage. One of the top projects, for example, was a number of council-owned buildings in Atherstone including the leisure centre, community hall, library and clinic. Each building was visited and assessed for existing heat plant, the proximity to each other and the potential heat network route and energy centre location to link the buildings together. Detailed energy modelling was carried out based on DEC information and fuel bills received from the council. A combined peak load and annual demand profile was derived from the modelling, allowing the energy centre heat plant and heat network to be sized. This process was carried out on each area identified, with the work being divided between the consortium partners.

Another example was a new build 400-house development in Hartshill. A large water-filled quarry was identified close to the site and this was confirmed to have more than sufficient energy to heat the entire development through water source heat pumps and low temperature heat network. Our calculations confirmed the heat source capacity and the development heat demand. The final design comprised 2.6MW of water source heat pump generating 4.45GWh of heat per year and a 50 – 60°C network temperature depending on time of year. The financial modelling carried out by the consortium provided a 20-year IRR of 12% with a 3.5year payback. The customer heat price was set at 4.8p/kWh which included all operation and maintenance of the network and energy centre.

The final report and presentation was reviewed by DECC who stated this was one of the best HNDU studies carried out to date.

We recommend that a feasibility study is undertaken before the decision on any major project is made, call us direct to discuss yours. 

Call Infinitas-Design on 07813 069940 


Case Study 8 – Scottish Borders College, Galashiels

Date – Q3 2014 – Current


Infinitas Design Ltd was engaged by SHARC Energy Systems to design the UK’s first sewage heat recovery heat pump system for Scottish Borders College in Galashiels. The college is a higher education establishment with 5 separate campus buildings of various ages and uses. Each building was equipped with its own boiler plant of various types, ages and conditions and different heat emitters including radiators, air handling units, fan coils and hot water cylinders. The goal of the project was to link the 5 buildings to a new central water source heat pump energy centre via a buried low temperature heat network. Scottish Borders College Galashiels-Infinitas Design Renewable Energy Consultants

Infinitas’s project responsibilities spanned all stages of the project process commencing with initial client discussions, site survey and feasibility study in late 2014. The primary energy source for the heat pump system was the nearby combined sewer; sewers tend to run at temperatures exceeding those found in the ground or natural water sources due to the discharge of showers, washing machines and other domestic and commercial waste. During the feasibility stage, the sewer flow rates were provided by Scottish Water enabling Infinitas Design to calculate the energy capacity and availability for the SHARC system.

A combination of half hourly metered gas data and monthly gas bills were used to establish the annual heat demand profile for the college, taking into account non-heat uses of gas such as cooking. Infinitas Design established the building peak thermal demand and when coupled with the available heat capacity within the sewer, an 800kW heat pump system was found to supply almost 100% of the demand in all but the very coldest of years.

Following contract close, Infinitas was appointed to carry out detailed design on the energy centre, the 1km heat network and the interfaces to each of the 5 gas-fired plant rooms. The gas boilers were initially retained to provide individual back-up to the buildings, enabling each to be isolated from the network under different circumstances. Two Carrier 30XWH water source machines were used rated at 400kW each. Infinitas Design completed the end-to-end system schematic, general arrangement drawings and specifications for the equipment including the heat pumps and supporting equipment as well as the pre insulated buried pipework and direct interface to each plant room. The system was installed during 2015 and has been operating with a seasonal COP of 4.2 in the period since.

Infinitas completed the successful renewable heat incentive application for the system and continues to work with SHARC Energy Systems to improve the system efficiency. The latest developments we are working on (2018) include additional solar PV, battery storage and consolidation of all remote boiler plant for discharge into the common network either as top up for or replacement of heat from the heat pumps.


Scottish Borders College Galashiels-Infinitas Design Renewable Energy Consultants  Scottish Borders College Galashiels network Infinitas-Design Renewable energy Consultant 

Network under construction 2015


Case Study 9 on Nottingham City Council

(NCC) HNDU Feasibility Study


Infinitas Design provided the technical feasibility study for a HNDU project being carried out by CJR Midlands and SHARC Energy Systems in Summer 2014. The key focus of the study was the opportunity to deploy sewage heat recovery as a replacement for part of the NCC-owned heat network serving a local leisure centre, ice arena, student accommodation block and 244 council houses.

Infinitas Design was engaged to carry out technical surveys on the leisure centre, ice arena and student block as well as the energy modelling for the council houses. We used a mixture of half hourly heat consumption data, monthly energy bills and EPCs/DECs to derive the peak heat demand and annual thermal profile for each of the larger buildings as well as the estimated demand from the council houses. The site surveys enabled the age and condition of existing boilers and heat exchangers to be confirmed as well as the potential connection points to a new heat network. 


Figure 1 Student block and leisure centre

Infinitas Design also calculated the potential heat capacity to be found within the local large sewer as well as the capacity to be found in the ground as a hybrid system was found to be needed comprising sewage heat recovery and both open and closed loop ground source.

Once the peak demand was known for the collection of buildings, we were able to size and route the low temperature heat network and site the energy centre. High level general arrangement drawings were created to size the centre and its heat plant. SHARC Energy Systems carried out the financial modelling with inputs from Infinitas.

The final design presented to NCC and DECC was a 2.2km network serving the buildings described with a 1MW heat pump system served by sewage heat recovery and an open ground loop. Annual heat generation was 3.7GWh and payback occurred in 11.5years with a competitive heat price in the region of 5p/kWh. We input to the sensitivity analysis to assess the impact of higher or lower system efficiencies and higher or lower heat demand from the properties.

The results were presented to NCC and we await the outcome of their decision to take this forward