By Tina Kramer Kristensen, Division Director in Ramboll Energy and Anders Dyrelund, Energy Planner and Market Manager in Ramboll and Head of IDA (the Danish Society of Engineers) Energy
Critics of the new planned data centres in Denmark have argued that the centres pose a challenge to the country’s green transition due to their “stealing green power.” As a result, the Danish Council on Climate Change has called for building two new offshore wind farms to ensure that the power needed for the data centres does not come from coal-fired power stations and upholds the Danish Parliament’s energy settlement regarding 55% renewable energy by 2030.
However, halting the expansion of data centres on this basis may be a short-sighted solution. Considering the positive effects of introducing data centres in Denmark – if we go about it wisely – may instead demonstrate how data centres can transform Denmark into a greener country.
A greener alternative to other power sources
Data centres deliver data services to the entire world. If they aren’t built in Denmark, they will simply be built elsewhere. Should Denmark, then, also turn down other industries? One could, in fact, blame us for exporting energy-heavy industries that hinder the process of reaching 55% renewable energy.
If we build new data centres in Denmark, our renewable energy goals actually become more obtainable. As the number of data centres increases, the percentage of renewable energy can adjust accordingly (eg 50%) without making Denmark a less “green” country. This is a good example of how a random, fixed goal should not be applied directly as a basis for decision-making.
Data centres are greener than many other power consumers. They are connected to the high-voltage grid and use power without placing a strain on the distribution grid in terms of capacity and loss. The consumption from these centres is evenly distributed throughout the year.
In addition, most data centres pay for green power themselves. Denmark can even offer a package solution with new offshore wind turbines and backup from gas-powered CHP plants that will only need to be paid for as long as it remains feasible to retain them.
Surplus heat for a greener country
Surplus heat can from smart data centres can be used by district heating grids in neighboring communities, such as in Odense, contributing to “greening” Denmark. These smart data centres may result in Denmark becoming even more sought-after as a host country and hub for data communication.
The heat pump that utilises the data centres’ surplus heat will not interfere with the capacity in the power grid or electricity production since it can be disrupted at any time due to district heating storage and backup. In this way, the use of heat from data centres also contributes to the effective utilisation of wind energy.
Large heat pumps at data centres can also be designed to generate district cooling on the hottest days of the year. In fact, one could say that cooling is a waste product of large heat pumps.
An increasing number of data centres will be located so far away from big cities that it will make no sense to utilise the heating benefits. Since 1976 we have successfully ensured that new electricity capacity is situated close to cities where district heating can be utilised. By doing the same with data centres, we ensure the safest and most efficient infrastructure for electricity and data power in big cities.
The levy on surplus heat recently imposed by Danish tax authorities to encourage greater efficiency has actually had the opposite effect. Instead, it functions as a tax on the efficiency and saving of power needed to utilise surplus heating. If one decides to, for example, invest in a better heat pump and lower temperature specifications to save electricity, a surplus heat levy would be imposed.
Debate continues over the use of big heat pumps in large district heating systems, even though they have proven advantageous from a socioeconomic perspective – resulting in administrative delays and uncertainty when it comes to projects.
Note: A version of this article “Data Centres in Denmark support the Green Transition of our Energy System” was first published in the Danish technical journal Ingeniøren. This is an English translation of that article. Read the full article (in Danish) here.