There are about 3.6 billion cooling units on planet Earth today, according to the Green Cooling Initiative. That includes not only good ole’ AC units but also refrigerators for perishable medicines like vaccines, mobile freezers for food shipping, climate control systems at data centers, and many other things that we tend not to think about.
That’s already a lot, but a new study suggests that the global total for cooling appliances could reach 14 billion by 2050. It’s an overlooked threat that could undermine efforts to combat climate change — which is why the paper’s author partnered with a high school dropout and former poultry farmer to tackle it.
First, the new study: It’s called “A Cool World - Defining the Energy Conundrum of ‘Cooling for All’” and was put together by an industrial academic at the University of Birmingham in the UK named Toby Peters. His area of study is devoted to the development of advanced, low-energy cooling technology.
By Peters’ calculations, global energy consumption attributable to cooling will have to be cut down to 6300 terawatt-hours-per-year by 2050, if we hope to keep the now inevitable average temperature increase due to greenhouse gas emissions below 2 degrees celsius.
To put that in context, that’s a little bit less than double our current annual energy usage for cooling, 3600 terawatt-hours-per-year. So at first glance, you’d think this would be pretty easy. But, if we stay the present course, with no new cooling innovations, Peters believes we’re on track to hit 19,600 terawatt-hours-per-year in 2050. Based on his survey of new technologies, he thinks that number will only dip down to 15,500 terawatt-hours-per-year without a major planning initiative to manage humanity’s chill needs.
One reason for these expected jumps is that large populations in India, China and elsewhere are transitioning into middle class-status and all the higher standards in comfort that comes with it. Right now, the United States uses more electricity just to air condition its buildings than the entire continent of Africa uses period. So, if a few billion more humans are going to start clamoring for 70-degree living rooms, non-spoiled medicines, and whatever else, you can imagine the energy load adding up pretty quickly.
Peters is, of course, not the only one talking about this. The United Nations’ Intergovernmental Panel on Climate Change estimates that simple, home air conditioning by itself will contribute 4000 terawatt-hours-per-year to global energy use by 2050, and 10,000 terawatt-hours-per-year by 2100. And Computer Weekly found that internet servers and data farms quadrupled their air conditioning use from 2007 to 2013 and are likely to double again that within the next five years.
This is why Toby Peters has teamed up with Peter Dearman, a self-taught engineer whom he describes as “the classic British garden-shed inventor.” The two hope to develop and market Dearman’s long-gestating idea for a refrigerated trucks that run solely on liquid nitrogen.
The idea actually came from Dearman’s father, a Hertfordshire poultry farmer where the younger Dearman started working when he quit school at the age of 15. The concept — letting liquid nitrogen pump engine pistons as it expands into a harmless gas — is so simple that the first prototype was made with an old motor from a Yamaha quad bike.
Their refrigerated trucks essentially double-up the liquid nitrogen’s role. It is first circulated through heat exchangers within the vehicle’s storage area, acting in its liquid state as -320 degrees Farenheit coolant. Then, as it warms up toward its evaporation temperature the nitrogen is siphoned off to a Dearman engine, where it comes into contact with a mixture of water and glycol that has been warmed by the ambient temperature. That finally leads it to expand into a gas in the piston chambers. Then, and this probably goes without saying, the nitrogen is ejected out in to the open air which is already 78 percent nitrogen anyway.
There’s not really much glib to add here. This is some cracking good British tinkering, some Ace-level Wallace and Gromit level innovating. Let’s hope there’s more stuff like this, so we don’t turn the entire planet into a Houston-style hellscape of scorching deserts and corporate skyscrapers with central air.