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Energy storage project offers potential for data centres

Energy storage project offers potential for data centres

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The data centre industry is continuing to explore innovative ways to reduce its carbon footprint, amid pressure from various authorities. Robbert Hoeffnagel of Green IT Amsterdam talks us through the findings of an energy storage project which took place at the Johan Cruyff Arena in Amsterdam and the implications of this for the future of data centres.

The European EV-Energy project is working hard to map and promote legislation and regulations of local and provincial governments that can accelerate what is officially called ‘decarbonisation of the energy and mobility sector’.

This also affects the integration of data centres and smart grids.

A project on battery storage at the Johan Cruyff Arena in Amsterdam shows how this can be achieved in practice and the benefits that this can bring.

Last summer, the Johan Cruyff Arena in Amsterdam officially launched a battery system for storing electrical energy.

This opening followed an earlier project carried out by the stadium where a large part of the roof was filled with solar panels. Generating energy through solar panels is interesting – especially if this energy can also be used immediately.

For the arena, however, many of the activities that take place here are planned in the evening hours. Storage of the energy generated by solar panels in batteries was therefore an important next step.

61 racks of batteries

It is therefore logical that last year’s opening of a hall with 61 racks full of batteries has already received some significant attention. We are now more than six months further in and it is becoming increasingly clear how important this project is – especially for the data centre industry.

This project is not only about storing energy in batteries.

In order to justify the relatively high costs of batteries, we need to develop a business case that is as broadly defined as possible. In other words: the batteries should be used in as many ways as possible so that the investments can be recouped.

That is precisely the phenomenon that makes this project very relevant for data centres, which are now also discussing the possibilities that arise from integrating batteries and UPS systems with the energy networks of grid operators.

A subsidiary of the Johan Cruyff Arena – called Amsterdam Energy Arena BV – has invested in a room filled with 61 racks full of batteries. These come from Nissan’s electric car – the Leaf.

After a number of years, the capacity of the batteries of these cars drops from 100% to 80%. This decline means that the batteries are no longer suitable for use in an electric car and therefore need to be replaced.

What to do with so many ‘useless’ car batteries?

It turns out, however, that these batteries are still perfectly suitable for storing electrical energy in, for example, an energy storage system linked to solar panels.

The Amsterdam Arena has now installed 61 racks with 590 battery packs. Good for 3 MW and 2.8 MWh.

Generating and using

What exactly does the arena use the stored energy for? This is first of all to compensate for the mismatch between the moment of generation and the time of use. The 4200 solar panels on the roof of the stadium generate electrical energy during the day, while many sports matches and concerts, for example, require energy in the evening hours.

These are serious amounts of energy. If the arena is running at full speed in the evening, the energy stored in the batteries is sufficient to meet the energy requirements for an hour.

If not all systems are actually switched on, the arena can extend this period to three hours. Outside this period, energy will have to be taken from the grid.

It is interesting to note that it is of course not necessary to draw maximum electrical energy from the batteries every evening. At times when there are no events planned Amsterdam Energy Arena BV can use the storage capacity in other ways.

Think of energy services that are delivered to the grid. This will give the local grid operator more and better opportunities to keep the grid in balance. This can be done by temporarily storing energy from the grid in the batteries of the arena or by drawing energy from them and transferring that electrical energy to the network.

Peak shaving

However, the Amsterdam Energy Arena also provides other services; for example, electric or hybrid cars can be charged via bi-directional charging stations in the stadium. But the other way around is also possible: temporary energy storage in the batteries of these cars. Peak shaving is also possible. Depending on supply and demand, peaks and troughs in energy consumption can be absorbed by using energy from the batteries.

Another remarkable application: backup power during events.

Many major artists who give concerts in venues such as the Amsterdam Arena generally do not rely on the backup energy supply in the venues where they perform.

In too many places there are problems with the quality and robustness of the network, in their experience.

They prefer to bring their own diesel generators to ensure uninterrupted power supply during their events.

With all the extra costs that entails, of course. In the case of the arena, this is no longer necessary as these artists can now call on the battery storage.

Future for data centres

With this energy storage system, the Johan Cruyff Arena in Amsterdam is an interesting example of what might be the future of many data centres.

European projects such as EV Energy and CATALYST are working hard to enable the integration of data centres and smart grids.

Batteries and UPS systems at the data centre are connected to the grid via smart management software. The advantages for grid operators are then, of course, clear.

As with the Amsterdam Arena, they can then use the storage capacity of a data centre – the batteries installed there – to help keep the network stable. Because data centres may invest more in renewable energy generation, they may also be able to supply energy to the network. Peak shaving and a better organised form of backup power is also possible.

Of course, this also creates interesting opportunities for data centres. Until now, they function on the basis of a business model that has only one financial pillar: selling space for processing data.

Especially in many commercial data centres we see that the margins on projects of this kind tend to decline: the projects are getting bigger, but the margins are getting smaller. However, an integration of the data centre and smart grid makes it possible – what we will just call – to put ‘grid services’ as a second financial pillar under the business model of a data centre.

Provided this is done on the basis of sound agreements, new turnover will be generated. Initially of course modest in size, but at the same time with a relatively high margin.

Financial possibilities

The same applies, of course, to data centres that in the future want to supply residual heat to customers for a fee.

These transactions will also have a relatively high margin and can therefore make an interesting financial contribution to the operation of data centres.

The project on battery storage in the Johan Cruyff Arena could very well serve as an example to the data centre industry.

Although at the moment the storage capacity at the stadium is not yet sufficient to supply energy to external customers, this project does show that developing and delivering energy services offers interesting opportunities to data centres.

The energy transition facing the data centre and ICT sector could thus offer unexpectedly great opportunities – not in the least financially.

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