How to build your own DIY off grid / grid down Solar Power Back up system from scratch

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This article provides detailed instructions for building a Solar Power Grid Down Backup System from scratch.


The system is designed to generate alternative power and serves as an excellent way to utilize renewable energy.


It is also an excellent backup source of power in case of a grid-down situation.


This system is composed of five essential components, including solar panels, a charge controller, batteries, an inverter, and a kilowatt meter.



Regardless of the reason for building a Solar Power Grid Down Backup System, such as reducing electricity bills or achieving self-reliance in the event of a grid outage, it is an excellent way to provide alternative power while maintaining a reasonable level of convenience.



With this system in place, you can power essential household appliances, including a freezer, lighting, water pump, communication devices, and tools.



Moreover, the system can also charge all your electronic devices, from flashlights to Kindles, ensuring you stay connected and entertained during power outages.



The Off-grid Solar Power System is constructed using five primary components. The first component is the solar panels, which generate the power needed to run the system.


The second component is the charge controller, which regulates the flow of electricity from the solar panels to the batteries.


The batteries serve as a storage unit for the energy generated by the solar panels, which can be used at a later time.


The fourth component is the inverter, which converts the stored DC power from the batteries into AC power, which can power household appliances.


Finally, the fifth component is the kilowatt meter, which measures the energy consumption of each device and determines the amount of energy needed to generate per day.

Here we use 100-watt monocrystalline panels, a 40 amp MPPT charge controller, a 1000 watt pure sine wave inverter and to store the energy, 446-volt golf cart batteries totaling 470 amp-hours.




The first step in building an efficient Off-grid Solar Power System is to determine the size of the system required based on the number of devices you want to power simultaneously.


This is crucial in determining the size of the inverter needed for the system.


The inverter is responsible for converting the DC power generated by the solar panels and stored in the batteries into AC power, which can be used to power household appliances.


If your inverter has a capacity of 1000 watts, it means that you can run devices that require a total power of up to 1000 watts simultaneously without any issues.

After assessing all the necessary devices that you require to power during a power outage, you will have an estimation of the amount of energy you need to produce each day.


This evaluation provides valuable insight into the power demand of your household and aids in determining the Off-grid Solar Power System’s appropriate size.



The battery bank is made up of four six-volt Duracell SLIGC 125 golf cart batteries that are connected in series.


These batteries are specifically designed for golf carts and are ideal for use in the Off-grid Solar Power System as they deliver a consistent amount of power over a longer period and can recharge quickly.


By connecting the batteries in series, the voltage is increased, allowing for more power storage and longer run times.



Choosing the right location to install the solar panels is critical in ensuring that the Off-grid Solar Power System operates efficiently.


When selecting a spot, it is essential to consider the sun’s angle, which varies depending on the season.



In the winter, the sun is lower towards the horizon, while it is closer to directly overhead in the summer.



Installing a sun-tracking system would be ideal as it ensures that the panels are always positioned directly at the sun, resulting in maximum power generation.


Additionally, it is recommended to install the panels as close as possible to the battery bank to minimize energy loss due to resistance caused by longer wires.



Choosing the right wire gauge is also essential to transmit the power from the solar panels to the batteries effectively.



Between the panels and the batteries is the charge controller, which plays a critical role in controlling the batteries’ charge level.


It ensures that the batteries receive the correct voltage and prevent overcharging, which can lead to battery damage.



In our system, an MPPT Solar Charge Controller is used. When solar panels are wired in series and connected to an MPPT charge controller, the voltage is combined, providing sufficient voltage to charge the batteries.




The MPPT charge controller is highly efficient in charging batteries, providing continuous charging throughout the day as long as the sun is out.


Compared to PWM, the MPPT charge controller is more efficient, making it an ideal choice when the solar panels are far away, and you want to save on wiring and installation costs.



To ensure the safety of the Off-grid Solar Power System, it is essential to have both an automatic and a manual way to disconnect power in each segment of the system.



The final step in securing the system involves installing a 300 amp manual switch at the battery box that can cut off power from the batteries to the inverter during an emergency.



Additionally, a 200 amp fuse is included in the system, which will blow automatically in case of an overload or short circuit.

Another crucial aspect of safety is proper grounding. Grounding is simple to achieve by driving an eight-foot grounding rod into the ground and connecting it to the system’s metal components, including the frames of the panels, the charge controller, and the inverter, using copper grounding wire and lugs.



This prevents electrical shocks and protects the system from power surges or lightning strikes. Grounding helps to dissipate excess electrical energy safely into the ground, reducing the risk of damage to the system