Build Your Own Solar Power Generator

Icon of solar panels and the sun.

Introduction

In remote areas it may be necessary to power conventional electronics longer then a battery will hold. A solar power generator can help provide power for quite some time.

Conversion

A portable trailer mounted solar panel. Solar Panels come in a variety of sizes and packages, ranging from bare thumbnail sized panels where you are expected to solder leads to them, to integrated solutions like this.

A solar cell converts light directly into electricity using the “Photovoltaic Effect”. There is no fuel, steam or thermodynamics involved. When light hits a solar cell, it instantly produces electricity. Solar cells today do not store electricity. In other words, when the light is taken away from the cell, it stops producing electricity. It is very common to store the electricity from a solar cell in a battery.

You can store electricity generated from a solar panel in a battery such as a typical car battery or you could use a Deep Cycle battery for more storage capacity. Typical car batteries are not recommended for use in solar power systems. They have a very small range of operating voltage and if discharged too deeply, the battery will be irreparably damaged. Deep cycle batteries have a wider operating voltage range and are more suitable for use in solar power systems. If you are using a large solar panel to charge your battery, it would be wise to purchase a charge controller to regulate the current flow.

Once the battery is charged you can connect an inverter to the terminals. Connect the negative terminal first. An inverter will convert the battery's DC current to usable AC current which you can use to power AC appliances.

Ac vs Dc

DC batteries hooked up to inverters.

AC and DC voltage waveforms. Alternating Current (AC) is the type of electricity found in the outlet in your home. DC Direct Current is what you would find in the outlet of your car. DC electricity is also the type of electricity stored in batteries. Generators at big power plants use rotating alternators to produce AC electricity while the dynamo found in your bicycle (still a rotating machine) produces DC. Commercially available solar cells only produce DC electricity and their excess power output is most readily stored in deep cycle batteries. In order to run most appliances in your home, you will need to use a power inverter which changes the DC voltage to AC. Inverters range in size from the very small 50 watts all the way up to 5Kw. You should consider what appliances and equipment you intend to run off your power inverter. Cheaper power inverters will typically use a square wave output signal to create the AC voltage. More sensitive equipment such as computers will require pure sine wave outputs. Pure sine wave power inverters are typically more expensive.

Some solar panels contain built in inverters, making their use more straightforward.

Putting it together

Tailor these steps to the instructions included with your specific equipment. Consult an expert before going forward for safety.

Hook up the Solar panel to a battery charger circuit, and that circuit to the battery. Charge. Then use an inverter if AC power is needed, and use until charge is depleted. Repeat.

Maintain

Your solar panel needs to be pointed at the sun for it to work well. This means that it may require adjustment throughout the day if it can't automatically track sunlight.

Your solar panel needs to be clean and free of obstructions. Less light directly results in less power.

Batteries will eventually degrade and require replacement.