Three common myths about solar-powered water pumping

By Andrew Armstrong (Water Mission), RWSN co-lead for Sustainable Groundwater Development

Solar pumping is the trendiest technology in rural water supply today. Policy-makers and practitioners are eager to better understand its benefits and limitations and the private sector is responding with a variety of product offerings. Much of this interest is motivated by the Sustainable Development Goal to increase water service levels in the most remote areas. A more compelling driver is that rural water users are willing to pay for service that is accessible near or within their homes. There is currently no more promising technology for meeting these expectations in off-grid settings than solar pumping. Despite this high interest and the fact that solar pumping technology has been around for decades, a great deal of misinformation is being propagated.

This post aims to address a few of the most common misconceptions.

Myth #1: Solar pumping is too complicated and not appropriate for remote, rural settings

The most common barrier to adoption of solar pumping is misunderstanding of its complexity and applicability. The technology is often avoided because of perceived technical and management challenges, which are in fact common to any rural water supply system. In reality, the design and installation processes associated with solar pumping are no more complicated than other motorized pumping schemes. Operation and maintenance is more straightforward than with handpumps and generator powered schemes which, as indicated in recent evaluations published by UNICEF and the Global Solar and Water Initiative, likely leads to higher functionality and reliability rates.

Solar pumps are applicable across the same head and flow profiles as grid- and generator-powered pumps, and most solar pumping equipment available today is essentially “plug and play”. External power backup for periods of low sunlight are rarely necessary if water demand is estimated and storage is sized appropriately. In addition, current off-the-shelf computer software tools simplify equipment selection and automatically consider daily and seasonal weather and solar irradiation fluctuations when estimating water outputs.

The high capital cost of solar pumping equipment often brings its large-scale applicability into question. However, the life-cycle cost benefits of solar pumping are well documented and are within and on the lower end  of IRC’s WASHCost benchmark ranges for piped schemes and boreholes fitted with handpumps. There is no fuel cost associated with solar pumps, and the cost of maintaining power generation equipment is greatly reduced because solar modules have no moving parts and long functional lifespans. Furthermore, the cost of solar modules, which represent the most expensive element of a solar pumping scheme, continues to decrease at a rapid rate.

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Click here to read about the advantages of solar pumps compared to alternative technologies commonly utilized in remote, rural settings.

Myth #2: All solar powered water pumping equipment is created equal

Equipment manufacturers have taken advantage of demand and have flooded the market with solar pumping products of all varieties and price tags. Unfortunately, many are of poor quality and likely to fail in a fraction of the lifespan of higher priced, higher quality equipment. Low-quality products seldom come with warranties covering the first few years of operation during which failures are most likely to occur. Uninformed customers often fall into the trap of choosing cheaper equipment without considering that low-quality equipment fails quicker and costs more to maintain in the long-term. This results in solar pumping schemes which were expected to function for years failing and being abandoned after a few months in operation. The best way to guard against this is to stick with brands that have a proven track record for durability and reliability, even if it costs more up-front. It is also important to verify that products adhere to internationally-recognized certification and testing standards.

Another related challenge is that imitation spare parts for major brands are easier to find than authentic ones. Logos and barcodes can be forged such that it becomes difficult to detect if a part is counterfeit. This issue can be resolved by sourcing products from trusted dealers with good technical support capacity. The private sector can also have a positive influence on product quality. By providing local dealers with exclusive access to advanced training and support networks, major manufacturers can incentivize sales of quality equipment. In fact, some solar pumping suppliers such as Bluezone Malawi  are choosing to base their business model solely on high-quality products.

Myth #3: Scaling-up solar powered water pumping will lead to widescale depletion of groundwater aquifers

There is concern that solar pumps, because they can operate automatically whenever the sun shines, could pose a long-term threat to groundwater resources. It is true that exploitation of groundwater paired with low or misunderstood aquifer recharge can lead to potentially irreversible depletion, and there is a deficiency of good hydrogeological data in countries where the most interest is being placed on solar pumping. However, abstraction technology is just one of many factors that influence aquifer sustainability and solar pumping should not be devalued because of potential risks which can be mitigated. It is also important to note that the risk of groundwater depletion due to over abstraction with solar pumps depends on the application. Domestic supply withdrawals, in comparison to agriculture and protracted emergency applications, are likely to have negligible impacts.

