Please go to <a href="http://www.severalworld.co.uk/engineering-timelines/timelines.html/why/lowCarbonCopenhagen/copenhagenDistrictHeating_03.asp">http://www.severalworld.co.uk/engineering-timelines/timelines.html/why/lowCarbonCopenhagen/copenhagenDistrictHeating_03.asp</a>