Should District Heating ecosystems be integral to Data Centre design?
Even amongst those of you who avidly scrutinise the plethora of technology related articles that are published each week, it may have gone unnoticed that, alongside the ever increasing demand for data centres, there has also been a significant upturn in the level of interest being shown towards the use of district heating as a means to alleviate the traditional and generally inefficient sources of space heating and hot water and, by doing so, reduce Europe’s (and the world’s) carbon footprint. For example, the UK government, via the Department for Environment and Climate Change (DECC), in the hope that by 2030 the number of connected properties would increased from just under 200,000 (or 2%) to 20%, set aside £7 million so that local authorities could investigate the viability of district heating in their areas.
Probably, although arguably, one of the key drivers behind this increased fascination with district heating is the European Union’s (EU) binding 2030 Climate & Energy Framework, which was adopted in October 2014. This framework, which has 1990 as its reference year, builds on earlier directives and sets out to reduce greenhouse emissions by at least 40%, increase the share of renewable energy being used by at least 27% and improve energy efficiency by at least 27% all by 2030. In addition, the framework forms the foundation of the 2050 Low-Carbon Economy framework which aims out to cut emission levels in Europe by 80% by 2050. Now, although at first glance these two areas of technology may appear to be unconnected, if you dip your toes further below the surface you will soon realise that they both have one very important factor in common: heat! All district heating networks require a central heating source that can heat the distributed water to temperatures of between 85c and 120C (depending on individual provider’s requirements) and all data centres have an urgent need to dissipate the vast amounts of heat that they generate on a daily basis.
But what has all this to do with data centres? Often, as is the situation in the UK (DECC, Heat Pumps in District Heating: 2016), the focus of attention, with regard to district heating heat sources, is Combined Heat and Power (CHP) technology. However, the amount of waste heat generated by other sources, such as data centres, is often ignored. Yet, if this heat were added to the equation, and in Central London, for example, it is estimated that approximately 70% of the heat generated from potentially useful sources is wasted, the balance could tip in favour of implementing, what could otherwise be, an uneconomic district heating network. In addition, integrating waste heat from data centres into a district heating network produces major cost benefits from the data centre provider’s perspective. Therefore, to answer the earlier question – would a data centre rather utilise part of its cash-flow on waste heat disposal, or would it rather increase its revenue by recovering the heat that it generates and selling it on to a district heating network?
Although it may be thought that this suggestion would impose further restrictions on data centre location, particularly given the current trend towards using water as a cooling medium, this is not necessarily the case. Additionally, as far as Esa Muukka, the CEO of Mäntsälä Sähkö and its parent company, Nivos Oy, is concerned, the size of a data centre may not prove to be a limiting factor either. In a recent interview, Mr Muukka suggested that, where it may be uneconomic, or difficult, to link together multiple heat sources to form a larger district heating network, the recovered heat could be utilised effectively on a smaller scale, primarily within the properties that are in close vicinity to, or integral to, the data centre’s own building. However, he went on to say that:
“This could result in a big change for existing district heating companies because, if they are not careful, (unless they create partnerships with the data centre companies) they could find that they are left out in the cold.”
Furthermore, based on Mäntsälä Sähkö’s “Finnish Climate Action of the Year 2016” award winning partnership with Russian internet search engine and data centre provider, Yandex Oy, Mr Muukka would suggest that, with careful district heating network planning and data centre design, not only can air act as an effective coolant for large scale data centers but it will, as a by-product of the cooling process, provide district heating networks with a scalable, efficient and cost-effective heat source that can significantly reduce operational carbon emissions.
The level of confidence that Mr Muukka has with regard to his suggestion is borne out by the fact that in Mäntsälä, Mäntsälä Sähkö and Yandex Oy have achieved just that. Although Yandex’s Phase 1, 10 mega watt data centre is not fully optimised for heat recovery, full optimisation will occur in the centres build in Phase 2, through the use of air source heat pump plant, the city’s district heating network already receives half of its annual distributed heat energy from the plant and, as Mr Muukka goes on to explain:
“This benefits our consumption of natural gas in our heating centre and network. We have halved the consumption of natural gas already in the first phase and our CO2 emissions are 40% lower – so we have already met the European target. And when Yandex starts to build up the second phase, and they are going to build four similar plants all together, then we are actually going to receive more heat than we can utilise in the network. So, after the second phase, we will take all our distributed heat from Yandex. Consequently, except for emergency provision, this will basically alleviate requirement for natural gas in our city centre and industrial area district heating plants and, consequently, we will no longer have any CO2 emissions.”
So, to sum up, it can be seen that there is direct correlation between data centres and district heating systems. Hopefully, over time, more businesses will recognise the potential that exists in this area of technology and design mutually beneficial systems which will not only meet the requirements of the EU’s directives but which will, in turn, ultimately prove profitable for environment in which we live.
Esa Muukka will be one of the guest speakers at the Nordic Digital Business Summit which takes place at the Kaapelitehdas in Helsinki on September 22nd 2016.