Alastair Mumford of Regen SW disrupted my morning by asking

Does planning policy aid heat networks?

https://www.dhirubhai.net/pulse/does-planning-policy-aid-heat-networks-alastair-mumford

 (I've missed the free vend on the coffee machine whilst responding )

Here was my response.

Hi Alastair Mumford

planning policy is critical. Or you could say,

piss-poor-planning=piss-poor-performance

Firstly there needs to be a top down "will to succeed" and the planning policy is where this is encapsulated and enshrined in "we must achieve".

Secondly, all networks need customers and planning policy is the difference between stakeholders getting on-board and bringing heat demand for the greater good over a longer period or not bothering. Even if the network doesn't exist this can mean making buildings "DH ready" by having easier connections at street level, appropriate temperature levels and dynamic controls (so that they don't demand heat at 95C just because someone wanted smaller rads and couldn't foresee any value in modulating flow temperature with prevailing ambient to drop to say 65C on a milder day. Lastly in this aspect, the return temperature of a network is defined by the heat take customers. Wider temperature difference is good in normal networks but very good in heatpump networks as more "free heat from sub coolers can be achieved (10% for every 15K). The controls bit is also useful if thinking of lower temperature sources; stop and ponder "what is the right temperature for a building that needs heated to 21C and hot water at 50/60C?" In my opinion 65C should be enough and for space heating a "back setting or night setting can reduce the early morning peak demand perhaps allowing 40C or 50C to keep the chill off overnight.

This thinking about other sources of heat brings some honesty and clarity to the often overused statement of "we are heat source agnostic".

Yes there are lots of sources but some reward good design exemplified by lower temperatures. Our client in Drammen Kommune

https://www.bbc.co.uk/news/business-31506073 READ ALL ABOUT IT...

drops the temperature by 1K whenever possible as he knows this shaves 1.5% off running cost of the heatpumps. He also paid for some of the cost of adding plate heat ex-changer surface at the hospital as it dropped the net by 5K so 7.5% of total annual running cost.

so this brings another question. If big heatpumps are to be considered what other advantages can be accrued with correct design influenced by correct planning policy?

Well, Thermal storage happen by accident with thermal nets but more can be achieved with better design. So better load scheduling, better creation of network volume to add storage capability, better consideration of night time return line bleed. For sure some of this is only pertinent to heat generation techniques where the cost of fuel is sometimes "negative" eg large heatpumps running on surplus power tariffs.

It is no accident that our 2050 targets include a large amount of electrified heat.

We need to do better than burning stuff better or burning different stuff.

Last year 91% of the heat from Drammen's main energy center was
zero carbon, zero emission, produced cooling as a by-product (66%) and was 80% cheaper than gas.

Lastly; is it always going to be about heating? what about cooling. The only rising utility?

Maybe we should have ambient nets that circulate 15C water and let each user decide if they will add or subtract heat at their locale with balancing being done centrally or perhaps even SUB-locally at foul water interfaces or harvesting 20C waste heat from EfW plants.

So perhaps a point of view with a technical slant but I prefer to look on it as a "performance slant"..................and you tend to get the performance you plan for.

So planning underpins great thermal networks but we need to decide what we are planning for and it needs to be better than something that will be obsolete or obstructive to our 2050 goals such as combustion based 80C nets.

We are the first generation to feel the sting of climate change, and we are the last generation that can do something about it. Jay Inslee.