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Municipalities & Water Pumping

In addition to district heating, water pumping is a thoroughly intensive process which requires a lot of energy use. Many municipal water companies in Eastern Europe and in the Former Soviet Union cannot pay their electricity bills. The issues are complex, particularly since water tariffs rarely rise as fast as electricity tariffs, further straining a city's ability to pay.

Many cities in the region cannot provide regular service in large part because electricity is too expensive, and the debts are piling up. The result is that water is pumped only a few hours a day or not at all. Part of the answer is energy efficiency. Reducing energy waste reduces costly electricity purchases while also improving the quality of service.

The opportunities for reducing energy waste in municipal water systems are almost limitless. What is needed is attention and care and interestingly, not a great deal of money. WHAT IS NEEDED IS LEADERSHIP FROM THE CITY HALL AND THE ATTENTION OF MUNICIPAL WATER MANAGERS.

Reducing water losses from leaks and inefficient use is another tremendous opportunity, because saving water means saving energy. Because water is so heavy, pumping it from Point A to Point B takes a lot of energy. If a liter of water does not have to be pumped because it is saved somewhere else in the system, that means less electricity use.

Many municipal water utilities in developing countries typically have system water losses which range between 30 percent and 60 percent. Even many municipalities in developed countries see water losses between 15 percent and 25 percent. In addition to leakage, issues such as theft, consumer waste, and inefficient delivery all directly impact the amount of energy embodied in each unit of water consumed. In effect, water equals energy in municipal water systems.

The Specifics

There are problems that municipal water managers may never think about, and if they do, the leadership in cities rarely concern themselves with energy issues in water delivery. But some attention can lead to impressive results. Problems are common in the areas of:

  • leaks
  • high friction losses in pipes
  • improper system layout
  • system over-design
  • incorrect equipment selection
  • old, outdated equipment
  • poor maintenance, and waste of usable water

However, solutions to mitigate or remove these problems are readily at hand. It may involve changes such as:

  • system redesign and retrofitting of equipment
  • pump impeller reduction
  • leak and loss reductions
  • equipment upgrades
  • low-friction pipe
  • efficient pumps
  • adjustable speed drive motors
  • capacitors
  • transformers
  • maintenance and operation practices improvements
  • water reclamation and reuse.

In the case of the United States, audits of city water systems found the most cost-effective measures included:

"Base loading" the most efficient plants in multi-plant water systems. The most efficient plants should be the first in operation to meet normal operating needs, and the most inefficient facilities should be used only for peak times.
Shifting operations to when electricity charges are lower in cases where electricity charges vary over the course of the day.
Modifying pumps to be more efficient.
Projects which had longer-term paybacks included variable frequency drive installation and installation of energy-efficient motors.

For an additional case study on water efficiency in Iasi, Romania please go to http://www.resourcesaver.com/ewebeditpro/items/O50F1144.pdf