BDEC's district energy report gets a fresh preface -- a 30 year update
There is a proposal being pushed by Burlington Electric Department (BED) to connect a steam transmission line between the J.C. McNeil Generating Station and the hospital. It's not good. Indeed, it's an idea that should have been stopped early at an internal BED meeting after about 10 minutes of discussion.
In 1992, Dermot McGuigan and I developed a project proposal to serve Burlington with low-temperature district heat that would have taken heat from the cooling water at the McNeil Generating Station. It was a project for its time and the future, which is now here.
In 2023, district energy system supply temperatures in new systems are so low that uninsulated pipes can be used. (Lund, et.al., 2014, https://doi.org/10.1016/j.energy.2014.02.089) created a widely reproduced graphic that illustrates the long-running temperature trend in district energy systems (also called district heating and cooling). The notion of using steam in a new system today is unfathomable.
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| (Lund, et.al., 2014) District Heating and Cooling Progression, revised 2018 4dh.dk [Full Size Image] |
The Burlington District Energy Project was described in a Pre-feasibility Report. We did not put all of our best ideas into the draft that circulated. It was a document for soliciting project support, not a free gift of all business secrets. That said, the draft report provided considerable information about how to build a system for the future, which is now the present. Unfortunately, if we release the report now, it will be confused with the steam pipe that BED is pushing so hard.
Dermot and I have written a preface to the draft Pre-feasibility Report and placed it on the cover of the electronic version of the report. It describes our current opinion about district systems. Until BED makes available the engineering and economic reports for the currently proposed steam pipe, it would be best to simply release the cover with the new preface:
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| Pre-feasibility Report Cover with preface [Full Size Image] |
This draft report reflects the time in which it was produced, almost a quarter-century before the Paris Agreement. The UN Framework Convention on Climate Change was still being circulated for signatures in 1992. A Public Service Board (PSB) environmental externalities investigation and rule negotiation was underway – expressly excluding biomass from qualifying as renewable. (Docket #5611) The Kyoto Protocol and GHG Protocol would be years into the future.
The Burlington Community Energy Project was the best possible proposal, anticipating thermal demand reductions, the need to continue lowering system temperature, direct customer connections, and other innovations mainly originating from Europe.
But it was quickly apparent that the project would not move forward. The barriers were neither technical nor financial. The window of opportunity to use McNeil as motivation for developing a low-temperature district heating system passed quickly.
Combustion — biomass or otherwise — must cease, including at McNeil. Large-scale centralized district heating is questionable (with exceptions like geothermal or byproduct heat from data centers). Zero-energy building performance standards offer a low-impact way forward, possibly combined with community energy systems that use zero-emission energy sources, scaled ground-source and water-source heat pumps, very low temperature thermal systems (4&5GDHC), thermal storage, and thermal recycling.
- Peter Duval
- Dermot McGuigan
04 July 2023