Prototype solar photovoltaic water Pump for Kenya rural application: Kiserian
Abstract
A solar photovoltaic water pump for rural
domestic water supply to North Kiserian (l!oS, 36ioE)
village is developed. The solar prototype pump
consists of a 4.4KW-peak power Solar Generator,
having 480 solar modules of ten, 10 x 10 cm, polycrystalline
silicon solar cells. The modules are interconnected
in series and in parallel to provide direct
current at lOOV to 350V depending on the solar
irradiance and load current. The solar generator is
inclined at an angle of 50 (degrees) toward North.
Tracking of the solar generator maximum power point at
any solar irradiation is obtained via the power
conditioning inverter, the solarverter. Solarverter
compensate for the'solar cell temperature during MPP (
tracking as well as providing alternating current of
variable frequency in a voltage proportional to
frequency control by pulse width modulation to the 3kw
rating submersible motor-pump set. Water is pumped
through 600m of 80mm diameter pipe at a monometric
, 3
head of 70m to a 45m storage tank from where it~s
distributed to the village. Chlorination is done on
the main rising pipe.
Efficiency of the whole system of between 1%
and 2% is obtained with a water output per day ranging
from 32 m3 to 45 m3 pumped on clear days depending on
the actual static water level in the borehole. Static
water level varies between 1m and 5m being at 5m for
most of the year. Annual mean daily water output is
found to be 17.7 m3/d at a global solar insolation of
4.74 KWH/m2d for the period from 1983 to 1984.
Low system efficiency observed is heavily
affected by the solar generator efficiency which is
found to be between 3.5% and 5%. The solarverter
exhibit~ a constant efficiency of 88% for the whole
pumping range and the motor-pump set together with
pipework and connections has a daily performance
efficiency of 32% to 48%. Water output projections for
an equivalent solar PV water pump as the prototype at
Kiserian indicate that, at 70m head, 19m3/d to 26 m
3
/d
annually can be pumped in Kenya rural areas depending
on the actual location. These water outputs are enough
to supply domestic water to villages with up to 1000
inhabitants.
Citation
MSc.Sponsorhip
University of NairobiPublisher
University of Nairobi Department of Engineering