With solar submersible well pumping in full swing, we have decided to write a small guide to help the user find which drive device they need based on their needs. This guide will help anyone to know how solar submersible pumping works, what parameters to take into account and how to size our installation.
What is a Solar Submersible Water Pump?
At present, the extraction of water is still the main use of solar energy, since a solar pumping system can work anywhere without having to be close to the electricity grid. It is a water pump that works mainly with direct current and whose power comes from the photovoltaic modules. The voltages at which they work are 12 volts and 24 volts, the amp ranges vary according to the power of the equipment.
Submersible Solar Water Pumps
They are those that are placed below the surface to extract water from wells or wells, bring this water to the surface and drag it a certain distance to deposit it in water tanks, pools, cisterns, etc. This is if the solar pump output is not carrying a load.
Flow estimation
At this point we need to know the flow, what amount of water do we estimate is necessary? In this case, it is the customer who must know their demand, taking into account their use: domestic consumption per person, for animals, irrigation, etc. If you do not know how much water you need, again we can establish an approximate calculation using the following figures: 30 liters/day per person, 40 liters/day per cow, 10 liters/day per sheep... however, it is important that you carry out later an in-depth calculation of these parameters, given that water consumption can vary ostensibly, for example, depending on the climate of the installation in question. Let's imagine that in summer, the most unfavorable time (if we want to size the pump to cover our needs in that case), our demand is 7m3 per day (remember that 1l is = 1*10^(-3) m3); that is, 7000 liters. When we know the flow rate and the head that we require, we must consult the curves of the pumps to know if it adapts or not to our needs:
How can we know the daily production of the pump?
DC pumps vary their working regime depending on the power supplied by the photovoltaic panels (whose production in turn varies depending on solar radiation). The curve offered by the manufacturer reflects its nominal operation, that is, to obtain the daily production, it would be enough to multiply this production by the peak solar hours (PSH) of our region.
Peak solar hours help estimate production by establishing a hypothetical constant solar irradiation of 1000 W/m2; that is, it is a parameter that normalizes the variable daily production in a series of hours of homogeneous production to simplify the calculations.
You can easily check the peak solar hours based on your location by searching the Internet for an approximation of it. Again, in order to establish a simplified calculation, we recommend using the following example: Summer: from Madrid to the north of the peninsula, 6 hours a day. To the south, 7. Winter: from Madrid to the north, 3. To the south, 4.
If we return to our case, and imagine a facility south of Madrid, the flow that the pump we are analyzing is capable of driving daily in summer, based on this approximation, will be: 1.1 m3/hour x 7 hours = 7, 7 m3 daily. If our initial need had been established at 7 m3, we can verify that this pump adapts perfectly to our needs. If this is not the case, it is as simple as carrying out one or two more interactions, testing with other pump models to make sure which solar pump best suits our needs. Contact us to receive information to acquire your perfect kit.
