Use of a ground water heat pump (GWHP) to cool FTTx street cabinets

Member company: Eurofiber
Country or geographical scope: Global
Period: 2015-
Segment of the value chain concerned: Internet service provider
Product/service category involved: Street Cabinets

Abstract:
ISP’s can achieve significant reductions in their energy usage, and thereby reduce their greenhouse gas emissions, by switching to GWHPs to cool their street cabinets, rather then using conventional air conditioning. In addition GWHPs require less maintenance reducing the amount of truck rolls needed for service.

Context

As a sector we are well aware that every party has a responsibility to reduce their carbon footprint. Digital services are often a way to reduce the need for travel or transport of physical goods. However digitization itself is not currently free of its own impact on the environment. Therefor as a sector we must act to reduce our own footprint as well. We cannot however do this alone and we believe that by sharing best practices we can help and inspire others to go beyond their current efforts, ultimately to the benefit of all society.
 

Solutions

Active equipment used by the broadband service can require cooling to ensure uninterrupted service. Traditionally this has been done by using conventional air conditioning. This is an effective method of cooling, however it requires addition power, and thus carbon emissions. An alternative that has been used by Eurofiber for its street cabinets is to cool them by using a ground water heat pump (GWHP) instead. What a GWHP does is to keep the air in the street cabinet stable by pumping up ground water from a well deep in the earth. The temperatures there are relatively stable at around 15 °Celsius year round. By pumping this water through a heat exchanger the GWHP can cool during the summer and provide heat during the winter, which also eliminates the need for a separate heater. A GWHP has a very low energy consumption and requires little maintenance, which reduces their footprint further by reducing the amount of truck rolls.
 

Results

Eurofiber has been able to use GWHP systems to cool some of their street cabinets. Given the need to dig fairly deep to reach ground water of the correct temperature this is not always feasible. Where it is possible it works very well though, energy consumption at peak is only 3% of what a conventional air conditioned street cabinet would use and maintenance costs are much lower, making it an ideal solution.
 

Conclusions

As enablers of digitization the broadband sector is already doing much to help other reduce their footprint. We must however as a sector do more and also look at our own footprint. An important step in this is the transition to full fiber networks. However even fiber networks use active equipment that requires cooling. The example of using ground water heat pumps is an example of how we can reduce our own carbon footprint by both reducing our energy usage and reducing the need for maintenance.