The Danish district energy company HTF is establishing district cooling in Høje Taastrup city centre. Driven mainly by heat pumps, the system aims to preserve heat supplies and ensure a low price on heat while at the same time providing energy-efficient, cost-effective and environmentally friendly district cooling.
Ramboll has developed the business plan and project proposal, and mapped the potential supply areas. Currently, Ramboll is working on the technical designs to be used for the tender phase for the heat pump and thermal store facilities.
A new network of pipelines
In essence, district cooling is the distribution of cold water to buildings in need of cooling. During the feasibility study and mapping of potential cooling customers in the area, several office buildings with a high demand for cooling were identified.
- The project involves building a network of pipelines, where you construct only parts at a time. Not all buildings are ready to be connected to a district cooling network so it will be an ongoing process to build up this climate friendly and long-term energy solution, says Peter Kaarup Olsen, Senior Consultant at Ramboll’s Energy division.
Supplying cooling for vegetables, fruits and flowers
Ramboll created a business plan and a project proposal for the southern part of the municipality by outlining finances and developing a fictive district energy network. During 2014 mapping was carried out and it showed a great potential for district cooling.
- Specifically in the southern part of Høje Taastrup, we’ve begun the development of the district cooling network which will include “Copenhagen Markets”. The 67,000 m2 roofed halls are ten metres high and form the largest Northern European wholesale market for fruits, vegetables and flowers, says Peter Kaarup Olsen.
Socio-economic and financial benefits
Ramboll has been involved in the project since its initiation. A 2014 feasibility study showed a significant socio-economic and financial gain by establishing centralised cooling in the municipality of Høje Taastrup. By utilising excess heat driven by heat pumps HTF will supply consumers with cooling and 10-15% annual energy savings.
- The installation of centralised cooling has multiple societal benefits compared to individual chillers. It enables utilisation of significant amounts of waste heat, reduction in investment costs, utilisation of wind energy and flexible electricity consumption when cooling and heating are co-generated, says Peter Kaarup Olsen.
Centralised cooling leads to higher efficiency
The project will be financed by selling the excess heat to the municipality’s district heating consumers together with the economies of scale.
- By installing few centralised cooling plants, instead of multiple decentralised ones, you use less power overall due to enhanced efficiency. Further, you will reduce costs for investment and O&M (Operation and Maintenance). Thus, the amount of energy needed will decrease and you achieve higher efficiencies. The cooling network should exploit synergies with district heating through co-generation and storage of heat and cooling which results in an intelligent use of energy, says Peter Kaarup Olsen.
The convergence between heating and cooling constitutes a challenge when seeking to include all excess heat in the network. Particularly during summer, when cooling consumption is at its highest and heating consumption at its lowest, the changing heat production makes it difficult to store the excess heat. Here, solutions such as storing the energy in the groundwater or constructing a comprehensive lidded storage pit, as seen in Vojens, are considered.
With 30 years of experience within district energy Ramboll offers a full range of services and has served as energy advisor for HTF for many years.