About the Building

NHS Grampian’s new Energy Centre was commissioned to serve the current and future energy requirements of the Foresterhill Health Campus, and in response to:

• failing and insecure current energy production facilities, with boiler plant nearing the end of its economic life and high associated labour costs
• increased energy requirements associated with recent and future developments at the Foresterhill Health Campus
• steep increases in energy costs, driven by volatility in the world energy market
• NHS Grampian, NHS, Scottish Government and Central Government initiatives to implement more sustainable energy production methods to reduce carbon emissions.

Project Drivers

Following detailed assessment of potential options using criteria including lifecycle costs and value for money, it was decided to replace the existing boiler house with a new energy centre comprising more efficient plant on a brownfield site. The new plant includes a gas turbine combined heat and power plant, a biomass boiler and three dual fuel boilers.

These will provide heat, and around 90% at peak loads of the electricity requirement of the Foresterhill Health Campus. The key drivers were to:

• replace the current plant that was no longer capable of delivering against target cost, sustainability and reliability KPIs
• meet increasing site energy demands from new and redeveloped facilities supporting new clinical services designed to improve patient treatment and care, together with additional medical teaching and research facilities for the University of Aberdeen
• respond to NHS and government initiatives to implement more sustainable energy production methods to reduce CO₂ emissions by 15%
• reduce site energy costs of £6.2m per annum by 15%.

‘The BREEAM Excellent rating secured by the new Foresterhill Health Campus Energy Centre reflects the overall project team commitment made to sustainability. The centre will provide reliable and efficient energy supplies capable of meeting patient care, staff and visitor requirements for years to come. It will reduce energy costs and carbon emissions through improved generation efficiency, and incorporates flexibility to meet future expansion requirements.’ NHS Grampian

Green Strategy

Project success came from a whole-team effort, right from the start:

The client was educated in BREEAM from previous projects, and committed to getting the most out of this project and the team.

An experienced AP Assessor was appointed at an early stage to carry out a pre-assessment, identify strengths and weaknesses, and assist the team in reviewing and achieving all potential credits throughout the design process.

The design team, including building services, civil and structural engineers, architect and ecologist, took the assessment very seriously and worked with the assessor to review and achieve all credits where possible.

The contractor was equally driven to help achieve as high a score as possible through excellent site and waste management and achieving an exemplary Considerate Constructor Scheme score.

Environmental Features

• Management (90%) – missing just one credit for a full score.
• Energy (85.71%) – use of biomass and CHP plant helps to substantially reduce carbon emissions
• Water (83.33%) – all practicable efforts taken to reduce water waste
• Waste (83.33%) – the building design lends itself to being low waste, further enhanced by contractor commitment
• Transport (81.82%) – the Campus already has good public transport links and amenities on site, plus the site layout was well designed
• Land use and Ecology (80%) – brownfield site with little value, and careful co-ordination to avoid impacting adjacent trees.

‘The BREEAM assessment framework enables values to be placed on a variety of sustainability issues, facilitates benchmarking between projects and allows measurable improvements to be made from project to project. This makes it easier for design and construction teams to adopt a holistic approach to sustainability.’ Mott Macdonald

Technologies Used

• one gas turbine CHP unit providing base load steam demand and 5.3MW of on-site power generation
• one 1.5MW biomass steam boiler fuelled on locally sourced wood chip to meet the higher winter steam demand
• two 8.5MW and 1 x 6.5MW dual fuel (gas/oil) steam boilers to meet peak demand.

The steam plant configuration was designed with N+1 redundancy to provide security of supply with a 1MVA standby generator providing ‘black start’ capability and a gas booster set providing 2000m³/hr at 18 bar pressure.

The entire plant is housed in a single building with integral woodchip delivery and storage using fully automated flatbed ‘walking-floor’ trailers. The plant is designed to provide a 16% reduction in CO₂ emissions (9830 tonnes/annum) and a 39% reduction in energy costs (£2.95m at 2010 prices).

Air dispersion modelling using ADMS was undertaken to determine the minimum height of flue stack required to ensure there was no increase in levels of air pollutant concentrations (NO_x, CO, PM₁₀ and PM_2.5 particulates) at local sensitive receptors.