Sweden’s Arlanda airport is to use two cogeneration plants fuelled with biomass and innovative technology to recover heat from an underground aquifer to supply further thermal energy. Other European airports use gas-fired cogeneration, solar PV, biomass boilers, wind and geothermal energy on-site, as Mark Rowe and M J Deschamps report.
|Berlin BER Airport trigeneration power stations such as this one,will be operated 24 hours a day by E.ON Edis to provide heat, cooling and power to the Berlin-Brandenburg International Airport, Germany|
|Source: Berlin Airports|
For environmentalists – and, indeed, many others who wonder where our energy will come from in the future – the aviation industry could seem to embody everything that is wasteful about the world’s current dependence on fossil fuels. Aircraft guzzle kerosene in a way that suggests aviation is prepared to be the industry that swallows the last drop of oil. Airports often seem inefficient and more interested in promoting consumption than in using resources sparingly or turning to novel ways of maintaining on-site power.
On closer inspection, though, the picture is less categorical. In Sweden, Stockholm’s Arlanda Airport is a pioneer in cogeneration and on-site power production, aiming to cut kerosene use and to address its whole carbon life cycle.
Most recently, Swedavia, the airport’s state-owned operator, has been developing a project with partners including Scandinavian Airlines (SAS) to establish a new cogeneration fuel resource.
Plans to develop a biorefinery plant close to Arlanda were first announced last year. The intention is to build power plants fuelled by waste and agricultural products that can both power on-site operations and contribute fuel for a biomass blend of kerosene used by aircrafts. The goal would be to produce 50,000 tonnes of fuel per year, which would enable Arlanda to become a carbon neutral airport.
More detailed plans were announced late in the summer. Several locations were identified as potential sites for the plants of two alternative configurations. The two plant set-up options were to produce bio-jet fuel on site, or to produce an intermediate product – a synthetic crude oil known as a Fischer-Tropsch (FT) product. The FT synthetic oil would then be further refined and upgraded at a refinery.
A site at Brista was chosen for a CHP plant with a full production of bio-jet fuel and Igelsta was picked to host a site for producing the intermediate FT product. Both sites are served by good road and train connections for supplying biomass.
The Brista plant will have a generating capacity of 230 MW, and Igelsta 460 MW. They would be expected to operate for 8000 hours per year, with 5000 hours of heat production. Their energy efficiency from biomass to fuels is projected at 46% for Brista and 44% for Igelsta. The total energy efficiency with heat included is forecast at 79% for Brista and 73% for Igelsta. District heat production from the two plants is likely to be 279 MWth.
The plant at Brista is connected to the north-western district heating network of Stockholm. The Igelsta plant will recover low-grade heat for industrial and district heat use. There will also be an air separation plant (involving oxygen and nitrogen production with a supply and storage system); and a biomass gasification plant (with feedstock handling, preparation, storage, drying, feed mechanism, gasification, reforming, gas cooling, and gas clean-up).
In addition, the project involves a gas cleaning and conditioning plant (this involves gas clean-up and sulphur and carbon dioxide separation); and a power and steam system plant, with a steam turbine and gas/biomass boiler combined, for heat and power production, boiler feedwater, process steam and cooling water.
The total combined cost of the Brista and Igelsta plants is put at €1.2 billion. The complex is expected to open in 2012, working up to full-scale production within three years.
The project also involves LFV, which operates Sweden’s airports and its air navigation service, with the reasoning that this will encourage a joined-up and highly efficient power production system. The main technical objectives of the plant are to be biomass-based with fluidized bed gasification technology integrated with a physical gas cleaning and conditioning process, and a slurry-based synthesis plant, where the steam and power needs have been balanced with a biomass boiler plant. Nykomb Synergetics, which is leading the project, reckons that if you add in production of other hydrocarbons and district heating, carbon dioxide emissions at the airport could be cut by 150,000 tonnes per year.
CARBON FOOTPRINT OF A SMALL CITY
This project is far from being the entire picture when it comes to on-site energy initiatives at Arlanda. Swedavia argues that it had to address energy consumption as the power demands of 15,000 employees at companies and organizations at Arlanda give it the carbon footprint of a small city.
Energy consumption includes space heating, electricity and cooling. Energy efficiency initiatives have targeted: heat recycling in the terminals; more efficient ventilation; variable speed electric motors; and more efficient, better controlled lighting indoors and outdoors. In terms of technical operations, on-site power – to be boosted by the Brista-Igelsta project – is to assist with vital functions by powering runway de-icing vehicles, wheeled shovel-loaders and the trucks, ploughs and blowsweepers that keep snow off runways.
