ECN, Equinix and Nuon: Researching data center excess heat to expand on existing heat networks
In a recent project, ECN, Equinix and Nuon examined the possibilities of using residual heat from data centers to feed in to heat networks of Nuon in the South East region of Amsterdam.
Upgrading data center heat: a financial scope
The findings confirm that technically speaking, it’s feasible to upgrade low temperature residual heat to higher temperatures (from 90C to 120C) using innovative heat pump technology. The total cost of heat resulting from the technological solution results in approximately € 4,10 per GJ heat, based on current electricity prices.
Part of these costs lie with the datacenter, to power the cooling systems that supply heat to the heat pump. Conversely, in the new system there will be no need for cooling towers anymore. This is because ‘exporting’ heat to a heat network will automatically leave the datacenter with cold water which can be used as cooling.
CO2 emission and energy reduction
Whether CO2, energy consumption and costs of producing heat are saved with the upgrading of heat from a datacenter into a high temperature grid, depends highly on the chosen reference situation:
- Assuming that the current heat supply from a combined heat and power plant (CHP) is fully replaced by upgraded data center heat, the new situation will lead to an increase of CO2 emissions, energy consumption and operational costs for producing heat.
- Assuming that the upgraded residual heat is used to expand the existing heat net and gas-powered decentral heating boilers will be replaced – the new situation will lead to a decrease of CO2 emissions, energy consumption and operational costs for producing heat.
The above seems to imply that it is not recommended to replace CPH heat by upgraded data center heat. However, using upgraded data center heat instead of decentral heating boilers could result in an interesting business case, from a CO2, energy consumption and operational cost perspective.
The CAPEX for the heat pump is estimated between €4,5 to €9 million depending on the required heatpump technology.
Is it worth the investment?
ECN, Equinix and Nuon are currently further doing research to get a more accurate estimation the CAPEX of the heat pump, which is currently still quite broad. The results imply that it is not profitable or beneficial to use data center heat as a replacement of CHP delivered HT heat. However, datacenters could make a good substitute for decentral heating (gas)boilers in terms of CO2 emissions, energy consumption and operational costs, when a network needs to be expanded and there is no CHP capacity left, or in the absence of a CHP.