Director,
T.E.(Terry)
Manning,
Schoener 50,
1771 ED
Wieringerwerf,
The
Tel:
0031-227-604128
Homepage:
http://www.flowman.nl
E-mail:
(nameatendofline)@xs4all.nl : bakensverzet
Incorporating
innovative social, financial, economic, local administrative and productive
structures, numerous renewable energy applications, with an important role for
women in poverty alleviation in rural and poor urban environments.
"Money is not
the key that opens the gates of the market but the bolt that bars them"
Gesell, Silvio The
Natural Economic Order
Revised English
edition, Peter Owen, London 1958, page 228
Edition 9:
The following pages contain information on factors
which condition choice of array size and pump model. If you are more interested
in other aspects concerning installation, please return to installation index.
Photovoltaic panels are generators of electrical
current which have special features. The concept "power" is relative,
nominal and theoretic. The "power" rating attributed by the
commercial world to a PV panel is the electrical power the panel could
theoretically produce in a situation of full irradiation, in a cool
environment, at the nominal voltage. However, such conditions in reality are
rarely, if ever, met in the field. This means that your PV panel is not going
to produce in real life the power its manufacturers have attributed to it.
Furthermore, in reality the PV panel is not a producer of "power" at
all, but a producer of electrical current proportional to the amount of light
it receives. It should be rated according to the amount of current it actually
produces in real operating conditions rather than on its "rated
power". Unfortunately PV panels are still, for "historical"
reasons, classified according to their "power". While there is indeed
a relationship between "power" and "current" it is very
easy to make mistakes as in a given application the panel must be able to
produce a certain MINIMUM CURRENT.
a) The coupling ratio needed to turn the pump. This is a function of the
cam size used and the pumping head.
b) The speed the pump is to run at. This is a function of the desired capacity.
c) The energy needed to start the pump. This is a function of the depth of
submergence.
The coupling ratio needed to turn the
pump is proportional to the current absorbed by the motor. The greater the
ratio, the more the current required. In equal conditions, a 65 watt nominal
panel will produce more current (about 30% more) than a 50 watt panel. Two 65W
panels in series produce more current than four 50 watt panels in series,
regardless of the fact that the two 65W panels have 130W and the four 50W
panels have 200W. The four 50W panels in series obviously develop more power
than the two 65W panels because they are working at twice the voltage. But they
produce less current.
Therefore, in a Solar Spring installation with a 2.0mm cam at 100 meters head,
the pump has a given ratio and needs a given minimum current. This can be
supplied by 65W panels, either two or four, but not by 50W nominal panels in
series, whether two or four, irrespective of the overall power in play. If the
minimum required current is not there, the pump will not turn. Obviously four
50W panels connected in parallel to form 2 x 100W panels, would, instead,
develop the minimum required current. An appropriately designed electronic
controller can, in fact, switch panels from series to parallel mode to meet
this requirement.
The speed at which the pump is to turn is proportional to the available voltage. The higher the voltage, the higher the speed and the higher the capacity. Therefore four panels in series give a higher voltage, speed, and capacity than two panels in series. Solar Spring motors are optimised to run at 60V, which is a typical operating voltage of four 12V solar photovoltaic panels.
The energy needed to start the pump depends on controller design. The present Sunprimer MK II controller is built so that the energy required for start up is a function of the maximum voltage of the panels. It is therefore low where two panels are used and high where four panels are used. Therefore the pump starts more easily with four panels and can be more deeply submerged. Where two panels or with 24V battery sets are used, the controller automatically brings start up energy up to the level normally given by 4 panels.
This installation manual is very complete. The manual, together with the specifications and the technical data supplied, must be read and understood. The person carrying out the installation must be capable of assessing the many variable parameters in play when making a choice which model of pump to install, the array required, and the accessories (cable size, for example) to be used. In conjunction with solar pumps, experience is needed, and no instructions, however detailed, can cover all applicable aspects and parameters. Nor can they substitute the competence and common sense normally required of a pumps installer and a solar pumps installer in particular. The Solar Spring pumps are new generation solar piston pumps. They behave differently from other solar pumps available on the market. Dealers and users are bound to be prudent and familiarise themselves with the technology before attempting installations. The full range of fail-safe devices incorporated in the Solar Spring technology to protect the system against all reasonably foreseeable abuses may not be taken as a substitute for due competence experience and knowledge on the part of the installer.
You may have purchased your Solar Spring pump as part of a kit enabling you to install your solar water pumping system within one hour, provided provision has already been made for a suitable panel support base. In this case you will already have discussed your requirements with your supplier and identified the system best meeting your needs. If you have not, the following notes may be found of help.
One of the outstanding characteristics of alternative energy systems, and of photovoltaic systems in particular, is their flexibility. Your water requirements may change from season to season. You may wish to move your system from one place to another or to use part of the PV energy available at a given time for other purposes. You may wish to phase your purchases over a period of time to lessen the impact of initial capital investments. Solar Spring water pumping systems have been designed from grass roots level to enhance this intrinsic flexibility. Just the one system will in any case operate:
-at any depth up to 150m
-with any combination of PV panels up to 400Wp
-at any voltage between 24V and 80V
-at any speed up to 3000 rpm
-at any amperage up to 4.5 amps after start-up at 1.5 amps
It is possible to optimise your Solar Spring pump to your specific requirements so that your system is as efficient and your capital expenditure as low as possible.
