Comment on A new cooling technology freezes food without warming the climate
kalkulat@lemmy.world 2 days ago
The link says ‘zero-emissions-cooling’
The article sez: “It relies on the temperature change of materials called shape memory alloys (SMAs) when they are stretched and released.”
How do you stretch something without producing any emissions?
I thought the same thing.
Seems they are mainly saying they developed cooling method that doesn’t rely on a greenhouse gas for a refrigerant. Not nothing.
…and if you stretch and release something off solar/wind power greenhouse emissions will be very low indeed.
I’m curious about lifespan of these systems. I don’t know much about SMAs, but my intuition says they degrade. Am I wrong? I hope I am :)
They are not new technology the idea has been around since at least the 1980s. There is a reason we don’t use them and it’s because they are mechanically complicated and inefficient. Those in terms of power use and maintenance requirements.
However with the move to renewable energy maybe that efficiency limitation isn’t as much of a problem as it used to be. Especially if it means you can get away from toxic compounds.
Although I have never seen a commercial grade implementation of the technology. It’s always just been demos that don’t really achieve enough cooling to be anything other than a curiosity.
They are not new technology the idea has been around since at least the 1980s. There is a reason we don’t use them and it’s because they are mechanically complicated and inefficient
Not trying to completely throw away your comment here, but I saw this exact same comment repeated ad nauseum about electric cars 15 years ago.
It took about a century to get decent electric cars so I stand by my statement. It may no longer be true in the 22nd century, but there are fundamental issues with this technology that have not been addressed. I can’t imagine where likely to see solutions anytime soon, mostly because I don’t think there are solutions, I just don’t think the technology works.
Pressure change refrigeration is just so much more efficient. The light on your refrigerator consumes more energy than the refrigeration process, so it’s not like there’s even a massive impetus to make the system even more efficient because it barely uses energy as it is.
Where this technology might come in handy is where size is a severely limiting factor. Such as on satellites or small drones.
Oh geeze, it’s that rubber band refrigerator that (I think) Tech Connections demoed?
Gladaed@feddit.org 2 days ago
You can’t. It’s a different kind of heat pump.
If it is more efficient than vacuum-compression it’s good.
Most refrigerants are extremely toxic and extreme green house gasses. But there are safer alternatives, eg. CO2.
echodot@feddit.uk 2 days ago
I don’t think shape change materials are all that efficient. The problem being is you still need some mechanism to compress the material again, which obviously uses energy. As you say their main advantage is that they don’t use traditional refrigerants. But the trade-off for that is that they are mechanically more complicated and probably for any given amount of cooling will require more electricity.
You can trade those off with renewable energy sources of course so it may still be worth it but technically they are worse efficiency than traditional vacuum pumps.
Gladaed@feddit.org 2 days ago
Some sources claim much higher efficiency. This makes sense to me since you are not limited by your coolant’s properties so much and don’t have to maintain pressure. But I can’t do in depth research for you.
echodot@feddit.uk 1 day ago
What sources?
The article doesn’t list any. All it says is they reached a cooling temperature of -12°C, but has no information on the energy used to achieve that.