The European Commission estimates an increase of emissions from 65 million tons CO2 eq. in 1995 to about 100 million tons in 2010. HFC’s are the fastest growing environmental pollution of the European Union. In Europe, fruit and vegetables are commonly kept in cold stores. These stores are very energy intensive – in the EU, refrigeration accounts for 10-15% of all industrial electricity use – giving rise to high carbon dioxide (CO2) emissions. The stores also leak refrigerants, which are extremely powerful and persistent greenhouse gases (HCFC). Standard fruit cold stores are flat and request a lot of energy for transmission (special through roof), ventilation, air circulation (fan power), door losses, metabolism, lighting and lift trucks. An energy consumption of 8,1 million kWh per year is expected, equal to 4,9 ktons CO2 / year. The refrigerant volume of a conventional store will be 7,5 tons of HFC, with a leakage of 5% and a CO2 eq. ratio of 3.800 kg/kg this contributes 1,4kton of CO2. The total emission of a conventional store will be 6,3 ktons CO2 eq.
The aim of this project was to reduce CO2 equivalent emissions of conventional cold stores by 70%. This reduction would be achieved by doubling the height of cold stores, installing an innovative air distribution system to guarantee a microclimate in the store and 100% automated internal management, and switching from HCFC to natural CO2 refrigerant energy efficient design.
The HEIGHT project designed a complete new type of store by doubling the height and creating fully automated logistics. Major advantages found were:
- less heat transfer by walls: a smaller surface/content ratio;
- minimal energy losses by open doors;
- minimal lighting;
- intensive use of space so the capital intensive automated systems become reasonably priced;
- central refrigeration system with high quality components and energy efficient control system;
- more efficient air distribution saves ventilation energy; and
- use of ammonia and CO2 to avoid HFC refrigerants.
The Height technology demonstrated that a high rise cold store using CO2 /ammonia technology offers considerable energy saving of around 75% compared to conventional cold stores. It is the first to use this innovative cooling technology, and its demonstration value is therefore high as demonstrated by the interest it generated among several industry magazines and important actors in the cooling sector.
Though the concept is in principle replicable for all cold stores, a limiting factor is that it can be implemented only in newly built cold stores and requires a high initial investment. The project, however, showed that as a result of the energy savings a reasonable payback period can be achieved (6.5 years).
The installation of the cold store has so far resulted in the creation of 13 jobs. These jobs are mostly higher skilled (process operators) than those connected with conventional cold stores (mainly fork lift drivers).
This project has been selected as one of the 23 Best LIFE Environment projects in 2009-2010. Further information on the project can be found in the project's layman report.