Good recent eco-design work at the airport has already helped to achieve low net carbon dioxide emissions from space heating in other buildings at the airport. Across the entire airport, carbon dioxide emissions from space heating are 95% lower today than in 1990.
The airport aims for space heating of all its buildings to be based on biofuels. Swedavia says it is now accelerating the final processes of removing the last oil-burning energy systems at the airport. Most buildings at the airport are already warmed with district heating based on biofuels.
An aquifer that the airport authorities opened up two years ago in the nearby boulder ridge of Brunkebergsåsen has accelerated Arlanda’s switch from fossil fuels to on-site power. The underground water reserve – almost 2 km long – cools and heats 500,000 m2 of terminal space. Water from the aquifer delivers cooling in the summer and heating in the winter. Cold water is pumped out of the aquifer in the summer months for the airport’s district cooling network. Warmed-up water then flows back and is pumped underground and stored until winter, when it is used to melt the snow in aircraft parking stands and pre-warm the ventilation air in buildings.
In the long term, the aquifer will reduce the airport’s annual electricity consumption by 4 GWh and its district heating consumption by about 15 GWh.
COGENERATION A GOOD FIT FOR AIRPORTS
Arlanda is far from being alone in its work in on-site power. COGEN Europe sees several airports as good examples of the application of cogeneration. Madrid airport now draws power from a 33 MW power plant operated by the Wärtsilä Corporation, an example already examined in depth by COSPP.
|This terminal under construction at Berlin’s BER Airport will eventually have its electricity, heating and cooling needs met by gas-powered CHP Source: Berlin Airports|
In Canada, Toronto Pearson International Airport has constructed a three-turbine heat and power cogeneration plant fuelled by natural gas. The plant is the first in a series of natural gas turbine facilities built to meet the province of Ontario’s alternative clean electrical generation goals. Pearson’s airport authority worked with the federal and provincial governments on the environmental assessment underpinning the project.
But Europe probably hosts the greatest concentration of airport on-site power projects. European airports are increasingly looking to on-site power production and cogeneration to become more sustainable and environmentally responsible – not just through reducing energy consumption, but also by becoming independent from the energy grid.
In Germany, a new international airport is being constructed with on-site power production as an important part of its business plan. When the Berlin-Brandenburg International Airport (BER) opens in June 2012, all air traffic in Germany’s capital region will be concentrated south of central Berlin, with BER securing the air traffic infrastructure for the region and placing high importance on the use of renewable energies.
About half of BER’s energy supply is slated to be provided through highly efficient trigeneration. Gas-powered plants at the airport will simultaneous provide electricity, heating and cooling.
On-site power stations run by German utility E.ON Edis (a subsidiary of energy giant E.ON) became fully operational in June 2011 to complete a €40 million investment project. The plants, which have four gas-powered CHP modules, provide cooling services for the airport and will meet BER’s eventual basic power demand of about 8 MW.
The efficient combined power-heat-cooling energy process will supply the airport’s basic heating and cooling power needs. If necessary, it will also power an emergency diesel generator with an output of more than 10 MW, which will be able to continue to supply electricity to all BER’s essential operational and security systems. The power station complex includes three modern utility buildings and features Germany’s third-largest cold water storage tank, with a capacity of 3500 m3.
Cogeneration is also a central element of the airport’s infrastructure, said Manfred Körtgen, managing director of operations for BER at Berlin Airports, which runs civil aviation infrastructure for the Berlin and Brandenburg region. ‘For an airport the size of Berlin-Brandenburg International, having access to a dependable, environmentally friendly and cost-effective supply of combined power, heat and cooling energy, as well as the secure provision of emergency power, is a decisive factor,’ he said.
Elsewhere in Germany, Leipzig/Halle Airport, at Schkeuditz, has already largely achieved self-sufficiency in heating, cooling and electricity. An on-site cogeneration unit, paired with 1000 m2 of solar cells meets the majority of the site’s energy needs. The airport’s environmental credentials are also boosted by two underground cisterns that collect about 3000 m3 of rainwater each year for use in washing aircraft.
UK AIRPORTS TURN TO ON-SITE POWER
UK airports have also been pushing ahead with on-site power. Manchester Airports Group (MAG) – which operates Manchester, East Midlands, Humberside and Bournemouth airports – is incorporating on-site power utilities into their operations as part of its sustainable future goal to make its airports carbon neutral by 2012.
