Central cooling units with ice storage make a cooling network independent of fluctuations in renewable energy sources
Cooling networks will rapidly gain in importance in the coming years and decades and there are two reasons for this development. Firstly, the demand for cooling for industry, offices, homes and data centers is also increasing significantly due to global warming. Secondly, with the commitment to achieve climate neutrality in Germany by 2045, CO2 emitters must be reduced. However, the decentralized cooling generation currently in use is a very energy-intensive sector with a poor CO2 balance.
Why a central cooling supply has advantages
Cooling networks benefit from the efficiency potential of a central cooling system. The centrally provided cooling capacity can often be lower than the sum of the installed cooling applications of the consumers, because not all consumers call up the full capacity at the same time. By using additional energy potential, e.g. waste heat, up to 70% of the energy consumption for generating cooling can be saved. In addition, the investment costs for a central cooling system with the same output are lower than those for several decentralized systems.
Government funding and expansion of district cooling
Because of the potential for energy savings, the expansion of cooling networks in Germany is extensively funded by the Federal Office of Economics and Export Control, as well as various state programs. Consequently, many local and regional energy suppliers have incorporated the central supply of district cooling into their services. Munich and Vienna, which have invested heavily in cooling networks in recent years, are particularly far ahead. They each have created almost 30 kilometers of district cooling networks with the capacity to cool at least 100 office buildings. Further expansion steps up to 2030 have already been defined. Unlike cold local heating networks, which generally operate at temperatures between 10 and 30°C and supply heat to specific neighborhoods, cooling networks for cooling entire city districts have an operating temperature of 6 - 10°C.
Exploiting the potential of a central cooling system with ice storage technology
Ice storage systems significantly improve the efficiency of central cooling and expand the energy options for cooling. Thanks to the buffer function of the ice storage system, cooling can also be generated and reliably supplied with fluctuating wind or solar energy. If wind or solar power is not available to the required extent for cold production, the cold from the ice storage system is used, which was previously stored there with surplus energy.
Investment costs (CAPEX)
By using ice storage as a supply buffer, the capacity of the refrigeration system and the associated electrical supply (transformers, switchgear, cables, etc.) can be reduced.
The ice storage tank enables lower flow temperatures for the cooling supply. This reduces the investment costs in the cooling network. Lower flow temperatures allow for smaller pipe diameters, smaller pumps and smaller heat exchanger surfaces in the transfer stations.
Operating costs (OPEX)
Compared to decentralised solutions, a centralised cooling system has lower maintenance and service costs. These costs can be further reduced by using ice storage systems to provide a share of the refrigeration, thereby reducing the number of chillers required.
Cold generation can take place at night, when the outside temperature is lower and the chillers can run at higher capacity. This makes refrigeration less energy intensive and reduces CO2 emissions. The savings in operating costs are even more significant when favourable electricity tariffs can be used at night.
The ice storage system reduces peaks in electricity demand. This, together with a smaller number of chillers, reduces the connected load of the district cooling network. As the connected load is usually included in the basic electricity price, the electricity costs for refrigeration are also reduced.
Why the sp.ICE ice storage system is the right solution for district cooling
The importance of charging time
In addition to sufficient cooling capacity, the charging time of an ice storage system is a decisive factor for the performance and efficiency of the entire district cooling network. The charging time is the period of time that an ice store requires to generate and store cooling energy in the form of ice.
Fast loading makes a significant contribution to ensuring that as little energy as possible is lost for ice production and has a positive effect on the overall efficiency of the system. When discharging the cold, fast unloading ensures sufficient cooling energy for peak demand in the district cooling network. This is particularly important for larger district cooling networks in densely populated urban areas, where the demand for cooling can rise sharply. With integrated ice storage, the network can be planned with a smaller number of chillers.
A long charging time, on the other hand, can lead to bottlenecks that jeopardize a continuous cooling supply and also increase energy consumption.
The sp.ICE dynamics
The extremely short charging time of the sp.ICE, which is made possible by the patented capillary tube technology, ensures the cooling supply even at peak loads. The sp.ICE can be charged in 6 hours and store surplus energy from wind or solar power plants as cold.
The scalability of our ice storage technology enables capacity planning that adapts to the size of the cooling network and the number of consumers. If an expansion of the district cooling network is planned, the ice storage capacity can be upgraded accordingly.
In this way, the sp.ICE helps to reduce the ecological footprint of cooling production, reduces CO2 emissions through the efficient use of renewable energy sources and helps to exploit the potential of district cooling.
