The ongoing effects of climate change are aggravating the ever-increasing issues with water scarcity. The latest statistics claim that 2 bn people globally experience extremely high-water stress, and 4 bn people experience severe water stress. The solution to counter water scarcity is to involve both holistic river basin and water cycle thinking. Involve the agriculture industry; as well as cities/households and traditional industrial manufacturing; and energy providers, all of whom take their water from the same water resources.
In many cases, it has proven to be a very difficult transition, to move towards working across the different sectors. The good news is that in each individual sector, development is ongoing to find smart water solutions, often based on digital concepts.
Use the available resources more intelligently
Within the agriculture industry, which on a global scale represents 70% of all freshwater consumption, a lot of new developments are ongoing to utilize the water available more intelligently. These developments include:
- more efficient methods to limit evaporation when water is added to the fields and
- very advanced satellite control of sprinkler systems considering both weather forecasts, crop growth status, soil type, etc. to maximally utilize the water available.
As a leading manufacturer, Danfoss sees a steady increase in the use of variable speed drives (VSDs), which offer the vital controllability we need to make more intelligent use of our limited water resources. The Danfoss VLT® AQUA Drive and pressure transmitters are dedicated products made especially for this industry.
The hidden water resource
Within cities and for household purposes, many investments are being made to secure the vital water supply we all depend on. These investments can be very capital-intensive. At the same time, it’s estimated that more than 30% of all the global clean water produced for household use/cities is lost in leakage – the lowest figure being 5% and the highest about 80%.
The combined leakage is often split into 3 sub-groups:
- Background leakage (small leakages from joints)
- Un-reported leakage (leakage from small cracks), and
- Reported leakage (water leakage is visible)
Reported leakage is typically less than 20 % of total leakage
For example, based on investigations made in New Zealand, it has been proven that obvious leaks, such as major bursts shown above, do NOT account for the majority of water lost. In fact, less than 20% of water loss is related to “Reported Leakage”. Timewise, these obvious leaks are typically stopped within hours, whereas the two other types of leakage continue to run 24/7, 365 days each year.
Average 38% reduction in leakage
The background and unreported leakages can be reduced by either replacing pipes or implementing pressure zone management. Replacing pipes is of course a very expensive solution whereas pressure zone management has proven to be a very cost-effective way to reduce water leakage. The basic principle is to split the city’s water distribution system into pressure zones, installing a booster pump (consisting of a pump, VSD and pressure transmitter) in each pressure zone to operate on the lowest possible pressure. Statistics from 112 pressure zone management cases in 10 different countries show that on average, a 38% reduction in leakage was obtained, together with a 20 – 40% energy reduction, and a reduction in new leakages of more than 50%. In many locations, reducing leakage has proven to be the largest “untapped water resource”.
Save water by regulating use to a real need
Many industrial facilities use large volumes of water both for processing and cooling purposes. As water is often relatively cheap, there has not been a lot of focus on whether less water could be used – except in locations where water scarcity has threatened to reduce production capacity. Several years ago, Danfoss’ own central factory, located on the island of Als in southern Denmark, experienced a situation where lack of water could become a critical issue. Over a few years, an internal focus on reducing both water for cooling and production processes resulted in an 80% reduction in water consumption. The key issue was of course regulation of water usage to follow the real need. Once again, VSD technology was the right control handle for solving the problem.
As has been described within all the three main segments using freshwater, the solution to our challenges is to deal with water in a much more intelligent way. Often digitalization and VSDs are the key components offering vital controllability, enabling us to limit water scarcity issues instead of creating new water facilities. Utilizing this “hidden water resource” often proves to be much less expensive than the alternative: generating new water sources.
Learn more about using VSDs in water management here. And discover more Danfoss water management solutions here.
Author: Mads Warming, Global Vertical Development Director for Water, Wastewater & Pumps