Purchasing Solar Pumping Equipment
Quality of products
Once the daily water requirements are known, the design, purchasing and installation, testing and training of users will be either done by the project implementing organization or a hired knowledgeable contractor depending on the level of expertise available. However all this tasks should be clearly indicated at the Tender document.
For organizations with low solar water pumping expertise, it’s highly recommended that they just provide water requirements and leave private contractors to propose design and take the lead in all other aspects.
As organization expertise increase, private contractor role can be minimize as proposed in table below.
Organization experience in Solar Pumping
Daily Water Requirement
Provision of Equipment
Installation & Testing
Handover & training to water committee
Attention: If the system is hybrid (solar + diesel generator) the design to be proposed should be such that maximize the reduction of diesel demand.
When tendering, it is highly recommended to include the following points for solar water pumping equipment, in order to be able to compare different offers.
System Planning and Design
– Design and install systems using computer based tools and with adequate controls and protections to be able to withstand weather anomalies.
– For the location the solar array should be tilted at a (specify degrees and azimuth angle).
– The design life of the system must be 25 years. System design should eliminate as much
as possible the use of components with a short life, for example batteries (typical life of 3-5 years). In this sense, solar tracking is not an option due to the maintenance requirements and risk of breakdown in the given locations.
Quality of products.
– Solar modules must be approved to IEC/EN 61215 and 61730 or UL 1703 certified and listed. All modules must be of a robust design.
– Control equipment must meet EN 61800-1, EN 61800-3, EN 60204-1 or internationally recognized equivalent standards
– Control equipment must provide diagnostic indicators and show status.
Attention: the market is flooded with bad quality solar modules. Cheap uncertified modules might drop their output only after a few months, making the system not to meet water requirements.
Note: a solar pumping scheme that works for the first 2 years, will very likely work for many more. Therefore, it is of paramount importance to ensure proper maintenance and servicing at least during that period. In this sense, servicing will be easier if solar pumping schemes are clustered in the same geographic area.
Proposed Check-Up Summary to evaluate Tender proposals.
1. Daily water output meet requirements
2. Full list of equipment provided together with technical specifications 3. Operation and Maintenance programme developed
4. PV modules approved to standards
5. Protection for low water level, SPU and under/ over voltage make part of system proposed
6. Control equipment quality to standards
7. Warranty of equipment detailed
8. Availability of service explain
Proposed deliverables to be provided by awarded company before last payment is made.
1. 2 day hand-on training provided on-site
2. Panels tilted at agreed tilt and azimuth angles (+/- 5 degrees) 3. Full testing, installation and commissioning report handed to
Project Implementing Organization