Bunhill Heat and Power Network (BHPN)Bunhill

Islington Council Energy Services won the Homes & Communities Project of the Decade Award at the Association for Decentralised Energy's Awards Dinner on the 19th October 2017 for Bunhill Heat & Power.

Islington developed Bunhill Heat and Power Network to provide cheaper, 'greener' heat to the local community, reduce fuel poverty and improve energy efficiency. It is the Council’s ground-breaking, innovative scheme involving retrofitting two kilometres of combined heat and power supplied district heating in an inner-city environment. The scheme began supplying heat and hot water in 2012 and it now serves over 860 dwellings, two leisure centres and four office blocks. Bunhill is a catalyst for driving regeneration in the area through investing in infrastructure and keeping energy bills low.

Islington Council has been working on developing heat networks since the mid-2000’s; this has been driven by many factors, including increasing energy efficiency, reducing carbon emissions and reducing fuel poverty. In 2003 a borough-wide heat map was commissioned, which served as the foundation of our 2010 Decentralised Energy Strategy. Bunhill was identified as the ideal location for the project because of the area’s high heat density and levels of fuel poverty (13%) and below-average life expectancy.

Developing the scheme

Developing the network in one of the most concentrated cities in the world brought its own unique challenges. London contains some of the most congested utility routes in Europe. To ensure minimal inconvenience, it took cautious planning and analysis to identify the best route for the network to follow.

For the wider development of the programme, funding was one of the major challenges. During a time of unprecedented budget constraints, particularly in local government, Islington Council sought funding from a range of different sources; the first network was funded by grants from the Homes and Community Agency, and the Greater London Authority.

Islington Council sought to connect to private developments. To achieve this, the council rewrote its planning policies to encourage connection to DE networks by requiring a higher level of carbon savings for developments in areas where a network exists.engine 

In order to assist developers, building owners and building services designers, Islington Council created and published detailed guidance for how systems should be designed in order to get the best out of connecting to their networks. Through this endeavour, they have connected over 220 private dwellings to the network; a number which will continue to grow alongside the network.

Bunhill Energy Centre houses a 1.95MWe gas CHP engine and 115m3 thermal store. The network comprises one kilometre of trenching which holds two kilometres of insulated district heating pipework. The network has been future-proofed, allowing it to connect to new developments as they emerge. The Energy Centre includes improvements to the public realm, increasing public open space, retention of trees, large areas of new planting, sustainable materials and urban drainage. It was designed to be visually appealing and in keeping with the local area. A local architect’s firm developed the final design which comprises an FSC green oak timber enclosure and clad thermal-store with low-level soft landscaping.

Benefitting residents

At the heart of Bunhill Heat and Power is local generation for the benefit of local people; the council were keen to engage with residents throughout its development. The project educated residents on energy security issues and how they can work together to reduce energy use. Islington Council open the doors to the Energy Centre every year as part of Open House London and were ranked as the fourth-best attraction by Time Out in 2013.

Islington Council also engaged with their residents through:

  • Interactive information sessions
  • Consultation on design
  • Regular correspondence during construction
  • Holding a launch event
  • Information boards at the Energy Centre, including a history of power generation in the borough, a map of the network and an explanation of decentralised energy

A film was produced by Moreland Primary School, providing a simple explanation of the system to residents: 

Islington Council are committed to tackling fuel poverty, which is why they have delivered a 10% saving on energy bills for our tenants. Their fixed heating bills are set at least 33% lower than the government threshold for fuel poverty.

The network provides a customer-focused approach; it is integrated into the core functions of the council and we provide a high level of customer service. This includes unrestricted contact hours, a four-hour response time for vulnerable customers (66% quicker than Heat Trust regulations) and an annual flat rate price to protect residents from volatility in global energy markets.


Phase 2  Waste Heat Utilised from London Underground

Energy Centre 2Islington Council’s Bunhill Heat and Power Network (BHPN) is the first scheme in the world to take waste heat from an underground train network and use it to provide lower  cost, greener heat to local homes, schools  and leisure centres.  This scheme has the  potential to be replicated not only across Islington and London but in any major city with an underground network. That’s because heat networks, such as BHPN, are able to harness a wide range of renewable and waste heat sources that are already available within a city. This project is playing an important role in Islington’s commitment to reducing carbon emissions, helping lower heating bills,  improving air quality and making the capital more self-sufficient in energy. This innovative project of recycling waste heat from the London Underground to heat local homes will make a significant contribution towards making Islington a more energy efficient Borough.

Islington and TfL have worked closely on this project to make sure waste heat from the Tube network can be used to heat and provide hot water to local buildings and homes. The extension of BHPN was coordinated with TfL’s upgrade of their existing ventilation shaft and careful joint working was required to ensure that all elements of the construction were fully integrated and coordinated on the small site. Why are we doing this?The project brings a number of key benefits for local residents and the wider community:   

The Bunhill phase 2 extension to the Bunhill Network will bring cheaper, greener heat to another 550 homes and Moreland School.

  • This is on top of the 800 homes that were already receiving heat from the network   All Islington Council tenants connected to the network receive a 10% discount on their heating charges.
  • The Bunhill phase 2 extension to the Bunhill network will result in approximately a 500 tonne reduction in carbon emissions per year.
  • Adding a new Energy Centre to the Bunhill network increases the resilience of the network as one Energy Centre can take over if the other one develops a fault or requires maintenance.
  • The new Energy Centre and extension to the BHPN helps the capital become more self-sufficient in energy.
  • The project has increased understanding of the opportunity that waste heat can play in decarbonising heat networks, how waste heat can be integrated into heat networks and the role that heat networks can play in decarbonising a city’s heat supply and supporting its wider energy system.

A template for the future? Heat networks work best in densely built, urban areas as heat has to travel shorter distances to the buildings connected and so there is less heat loss in the pipework. The Bunhill 2 project is a world-first in taking waste heat from a Tube network ventilation shaft and the partnership with TfL provides a template that has the potential to be replicated across London using the many ventilation shafts on the Tube network. Many major cities across the UK and around the world have underground railway systems, all of which need to vent heat to ground level, so there is a huge amount of potential for this project to be replicated across the globe.map

In addition, urban areas have a large variety of waste heat sources, such as data centres, that could be harnessed in a similar way to provide heating and hot water to local homes and businesses. 

Opportunities for more local energy networks in Islington 

Given their potential to provide lower cost, greener heat, Islington is exploring opportunities to connect more homes and businesses to heat networks, using waste heat sources, both through further connections to the Bunhill network and by building new energy centres and networks. Learning from the Bunhill 2 project will be invaluable to this process as well as the partnerships that have been estab-lished during the construction of Bunhill 2.