AI chips could drive technical innovation in fields from PCB materials to district heating

The semiconductor business as we know it today represents a tremendous global success story, achieving consistent and strong growth year on year. Analysts expect it to exceed $1 trillion in sales by 2030, and some predict a further doubling over the following decade. The overall figures are extremely impressive, although some sectors are stronger than others. While automotive has enjoyed a strong run for many years as vehicles have electrified, recent performance fell below expectations.

Markets for PC and smartphone chips also appear cooler than in the past. AI chips rank high on the list of what’s hot right now, particularly chips for generative AIr. The top companies in this space are looking clever indeed, and data centers invest in both hardware and software to satisfy end-user demand for AI-based services.

While everybody, it seems, loves the effect AI services can have on their lives and work, data center energy demand remains a critical concern. Questions include how to supply enough energy as we try simultaneously to establish greener grids fed by weather-dependent renewable sources, as well as how to deal with the waste heat that’s produced. Data center cooling has posed a major challenge for some time, and while computer and power supply efficiencies have seen continued increases, total power has also gone up. Therefore, the waste heat we need to dissipate has continued to increase.

The logic for building hyperscale data centers in colder climates, for easier cooling, is obvious. Today, the world’s two largest data centers are in inner Mongolia, where the average temperature is just 6°C, which simplifies air cooling. On the other hand, the third largest is in Nevada. One benefit here is that a plentiful supply of solar energy exists. The operator claims the campus works on 100% green power. This data center, the Switch Citadel Campus, continues to scale and ultimately plans to have a power rating of 650MW. Proximity to users provides another advantage, as the connection with the San Francisco Bay area claims to take only 4.5 milliseconds.

While it seems smart to power these energy-hungry facilities from renewable sources, we are also getting smarter about how we handle their waste heat. We have historically regarded the heat from our electronic systems – including everything from small PC power adapters to server cabinets – as a nuisance that requires quick extraction to prevent damaging the precious silicon and ensure reliability. Instead, we can regard the heat from data centers as a valuable resource and use these facilities to replace conventional heating plants in district heating systems. One current project in the Tallaght district of Dublin, Ireland, uses waste heat from the nearby AWS data center to warm local public buildings, as well as parts of the city’s nearby Technological University and over 130 affordable homes. AWS has installed heat collection systems at its data center and provides the heat at no cost as part of its sustainability commitments.

This project is not the only one. Other research investigates the practicalities and costs of capturing heat from data centers for transfer into district heating networks. Data centers today typically use either liquid cooling or air cooling. Liquid cooling is preferable if the data center supplies the local heating network. Although it costs more than air cooling, the extra cost could be offset through tariffs for the excess heat. EU research suggests that some data centers provide power intensity comparable to that of a heating plant, and this trend will likely increase as servers become more powerful and GPU-centric in the future.

Heat recovery of this type could become a valuable tool in our battle to decarbonize and improve sustainability. Clearly, there is a lot to learn about the recovery and storage of heat energy, in the same way that we have built our knowledge of capturing and converting wind and solar energy, and how we developed effective strategies for storage, including battery systems of all sizes from consumer to utility grade.

Recovering heat from electronic systems involves engineering down to the board and component level. Our specialist subject here is board design, where many of us have extensive experience in engineering PCBs and assemblies to manage heat away from sensitive silicon components, preventing thermal damage and achieving system reliability targets. Scientists develop thermally efficient dielectric materials and thermally enhanced substrates, which produce remarkable formulas with very high thermal conductivity.

As we increasingly view waste heat from systems as a valuable commodity to extract, store and reuse, we can expect further improvements in the properties of thermal materials, leading to even higher conductivity values. Moreover, these materials will integrate into c more all-encompassing heat recovery systems that efficiently capture, store, move and use that waste heat. Closing the loop like this, as opposed to traditional open-loop systems that freely dissipate any heat into the surrounding ambient atmosphere, aligns with current efforts to try to establish circular systems that ideally generate zero waste while supplying connected systems acting as consumers.

District heating systems have a long history and operate in many major cities worldwide today. Pumped hot water typically serves as the medium, although Manhattan is famous for its steam-based system that has provided many iconic images of the city and led to a few accidents. Limitations imposed by both physics and finance mean district heating systems arguably only work above a certain building density. Metropolitan areas prove ideal, and environmentally driven incentives could help overcome commercial issues. We can certainly expect AI data centers to produce more waste heat, so the future could contain more instances of schemes like AWS in Dublin, as well as further technical development of systems for capture, distribution and storage.

Alun Morgan is technology ambassador at Ventec International Group (venteclaminates.com); alun.morgan@ventec-europe.com. His column runs monthly.