Case study

Combined Renewable Heat & Electricity Project

SES HQ in Sunderland SES HQ in Sunderland

As part of the Sunderland Low Carbon Demonstration Project, Decerna have been supporting Sustainable Enterprise Strategies (SES) in Sunderland with low carbon consultancy.

SES are a social enterprise and community interest company based in the Hendon area of Sunderland who focus on supporting the growth of SMEs in the North East. SES’ core activity is managing 30 individual office suites which they rent out to start-up businesses who are looking for low cost, good quality office space. In addition to this, the CIC focus on creating, supporting and expanding local SMEs by way of European & nationally funded business support, specialist training and procurement of low cost finance and business loans.

Following initial discussions with Decerna, SES expressed an interest in looking into solar PV deployed on the roof of the building. After further discussions on site, and a review of existing electrically powered heating, SES also requested that Decerna look into the feasibility of replacing the existing heating system which a renewable heat source.

Outline & objectives

The overall aim of the consultancy support was to help SES investigate the potential for renewable energy on site, namely, solar PV to produce electricity and Biomass to provide renewable heat. The first objective was to review the unique roof structure and provide an outline of how much solar PV could be deployed. The second objective was to carry out an inspection of the building and carry out heat loss calculations based on measurements of walls, windows, doors, floors and ceilings to identify the heat demand of the building. With this information, and taking into account the occupancy and use of the building, annual heat demand could be predicted. The final objective was to use this data to specify a renewable heating system powered by Biomass and provide a full financial model for the system over a 20 year contract. Across both areas of the feasibility, it was important for SES to receive a final report that laid out the findings in lay terms so that all at the company could review and consider the technologies.


The report submitted to the CIC in early August 2015 presented a full feasibility for a solar PV System of 28.75kWp deployed across three individual roof sections on site. As each section of the roof had its own dimensions and shading profile, a generation estimate was constructed for each portion. The financial model took these generation estimates and combined them with the installed cost of the system and the Feed in Tariff payments to provide a 20 year forecast on the Return on Investment of the installation. Existing billing data from the site outlining trends of electricity consumption over the year was also input into this model so future savings on avoidance of grid electricity could be forecast over the contract period.

The second section of the report addressed the existing electrically powered heating and provided a full feasibility for a replacement heating system powered by Biomass on site. Data on the thermal properties of the main walls in the building was unavailable so following a site visit and inspection of the building, a model comprising 2mm thick steel, 50mm thick insulation, a damp proof membrane & 12mm plasterboard was built to accurately generate U Values.

Following detailed heat loss calculations for the building based on the model above and inspections of the other building materials, a 199kW pellet fed Biomass boiler to provide 100% of space heating on site was specified. A financial model was included in the report taking into account the initial outlay for the installation of the system, the Non-Domestic Renewable Heat Incentive payments and the savings of avoiding the extremely expensive electrically powered heating. In addition to this, the model considered the cost of pellet supply over the next 20 years (including annual inflation) and factored in annual maintenance costs for the system.

With a full feasibility for both renewable electricity and renewable heat generation on site, SES are now better informed as to how they could improve their environmental performance whilst cutting buildings costs and generating a regular, fixed income to benefit the company.

Client testimonial

Kevin Marquis, Director, The Co-op Centre:

"Narec Distributed Energy made what can be very complicated and confusing information accessible to laymen like us.  In so doing, they have enabled us to make an informed decision on what is the best renewable energy source – solar - for SES, both commercially and what is in keeping with the nature and design of our building"

Further information

Narec Distributed Energy provide various services for community, commercial and industrial buildings, in order to reduce their carbon footprint and operational costs.  We work on various community energy projects, specifically currently supporting community groups through our ERDF project BEST, and also working on various Rural Commmunity Energy Fund (RCEF) projects.