This column takes us beyond the boundaries of traditional U.S. pumps and pumping systems I have covered before by looking across the ocean to the Middle East pumping practices, differences and similarities. I will discuss some of the inner workings of the Israeli water infrastructure and its attention to pump efficiency and pumping system reliability.
Bird’s Eye View
In Israel, nearly all water is publicly owned. The state acts as the legal guardian and manages the water in the best interest of the public. According to information from OECD.org, water reforms have shifted the responsibility for water treatment from municipalities to water companies on the municipal/regional level. The reform was intended to increase efficiency.
Concerns about water scarcity, climate change and environmental protection have prompted reforms to build seawater desalination plants, which significantly change traditional north to south geographical water allocation, according to OECD.org. Some of these efforts are paralleled in the U.S. by legislative-aimed processes to establish pump efficiency standards and regulations.
The yearly production of water in Israel is 2,000 million cubic meters (50 billion gallons) and almost equally comes from three sources: Jordan River and underground reservoirs, desalination plants and wastewater.
Practical Operational Structure
As the water industry shifts toward privatization, the trend is to gradually shift management of local water resources from the municipalities to privately subcontracted water companies. One of the largest water companies in Israel is the governmental Mekorot National Water Company. The activities of the company are derived from a law that authorizes Mekorot both as a supplier of water and as the national water authority.
Mekorot supplies 90 percent of Israel’s drinking water and 70 percent of the country’s total water consumption. The company delivers water to the urban, industrial and agricultural sectors, as well as to the Hashemite Kingdom of Jordan and the Palestinian Authority under commitments made in international agreements. With Israel being roughly half the size of New Jersey, the logistics of the water infrastructure has some similarities with the watershed management by state and county governments in the U.S.
Mekorot operates approximately 3,000 water supply, water treatment, infrastructure, wastewater treatment, desalination and other facilities throughout Israel. The company oversees 664 stations, 30 brackish was desalination facilities, 10,500 km of waterlines, 635 concrete and steel pools larger than 500 cubic meters, six laboratories, and eight operating and control centers.
Pumps
Most of the water pumps in Israel are vertical turbine types, and a smaller percentage is single stage double suction types. This is reflective of the general topographical terrain of Israel—rapid transition from the desert plan to mountains. Significantly higher pump heads are required in Israel generally than in the U.S., although some similarities exist.
Even for a rough estimate, based on the numbers presented above, the 50 billion gallons of water per year, if assumed equally distributed between some 3,000 pumps in Israel, an average pump moves 2,000 gallons per minute (gpm). If one further assumes 100 pounds per square inch (psi) developed pressure for such typical pump (230 feet of head), a typical motor power would be 2,000 x 230 x 1.0/3,960/0.80 = 150 horsepower (hp), with an assumed average efficiency of 80 percent.
That is, of course, an “average” picture, a very rough ballpark estimate, and some of the vertical turbine pumps in Israel are at much higher horsepower (hp), with some as high as 6,000 hp. With that, one can estimate the total energy consumption of these pumps being nearly 150 x 3,000 x 0.746 = 350,000 kilowatt (kW) = 350 megawatt (mW), or roughly a 20 percent of all electrical power generated in Israel. In other words, the energy supplied for the water needs is very significant. At an assumed cost of $0.10 per kW, this translates to $500 million per year. Thus, saving even 1 percent of this energy through pump efficiency improvement would save the country nearly $3 million per year.
Not surprisingly, the efficiency improvement programs are taking more attention at all levels of infrastructure—geopolitical, environmental, technical and economical.
The approach to efficiency improvement is through field study of actual operating pumps and determining the actual efficiency versus original equipment manufacturer (OEM). The resultant data is processed, and a new impeller is designed specifically for new or updated flow conditions, making a replacement of the entire pump to fit new operating conditions unnecessary. The pump’s BEP is shifted, resulting in increased efficiency and better reliability.
Such an approach is obviously advantageous for cost savings, since there is no impact on piping modifications usually associated with pump changeovers, foundation modifications, etc.
Summary & Conclusions
Customized design of pump impeller hydraulics is gaining momentum at all installations around the world, especially for the pumps with significant energy levels. In Israel, this trend is further enhanced by the regulations that are applied by the government agencies as a mandate to apply methods and technology to conserve energy and pump water in the most effective and efficient way, with minimum expenditures avoiding entire pump changeover.
In upcoming columns, I will offer updates on what is going on in Israel as well as developments from other parts of the world. Please send me comments about similar efficiency programs that are happening where you live.