Project Focus: Wessex Water ops centre gets sustainability upgrade
Wessex Water's award-winning HQ in Bath has recently been fitted with 961 solar panels installed to generate 230,000 kWh per year
Mike Caple, Head of Facilities Management, Wessex Water: “The Operations Centre has remained at the leading edge in sustainable construction and operation in the UK since its completion in 2000. Throughout a challenging but enjoyable team project, the introduction of Photovoltaic renewable energy represents a new chapter in the building’s evolution and combined with a new Building Management System underlines our on-going commitment to drive down energy consumption, carbon emissions and running costs. ”
Julia Carling, Project Manager, Wessex Water: “This solar PV project was a great opportunity to increase our renewable energy self-generation portfolio whilst reducing our carbon emissions and energy bill. There were many challenges that had to be overcome but with our in-house skills and those of the contractors we were able to find solutions and learn from the project. ”
Nick Spicer, Operations Director, Your Power UK: “As an already award winning sustainable building it was important we got the design right for this project, not just technically but also aesthetically. We worked with our mounting systems partner, Sunfixings from inception to ensure the design was technically proficient. Working with Wessex Water has once again been a pleasure.”
John Leonard, Energy Manager, Wessex Water: "The Operations Centre is our headquarters and therefore should represent the business's attitude towards energy both to the staff and the wider community. With this project we have managed to reduce our grid power demand, and our annual carbon emissions as well as raising staff awareness of energy and carbon.
by Julia Carling, Energy Generation Analyst, Wessex Water
The installation of a solar photovoltaic (PV) system on the roof of Wessex Water’s Operations Centre in Bath has underlined the utility’s commitment to sustainability.
Wessex Water’s Operations Centre was designed with sustainability in mind; the natural ventilation, motion and light level sensitive lighting, solar thermal water heating and rain water harvesting have all helped the building to outperform similar sized buildings for the past 15 years.
As part of the company’s ongoing commitment to sustainability there have been various improvements to the site over the past few years and these will be continuing for the foreseeable future.
In 2013, 35 AMR sub meters were installed to enable the identification of opportunities for energy improvements. These meters not only provided greater visibility of building and staff requirements but were also a key tool for staff engagement.
In 2015, various teams across the business worked with contractors to design and install a solar PV system that would provide the most cost effective renewable generation system on the available space whilst being sensitive to the rural setting.
During 2015 the facilities management team started the process of replacing the existing Building Management System with a new and improved system. This is a phased project, with plans to integrate the previously installed sub meters and newly installed solar PV system.
Site improvements are always on-going, such as the replacement of old inefficient light bulbs with more efficient LEDs as they come to their end of life.
Solar PV Installation
By far the most significant impact to the building sustainability rating has been the implementation of the 250kW rooftop solar PV system.
This system was installed by Your Power Ltd in November and December 2015 and was commissioned in time for the Feed in Tariff (FIT) deadline on 31st December 2015.
The designed was tailored for the building to work with the existing folded aluminium seam roof, electrical setup and staff requirements.
As the Operations Centre is the head office for Wessex Water it holds over 500 staff including construction, legal, PR, HR, IT, customer services, operations and most importantly the control room staff. The control room provides support 24 hours a day and relies on critical essential services.
There were many challenges as part of the project. The main three were:
• Working around staff requirements and planning the works in line with existing maintenance shut downs.
• The structural condition of the roof after 15 years and with limited installation details available.
• Managing construction work and deliveries as well as normal deliveries for a functioning office.
Of these challenges the roof proved to be the most problematic. Fortunately, the roof was in good condition and had weathered well. A thorough structural survey by our in-house structural surveyor was required, along with multiple pull tests with the help of sub-contractor SunFixings. With the unique design of the roof there was always going to be an element of risk in regards to the weight loads and penetration fixings. To manage this risk the panel mounting was carefully designed and included additional temperature expansion gaps and supports.
Why Solar PV?
The project requirement was to provide building and location-appropriate renewable energy that could reduce the dependence on the national grid and reduce the carbon footprint of the building whilst also contributing towards the company’s renewable energy target. Solar panels met all of these requirements.
The Operations Centre already had solar thermal panels on the roof and based on the limited ground space and sensitive location of the building other renewable options such as wind turbines, hydro turbines, geothermal were not viable.
The original roof had been designed to enable easy access for maintenance which helped with surveys. During the surveys it became evident that it would be possible to mount solar panels flush to prevent visibility from the ground.
The 961 panels total 250kW and through the 10 inverters are capable of generating over 230,000 kWh per year. Of this, over 97% will be displaced on site. The only export will occur during the summer weekends when the generation exceeds the office’s energy demands.
The energy generated will prevent the release of 113 tonnes of carbon dioxide emission per year and contribute towards the company’s renewable self-generation target which is 24% by 2020.
The project is expected to recover its costs in less than six years and will save on energy bills and carbon taxes. The project was commissioned and FIT application submitted prior to the FIT rate digression and scheme rules change which helped to make the project feasible.
- You can hear more on the role of renewables in the water sector at WWT's Water Industry Energy conference in Birmingham, 22nd June 2016. Details: wwt-energy.net
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