Latest post: What lies beneath: the hidden heat network at the heart of the City

citigen (1 of 1)-5 small

District heating networks are largely an unknown quantity in the UK, where the gas boiler is both ubiquitous and cheap. Contrast this with Denmark, where two thirds of space and water heating is delivered through pipes to buildings in the form of hot water or steam.

Producing heat in this way has a number of advantages – it provides a market for the heat from Combined Heat and Power (CHP) plants, which means you can boost the efficiency of electricity production by around 30-50% compared to conventional power plant. Networks are highly flexible, meaning you can integrate new heat loads and, over time, switch over to low-carbon energy such as electric heat pumps or biomass. They can also provide a valuable means of balancing the growing share of renewables on the electricity grid, particularly when combining large hot water storage with CHP and heat pumps. Finally, heat networks can connect buildings in high density urban areas where individual heat pumps or biomass boilers are unfeasible due to space requirements.

This is why our decarbonisation pathways feature a key role for heat networks in meeting the 2050 target, which will most likely require a near total decarbonisation of the building stock.

It’s worth noting that in the past, poor scheme design, inefficient systems and poor user functionality mean that district heat suffers from an image problem, although recent high efficiency systems going into new homes are going some way to address this issue. However, the main reason behind the contrasting positions in the UK and Denmark is down to the ready supplies of cheap gas from the North Sea. In Denmark, the 1970s oil crisis sparked a drive for efficiency which saw the expansion of local authority-led CHP schemes. It therefore provides a useful example for thinking about how the UK can in time move away from gas.

With this in mind, a few of us headed over last week to the Citigen district heating and cooling scheme which occupies a grand old building in the heart of Smithfields market, emblazoned with the building’s old function – ‘Port of London Authority’.

Over two miles of pipe crisscross the city in a half loop running east across to the Barbican Centre and Guildhall, linking in Smithfields market, a police station and the City of London Corporation offices along with a mix of private sector customers.

citigen (1 of 1)-3

There is something quite impressive about the dense network of pipes and machinery set against a backdrop of the aging exposed brickwork. The building itself originally housed a coal-fired power station built at the end of the 19th Century with iron shipped down from the Peak District.

The Citigen system was built a hundred years later, initially with two modified ships’ engines running on diesel and gas. These have recently been stripped out, soon to be replaced with two new gas CHP engines. Other changes are afoot. The diesel for the old CHP engines was stored in a colossal tank about 30 metres high. Removing this has created space for a large hot water thermal storage tank, allowing the plant more flexibility in choosing when to operate and responding to changing prices. What I hadn’t anticipated was the sheer height of it, as we peered down through the gangplanks to the floor below and then back up to the high ceiling above.

As well as producing heat and electricity, chilled water is piped through a separate set of pipes to the office blocks on the network, produced by four large chillers which hummed gently as we walked by.

After the tour, we sat in the Citigen offices and talked about the scheme expansion plans over a cup of tea. London is currently straining to meet a targeted 25% of its energy needs from local/decentralised energy plants by 2025. This is helped by a requirement for developers of new buildings to first look at connecting to a local heat network before designing individual heating systems. Whilst this provides a ready market for network developers, expanding into existing buildings through retrofit is typically much trickier. This suggests that under current policies, it will be a struggle to meet the target without strong growth in new build or additional policies targeted at existing buildings.

There are also big questions around who will own and operate the schemes. Unlike electricity and gas, heat is currently unregulated. Whilst heat networks need to compete on price with other forms of heat, surveys highlight consumer concerns at being ‘locked-in’ to contracts. Consumer groups like Which? also point to the lack of transparency in the varying approaches to pricing. This contrasts with the Danish public ownership model, where all prices are published online.

Here at the CCC, we’ve just kicked off a research project which is looking at the role heat and cooling networks can play to 2050, feeding in to our Fifth Carbon budget advice to Government later this year. The work is going to focus on transitions – both from high to low-carbon but also from high to low temperature networks (these are generally better suited to heat pumps). It’s also a chance to consider questions around different owner and operator models and assess the policies required to achieve different levels of heat network uptake over the next 20 years. If you’re interested in feeding in to our thinking, please email jenny.hill@theccc.gsi.gov.uk.

This blog was written by Jenny Hill who heads up the work on heat in the CCC secretariat.

Respond on Twitter: tweet us at @theCCCuk

Previous blog posts

CCC visits Northern Ireland

IMAG1085 1

Our Chairman Lord Deben, Chief Executive Matthew Bell and I spent 2 days in Northern Ireland in March 2015 on invitation of the Environment Minister, Mark H. Durkan. In emission terms, Northern Ireland (NI) is the smallest of the devolved …

CCC visits Northern Ireland

The challenge: keeping the taps running and water bills affordable

droplet_4

Managing water demand, and adopting more flexible approaches to improving resilience, will help maintain affordable bills and secure water supplies over a longer period.

The challenge: keeping the taps running and water bills affordable

First CCC meeting north of the border

IMG_3470

On a cold January day, I joined our Chairman Lord Deben, other members of the Committee on Climate Change and colleagues from the CCC secretariat on the train at Kings Cross to head to Edinburgh for our January Committee meeting. …

First CCC meeting north of the border

Climate Change in 2015

SMALLWeb ASC tap Large (2)

Climate Change in 2015: A new blog post by Matthew Bell, Chief Executive of the Committee on Climate Change.

Climate Change in 2015

Community ownership in action

20140506_145251

Meeting the UK’s climate targets will require a steady expansion in the supply of low-carbon electricity, for example from renewables. Most renewable energy projects in the UK are owned by private firms. This contrasts with experience in some European countries …

Community ownership in action

New long-term investment scenarios point to the need for much greater flood resilience

Thames Barrier closing

On Tuesday, two much-awaited flood investment documents were published (see previous blog). Both Defra’s six-year Investment Plan and the Environment Agency’s Long-Term Investment Scenarios (LTIS) paint a positive picture of how much can be achieved in managing flood risk in …

New long-term investment scenarios point to the need for much greater flood resilience

Six flood defence questions the Autumn Statement should answer

Money

On Wednesday, the Autumn Statement is expected to make significant announcements about future investment in flood and coastal defence. No new money is expected.  Instead, two major publications have been promised: A six-year capital investment plan: a list of individual …

Six flood defence questions the Autumn Statement should answer

Adapting to flood risk in a changing climate

LEEA37_20140212_1200_Local_NPP_retouch

our latest blog post asks: is current policy helping to address the expected increase in future flood risk? 

Adapting to flood risk in a changing climate

The IPCC Report and the UK 2050 target

temperature photo

This month saw the release of the new Synthesis Report by the Intergovernmental Panel on Climate Change (IPCC). The previous IPCC assessment, back in 2007, was a key piece of evidence in setting the UK’s 2050 target to cut national …

The IPCC Report and the UK 2050 target

View older blog posts