The event focused mainly on the opportunities, challenges and new solutions offered by district heating and cooling networks.
On the 1st October 2015 the SIRACH network (Sustainable Innovation in Refrigeration Air conditioning and Heat pumps) visited Newcastle University and the Joseph Swan Centre for Energy Research.
The event focused mainly on the opportunities, challenges and new solutions offered by district heating and cooling networks.
Star Renewable Energy's Dave Pearson's series of posts continue his thoughts on district with a musical theme
So, we’ve whistled Waterloo, chortled at Father Ted, flopped around with Hugh Grant’s fringe and marvelled at Captain Caveman and the Teen Angels, but does it not all come down to those rogues Liam and Noel?
Where to start? Well in a very practical sense, anyone that picks up the gauntlet of progressing the way we do things has to be Standing on the Shoulders of Giants. Whether that is such luminaries as Lord Kelvin or even just personal family such as grandfather, father and brother.
Lord Kelvin was most definitely ahead of his time. Sure some of his calculations were a bit optimistic, predicting COPs of 35 was a bit far-fetched when in reality we are unlikely to exceed 8 and even 3 is a tough gig when working with non-optimsed buildings. Never Forget (oops wrong band) that we are trying to heat a building to 21°C. Using water at 82°C is just lazy.
Dave Pearson, from Star Renewable Energy, in his series of posts on district heating, considers the economics of heat pump systems.
So we don't need fire like a caveman, they come in BIG as well as small sizes (but big is better) and sources of heat are all around. But, why would anyone want to use a big heat pump? They cost ten times what gas boilers do. They aren’t as compact and the fuel doesn't just squirt out of a small pipe.
Well ABBA kind of spell it out, albeit it takes a good few of their songs to build the picture.
Picking up on last month’s idea, it has to start with 1974’s Waterloo. Someone asked me which bits of Britain are suitable for heat pumps and I honestly answered…the wet bits. Waterloo perhaps also as it is a battle to get the technology understood but also because after several years ABBA landed on the scene in a big contest. I was only 1 year old. Cripes.
Where next? Happy New Year, Happy New Year? … well it was for Drammen district heating network in Norway. It cleared its 12 month observation period: not without some stories to tell. Maybe we will write a musical one day. Now in its 3rd winter it is churning away at 14MW at 90C lifted from the fjord at 2C.
So, my first blog post observed our society’s fascination with burning stuff like cavemen to produce heat. In reality big heat pumps like this one...
...can deliver heat from numerous sources up to 90°C and still be more cost effective than gas and qualify for the RHI. This presentation shows how an entire university could be heated with heat from a river.
My second post emphasised how important it is to understand how the heat pump “magics” heat from nowhere. It is a bit abstract but, hey, it works! Of course the bigger message was that big heat pumps behave differently from little-uns. The project shown in the link above delivers heat at 90°C from a fjord with a delivery ratio (or COP) of over 3.0. We get 3 x the heat out as electricity goes in...’cos the rest is sucked out the fjord.
So my third blog post got me thinking about that and I realised my foundation analogy had to be ”Four Weddings and a Funeral”: a classic Hugh Grant "rom-com" where he meanders through life missing a golden opportunity whilst everyone else strikes the “love jackpot” (apart from the poor bloke who dies).
Big hair, big shoulder pads it even had the big classic smoozy song sung in this case by Wet Wet Wet: “Love is All Around”.
Wet Wet Wet
So how on earth is that having anything to do with big heat pumps? Well, aside from being massively simple and easy to join in with (a la karaoke) melodic cheese-pop, it’s really simple: Wet Wet Wet is all we are looking for with big heat pumps. And that really is “all around”. Water. If it ain’t frozen you can easily take heat out of it.
Sorry to disappoint that it isn’t terribly complex. However let’s put some numbers on it...
The River Thames has a flow rate of approx 200m3/s and is rarely below 5°C. Taking even just a tiny portion of this say 5% and cooling it by 2 degrees would deliver 84MW of heat to the heat pump which in turn would deliver 1.5x this, as heat at anywhere from 60°C to 90°C depending how well the buildings and network were designed > 120MW. Enough to heat all of Westminster and every council tower block in London I suspect...from 5% of the Thames. The key observation back from blog#2 is that this needed be constrained at 45°C like the little ickle heatpumps in Kingston Upon Thames (that also happen to be filled with HFC...but that’s another story).
Or what about a sewage treatment plant with only 2000 l/s flow at 10°C being discharged into the river? Yup, cool it down by 10 degrees and you have another 84MW of heat...
Or what about a power station? Well they each dump more heat than electricity produced so they have typically 1GW of waste heat.
Hey, even the London Underground pumps out 30 million litres of water a day worth >22MW of heat.
On a lesser scale, what about big bore holes? I don’t mean little holes with plastic pipe that struggle to lift 10kW out the ground, but proper Yorkie-bar-esque open loops. London and much of the country sits atop a moving puddle of aquifers. We don’t get anything like as much as from a river but even 20 l/s from one borehole cooled by 7° is close to 600kW extracted and therefore around 900kW delivered heat at over 70°C.
There are other sources such as air source but as much as they have some merit on a small scale, we’re going to struggle to get hundreds of kW from these when it is really cold and still deliver at high enough temperatures.
Heat is all around
So, to prevent going on as long as Martii Pellow and the Wets did (15 weeks I recall at number 1 and 37 weeks in the top 75), LOVEISALLAROUND let’s just assume that heat is all around us...and so the feeling grows...quick pass me the karaoke mic and let’s shout it out that heat doesn’t need fire, heat pumps work best when big and sources of heat are plentiful. Now what about next time’s inspiration... (don’t worry it isn’t Bryan Adams and Kevin Costner)...
