Solar PV water pumping study - FINAL REPORT ... - UNDP, Namibia

Feasibility Assessment for the Replacement of Diesel Pumps with Solar Pumps
FINAL REPORT: September 2006
The numbers in the cells represent the years-to-breakeven between PVP and DP. The
yellow fields represent years to breakeven for the Grundfos and Lorentz PVPs. The light
green fields represent parallel Grundfos systems in the same borehole (assuming borehole
suitability) and the blue cells represent the Total Energie TSP 2000+ series of pumps. The
grey fields marked “Diesel” indicate that the diesel option is to be selected. This is however
not due to the diesel pump solution being more viable but due to the lack of a PVP solution at
these operating points.
The figure below shows hydraulic load lines which are used to indicate what the breakeven
periods are for PVPs versus DPs. For example, the brown load line (250m 4 /day) shows that
a PVP operating on that line will breakeven from the start. All PVPs operating to the left and
the bottom of that hydraulic load line will also breakeven from the start. Similarly, PVPs
operating on the red load line (1,000m 4 /day) will breakeven in less than 2.5 years, which
decreases to 1 year as
the operating point
approaches the green
load line (500m 4 240
/day).
The orange and the
yellow areas indicate the
operating range where
PVPs are more cost
effective than DPs. The
orange area indicates
where PVPs break even
from the start. The grey
area indicates where DPs
are the technology of
choice.
High level market assessment potential
It is estimated that the total number of PVPs installed in Namibia to date is approximately
1,220 units. A survey showed that the uptake over the last five years was about 670 PVPs of
which a third (225 units) was installed during 2005.
The borehole statistics 1 for Namibia indicate that 95% of the 51,500 boreholes are less than
200m deep. Taking into account that not all boreholes are operational, that not all boreholes
contain water suitable for consumption and that assumptions were made for incomplete
borehole statistics, it was estimated that there are approximately 20,000 boreholes with a
hydraulic load of less than 1,000m 4 /day and another 10,000 boreholes with a hydraulic load
between 1,000m 4 /day and 3,000m 4 /day.
If the take-up of PVPs over the next ten years is 20% of the above number of boreholes then
the potential market would constitute an average of approximately 600 PVPs per annum.
This would mean that the current installation rate of 225 PVPs (2005) per annum needs to
triple.
The high market potential for solar suitable boreholes, the improved technology and the
superior financial performance of PVPs coupled with the availability of finance, indicate that
there is significant potential to increase the uptake of PVPs.
1 Information provided by Division of Geohydrology, Department of Water Affairs (DWA), Ministry of Agriculture, Water and
Rural Development
Head [m]
200
160
120
80
40
0
Solar pumps
0 10 20 30 40 50 60
Daily flowrate [m 3 /day]
Diesel pumps
250 m4/day: = 0 years 500 m4/day: < 1 year 1,000 m4/day: < 2.5 years
1,500 m4/day: < 4 years 2,000 m4/day: < 6 years 4,000 m4/day: < 8 years
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