In 1903, the municipality of Frederiksberg on the western edge of Copenhagen had a waste problem: its population had skyrocketed and the land available for dumping trash had run out. Borrowing an idea from Hamburg, the city’s government decided to burn the waste, and use the byproduct, the energy this generated, to heat its municipal buildings.

That small-scale solution has since developed into a city-wide heating system, known as district heating, that provides clean, cheap heat for 98% of homes in Copenhagen. The idea is basically the same, though the energy source has changed. A network of pipes distributes water heated by the waste energy from industrial processes to homes across the city, saving 200,000 tonnes of oil every year, and through this the 665,000 tonnes of CO2, a reduction of 20% from the levels which would otherwise be released into the air through burning it. The air is cleaner, and households pay lower bills.

Cities everywhere are struggling to keep their air clean and emissions down, and Copenhagen’s system shows that individual cities can make radical and beneficial changes. But experts argue that, for the benefits to be felt, governments have to plan painstakingly, so that individual households don’t bear the whole cost of cleaner heat.

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A history of heat

Power stations and factories produce heat as a by-product. Normally this is wasted, but in a district heating system it is used to heat water which is then carried to homes. Instead of each individual household having its own boiler, usually powered by oil or gas, they 'plug into' the network, and heat their homes from the collective supply.

Building a network of pipes that connects an entire city requires huge investment, and creates a lot of disruption. After 1903, Denmark’s district heating network expanded slowly: until the 1970s, it only provided heating to around 30% of the country’s households.

"Heat is a local issue; there you can do something"

Then, in 1973, OPEC declared an oil embargo. The cost of oil, and therefore heating, shot up. Denmark, an oil importer, was faced with huge energy costs. “In the old days, we imported all our fuels for thermal electricity production,” explained Birger Lauersen, from the Danish District Heating Association.

In 1979, following other energy crises, Denmark acted, passing its first heat supply act. This was a huge municipal program to map out a district heating network across the country. The government identified which areas were best suited to connect to a district heating network, then made it obligatory for new and existing houses in these zones to do so.

Each municipality identified by the plan had to implement a district heating network, find heat sources, and connect the homes. This comprehensive “heat planning” was “instrumental” to the development of today’s network, said Lauersen.

In recent years, with the infrastructure built, the centralised control of the system has been relaxed, and there is more involvement of private companies. “We have pretty much covered what can be covered with district heating,” said Lauersen. District heating now provides heat for 64% of Danish households.

A hot opportunity

District heating operates best in densely populated areas, where it’s cheaper to lay pipes between homes. It’s therefore naturally suited to cities, which explains its almost blanket coverage in Copenhagen. For Lauersen, as cities strive to become more sustainable, district heating is one of the most significant things which lies within their control to change.

Whereas increasing sustainability in the transport sector is made difficult by the decisions individual consumers make to drive, and the electricity market is European wide, heating is ripe for cities to change. “Heat is a local issue; there you can do something,” he said.

Paris has an extensive district heating network, as does Stockholm, and the Netherlands is planning to create one. The advantage of such networks is that they can be adapted: as cities transition away from fossil fuels towards renewable energy sources and biofuels, the old power plants which used to supply the network need to be replaced. New heat sources can be plugged into the existing network.

Denmark’s national plan meant that the cost of building the heating infrastructure was borne by the city as a whole. Costs weren’t passed on to the consumer, and heating suppliers aren’t able to hike prices to recoup costs or profit from consumers. The Danish district heating industry is governed as a natural monopoly, so customers aren’t charged more than it costs to provide.

Missteps

Elsewhere, things don’t work so well. District heating plans in London have been implemented haphazardly. The Guardian reported last year that unregulated British schemes are locking residents into high, fixed costs for the long term, forcing many to go without heat to keep their bills down. Companies claw back the costs for the infrastructure from their customers, and unlike in Denmark, profits aren’t limited.

For Lauersen, the ability to regulate depends entirely on the power cities can wield. “In Denmark and Scandinavia, the cities are usually relatively strong local entities,” he said. “In other countries, like the UK they're not so strong and have fewer resources, and fewer planning instruments.”

To benefit from district heating, cities need to make sure that networks don't develop unevenly. Districts need to connect to the network in tandem, so that the system can work efficiently and the burden of cost is kept off individual households. For that to happen, cities need the power both to make plans, and to implement them.

(Picture credit: Flickr/Chris Alban Hansen)

Anoush Darabi
anoush.darabi@apolitical.co