Using solar

Following a worldwide energy transition to renewable solutions, humanitarian and development actors are increasingly using solar photovoltaic solutions in their programmes, including water supply projects. A number of factors, such as reduced costs, reliable technology, a booming private sector, high solar radiation in vast areas of Africa, Asia and America, and environmental advantages, among others, have been pivotal to bringing about this renewed interest in solar PV solutions in the relief sector.

This expansion is also creating local value and jobs, mitigating climate change, and creating stronger community resilience

Despite its numerous advantages, solar PV water pumping is not a panacea and careful contextual analysis beyond technical considerations should be carried out before its adoption.

Advantages related to adoption of Solar Pumping Schemes

Low Operation costs since fuel is not needed and system run on sunlight
No dependency on erratic or expensive fuel chain supply (avoid also the risk of fuel theft) or faulty grids
Low regular maintenance requirements since solar panels and invertors have no moving parts

No pollution or noise produced

Extended lifetime (good quality solar panels are warrantied for 25yrs, invertors typically 6-8 years)

Modular solution that can be expanded easily by adding modules and other accessories

Disadvantages related to adoption of Solar Pumping Schemes

Capital costs typically higher than equivalent diesel solutions. However, systems prices are increasingly dropping
Lack of incentives for organizations to adopt better energy solutions in the field.
Inability to properly show benefits to donors and management. Some donor decisions dominated by initial investments.
System is dependent on solar radiation levels
Typically, spare parts and knowledgeable technicians are only available at capital level
Water stakeholders have not institutionalized their scattered solar expertise

Guidance Note on the Use of Solar Pumping.

Rationale for the Use of Solar PV Pumping solutions.

The factors mentioned above make conditions ripe for solar pumping to be considered as a default option for water provision in places with medium to high solar radiation, especially in off-grid locations, long term camp contexts or there where fuel is needed to provide water but its supply is too costly or erratic.

The presence of some  trained private sector contractors with good quality solar pumping equipment in literally every country, further support solar uptake and should be counted upon by relief and development organizations in order to facilitate adoption of solar solutions for water supply projects.

From an energy intervention point of view, prioritization of smart-energy, life-saving activities that also lead to a reduction in expenditure over time should make the support of solar technology for water provision a priority intervention.

Additionally, friendly environmental considerations make solar pumping technology a climate-smart choice, especially when considered against any diesel-based option. The high potential for cost-reduction would be only realized if analysis and funding decisions are based in costs over life cycle of schemes (or in other words, costs over time) rather than on capital costs of installations only.

1. Refugee/ IDP Camp context: mainstreaming of solar pumping.

In camp contexts with a perspective of being in place for more than 2-3 years, solar pumping should be considered as a default solution and from as early stage in time as possible [3], whenever solar pumping solutions are able to meet a significant amount of the water demand.

Solar pumping solutions should be the default option in refugee camps with high solar radiation and their adoption should be considered as early as possible.

Stand-alone solar systems should be favoured over hybrid (solar + diesel generator or other back-up power source) because of their higher cost saving opportunity and simplicity for operation and maintenance.

However care should be taken whenever a rapid change in context could translate into longer pumping hours, going beyond the solar day; for example when population figures are not well known or are prone to sudden increases at short notice (e.g. large refugee inflows) or when the behaviour of the aquifer is largely unknown (eg. unknown safe pumping yields or possibility of large variations in drawdown).

In older camps, solarization of water schemes should be prioritized looking first at camps with high recurrent costs to ensure water provision or with high potential of water shortages due to irregular or inexistent electricity or fuel supply to power water pumps.

2. Host community context: social aspects before technology choice.

Solar pumping is, from the technical point of view, equally appropriate for water supply projects at host community level (villages and towns). It should be considered as a default option especially there where diesel generators are used, in order to increase sustainability and resilience of communities. However, and as a difference with camps –where there is normally a permanent presence of relief organizations- aspects to do with ownership, operation and maintenance, add an extra-layer of complexity.

At host community level, adjustments related to the collection and use of water fees will need to be introduced and discussed, as solar solutions might not require constant inflow of funds to operate and it might take years for equipment breakdowns to happen. Therefore, current narrative of solar powered water systems for communities should shift from ‘tapping into a cost-free source of energy to pump water’ to ‘cumulating funds for system replacement’.

A well thought social approach, involving contribution from users, should come before technology choice. In this sense, prioritizing communities with strong social cohesion and coordinating approaches with government water offices should be a pre-requisite.

3. When solar pumping should be discouraged and current challenges.

Solar pumping should not be seen as a blanket solution to every water supply project, and its use is discouraged in some cases, namely:

  • Where theft and/or vandalisms of solar pumping schemes is widespread reported from past interventions
  • When the expertise of the implementing organization is low and private sector support cannot be counted upon
  •  Where solar technology does not bring any significant technical or economic advantage vs existing solutions in terms of amount of water supplied, cost saving incurred over time or simplicity of operation and maintenance of equipment

4. Issues related to Operation & Maintenance, Training & Evaluation.

Solar pumping schemes will suffer fewer breakdowns and have much less intensive maintenance than generator or hand pump schemes. However solar pumping schemes can and will experience technical problems at some point in time that cannot be solved at community level (or for which the organization in charge of water scheme will probably need support), regardless of the training provided in the past.

Geographical Clustering and Maintenance Service Agreements are a good way to ensure timely servicing and repairs in places where parts and technicians are only available at capital level.

As such it is important that service agreements are established prior to any installation, and renewed as years pass by, with a quality private contractor, water utility, water service provider of relevant government technical office.

Besides and since the single most important barrier towards a wider adoption of solar pumping solutions is the weak technical expertise of most WASH organizations, support from private sector, government and/or the donor community should be provided or encouraged for capacity building activities to take place in areas with high potential for adoption of solar pumping solutions (e.g. areas with high solar radiation and high dependency of fuel based solutions for the supply of water).

Additionally, ways of collaboration (with for example academic institutions, knowledgeable private companies or water utilities) should be encouraged in order to make training activities as sustainable or prolonged in time as possible.

Finally, since adoption of solar pumping solutions is many times based in the long life expectancy of solar products, it will be important to support evaluations of older (+5 years) solar systems, in order to build up stronger evidence on the adequacy of solar pumping technology for the given context as well as to inform future water strategies in the country of work.

Facts & Figures

  • Working life of solar modules warrantied to 25 years.
  • Cost of solar modules reduced by 80% in the last 10 years.
  • Cost recovery of solar pumping investments vs diesel technology is on average 0 to 4 years.
  • Cost reduction over life of the systems is -40% to -90% when compared to diesel generators
  • Well designed and maintained solar systems can function over 10 years without any major failure
  • Solar pumping Heads of +450m; peak pumping rates of +240 m3/h.
  • Water pumps with power motor from 150W to +220kW can be solarised.
  • Service agreement average cost with contractors to ensure functionality, about 1,500 USD/ year
The Solar Hub Team
The Solar Hub Team
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