In our alternative energy tutorial regarding connecting solar panels, we saw that photovoltaic panels of various sizes are often connected along with to produce higher wattages.

There are various small applications within the solar garden which can need more power than that provided by a single PV panel or solar kit, like water pumping for larger ponds or fountains, irrigation of the garden, multiple garden ponds, swimming pools or summer house lighting, etc. The list is endless.

However, before we tend to get carried away, let's assume we want a solar-powered water pumping system for our solar garden. this might be a much bigger pump for a water feature, fountain, pond, aeration and filtration for a pond, irrigation or submersible pump, whatever we wish. In this tutorial, we'll assume we need to power a typical 24 V DC (Direct Current) motor as part of the generic stand-alone PV system in our solar garden. Think about the basic setup below.

Simple DC solar Pump Motor

The DC motor which drives the pump can be provided directly from the solar panel or from optional storage batteries to be used at night once the sun doesn't shine. DC motors are typically more efficient and permanent magnet DC motors are typically most popular at intervals a star garden setting. DC motors that use carbon brushes need maintenance and ventilation making submersion awkward. Brushless DC motors overcome this drawback but at a price.

If used directly it's vital to match the DC motors power requirements to the photovoltaic panel. Ideally, the PV panel ought to be operated as near to its maximum power point (MPP) condition in all kinds of sunlight conditions. If {this is|this is often|this can be} impossible a DC to DC controller can be inserted between the PV panel and motor to improve matching and increase efficiency. If deep cycle batteries are used as part of the solar gardens system, then the solar charge controller can regulate the flow of current from the PV array to the batteries and from the batteries to the DC motor.

While the easy stand-alone DC system above can be used to offer 12V, 24V or 48V DC motors (or lighting systems) with or without a battery bank to power solar garden pumps and lights, this kind of system may need an oversized PV panel to work, 100 to 200 watts or more. However, we aren't restricted to using DC motors as part of our stand-alone off-grid installation, AC (Alternating Current) motors can also be used as AC motors are rugged requiring little or no maintenance, therefore are suitable for submersion in large garden lakes, ponds or at the bottom of a well.

When a stand-alone PV system is to deliver AC power for electrical motors (or lighting) an inverter needs to be used. Inverters convert the DC power coming from the battery into AC power that the motor or pump will use as shown.

More Advanced AC motor control

An AC system {is similar|is analogous|is comparable} in many approaches to the much lower power DC system except with an electrical converter other because the single-phase AC motor is operated using solar energy with an extra inverter. The power rating of the inverter ought to be at least five or six times that of the AC motor to withstand the peak surge current at start-up. Inverters for complete off-grid applications are obtainable from about 100 watts up to many kilowatts (kW) producing a modified sine wave or a pure sine wave output relying upon cost.

Replacing a single photovoltaic panel with an array or increasing the size of the battery bank to offer more storage capacity provides more power for a longer time permitting solar gardens to be used all year round as well as during the night. However, additional equipment is needed since the additional power needs to be regulated and controlled increasing the cost of capital.

We can additionally connect solar panels of various wattage and voltage ratings to charge multiple storage batteries and provided voltages over 24VDC. for instance, a part of the system could be used to serve as a power source for pumps and motors in one section of the star garden, while another part may serve as a power source for garden lights, etc as shown.

Multiple power system for solar Gardens

In this straightforward example above, 24V has used to power a DC pond/fountain pump motor while a 12V circuit is used for lighting the pond or surrounding garden. Schottky diode protection prevents one photovoltaic panel supplying the other.

Charge controllers regulate the charging of the batteries that are connected along in series to provide 36VDC in total to supply an AC inverter and pump motor, as an example. The possibilities to provide solar gardens power requirements are endless.