To help you determine how much energy you can
reasonably expect from each peak watt installed, you may refer to locally
available irradiance maps, or for a very general indication, to the seasonal
capacity tables for the Solar Spring in the technical
information. Solar Spring pumps are piston pumps and their capacity is (+/-
10%) proportional to the available irradiance and panel size. Once these and
the amount of water needed are known, a reasonable assessment of the system
required can be made from any of the tables supplied.
Contrary to common usage with centrifugal or other
solar pumps, it is PROHIBITED to regulate the capacity or head of Solar
Spring pumps by means of the opening or closing of valves or taps, even in
emergency situations. This is because very high pressures can be developed
within the Solar Spring piston system, much higher than those associated with
traditional pumping technologies.
THE PUMP MUST ALWAYS BE STOPPED BY INTERRUPTING ELECTRICAL CURRENT.
A current control device is built into the Sunprimer controller unit to
protect pump, motor, controller, and feed pipe against the formation of
excessive pressure in the Solar Spring system. The presence of such device is
not a substitute for the application of sound procedures during installation.
Where the pump is to be used with battery sets, two 3 amps fuses must be installed in series between the power
source and the electronic controller. Please refer to 24V
Battery applications for more detail.
As an extra safety measure a safety release valve with a capacity in
line with that of the pump may be fitted above the pump to release water into
the bore-hole in case of undue pressure build up in the pumping system.
However, Sunprimer controllers already incorporate a device which switches the
pump motor off in such situations.
Switches must never be placed between the controller
and the pump. Float switches must be fitted to the appropriate controller wires
supplied for the purpose. A manual on/off switch may optionally be fitted
between the panels and the controller for security purposes. This switch will
always be in "on" mode except during installation and maintenance.
Please refer to use of manual switches for more
information.
Your Solar Spring pump can operate in extremely varied conditions.
However, where the pump is installed just under the water level, in the
presence of dirty water and/or of algae in the water the pressure of the water
at the pump inlet may not be sufficient to ensure self cleaning of the valve
system. Where you intend to install your pump less than 1 meter below water
level, please consult your supplier before proceeding.
THE NOMINAL VOLTAGE OF SOLAR SPRING SYSTEMS IS 48V.
Solar Spring will not work with 12V.
Solar Spring with 24V systems using a Mk I/D controller may have difficulty
starting at high heads and/or where submergence is deep. Use the Mk I/E
controller for 24V systems.
NEVER use the Hyboost inertia amplifier with 24V applications. The use of 3mm
cams with 24V systems is not recommended.
In case of doubt, please contact your distributor BEFORE installation.
You must first identify the DESIGN MONTH you wish to
key the size of your installation to. The design month is the month when you
need most water. This will often be the driest month of the year, when water
consumption of animals, persons, and plants is at its highest and the
availability of water from rain, rivers etc. is at its lowest. Some other
factors may however also influence your choice of DESIGN MONTH, amongst them :
a) Seasonal variations in the type and number of stock to be watered.
b) Monthly or seasonal variations in the number of persons to be supplied
c) The size and probable duration of existing or traditional water reserves.
d) The type, rate of growth, and stage of maturation of crops being watered.
e) The size and type of water storage and distribution foreseen (for instance
channel , trickle, seepage, sprinkler, or flood irrigation)
Your PV array should be large enough to meet your requirements, but no
larger than strictly necessary. Remember you can always add extra PV generators
to your array or reduce the power of your installation at any time.
As a general rule of thumb, the nominal power of your array should be AT LEAST
25% greater than actually needed to pump the amount of water required at the
most critical period. So if the pump needs 280 watts at the motor at the
critical period, your array should be 360Wp nominal power.
Location :
Latitude :
Depth of borehole
Inside diameter of borehole
Yield of borehole
Maximum daily variation in water level (daily draw down)
Maximum seasonal variation in water level (seasonal draw-down)
Total vertical lift (maximum water level + height to water outlet)
Distance away of storage tank, if there is one.
Design month :
Are there any other potentially critical months?
In such case complete the form and calculate the array size needed for each
such month.
|
Persons |
Unit need |
Number of persons |
Total daily need
m3 |
|
|
(usually 20-40 litres/day) |
|
|
|
Type of animal |
Unit need |
Number of animals |
Total daily need
m3 |
|
Cattle |
(need 40-120 litres/day) |
|
|
|
Small animals |
(need 1 litre/day each 10kg) |
|
|
|
Poultry |
(need 20-50 litres/day per 100 birds) |
|
|
|
|
|
|
|
|
Type of crop |
Hectare need |
Number of hectares |
Total daily need
m3 |
|
Garden |
|
|
|
|
Young trees |
(need 55 litres/day in dry weather |
|
|
|
|
|
|
|
|
Other uses |
Unit need |
No. applications |
Total daily need
m3 |
|
Washing equipment |
|
|
: |
|
|
|
|
: |
|
|
|
|
: |
How
much water must be used each day in design month? Answer: m3
For how many days' use is storage required? Answer: no. days
How much extra water is to be stored? Answer: m3
How much extra water must be pumped each day for storage purposes? Answer: m3
Total amount of water needed each day in design month? Answer: m3
How much of the water is already available from other sources? Answer: m3
What is the net amount of water needed daily in the design month from your
Solar Spring system? Answer: m3
Menu installation Solar Spring pumps.
Some recommended technologies.
List of attachments to the Model.
Typical list of graphs and
drawings.
List of abbreviations used.
List of key words.
Documents for funding
applications.