East Midlands Airport (EMA), for example, recently finished installing two on-site 45 metre wind turbines, making it the first UK airport to install turbines of that magnitude. EMA worked with companies across Europe to deliver the turbines, which will meet 5% of the airport’s energy requirements, saving about 300 tonnes of carbon dioxide emissions each year, and generating electricity from winds as low as 5 metres per second. Two more turbines are expected to be erected in the next few years, to bring wind energy’s total contribution to the airport’s electricity consumption up to 10%.
Another initiative at East Midlands Airport began in March 2010, when the first cuttings for a 26 hectare willow farm were planted at the airport, kick-starting a £4 million project that will provide fuel for a biomass boiler that will heat and power terminal buildings. The first harvest is expected in 2013. The production goal for the farm is to harvest 280 tonnes of wood fuel annually, and in turn, to deliver a saving of 350 tonnes of carbon dioxide emissions.
Meanwhile, also in the UK, Bournemouth Airport’s new arrivals hall, which has been designed to be carbon neutral, has achieved its energy efficiency goals partly through the installation of 323 photovoltaic (PV) panels on the building’s roof. The 75 kWp solar PV array includes more than 325 Moser Baer 230 W PV modules by UK PV roofing specialists, South Facing. Through these installations, the building will secure annual carbon dioxide emissions reductions exceeding 50 tonnes.
Earlier this year, Bristol Airport, in South West England, also installed a small, vertical-axis wind turbine – the ‘quietrevolution qr5’ from the UK’s Aeolus Power – on the approach road to its terminal building. The turbine was installed as part of a pilot project. At just 20 metres in height, the turbine was selected for its low noise and vibration levels.
FRANCE, ITALY FOLLOW SUIT
Over in France, several airports are already employing on-site power. Paris-Orly Airport, for example, this year opened an on-site geothermal energy plant, providing heating for its terminals, and reducing annual carbon dioxide emissions by 9000 tonnes. The site is above a 15,000 km² natural hot water reservoir, called Le Dogger, which supplies water at 74°C from two 1750 metre deep wells.
Water extracted from Le Dogger is transported to a titanium heat exchanger at the surface, which transfers the heat to the airport’s hot water circuit, where the heated water is distributed throughout the terminals via a 35 km network.
The residual hot water is then returned at a lower temperature (40°C) to Le Dogger, at a location far from its point of extraction so that it does not cool the reserve itself. The heat exchange system allows the preservation of natural resources while reducing carbon dioxide emissions – compared with ‘all-gas’ heating, in fact, the 10 MW geothermal system will reduce Orly’s gas consumption by 4000 tonnes of oil equivalent. ‘Geothermal energy is a renewable and clean energy source and will complement the existing sources of energy. The plant… should later cover 30% of the total energy consumption at Paris-Orly Airport,’ said Franck Goldnadel, the airport’s managing director.
|In a UK first, East Midlands Airport is planting its own 26-hectare willow farm that will produce fuel for a biomass boiler situated in the terminal building|
France’s largest airport, the Paris Charles de Gaulle (CDG), also has an on-site energy plan, which is based on energy derived from biomass. The project envisages that a biomass boiler with a capacity of 14 MW will generate one quarter of the airport’s heating requirements. Located on the airport’s grounds, the biomass plant will allow the international hub to produce heat through the combustion of ‘green’ wood waste from tree pruning, supplied in the form of wood chips. The biomass boiler is slated to be commissioned by the end of 2012, and is expected to save about 18,000 tonnes of carbon dioxide emissions every year at CDG.
Finally, Italy’s largest airport, the Leonardo da Vinci-Fiumicino Airport in Rome, boasts major on-site cogeneration. In fact, the airport’s cogeneration plant produces enough electricity and heat to meet 90% of the its energy needs.
This figure is especially impressive considering that the airport’s surface area totals 1600 hectares, including 250,000 m2 of terminal floor space. Every day, the airport’s combined operations require an energy supply of between 21 MW and 26 MW.
The cogeneration plant at Leonardo da Vinci-Fiumicino occupies more than 2000 m2 of the airport grounds and contains three modular cogeneration groups – each using a Rolls-Royce engine with 20 cylinders, fuelled by natural gas and delivering 8.5 MW of power. Heat energy from the plant is recovered in three auxiliary-boilers – one for each motor – which use the heat of discharged gas that would otherwise be lost. Water enters at 92°C and exits at 130°C.
The plant also helps to cover the airport’s basic air conditioning demands during summer months, and can assist air treatment in other seasons. UK-based sustainable engineering solutions company Thermax has supplied hot water-driven chillers to Leonardo da Vinci-Fiumicino Airport with a combined installed cooling capacity of 8 MW, which are driven by hot water from heat generated by the three 8.5 MWe gas turbines.