Wanted: 30MW worth of compute capacity to warm my hometown of Groningen…
Building urban data centers to generate heat
Like all Dutch cities, my hometown of Groningen has created a plan for the transition towards a sustainable energy future (in Dutch). Part of this plan is the construction/expansion of a heat network (red zones) to supply heat to roughly 20.000 households and other buildings by 2030.
The development and operation of this heat network is done by WarmteStad, a joint venture between the city and water utilities. Extensive studies have been performed to identify potential sustainable sources, but specific details are lacking.
The target heat production is estimated at 22.763 “heat equivalent units”(WEQ) of 1000 m3 (30 GJ) each, roughly 228 GWh. In terms of data center servers running at 100% capacity during 24 hours every day, this implies a capacity of 26MW. Assuming 1kW servers deployed by 2030, this means approximately 3250 servers per year over the next 8 years.
Repurposed servers
The servers used for heat generation do not need to be new. For example, the Google facilities in Eemshaven might be able to supply them; data centers recycle their servers every 4 years. Reusing servers introduces zero additional embedded emissions, and ensures a stable predictable supply chain of well-tested affordable components.
Suitable locations
The servers could be placed anywhere within the designated suburbs, centrally in one facility or distributed in substations in each neighborhood. Single household appliances could be deployed for areas that are out of scope of the heat network.
One approach could be to issue a tender for 3 locations of 10MW each: Solicit proposals from data center developers to deliver 10MW (100 racks of 100 kW each) of heat, at a suitable temperature.
Affordable energy usage
The servers could run applications that are valuable and would have been run anyway, similar to the applications that are being run at “regular” data centers today. For example, the University of Groningen recently invested in a refresh of RUGCloud consisting of 36 servers; the 26000 servers for the city heating network could form a vast expansion of scientific processing capacity. The science budget could contribute to the cost of electricity used to power the servers, reducing the cost for the local community. Other companies like LeafCloud might be able to use/resell the added capacity. Or maybe Google could simply keep using their servers for their own cloud purposes, just located outside their data center facility.
Balancing the grid
Over time, as more servers get deployed, the 30MW of processing capacity could be coordinated with the power grid, to balance the availability of renewable wind sources. Industrial scale heat storage — e.g. salt based as provided by Cellcius — could be added to decouple the moment of processing from the moment of heat usage.
Recycle, reuse, rethink
The energy transition, achieving carbon neutrality and Net Zero targets all require net-new systems thinking. The way we have deployed and operated our infrastructure to date, got us exactly where we are today. Only a radically different cooperative approach to energy, community and urban integration can offer a path towards a sustainable future.