Green Water

Maria Parsons who works in our design team asked her father, Professor Steve Parsons, to write an article for us about a student project at Syddansk Universitet Sønderborg; a valuable and positive project trying to solve environmental problems.
Steve tells us about the origins, technology, establishment as well as progress and future plans of Project Green Water.

Origins
Green Water is still a relatively young endeavor growing out of a student project completed in 2012. Students were given the problem of how to utilize the energy source of the water in Sønderborg Sound adjacent to the University. What they came up with was a technological innovation, a unique system combining a heat pump with air conditioning (cooling) situated in the basement of the University. The prototype they created with a 7 kilowatt heat capacity and a much greater cooling capacity was a success, and the students graduated with flying colors receiving an Alsion Innovation Award into the bargain. The award was given in recognition of the fact that those involved had seen the very significant possibilities of utilizing seawater as a thermal energy source.

The Basics of the Technology
At a depth below 20 meters in Denmark water has a constant temperature of 7 degrees centigrade; this heat is then harvested through an integrated heating pump system – like a conventional refrigerator in reverse. The fact that the temperature is constant is important and means it is more efficient that a thermal ground system of pipes where on occasions the surrounding temperature can sink below 0 degrees centigrade. The uniqueness of the system is that it then uses the water for cooling – for air conditioning or perhaps for food storage (if the temperature is not low enough it is – under all circumstances – much more energy efficient than starting with the ambient air temperature). Obviously this technology holds the prospects of replacing conventional air-conditioning systems, which are high maintenance and use significant levels of electrical power. It can potentially save up to 90% of the energy consumed in comparison to conventional A/C, significantly lowering CO2 emissions.

The Establishment of Green Water
What was achieved, it was felt, was too important to just put to one side and move on. On graduation some of those involved set-up their own separate research project, Green Water, with the aim of further uncovering and developing the vast potential of the technology so that it could be utilized as part of the environmentally friendly energy solutions for the future – as a part of an integrate system of green energy. Enough promise was seen in the work for the local authority of Sønderborg, the University of Southern Denmark in Sønderborg, the publicly owned District Heating firm, and local industry to give their support – moral, financial and logistical – to Green Water. Sønderborg, a town with a population of 27,000, situated on the island of Als a relatively short distance from the border with Germany, is committed to Project Zero – to be carbon free in energy use in the foreseeable future – and support for Green Water is seen as part this commitment.

The Progress Made
Building on what was achieved with the prototype was scaled up ten times and made into an effective system with a 84 kilowatt heat capacity (equivalent of 10 households) – this time a separate building, named Hardeshøj Living Lab,  a few kilometers from the University was put at the disposal of Green Water. It was officially opened and up and running by October 2015. In the parlance of engineering/technology it can be considered “a proof of concept” and a living lab, working as a ´sandbox` (building ideas and prototypes into products) to test and improve the technology.

Plans for the Future
Green Water has been given money by the Sønderborg local authorities to show off the technology at an international scouting arrangement in the town with an expected attendance of 40,000 or so youngsters, by constructing a small mobile unit to heat a swimming pool. However, the next big stage of the work is another expansion of the technology to a 5 megawatt heat capacity (700 households). The plans are that it will be housed in a glass construction of some type so it will be fully visible as a working system – visitors will be encouraged and in this way it is hoped that the advantages of this green friendly way of heating and cooling will be seen and adopted by others in Denmark and in other countries. Future work will continue to improve and scale up the technology. The sea contains vast amounts of thermal energy, which unlike other renewable energy sources is not of an intermittent nature, and the technology offers the opportunity to fulfill the needs of heating and cooling for cities, populations and industries in coastal regions (it is currently estimated that about half the world`s population lives within 60 kilometers of the sea and three-quarters of the large cities coastally situated.

http://www.unep.org/urban_environment/issues/coastal_zones.asp