Below are some actions that can be taken to mitigate the risk of groundwater depletion:

  • Proper borehole development and pump sizing to safe yield – Ensures solar pumps are physically incapable of depleting aquifers. A good resource for this is the RWSN/UNICEF Guidance Note on Professional Water Well Drilling. Simple control measures such as float valves and switches can also be employed to prevent wasting.
  • Better groundwater monitoring alerts authorities to potential risk areas. Many countries successfully employ remote monitoring systems (see, for example, the USGS’s National Groundwater Monitoring Network. Read more here.
  • Water pricing in the form of tariff collections and abstraction charges enables sustainable and equitable allocation of groundwater resources, but requires sound management built on transparency and accountability. Prepaid water metering technologies may also play a role.

Further resources

Resources are available to equip rural water professionals with knowledge and skills and stop the spread of misinformation about solar pumping. Of note:

In order to generate rich discussion and continue raising awareness of existing resources around solar pumping, the RWSN Sustainable Groundwater Development theme will host a three-week e-discussion from 28 May to 15 June 2018. For more information or to participate in the e-discussion, join the RWSN Sustainable Groundwater Development DGroup.

(Photo credits: Water Mission)

 

 

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#RWSN @ #WWW : the presentations

RWSN co-convened two sessions at last week’s SIWI World Water Week in Stockholm and presentations are available to download:

WASHoholic Anonymous – Confessions of Failure and how to Reform

All presentations: http://programme.worldwaterweek.org/sites/default/files/panzerbeiter_lt_1400.pdf

Build and Run to Last: Advances in Rural Water Services

Continue reading “#RWSN @ #WWW : the presentations”

Visit to Water Missions – Deep South Innovators

Andrew Armstong at Water Mission headquarters
Andrew Armstrong at Water Missions headquarters

This year I was fortunate enough to attend the ‘Water & Health Conference’ at UNC, North Carolina, USA again. I was running a side event on WASHTech, and my partner in crime was Andrew Armstrong, Water Missions’ community development programs manager who gave a great presentation on the experiences of Water Missions in introducing solar water pumping and water pre-payment systems in Uganda.

On Monday 21st October, after the conference, I was in Charleston, South Carolina, standing in large a naval dockyard surrounded by towering steel cranes and fat oil depot tanks. On one side of the sparse car park was a sizeable array of solar panels and opposite was long, low warehouse on which the name “Water Missions International” was emblazoned in precise, blue lettering.

I was shown around the Water Missions International facility by Andrew. There are 27 staff based in this location and numerous volunteers. The building acts an office, workshop, storage area and display area, the latter being open to groups to visit and find out about their work.

Water Missions was created in 1998 in the wake of Hurricane Mitch, which devastated much of Central America, particularly Honduras and Nicaragua.  After running operations out of their environmental engineering firm for a few years, the founders sold their company in 2001 and set up the charity and today they work in Belize, Indonesia, Malawi, Mexico, Uganda, Haiti, Kenya, Tanzania, Peru and Honduras.

Continue reading “Visit to Water Missions – Deep South Innovators”

Assessing the potential of solar powered pumping for domestic water supply in Uganda

Update from Uganda on testing the Technology Applicability Framework (TAF) as part of the WASHtech project

WASHTech, THE project (2011-2013)

In Kanungu district of south western Uganda, the Technology Applicability Framework  (TAF) work was used to assess the potential of solar powered water pumping in the country.The exercise involved representatives from the Ministry of Water and Environment, Technical Support Units (TSUs),Kanungu district local governments, local NGOs, research institutions, private sector enterprises and beneficially communities. The assessment was based on the following dimension: social acceptance of the technology in the community, environmental dimension, and affordability of the technology by community members, skills and knowhow.

Solar powered pumping for domestic supply has great potential in Uganda if the following issues are adequately addressed:

  • Scheme operators and beneficially communities should provide adequate security measures to protect solar panels from theft. In addition, communities using solar water powered pumps and bore holes should be able to access loans from banks or financial institutions for replacement of highly expensive scheme components in the event of…

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Sustainability of solar water pumping in Uganda

Latest news from WASHTech project in Uganda: http://www.rural-water-supply.net/en/projekts/details/56

WASHTech, THE project (2011-2013)

    This video highlights steps of using the Technology Applicability Framework (TAF) to assess the potential solar powered water pumping for domestic supply in Kanungu district of south western Uganda

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