Shared systems - benefits and downsides
Generally speaking, sharing a heat-source can deliver huge efficiency gains if done right.
BUT sometimes 'right' doesn't quite describe the design and the results!
- if you go for full-blown district heating from a nuclear plant, as described in the piece about Helsinki, the Greenies will be in a quandary: welcome the huge efficiency, sustainability and cost-saving opportunity? or reject nuclear as a matter of principle? Seems now that Nuclear Nimbies (*) are alive and well in Helsinki, too! And if you do build such a system, what about back-up? Even a nuclear plant has to go off-line sometime, maybe unexpectedly. Where's the backup heatsource? It would need to be BIG to carry that load!
- In the same newsletter, Sandia Labs was profiled. Shared heat, steam, etc. from central plant being 'retired' due INefficiency and high cost!!!
In both these examples, the service life of the 'passive' parts of the system (pipes, valves, ...) was probably short and underestimated. And the costs of driving and maintaining the pumps needed to move the heat around is often forgotten or fudged for shared systems.
If you're a short-termist, replacing almost anything with new kit will deliver 'savings' - for a while. Then maintenance / refurbishment costs start in earnest and all of a sudden the customer is worse off! I expect through-life costing for the new systems at Sandia, if done honestly and completely, would far exceed the equivalent cost of central plant. But then: no-one ever thinks long-term these days....
* NIMBY = Not In My Back Yard
