Climate saving lo-tech: District heating

Around the world energy systems are developed very differently for geographical and for historical reasons.  This means that in a number of markets we have solutions that may be well-established in the local market, but with a great potential for expansion globally. Sometimes the geographical context is so unique, so that the export of the technology may not be meaningful. For instance, the energy system on Iceland is largely based on geothermal energy from the countrys volcanic underground. There are some, but not so many places in the world where the technology could be used in the same way.

District heating

A technology widely used in Sweden, but with limited implementation in other markets is district heating (and district cooling). In Sweden, the networks for district heating have been built and expanded for a long time, and provide the heat for roughly 45% of the heating market. They provide a lot of benefits. Central heat production, typically through a waste or biofuel fired boiler is ditributed through water pipes in the community through a two way system with heat exchangers in every building.  The system is quite efficient, a closed water system with low losses and with very low emissions. Due to the centralised solution, very good flue gas cleaning can be applied.

District heating is especially appropriate and efficient when the available fuels have a high moisture content, which is the case with many biofuels and with some waste fuel systems. The reason is that the distribution of water is done at a relatively low temperature, maybe 90 C. This in turn means that the flue gas from the furnace can be condensated to generate substantial additional heat and a very clean flue gas.

District heating systems are very often combined heat and power systems (CHP),  and through the combined solution, a total energy efficiency of typically 95% is reached, whereas a system for only power generation typically has an efficiency of around 40%.

District heating systems are also very good at using waste heat from industrial processes for the same reasons.

Why is district heating not used more today in an international context, given its many advantages?

Probably the most important factor is the challenge of the centralised approach. It requires a municipality that has the financial strength and competence to design and run the enrgy system for the community. In many markets this is currently not viable.

District heating remains a low-tech solution with a huge potential as a climate saver in many markets for the future.

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4 Comments

  1. Posted February 19, 2009 at 7:56 pm | Permalink

    District heating and CHP are also very common in Denmark. In fact, Denmark gets over half of its power from CHP. I’m associated with Recycled Energy Development, which is chaired by Tom Casten, the guy who coined the phrase “combined heat & power.” Here in the U.S., energy generation tends to be extremely inefficient, but estimates suggest that various forms of energy recycling (of which CHP is the biggest) would slash our greenhouse gases by 20%. That’s as much as if we removed every passenger vehicle off the road.

    • Posted February 20, 2009 at 9:49 am | Permalink

      Thanks Miggs! You’re absolutely right. The tricky thing in the US, (which I have written about in an earlier article) is that most American cities are built in a way which is, as you put it, extremely inefficient. They are spread out with low density over large areas and with poor infrastructure. This means that you typically cannot reach the same efficiency in a district heating system in a US city compared to a European city, due to the lower density. In addition, the implementation project will be more expensive, due to more digging and pipes.
      Cheers, Niclas

  2. Thomas Andersen
    Posted March 17, 2009 at 12:45 am | Permalink

    Jag är projektledare för tidningen “Look at Sweden-China edition”
    Jag leder frågeställningen om “district heating/district cooling” i dialog med kineser. Vanke Real Estate Ltd i Shenzhen bygger och säljer domestic buildings, för 20 Md RMB/ år–hög komfort och estetik,- förutom faktumet att lägenhetsköparen själv ansvarar för COOLING i första hand-alltså inte Heating. Tillväxtstäderna ligger utefter den kinesiska kusten,(Shenzhen i subtropiskt klimat) och även i inlandet är det i första hand cooling, som blir aktuellt under sommarmånaderna. Hindret att introducera District cooling, är att individuell elmätning ännu inte har introducerats, ens i Sverige i full skala. Därför sitter det små fula Mitsubishi aggregat utanpå de annars så snygga husfasaderna. Varje boende ansvarar för individuell AC, som kommer på elräkningen. Men givetvis skulle de kinesiska megastäderna spara energi och vinna stordriftsfördelar på att ha District Cooling(och på köpet heating)Om det dessutom inom en 20 års period kunde utgå incitament från Kinesiska regeringen om övergång till district cooling/heating, genom reglering av något slag, så skulle Kinas energiförbrukning minska i den delen.Problemet är att det finns lite “propaganda” för just District cooling i västbaserad media, eller forum.Det man talar om är District Heating, och då känner de som är berörda i Kina att frågan inte angår dom så starkt.Lösningen skulle vara att man kunde(I exempelvis min tidning som trycks på Kinesiska och distribueras i regionen)ställa upp en ekvation och demonstrera vilken
    infrastruktursatsning man måste göra, och hur den individuelle boende kan svara för sin del av förbrukningen. Kineserna är moståndare till kollektiv mätning eftersom de inte “vill betala vad grannen förbrukar”. Lösningen är att redovisa hela konceptet, och få alla; från Regeringen till privatpersoner, att förstå stordriftsfördelarna.

    MVH

    Thomas Andersen

  3. Posted May 20, 2009 at 11:04 pm | Permalink

    Engaging page!! Hope to come back soon!


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