The circular economy in the context of the data center

In the field of data centers, circular efforts are usually focused on upgrading, updating, reusing and disposing of obsolete IT products. Heat reuse – the process of capturing waste heat from the data center’s operations for heating purposes in other facilities – is also part of the thematic area of ​​circularity.

IT teams typically update their IT hardware on schedules that range from one to eight years, with a typical refresh rate of three to five years. The refresh rate slowed from 2015 to 2020, but is likely to increase again as the next generation of more energy-efficient IT data center equipment begins to hit the market in 2021.

Operators are expected to responsibly manage their obsolete equipment by maximizing the upgrade and reuse of server, storage and network products; reuse of spare parts components; and the reclamation and recycling of critical materials.

Best practice in equipment management is to upgrade or upgrade reusable equipment in the operator’s own data centers. Efforts must be made to minimize the percentage of obsolete equipment sent to landfills. Most states, states and provinces have laws designed to encourage or enforce recycling and reuse.

Data center operators must understand and comply with local regulations governing end-of-life products from their data center facilities. They will also have to take due care to check that the recycling products they choose manage the products and materials as promised and that the equipment does not end up in landfills. Data center operators who fail to verify the responsible management of their discarded equipment face heavy fines and reputational damage.

The reuse of recovered waste heat from data center cooling systems has become a topic of strong interest in many jurisdictions, especially in the European Union. Heat reuse is categorized as a circular theme, as the heat generated during the operation of the data center can be captured, recovered and used for efficient heating of other facilities, such as offices, swimming pools and greenhouses, or providing heat for central heating system.

Heat reuse systems are most efficient and economical when operating in conjunction with a direct liquid cooling system. The return water temperature will usually be much higher than can be achieved in an air-cooled to refrigerated or refrigerant-based cooling system.

Air-cooled IT equipment / chilled water heat removal system can power a heat reuse system, but will require more equipment and use of energy to concentrate heat. In both cases, plate and frame heat exchangers or a heat pump will be needed to concentrate the heat before transferring it to a heating supply circuit outside the data center.

In general, the return or return on investment in heat recovery systems is low, especially in smaller data centers. Innovations in data center cooling techniques will be needed to improve the heat recovery economy. These innovations could have the added benefit of reducing and possibly even eliminating water use in data centers – a significant advantage for new cooling technology.