Making supercomputing more carbon friendly

Revolutionary as it is, supercomputing comes at a cost: the electricity bills to power the massive computer stacks that are playing increasingly significant roles in research are eye-watering; especially now. Spends in the tens of millions are not unusual. This means the computing carbon footprint is also prodigious, but usually invisible to the scientists who use supercomputers in their work - ironically often to study things like climate change! But awareness is improving, and the industry is also taking steps to shift computing loads to countries and centres with the best carbon credentials and renewable energy provisions. Finland’s one of them, as we’ll hear shortly. James Tytko has been investigating…

James - A lot of the most cutting edge scientific research would not be possible without large scale computations. From algorithms able to analyse biopsy images for faster cancer diagnosis, to modelling the weather in space to keep our telecommunications systems online, they help us solve problems unfathomable to science of the not too distant past. But it all comes with a cost: training large language models like ChatGPT, for example, requires a computational grunt which results in the equivalent of 100s of tonnes worth of co2 emissions. Since illuminating this hidden cost of computing to conscious researchers like himself with a nifty online calculator, Loic Lannelongue has been raising the alarm for what he sees as the much overlooked side-effects of conducting computational science. I caught up with him at Jesus College, Cambridge, and started by asking him to outline the key causes of computing’s carbon footprint…

Loïc - The main one people think about is energy usage; all the electricity you need to provide to the data centre to power the computers during the task. How much electricity you need depends on what type of computer you have and the task you're doing on the computer. The carbon footprint of producing electricity most of the time depends on where you are in the world. If your country has an energy mix that's mostly relying on renewable energy or low carbon energies like nuclear, then the carbon footprint of using electricity is really low as opposed to using gas or coal.

James - Part of the problem here is that perhaps a lot of researchers aren't fully aware of the problem as you've outlined it.

卢瓦-是的。这是一个很好的观点。而且,随着chers are really starting to be aware of this topic and are really picking up on it and are really interested. And for a long time what was missing was tools to do it, and now more and more tools are available to estimate these carbon footprints. So we are starting to move in the right direction. But because the carbon footprint is so remote, it's in a data centre you don't see, you're just using a laptop so it doesn't feel like you're using a war machine in another part of the world. It's easy to just ignore the problem.

James - And so plugging this information gap has been what you've focused your time on recently.

Loïc - Yeah, so it's all part of this, what we ended up calling this green algorithms initiative. So it started as a calculator online, and then we realised, okay, it's great now any scientist can go and plug in some numbers. The carbon footprint of computing depends in part on where you are in the world and what's the electricity source. Now, let's say you are in Australia and the carbon intensity in Australia is really high because everything is powered by coal. It's not your fault you're based in Australia, and you can't do much about it. You can make your models a lot more efficient, but at the end of the day, it's limited by the fact that all your electricity comes from coal. And that's where you can have collaborations between institutions to say, okay, it's so easy to move computing across. You can have your data centre halfway across the world in a country that has very low carbon footprint and relying on lot on renewable energy.

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James - To see one such collaboration between science and sustainable computing. I traveled to Helsinki to speak to the organisation behind Europe's most powerful supercomputer, which claims to have sustainability in mind from start... to finish.

Kimmo - We have a joint effort with nine other countries. This supercomputer is called LUMI. LUMI is the Finnish word for snow. That's the name of the supercomputer that's number three in the world at the moment, and number one in Europe.

James - Kimmo Koski - managing director of Finland's IT Center for Science, a nonprofit state enterprise owned by the Finnish government and higher education institutions in the nation. I asked him what makes Finland the ideal location for this sort of industry.

Kimmo - First of all, we have a lot of carbon free electricity, robust infrastructure, good electricity systems, networks, etc. So, the environment is ideal. And then it's very cost efficient too because the electricity price in Finland, it's much, much less, especially for the renewable ones because of taxation than in many places in central Europe.

James - Who are the main beneficiaries of LUMI's computational power?

Kimmo - LUMI is meant for a quite wide audience. For example, from the medical side, artificial intelligence, climate change. I will claim that it's one of the most eco efficient computers in the world because, first of all, the electricity that's used in LUMI is fully renewable. In this case, hydro. One fifth of the flats in that area where LUMI is located is an old paper mill in the city called Kajaani. One fifth of the flats are being warmed with the waste heat of LUMI. So, we are contributing also this way to a very, very, very small carbon footprint.

James - So some positive developments in Finland. I asked Loïc whether LUMI sets a good precedent for the greener data centers of the future.

Loïc - Something that I think is really important is if we start to talk about inter institutional collaborations, we really need to keep that equitable. A lot of countries rely on high carbon power sources and we don't want to unfairly penalise researchers there saying, oh, you can't do computing in your institutions anymore, and we don't want to be holding all compute and all data which is what could be tempting to do. Say, oh, that's okay, we're going to do the compute for you. It's not just saying, 'oh, let's just use all the Nordic countries, which rely a lot on renewable energies'.

James - It's obviously a positive thing that LUMI uses a hundred percent hydroelectric power, a sustainable energy source. But what people have to weigh up in those circumstances is that it could be robbing Peter to pay Paul, it could be being used at another part of the country's infrastructure, which now has to rely on non-renewable energy sources.

Loïc - Yes, that's the challenge and that's the difference between building renewable energy facilities directly, so in practice you are adding to the energy grid, or having a green energy contract. It doesn't mean they add more renewable energy to the network. It just means part of the renewable energy is dedicated to you, but at the end of the day, it's still the same amount of renewable energy in the total network. So it doesn't really reduce the total carbon footprint of the country. Until the entire country or the entire place is powered by renewable energy, the data center is probably not zero carbon because there's still gas being produced for other sources.