Still about DH, It came to my mind that I might get that simple answer about the piping lifetime and after the fossil fuel depletion we just abandon the use of the network which should be then near the lifetime end.
Well, what I'm sure about is that the networks in different cities are renewed almost every year with tens of kilometers of new piping. For example, the available annual reports on net for "Helsingin Energia" showing the amounts of added networks and the renovated parts.
From these reports, Helsinki network in the year 2001 was renewed by 22.1km of piping plus the expanding of the network. And from Helsingin Energia annual report 2004, the total length of the new district heating pipelines constructed during the review year was 14.4 km. A 7-km section of the district heating network was renovated and modified. The total length of the district heating network was 1,218 km at the end of the year. In addition, HelenDistrictHeat had a 6.6-km district cooling pipeline constructed for HelenCooling (I couldn't find the report of 2007 on net for more upto date information).
So, in the same network we'll have a combination of different lifetime. The question is, if the decision been taken already by replacing the DH central systems by electrical radiators at the heated space when should we stop renovating the networks and stations? if not, what's the plan after the price of fossil fuels is not economical?
In general, the fossil fuels depletion and the time just before the depletion won't be that easy!
Imagine the price of the last 100 barrels or maybe bottles of oil. What will happen if new discoveries of oil appeared in some place?
Anyway, away from that future jungle I think in countries like
I hope they have the solution already!
