|Birmingham city centre is now served by an extensive CHP-based district heating system
Two main themes emerged from the UK Combined Heat and Power Association (CHPA) Awards this year: the popularity of schemes based on gas engines, and the increasing use of CHP as part of wider energy solution, integrated with other technologies, particularly for homes and buildings.
Thus gas engine-based schemes won the industrial and commercial sector award (an ice cream factory), the public sector award (a major district heating scheme) and the campus and residential award (Liverpool University). The first-ever international award went to an engine-based scheme in Kenya – but fuelled with biogas.
Also new this year was the ‘integrated energy’ award, which was won jointly by two entries: a new district heating scheme in Bath that uses both gas-fuelled CHP and biomass heating technology to serve a mixed development; and another gas engine-based scheme for York Teaching Hospital that integrates demand reduction as well as new energy supplies.
Continuing the theme, the winning entry in the innovation category integrated micro-CHP, ground source heat pumps and heat storage facilities to form an innovative low-carbon energy solution for a Glasgow school.
As last year, CHP schemes working in a district heating (DH) context were plentiful. Commended in the innovation category was a project to make a physical and contractual link between heat available from a Coventry incinerator and a new DH system.
CHPA President Lord Risby presented the awards at a dinner held in London in November. Addressing the industry, Risby made an important point about the strength of UK CHP engineering capabilities, and its export around the world: ‘Behind the scenes, unbeknownst to the general public, your projects are helping to run our cities and our industry, ensuring they provide the energy we need at a lower cost. It is through evenings like this that we are able to demonstrate to the world the energy engineering skills, the sales dynamism, and the back office support that allow your companies to build and grow across the UK and globally.’
CHPA director Dr Tim Rotheray spoke of the ‘feel-good factor’ at work in the UK CHP and DH industries in recent years: ‘These awards are a tangible recognition of your successes at delivering a transformation in the way consumers’ energy needs are met. I was genuinely excited to see what our members are doing to deliver low-carbon, low-cost energy services.
‘I cannot wait to see a few of these sites in person, and I am already looking forward to next year’s awards because I know of so many great projects which are still in the pipeline.’
Yet the undoubted optimism around the award winners should be tempered with some of the hard facts revealed by the UK government’s annual statistics on the industry. The CHP chapter in the latest Digest of UK Energy Statistics (DUKES) gives a more mixed picture of a slightly negative net capacity addition during 2013, and a trend of reducing energy outputs from existing schemes. While innovative CHP schemes are being built to serve buildings and work with DH systems, there is rather less action in the industrial sector, where schemes are much larger. Thus a healthy CHP-for-buildings sector can be hard to discern in overall statistics dominated by larger industrial schemes.
The DUKES snapshot of UK CHP data for 2013 shows that:
• The amount of certified ‘Good Quality’ CHP capacity remained (almost) steady during 2013, but actually reducing from 6175 MWe to 6170 MWe. Electricity generated by CHP in 2013 corresponded to nearly 6% of all electricity produced in the UK;
• The amount of electricity produced from certified schemes fell by almost 9% between 2012 and 2013, to 21 TWh in 2013;
• Carbon dioxide savings delivered by CHP in 2013 were lower than in 2012, due to lower CHP outputs and lower values of the carbon-intensity of electricity displaced by CHP;
• Some 67% of the fuel used in CHP schemes was natural gas, while the use of renewable fuel again increased and now stands at over 10% of total CHP fuel;
• The oil and gas sector has the largest CHP capacity, followed by the chemicals sector.
Clearly, short of an unlikely and major resurgence in industrial activity in the UK (it is ten years since the opening of what is still the largest CHP scheme in the UK, a 730 MW installation at a ConocoPhillips refinery in North Lincolnshire), the overall CHP sector is going to struggle to grow.
However, the CHPA award-winners illustrate very clearly the strength of both the CHP-for-buildings and DH sectors, but also the growing ingenuity which CHP engineers are integrating CHP with wider low carbon energy solutions.
|Aerial view of the Coventry incinerator now connected to a district heating scheme in the city
The Innovation Award was presented to Baxi Commercial for the complementary installation of mini-CHP, underground thermal storage and ground source heat pumps to heat the Victorian Notre Dame Primary School, Glasgow, Scotland. Baxi has suggested an imaginative model, incorporating a range of modern, low-carbon technologies and improvements to an old building that could be used by all schools in Glasgow.
