22 May 2008

ENERGY SUPPLY SOLUTIONS, NEW WAYS AND MEANS: THE USE OF NATURAL REFRIGERANTS AND THE ENERGY CONTRACTING SERVICE


Since 1994, the use of refrigerants containing CFCs is no longer permitted in
Switzerland, since they damage the ozone layer. Also since January 2004, there are strict
limitations on the use and method of use of the chorine-free refrigerants which have been
employed in their place (FC, HFC). Alternatives for use in heat pumps are offered by natural
refrigerants such as carbon dioxide (CO2), ammonia (NH3) or propane. The Zurich Municipal
Electric Utility (ewz) operates, within the framework of energy-contracting agreements
throughout Switzerland, heat pumps and refrigerating machines with a total power of 27 MW.
The most important aim of the involvement of ewz in the contracting market is the efficient,
cost-effective and at the same time resource and environment protecting provision of energy.
Where ever possible, heat pumps and refrigerating machines using natural refrigerants
(14.5 MW) are used. Experience so far has been uniformly positive, and reliability is on a par
with that of heat pumps using conventional refrigerants.