Of course we know it as Lego. Founded in 1932 they have become the most recognisable toy in history with estimated production of over 400 billion pieces to date.
What lego has produced or certainly “moulded” are inquisitive minds, minds that appreciate that imagination and work leads to a novel outcome. There can be few humans on the planet who have not played with Lego and every single one of them will have created a unique design.
This fluidity in the human mind and spirit is what underpins the recent Lego movie. Whether you have kids or not, whether they are aged 5-10 or not, go and see it. It is a masterpiece in human spirit in its own right with a story rich in mature meaning and cameos from more familiar stories from the ages. It’s also very funny. My son’s favourite bit is the Lego Batman saying “I only work in black… And sometimes very, very dark grey”.
Use your imagination
The same is true of heat pumps and their engineering. Basic rules, established over decades in refrigeration, exist in their design and application relating to pressure envelope, lubrication, maintenance access as well as the more fundamentals such as heat in plus work = heat out.
Where a mind, founded in the generation of lego is quite comfortable is the basic premise of a heat pump that so long as you have something that you can cool down and there is a need for the heat then a working system is plausible.
Rules exist beyond simple functionality
Primary activists in this emerged during WWII in Switzerland, a country prevented access to oil and gas but rich in hydroelectric resources. As Lord Kelvin predicted in relation to Niagara Falls, “great swathes of North American homes would be heated with electricity from the Niagara Electric Company and heat pumps”. Of course efficiency is always important as one want the greatest return for investment but when a heat pump is being considered in the “free world” with abundant sources of fossil fuel then the calculation becomes an economic one.
In the last decades we have seen rising fuel costs and greater interest in ancillary weaknesses of fossil fuel, primarily carbon dioxide release but also local air quality releases.
Harness renewable sources of heat
This position is somewhat flawed in that it merits sources of heat attributable to the sun as more valuable, purer indeed than harnesses bona fide sources of waste heat. Commendable in its purity, but in reality an unfortunate distortion towards the use of relatively cool sources of heat such as rivers and underground aquifers, likely to be below 10°C most of the year.
Contrast this to the heat rejected by many production processes from plastic forming (a lego again) and various distilling and brewing, to name a few. Lego is now manufactured from ABS and created by melting the material to 220°C. The dough like ABS is injected into moulds and cooled down. Ultimately as far as ambient but certainly in the immediate cooling zone closer to 100°C. I wonder, is any of this heat is harnessed for practical use?
A similar situation is being planned in Lund in Sweden where a particle accelerator is being developed to propel a single electron at twice the speed of light over a 600m track before it is diverted into a chamber. Will this solve the great conundrum of energy “creation” and make a clean fuel available for generations to come?
I have no idea, but I do know that the planned apparatus will result in 30MW of heat being rejected and they plan is to use heat pumps to boost that up to useable grades for the nearby city heating system. Ironic that a device that will render heat boosting obsolete will in the intervening period benefit from heat pumps.
Waste heat is not considered renewable
This waste heat is not considered renewable and hence in no country would be able to claim contribution to the legally binding renewable heat targets. Plaudits where plaudits are due, in the UK our leaders have gone one step further and incentivised this use of renewable heat. This fore-shortens the break even point of a big heat pumps making it a commercial reality but it makes the reality more pressing that subsequent support is made available. Why does it matter?
Well what we want is not a mechanism to use more renewable heat but a mechanism to use less “non-renewable fuel”.
Take this example of a distillery in Glasgow, next to the Clyde. The distillery has 20MW at 50°C the river has a significant flow at 5°C.
A heat network would have to run at say 75°C /45°C and so the efficiency of heat pump sourcing heat at 50°C cooled to 30°C would be around 6.0. Sourcing the heat from the river would be a COPh of about 3.0.
The cost per kWh of heat from the distillery would be the cost of electricity divided by 6p, so say 12p/6 = 2p. With the river as the source, the cost would be 12/3 = 4p BUT earning the RHI @ 3.5p, so a net cost of 0.5p.
The former is clearly the better heat pump as it uses half as much “new energy” but the latter is more likely as a project.
So some latitude and imagination (to evolve the rules) would allow a better outcome.
Rules aren’t always to be followed
The biggest rule we have to evolve is “you have to burn something to get heat”. A theme from blog #1 but still as relevant as ever.
Big river source heat pumps have reached the heights of the Independent on Sunday and comments by Ed Davey. The diatribe of comments slagging off this wonder of science is shocking.
Mr Davey said:
"This is at a really early stage, but it is showing what is possible. You never have to buy any gas – there are upfront costs but relatively low running costs.
"I think this exemplifies that there are technological answers which will mean our reliance on gas in future decades can be reduced. Here you have over 100 homes, you have a hotel with nearly 200 bedrooms and a conference centre that won't be using gas. It will be using renewable heat from the nearby River Thames”.
In due course, the RHI will not exist and life will revolve around unsubsidised solutions. If we are to carry forward the work of heat pumps, we will need to have achieved several things.
- A fundamental awareness of heat pumps’ existence. Sounds dramatic, but in reality they are not well known.
- A wider exist of what makes a good heat pump system (i.e. warmest possible source and coolest possible demand). Drammen, as fantastic as it is would use 30% less electricity if the heat was sourced from a data centre. Additionally, a chunk of the electricity could be attributed to the data centre or the cooling taken as “free”. Networks also can be lower cost if temperatures are limited to more sensible levels e.g. 70°C
- Heatpumps systems need to get more efficient and more flexible. There are still limitations on what can be achieved as compressors don’t exist for 70°C without being 500kW - a bit too big for individual buildings. Controls improvements can be achieved too
That’s about enough for now other than see the movie. It is awesome.
So how do you become an expert? 10,000 hours of practice. More on Malcom Gladwell’s bestselling book and pertinence to heat pumps next blog.