Use of Ice Storage to Optimise Air Conditioning Systems Size

Ice storage tanks act as thermal buffers. They use the physical properties of water and ice to store excess energy that can later be used to cool buildings when needed. They can be charged with cheap off-peak electricity or surplus solar and wind power. Water is frozen into ice, thereby storing energy. During the day, when cooling demand is high, the melted ice is used to cool buildings. The ice buffer storage system reduces the need to generate large amounts of additional energy at times of high cooling demand and unfavourable chiller operating figures to ensure the cooling supply for the air conditioning system. Instead, stored cold generated at more favourable electricity tariffs is used. The chillers can be sized for average demand.

The ability of ice energy storage systems to temporarily store energy when capacity exceeds demand not only provides benefits to consumers, but also helps to relieve the pressure on the electricity grid during peak periods and supports a more stable energy supply overall. As the share of renewable energy in the electricity supply increases, ice energy storage systems will be able to better absorb load fluctuations.

However, the use of ice as a cold storage for building air conditioning does not only bring the above-mentioned, primarily financial benefits. By increasing energy efficiency and reducing electricity consumption, ice storage systems contribute directly to the reduction of CO2 emissions. Using surplus renewable energy to produce ice not only reduces dependence on fossil fuels, but also minimises the overall environmental impact of air conditioning in buildings. This is an important consideration in the context of increased environmental requirements for new construction projects and a strong argument when bidding for public works projects.

Ice storage systems generally have a longer service life than conventional cooling technology for air conditioning buildings. With fewer moving parts and mechanical components, air conditioning systems using ice banks generally require less maintenance, have less downtime and have a longer service life. Features that have a positive impact on the running costs of air conditioning.

Ice storage units can be easily integrated into existing air conditioning technology to improve the energy balance or they can be planned as an integral part of the cooling supply for modern, energy-saving air conditioning systems in new buildings. They are used in the air conditioning of office buildings, residential complexes, hospitals, schools and in the cooling of industrial production. By integrating the storage units into cooling centres, even entire districts can be efficiently air-conditioned via a cooling network.

Surface cooling systems, which are usually installed as ceiling heating/cooling systems and provide buildings with a comfortable indoor climate all year round, work particularly well with the ice storage system because these systems use cooling temperatures that are only slightly below room temperature to provide indoor climate control. This extends the period during which the ice storage can provide cooling to rooms.