How Does a Solar Panel Run a DC Motor?

Operating DC motors from photovoltaic solar panels comes with some requirements in order for the motors to operate efficiently. DC motors require a stable power supply, which can only be achieved by installing some sub-systems into the overall motor system. The use of solar powered motors reduces greenhouse gas emissions, which leads to the global warming phenomena, especially when the application is used in an industrial, manufacturing environment.


Commonly called solar panels, photovoltaic cells are the heart of any solar power supply system. Modern PV cells are mostly made from mono-crystalline silicon. A chemical reaction occurs when the silicon is introduced to sunlight, producing electricity as the electrons become excited. The electricity produced depends greatly on the efficiency of the cells and the availability of direct sunlight. Sunlight conversion efficiencies of 33 percent are available as of 2010.

Power Trackers

Power trackers are used to condition the output electricity produced by the solar panel array. Not having a power tracker installed in a DC motor system would result in poor performance, especially when direct sunlight is affected by cloud cover and shaded areas. A power tracker will maximize the flow of electricity when directly providing power to the motors and will also regulate the amount the amount of electricity provided to battery systems to prevent them from being damaged.


Battery back-up systems are installed as part of your DC motor system for two basic reasons. Batteries provide stable power to the DC motors. Motors work most efficiently when there is no interruption in the amount of power supplied. Intermittent power fluctuations caused by direct sunlight interference are negated by a battery power supply. Batteries are also needed to store power for cloudy days or nighttime operation. Common solar batteries are made from lead-acid, lithium-ion and nickel-cadmium.

Motor Controller

Motor controllers are required to regulate the amount of power supplied to the motor, either directly from the solar panels or from battery packs. Motor controllers control the speed, or revolutions per minute, of the motor as well as the direction of operation. Controllers will also condition the power before it reaches the motor in order to maximize efficiency. Power application can be controlled manually, as in the case of solar powered cars; Programmable logic controllers are used for industrial applications; simple on/off switches are used for basic operations 2.


Using solar panels for DC motor operation is an environmentally friendly application that reduces the emission of greenhouse gases. The size and power needs of the motors used will dictate how many panels are needed. However, when it comes to using solar for motor operation, having more power than is actually needed is recommended, especially if a battery back-up system is not installed. Not having enough power available for the motors will result in poor, intermittent fluctuations in the motor's performance.

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