Article
SQFlex – The smarter choice when replacing hand pumps
Hand pumps are ubiquitous in Africa and other parts of the developing world as a relatively simple, human-powered means of obtaining water from shallow aquifers. But they are prone to breakdown and suffer from a range of other drawbacks, so advances in solar-powered submersible pumps have effectively made the manual pumps obsolete. Solar pumping systems are now being widely adopted and represent a reliable, long-term solution. According to World Vision Zambia, Grundfos’ SQFlex pumps fit the bill perfectly for communities that are upgrading from hand pumps.
Hand pumps have been around for centuries in various forms and have long been the established way of drawing water, especially in remote and rural areas. In Africa, millions of them are in use across the continent.
Until solar-powered solutions became available in Africa, there was no feasible alternative to manual pumps. Even where diesel- or petrol-powered pumps could be installed, they remained beyond the financial reach of most would-be users because of the expense of fuel and maintenance.
But hand pumps, despite being relatively cheap and representing an obvious improvement on the rope-and-bucket systems they replaced, they may pose a series of challenges.
Why hand pumps are a problem
Hand pumps, commonly found in rural areas where there is no piped-water infrastructure, can only be used where the underground water is close to the surface and produce only a restricted rate of flow. Operating them can be a time-consuming task, which means users typically have to wait in long queues for their turn at the pump.
The fact that hand pumps rely on so many moving parts means they are prone to breakdown, and because the technology is now regarded as obsolete it can be difficult to find spare parts. This often leads to higher maintenance costs than initially expected.
Some types of hand pumps use components made of galvanised iron, which can have a detrimental effect on the quality of water. Groundwater with low pH levels causes the galvanised iron to corrode and the resulting rust makes the water unsafe to drink.
Hand pumps can also inflict a social cost on users, who are in most cases women and children. The physical labour involved is tiring and the women often have to walk for hours to get to the nearest pump — and then walk home carrying heavy jerry cans of up to 50-litre capacity. These trips can prove dangerous, as the women and children may be exposed to violence and assault.
Women fetching water using a hand pump.
Solar solutions – an excellent replacement for hand pumps
According to OurWorldinData.org, the price of photovoltaic (PV) panels plunged from just over $100 per watt in 1976 to $0.38 per watt in 2019. This has contributed to the proliferation of solar-powered pumping solutions over the past decade, and they are becoming increasingly popular across Africa.
Among motorised pumping systems, PV versions are leading the way in developing countries. They are characterised by easy installation, low maintenance and zero operating costs — they exploit free, renewable energy from the sun and produce no emissions. The technology is reliable and the system can be scaled to provide multiple distribution points. This means that the right kind of solar pump, tied into a system of pipes, can feed water to a series of widely distributed taps that are more accessible to households. This reduces the time and effort required to collect water; time that women can spend instead with their families and on taking care of the household.
The SQFlex is a smart pump with a high-efficiency motor that can operate on both AC and DC power. There are helical models for higher-head, low-flow applications, and centrifugal models for lower-head, higher-flow applications.
The solution is available in a range of performance specifications, depending on the need. The SQFlex models most commonly used to replace hand pumps are the SQF 1-30 and SQF 1-70, which are well suited to extracting water from shallow depths. For deeper wells, other models can be considered.
The typical SQFlex models that replace hand pumps are SQF 1-30 and SQF 1-70.
All SQFlex pumps offer the full range of solar-power benefits: they are easy to install, incur virtually no maintenance costs and provide a reliable supply of water. In addition, they operate across a wide DC voltage range, from 30 VDC to 300 VDC, and do not require a specific voltage to run. The pumps have an integrated dry-run protection system, which is activated by an electrode. When the water level falls below the level of the electrode, the pump will automatically shut off to protect itself. It will resume operation once the water level rises above the electrode.
SQFlex specifications:
• Motor size: 0.3kW - 2,5kW
• Flow rates of up to 18m³/hour with heads of up to 250m (820 feet)
• Liquid temperature: 0°C to +40°C
• Enclosure class: IP68
“SQFlex is an all-in-one solar pumping solution that’s very simple to install and use. It has built-in dry-run and overheating protection, and when it’s installed correctly it doesn’t need much maintenance — apart from cleaning the solar panels to make sure they are operating at their best. Simplicity and durability have been key to this pump’s success ever since it was developed, and it is still unique in the market.” – Jakob Normann Olesen, Global product specialist on solar pumping, Water Utility, Grundfos.
SQFlex in action
World Vision Zambia procured 80 solar-powered SQFlex pumps to replace hand pumps in an initiative that has improved the quality of life for more than 20,000 people in rural areas across Zambia.
Women spend far less time on fetching water, and hygiene and sanitation around the task have improved considerably.
“It’s a game changer for our beneficiaries in the field. Most communities never dreamt of a time when they would see solar energy being used to pump water. Also, it used to be unimaginable that water would be readily available for people to use.” – Maybin Ngambi, Technical Programme Manager, World Vision Zambia