WASH Cluster – Groundwater Pumping GWP GWP3 2 What role should users have in deciding water supply system? In groups discuss the following points Areas for involvement Possible limitations Benefits of standardisation two scenarios; 1. Community pre-disaster 2. Post emergency situation Involving communities in pump selection
WASH Cluster – Groundwater Pumping GWP GWP3 VLOM Village Level Operation and Maintenance Pumps should be: –Easily maintained by village caretaker, requiring minimal skills and few tools –Manufactured in-country, primarily to ensure the availability of spare parts –Robust and reliable under field conditions –Cost effective –Choice by community of when to service –Choice by community of who will service –Direct payment by community to the caretakers
WASH Cluster – Groundwater Pumping GWP GWP3 Hand, Motorised or Alternative Energy? HandMotorisedAlternative Advantages-VLOM -Reliable - Very easy to draw water - Often quick to implement - Isolated rural areas have no access to energy services Disadvantages-Difficult to draw water, especially from larger depths -Water can be drawn when it is needed. -Higher chance of the mechanisms failing or needing repair -Repair requires skilled labour -Effect on the environment -Cost of fuel -Often very expensive especially PV -Solar can only pump during the day – need to store water
WASH Cluster – Groundwater Pumping GWP GWP3 6 Handpumps For smaller communities with 50-1,000 inhabitants handpumps are the most economical choice Electrical pump from Grid If power is reliable, and the community has a population of about 2,500 Diesel Pumps For a community with 1,000 to 2,500 inhabitants. However, running cost is 20%-25% higher than electrical pump Solar Pumps For communities with 600 to 1,200 inhabitants, small solar pumps are cost-effective when pumping lift is not high Choice of technology
WASH Cluster – Groundwater Pumping GWP GWP3 7 Choice of Handpump Technology The most important factors for stress on a handpump are the number of users and the pumping lift, both factors increase the workload exponentially. If the groundwater is aggressive, pumps have to be corrosion resistant. Depending on the size of the user group, family pumps or community pumps should be used. Shallow wells with less than 7 metres water table allow suction pumps; up to 15 metres lift direct action pumps might be used, deep well pumps can cover the complete range but are expensive. Easy to repair pumps allow village level maintenance.
WASH Cluster – Groundwater Pumping GWP GWP3 Range of Lift Suction Pumps: 0-7 metres Low Lift Pumps: 0-15 metres Direct Action Pumps: 0-15 metres Intermediate Lift Pumps: 0-25 metres High Lift Pumps: 0-45 metres or more
WASH Cluster – Groundwater Pumping GWP GWP3 9 Application Range of the most common Handpumps
WASH Cluster – Groundwater Pumping GWP GWP3 Solar power The high initial capital cost, 4 to 5 times higher than a diesel installation, is due to the high cost of PV panels. The power requirement is the product the pumping head and the water flow, expressed in m 4 /d (m 3 /d x m). For applications of less than 200 m 4 /d handpumps are more economically viable. For heads of up to 50 m and about 800 m 4 /d, solar systems are viable. From the economic point of view, large solar systems are less advantageous. PV systems become uneconomical compared to diesel systems at a range of 2,000 to 4,000 m 4 /d. PV power systems do not emit substances threaten human health or the environment. The Energy Pay Back Time is the time in which the energy used for the production of a module is compensated by the electricity generated with it. The EPBT for PV systems is presently about one to two years.
WASH Cluster – Groundwater Pumping GWP GWP3 11 Security and Maintenance of Solar Theft and vandalism of solar modules is a threat to solar PV systems. It is imperative to involve the community fully and to have complete ownership. Fencing off the system prevents theft. Fences should be 2 metres high, with barbed wire, and have gates with proper locks. Communities might decide to employ a night guard and pay his salaries. O&M by the community consists of wiping panels and keeping the water points clean. For maintenance and repairs, a maintenance contract with the supplier to provide the necessary back up may be signed. The technical back up should include spare parts supply. Long-term contract with a reputable, well established company are needed to achieve long service life of up to 20 years. Contracts should be endorsed and regulated by the government department in charge.