The aim of the installation was two-fold, says Baxi: to get the best out of ground source heat pump (GSHP) technology, and to combine it successfully with CHP. To achieve this, Baxi Commercial, working with Glasgow City Council, supplied and commissioned five SenerTec DACHS mini-CHP units, which were integrated with underground thermal storage and ground source heat pumps to create a system which offers affordable, safe and sustainable heat by playing to the strengths of each technology.
The council has calculated that the school will avoid more than 90 tonnes of carbon dioxide emissions annually, thanks to the combination, and will cut running costs by at least £48,000 ($75,000) a year, including anticipated payments from the UK government’s Renewable Heat Incentive scheme.
David Shaw, business development manager of SenerTec at Baxi Commercial, commented on the replicability of the project elsewhere: ‘One of the key goals of the Notre Dame project was to create a model of small-scale CHP that could be rolled out across other council buildings. Integrating CHP and heat pumps so that they will operate all year round is quite tricky, particularly in a reduced hours building such as a primary school. However, even during the summer months the CHP units at Notre Dame averaged almost 13 running hours per day, so we are very confident that this design approach can be repeated successfully elsewhere.’
Commended in the innovation category was Cofely, for making a connection between an existing energy-from-waste facility in Coventry which had lost its previous heat customer, and a new DH scheme serving buildings in the city centre. Innovation lies mainly in the contractual and commercial arrangements which confer advantages to both parties.
|Part of the 4 MW CHP plant installed at R&R Ice Cream
Credit: Edina UK
Industrial and Commercial Award
The Industrial and Commercial Award was presented to Edina UK for its work in helping R&R Ice Cream to overcome its electricity supply issues so that it could successfully expand its production facility.
R&R Ice Cream decided that the long-term viability of its Northallerton production premises would be best served by investment in a CHP plant. Installation of a ‘power island’ amongst existing buildings was designed and constructed by Edina with two gas engine-based CHP packages from MWM with a combined output of 4 MWe and 4 MWth supplying all the power for the factory. Previously hampered by grid supply limitations, the factory can now expand its operations.
The new CHP scheme at R&R Ice Cream in Northallerton will cut energy costs and thus help sustain the business into the future. Self-financed by R&R Ice cream, the containerised scheme will be maintained for ten years by Edina.
Commended in the industrial and commercial category was Ener-G for its installation of a containerised 500 kWe CHP unit at Elveden Forest Centre Parcs in Suffolk. The holiday village company is now planning to adopt CHP technology at several more of its sites.
Public Sector Award
In one of the strongest categories this year, Cofely was awarded the Public Sector Award for its city-wide DH network in Birmingham. Cofely has worked with Birmingham City Council and others to create a scheme to serve the city’s residents and local businesses.
The overall scheme actually links together several existing DH networks. The Birmingham CHP/district energy scheme is a hugely impressive city-wide project that will deliver considerable benefits to the City Council and major university and hospital sites in the city, among others. It will improve the city’s low-carbon credentials and deliver fuel poverty benefits to residents.
The latest part of the scheme to be completed was the installation of a 1.6 MW gas-fired CHP energy centre – designed, built and operated by Cofely – at the newly rebuilt Birmingham New Street railway station. This will provide an interconnection between the existing Broad Street and Aston University DH schemes while also providing low-carbon energy to local businesses.
The project, the result of a £7 million ($10.8 million) investment by Cofely, will see Network Rail join the Birmingham District Energy scheme, which operates under a partnership between Cofely, Birmingham City Council, Aston University and Birmingham Children’s Hospital. It also fulfils an ambition to unite the existing schemes in Birmingham, while making a significant contribution to the UK government’s desire to see district energy schemes supplying up to 14% of the UK’s heat demand, says Cofely.
The refurbished New Street railway station will need significantly more electricity than its smaller predecessor and CHP was identified as the ‘greenest’ way of generating the required electrical power whilst reducing the station’s carbon footprint. Integration with the city-wide district heating network has enabled a larger CHP engine to be installed than would have been possible in isolation.
The project has required the extension of DH pipework installed across the station and in the city centre to enable excess heat produced by the CHP unit to be exported onto the wider Cofely network. From here it will supply offices and buildings already connected to the scheme, including the National Indoor Arena, as well as the new John Lewis store adjacent to the station.
