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 About Bakens Verzet




T.E.(Terry) Manning,

Schoener 50,

1771 ED Wieringerwerf,

The Netherlands.

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 22: 04 December,2006

Detailed specifications of the Solar Spring pumps.
Components description.


The horizontal axis piston technology used for the Solar Spring pumps needs less than 300 Watts of solar-electric or wind power in the world’s most rugged operating conditions to pump water as high as 150m (450 vertical feet) with a flow of up to 27 litres/minute (7 gallons/minute) in shallow applications. It can be used with or without batteries. It is an economic solution to small-scale pumping problems in off-grid applications including water for livestock, alternative living, nurseries, micro-horticultural and industrial projects, high pressure washing, water for missions, schools, hospitals, refugee camps, nomadic groups, drinking water supply projects in developing countries, mobile units with batteries, fountains, week-end and holiday houses and camps, and isolated locations generally. It enjoys service in the world’s roughest operating conditions where competing technologies cannot be used, and thrives in low power applications.

The pump is made from stainless steel, with highly resistant parts operating within their normal design stresses in settings up to 150 metres (450 feet). Sacrificial anodes can be fitted for use with brackish water or waters containing particularly aggressive elements, which may shorten the duration of some parts. If in doubt, consult your supplier.


Uses power of one light-bulb.

Positive displacement.

Pumps from 150m (450 ft).

Capacity up to 11m3 per day.

Submergence to 50m (150ft).

Air-cooled motor can run dry.

Made from stainless steel.

Up to 60% subsystem efficiency.

Easy to install.

Fits in a 4 inch well casing.

Tolerates sand and aggressive water.

No trackers or batteries needed.

Is cost effective.


Photovoltaic (PV) panels generate electricity directly from the sun’s light, with no moving parts. They may be mounted on a fixed structure or on a solar tracker which follows the sun to extend daily operation. The solar array may be mounted some distance away from the water source. Most systems are designed to pump only during the daytime to fill a storage tank or pond. This is usually more efficient and reliable than using batteries. Solar Spring systems use an electronics device to connect the photovoltaic (PV) panels directly with the pump motor, eliminating the need for inverters and/or battery storage, but they also work with batteries and with wind generators.


The pump,

Inside the Solar Spring pump body there is an oval camshaft which drives two large horizontally opposed pistons which operate over a very short single action stroke. The length of the piston stroke varies with the size of the cam shaft fitted from 1mm to 1.5mm.  The pump mechanisms are bathed in non-toxic oil and are separated from the water in the system by means of stress-free gaskets. The pulsating flow of the single action system is made smooth by an internal damper and by the use of flexible drop pipe. All parts of the pump work within their normal materials stress levels to a depth of 150m (450 ft).

The motor.

The specially developed 4 inch permanent magnet 48V DC motor works efficiently at variable speeds. A brush type motor was chosen for reasons of efficiency, reliability and economy (brush-less motors need more complex electronics). Motor brushes, with normal solar daytime use, usually last up to 7 years. They can be replaced within a few minutes in the field without disturbing the wiring. The motor can turn at from 0-3000 rpm and is optimised to work best at 2000rpm.

The controller.

The Sunprimer controller provides a surge to start the motor and boosts the current in low sun conditions to prevent stalling. Its simple and robust circuitry is placed in a water tight enclosure which is usually fitted behind the photovoltaic panels. The controller is fitted with wires enabling float switches to be connected.

The inertia amplifier.

The Hyboost inertia amplifier is fitted to the shallow well (3mm cam) model of the Solar Spring which is used for installations where the water level is not greater than 45m (150 ft). The Hyboost is advanced but simple technology enabling miss-match in the hydraulic system to be absorbed and returned to system at the appropriate moment of the pumping cycle. Available current from the photovoltaic panels can be fully used and motor absorption and  pump capacity in some cases more than doubled. The inertia amplifier does not increase pump efficiency, but that of the installation as a whole.

The solar array.

Any combination of photovoltaic panels with a nominal power of up to 400Wp  can be used with the Solar Spring pump. Voltage at the motor can be anywhere between 24V and 80V. The DC motor is designed for 48V nominal voltage, with a standard operating voltage of 60V. It can also be run at half speed with a nominal voltage of 24V. Direct current is usually fed directly from the photovoltaic panels  to the pump motor. Neither inverters nor batteries are necessary. However, battery systems can be used where no water storage is required.

The rest of the system.

The system is completed by a flexible polyethylene drop-pipe supplied in one continuous length to enable installation by hand within a few minutes; by good quality submersible resin packed leak-proof electric cable; and by an appropriate length of good quality safety cord. Tracking systems for the photovoltaic panels are optional. Supports for photovoltaic panels can be ground, pole, or lattice type according to requirements imposed by prevailing climatic conditions.


Main menu Solar Spring pumps.

List of attachments to the Model.

Complete index of the Model.

Model Homepage.

Typical list of graphs and drawings.
List of abbreviations used.
List of key words.
Documents for funding applications.


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