It’s got to be ABBA.
In his latest post, Dave Pearson, from Star Renewable Energy, evaluates district heating using heat pumps as an alternative to burning chemicals to keep us warm and heat our water, and puts some perspective on the technology.
Star Renewable Energy's Dave Pearson blogs about district heating for Heat Pumps Today
Apparently, virgin biomass gets some folk bothered because it is the wrong type of trees and it is intensive forestation. There are also some voices concerned about air quality and, then, there is also economic aspects of labour mobilisation for “shovel ready” projects.
Lots to chew over and perhaps lots to bewilder us into the “same old same old”. But let’s try and stride forward with a mission. Scooby would so long as there was a sandwich in it for him.
How to save £1.44 billion a year
Biggies would seem to be:
It is pretty well noted that half of our country's energy consumption is for heating. That’s half of a staggering £32 billion.
Keeping it simple, if we can shave 30% off the running cost of 30% of the heating, we’d save 9% of £16 billion which is £1.44 billion...every year...for ever. Not only do we save that, but we don’t import the same volume of fuel which has to have knock on benefits.
It’s hard not to engage in the carbon question so I'll dig over that one a bit too, particularly in subsequent blogs.
Well, heat can come from burning coal, burning gas, burning oil, burning biomass, burning waste or harvesting “waste” heat. Keeping it simple, there are options, but most of them will be best done on a big scale.
There is also a distinct fascination with district heating which seems to be driven by large electricity generation wishing to be more efficient by harnessing the heat. If you convert a form of fuel that releases energy by combining oxygen with carbon and the carbon was “laid down” more than a few years ago then there will be a carbon emission. You can’t fudge the numbers by offsetting against displaced electricity. There is no getting away from the simple fact that your facility is releasing carbon dioxide. Period.
Addicted to burning
So, back to Captain Caveman.
Since the dawn of man (and women) we have evolved in our ability to harness fire. We no longer have to collect wood, or utilise animal fat we just flick a switch and a flame appears. There have been significant developments in controls but for all of that, we still are at best 90% efficient. We are without a doubt absolutely addicted to burning stuff and seem to be searching for ever more complex ways of burning other stuff...sourced from further away, needing more boats.
The problem with change is that is will either be early or too late.
If we seek to shift from fossil fuel too early, we will be fighting an uphill battle against fundamentally lower energy costs. As cost is big driver, just as new techniques that shift away from fossil sources evolve, so too will the cost of fossil fuels reduce. Simple economics of supply and demand alone tell us that, never mind incremental improvements of the status quo.
Let’s not even try and factor “Fracking” into the equation other than to observe the change in cost of gas in the USA. Presumably, this will lead to a lowering world wide once the ripples even out. Biomass markets will remain volatile for as long as schemes are deployed that harness beyond their locale. I've heard 12km used as a rational boundary. Sounds fine to me.
There is a funny word called exergy. It basically helps understand that energy cannot be created or destroyed.
However, where it seems to go amiss (and feel free to educate me) is that there is a belief that when energy is driven to the surrounding it is lost.
So where are we?
There is a general consensus that heating should be done differently in the future. Let’s be thankful first of all that heating (that consumer of over half our energy) is poking it’s elbows out a bit and muscling into the “Renewable” arena. I just hope that society and the financial lubricators haven’t taken complete fright at the rather stodgy performance of renewable electricity. Heat will be different. Honest.
Maybe if they made their investments on “exergy analysis” they would pick different horses.
What about district heating?
So, just where does this leave district heating?
Frankly, in a bit of a mess. It has been touted by anyone with a whim to burn 'alternative' energy as the best thing since sliced bread and then, boom, all of a sudden it has stalled as 'alternative energy' comes with a price.
That price might be fuel cost, kit cost, or iffy carbon credentials or even poorer trade deficit or, perhaps, the more local challenge of air quality.
However, before we either jump on the combined heat and power band wagon and shackle ourselves to a technology that generates more carbon and emissions than conventional centralised gas fired electricity production, what about that exergy thing and waste heat?
What if we could make energy flow 'uphill' with no local carbon emissions, no absolute requirement for fossil fuel or transport of fuel halfway around the world?
This link shows that there is more waste heat in London than required to heat all of London. Hat’s off to all those involved. Now, we just need to work out how to do it.
Leaving something for next week, the absolute efficiency of grid driven large heat-pumps is in excess of 180%. Not even just burning gas is that good.
So, in summary:
Thanks for now. More later on carbon impact of various techniques, base energy efficiency, how to design good networks, how CHP can be deployed correctly and how not to do it.
And remember, "We don’t live in caves so let’s evolve beyond burning stuff."
About Dave Pearson
Since demonstrating fridges could use propane instead of CFCs as a school project in 1989, Dave has worked in the cooling industry.
First in compressors, then industrial refrigeration design and automated freezer systems. Since 2008 when he took up the post of Director of Innovation for the UKs largest Industrial Refrigeration contractor, he has been getting to grips with the other end of life...heating.
Part of the team that has delivered over 30MW of heating projects around Europe, half of it at 90C, he has a “no fire” perspective of society’s heating needs and how these could be met in a far more sophisticated way.
Heat-pumps get a bit of a bad rep...or haven’t been heard of. This blog seeks to bring large industrial heat-pumps absolutely front and centre in the global fight for lower costs, lower carbon solutions.
A massive believer in finding a win-win whilst keeping a reasonably short-term perspective Dave could just perhaps have the secret that unlocks a new generation of heating. One that if deployed will deliver our legal obligations and save money. One that if ignored will leave us still stuck with some form of fire and fossil fuels for generations to come.