Energy storage - both high temperature and low temperature - is a vital element in the deployment of the flexible energy system, that will enable the conversion from conventional fossil fuel energy to green energy.

Throughout the past four years investments have been made into low-temperature heat storage to further develop and commercialise the PTES solution including a special lid technology. The goal was to create a commercial technology with well-documented and verified solutions that would address some of the key issues such as accumulation of moisture within the lid construction observed during previous deployment of the technology. In the beginning of 2020, the first large-scale lid solution applying the new patented design was completed and delivered to the Danish district heating plant Marstal Fjernvarme. The new and optimized lid replaced the existing one, which was of a previous design and damaged due to moisture accumulation.

“Over the past years, we have followed the development and optimization of the PTES technology for the purpose of establishing a potential cooperation in relation to our integrated energy systems with both high and low temperature thermal energy storages. The new solution looks very promising, keeping focus on providing utility companies with the necessary reliability and operational stability for long-term infrastructure projects”. says Svante Bundgaard, CEO at Aalborg CSP A/S.

The PTES technology has great opportunities and several projects between 200,000 and 1,000,000 m3 have already been identified in what is considered a promising pipeline within the European countries, even though the technology is still not implemented in many countries. However, with the new design concepts and a large-scale commercial project already implemented and under-going testing, the PTES technology will be a key element in the energy infrastructure development in the coming ten years.

Experience synergies creates new opportunities

Aalborg CSP holds profound experience in designing and developing complex energy and storage systems - nationally as well as internationally. An example of this is the integrated energy system project in Australia, where sunlight in combination with seawater is used to supply a desert-farming facility with freshwater, heating and electricity. Likewise, the system includes thermal energy storage units with 22,000 m³ high and 6,000 low temperature storage capacity. The PTES technology is thus a perfect match for Aalborg CSP, as the company is highly experienced within technology and system integration with key competences such as performance modelling and system design.

In addition to acquiring all right and patents for the technology, Aalborg CSP also strengthens their integrated energy system and energy storage department by welcoming two experienced specialists from Arcon-Sunmark. Both specialists will continue working on the PTES solution as well as the patented lid technology and will assist in ensuring the dissemination and implementation of both products.

“We know that the key to the future lies in cost-effective and reliable energy storage solutions. We are pleased that we now get to implement a technology that can help ensuring the expansion of the energy infrastructure in relation to low-temperature energy storage and help stabilizing and creating balance within the energy system. There is no doubt that this solution will be an essential part of the energy system of the future throughout Europe.”

Energy storage has for a long period of time been a focus area to Aalborg CSP. Throughout the years, the company has been working with high-temperature energy storage. They have, among other things, investigated the potential of using different mediums – such as concrete, molten salt and oil – with the purpose of enabling the production of electricity, when the sun does not shine or on windless days.

Energy for heating and cooling of homes constitutes 50% of the total energy consumption in Europe. It can be stored at temperatures below 100°C, at which temperatures the industrial excess heating, the heat pump interaction as well as solar heating can be utilized.