Data centers

Not only people need to stay cool, especially in a summer of record-breaking heat waves. Many machines, including cellphones, data centers, cars and airplanes, become less efficient and degrade more quickly in extreme heat. Machines generate their own heat, too, which can make hot temperatures around them even hotter. We are engineering researchers who study how machines manage heat and ways to effectively recover and reuse heat that is otherwise wasted. There are several ways extreme heat affects machines. No machine is perfectly efficient – all machines face some internal friction during operation. This friction causes machines to dissipate some heat, so the hotter it is outside, the hotter the machine will be. Cellphones and similar devices with lithium ion batteries stop working as well when operating in climates above 95 degrees Farenheit (35 degrees Celsius) – this is to avoid overheating and increased stress on the electronics. Cooling designs that use inn...

Generative AI is the hot new technology behind chatbots and image generators. But how hot is it making the planet? As an AI researcher, I often worry about the energy costs of building artificial intelligence models. The more powerful the AI, the more energy it takes. What does the emergence of increasingly more powerful generative AI models mean for society’s future carbon footprint? “Generative” refers to the ability of an AI algorithm to produce complex data. The alternative is “discriminative” AI, which chooses between a fixed number of options and produces just a single number. An example of a discriminative output is choosing whether to approve a loan application. Generative AI can create much more complex outputs, such as a sentence, a paragraph, an image or even a short video. It has long been used in applications like smart speakers to generate audio responses, or in autocomplete to suggest a search query. However, it only recently gained...