Commended in the public sector category was Warwick University, which has generated some of its own energy for many years through a CHP-based district energy plant. This has recently been extended with two new gas engine generators. The scheme incorporates several thermal stores for maximum operational efficiency and delivers low carbon electricity, as well as heat, to more than 60% of campus buildings.
|Exterior view of the refurbished mortuary building at Liverpool University, now housing a 4 MWe CHP unit
Credit: Edina UK
Campus, Community and Residential Award
Edina UK was the winner of a second award, the Campus, Community and Residential Award, for its involvement with the new Liverpool University CHP scheme. The University pioneered CHP in the higher education sector 30 years ago and its latest project involved the complex renovation of a derelict listed building to house a new CHP unit to enable the network to grow further.
Delivery of this latest scheme has included a good deal of ingenuity in restoring and adapting the listed mortuary building to host the latest gas engine-based plant.
Two packaged, gas engine-based CHP units from MWM, located in specialised acoustic containers, generate 4 MWe and 4 MWth so that the combined power from the existing Energy Centre and new installation now serves all the University’s buildings, including a leisure centre with swimming pool.
Commended in the campus, community and residential category was Edina UK again, for its CHP installation at Queen’s University, Belfast. One praiseworthy aspect of this 2 MWe scheme is the plan to export some of its products – heat and, possibly, carbon dioxide – to Belfast City Council’s nearby botanic gardens.
The International Award was won by Clarke Energy for its Kenyan Biojoule biogas plant, which uses an anaerobic digestion facility, fed by agricultural and food waste, to produce biogas to fuel a new engine-based CHP scheme – believed to be the first commercial biogas CHP scheme in sub-Saharan Africa.
From its base on Merseyside, Clarke Energy exports CHP units to many countries across this world. This 2.4 MWe engine-based scheme, featuring twin gas engines from Jenbacher specially configured to operate at the high altitude, serves a farm located at 2000 metres in Kenya, burning biogas produced at the farm to both provide power for the farm and to heat its greenhouses.
Reliable power helps to ensure consistent business operations and hence is a driver for economic growth and performance locally, says Clarke Energy. Surplus power is to be supplied to the local electricity grid, helping to stabilise local electricity supplies. The installation will also displace diesel previously used in the heating of greenhouses at the farm.
Commended in the international category was Salford-based Ener-G which, like Clarke Energy, is increasingly looking overseas and has successfully taken its packaged CHP technology to serve buildings on part of the Saint Peter’s University in New Jersey, US. A third CHP unit is now being added to the original two and the whole scheme is being operated in trigeneration mode.
|Closeup of the gas engine at the heart of York Teaching Hospital’s CHP scheme
Credit: Vital Energi
Integrated Energy Award
The Integrated Energy Award was given to two winners which demonstrate different aspects of integrating CHP technology with others. E.ON won for its DH scheme at Bath Western Riverside, and Vital Energi for its work on a new CHP scheme installed at York Teaching Hospital.
E.ON’s Bath Western Riverside project, regeneration of a brownfield industrial site (formerly a gas works) into a mixed development, will eventually connect 2000 homes, shops, schools and other buildings to a new DH network, using different fuel sources and demonstrating integrated energy at a district level. Starting with 800 homes, the scheme includes both a gas-fuelled CHP scheme and a wood pellet boiler, alongside low energy home design and sophisticated control technology for the heating systems to maximize efficiency.
Meanwhile, Vital Energi and its sister company, Vital Efficienci, shared the award for the installation and operation of a 1.2 MWe CHP scheme at York Teaching hospital, which was procured through the Carbon & Energy Fund (CEF) framework. Vital Energi first implemented a range of demand reduction measures, including improvements to lighting and HVAC controls, before installing the unit. The CHP scheme is once again based on a gas engine.
The new CHP engine will provide 100% of the electricity needed overnight and 50% of that needed during the day. The engine will run for the majority of the year and come offline for maintenance during the summer months when heat demand is at its lowest, says Vital.
The CHP engine, along with the hospital’s three 500 kVA standby generators means that York Teaching Hospital is now self-sufficient in electricity in the event of mains power failure. The project will provide guaranteed financial savings of over £12 million, and a carbon reduction of 45,000 tonnes, over its 15-year lifecycle, adds Vital Energi.
Steve Hodgson is a contributing editor on COSPP