TechWithRita

** this post pertains to smaller solar panels, ideally those less than 50 volts or the ones used for small projects (like with fountain pumps or LED lights) so, it’s not addressing house-converting energy **

First, lets get nerdy.

Solar panels, also known as photovoltaic (PV) panels, are devices that convert sunlight into electricity. Here’s a detailed breakdown of their function:

1. Absorption of Sunlight: Solar panels are made up of multiple smaller units called solar cells. These cells are typically made of silicon, which is a semiconductor material. When sunlight hits the solar panel, it’s made up of photons, which are tiny particles of light.
2. Generation of Electric Current: When sunlight hits the solar panel, the photons transfer their energy to electrons in the atoms of the semiconductor material. This process knocks loose electrons from their atoms, allowing them to flow freely. This flow of electrons creates an electric current.
3. Creation of Electric Field: Solar cells have an electric field created by the different charges on either side of the cell. This electric field acts to force electrons freed by light absorption to flow in a certain direction, thus creating a current.
4. Collection of Electric Current: The electric current generated by each solar cell is typically in the form of direct current (DC). Multiple solar cells are connected together within the solar panel to increase the overall current output. This combined current is then collected and fed into the electrical grid (for residential use, which is irrelevant here, but still good to know) or stored in a battery for later use.
5. Conversion to Usable Electricity: Since most household and commercial applications use alternating current (AC) electricity, the DC electricity generated by solar panels needs to be converted. This is done through an inverter, which converts the DC electricity into AC electricity that matches the voltage and frequency of the electrical grid or the appliances being powered (again, this is irrelevant here, but still good to know). Explained below is how to use the DC current)
6. Integration with Electrical System: **pertaining to residential rooftop solar panels** The converted electricity is then used to power electrical devices or is fed into the electrical grid. In grid-connected systems, excess electricity generated by the solar panels can be sold back to the utility company, allowing the owner to earn credits or revenue through net metering schemes.
7. Monitoring and Maintenance: Solar panels often come with monitoring systems that track their performance, including factors like electricity production and potential issues. Regular maintenance, such as cleaning the panels to remove dust and debris, ensures optimal performance and longevity.

In summary, solar panels function by absorbing sunlight and converting it into electricity through the photovoltaic effect, with the generated electricity being converted, integrated into the electrical system, and potentially stored or sold back to the grid (for some residential *professional* installations, but this is outside the scope of this blog, we only use DIY project / low-voltage solar panels).

Safety Precautions: let’s get serious.

Small, low-voltage solar panels up to 50 volts pose fewer safety hazards compared to higher voltage systems, but there are still potential risks that should be considered. Here are some safety hazards associated with these systems:

1. Electrical Shock: While the voltage of small, low-voltage solar panels is relatively low, there is still a risk of electrical shock if proper precautions are not taken. Direct contact with exposed wires or terminals can result in electric shock, especially if the wiring is damaged or poorly insulated. It’s essential to ensure that all connections are securely insulated and protected from accidental contact.
2. Short Circuit and Overcurrent: Short circuits can occur if the positive and negative terminals of the solar panel are accidentally connected, causing a sudden surge of current. Overcurrent situations can also arise if the system is overloaded or if there is a fault in the wiring or components. Both short circuits and over-currents can lead to overheating, fires, or damage to the system.
3. Fire Hazard: While the risk of fire from small, low-voltage solar panels is minimal compared to higher voltage systems, it’s still possible… especially if the panels are damaged or installed improperly. Overheating of wires or connectors due to environmental factors, loose connections or other faults can potentially lead to fire. Ensuring proper installation and regular inspection of wiring and connections can help mitigate this risk.
4. Chemical Hazards: Some components used in solar panels, such as lead solder or certain types of encapsulant materials, may pose health and environmental risks if not properly handled and disposed of. While the risk of exposure to these substances during normal operation is low, proper precautions should be taken during installation, maintenance, or disposal of the panels.
5. Mechanical Hazards: DIY solar panels are often installed in outdoor environments and may be subject to damage from weather conditions, debris, or accidental impacts. Broken or damaged panels can pose a risk of cuts or lacerations from sharp edges or exposure to broken glass. Proper installation and regular inspection can help identify and address potential hazards.
6. Fall Hazards: If installing solar panels on rooftops or other elevated surfaces, there is a risk of falls during installation, maintenance, or cleaning. Proper fall protection measures, such as guardrails, safety harnesses, or scaffolding, should be used to prevent injuries.
7. Environmental Hazards: Improper disposal of solar panels at the end of their lifespan can lead to environmental pollution and potential health risks from exposure to hazardous substances. Following proper recycling and disposal procedures is essential to minimize environmental impact and ensure compliance with regulations.

Overall, while small, low-voltage solar panels pose fewer safety hazards compared to higher voltage systems, however, it’s still important to follow safety guidelines, use proper equipment and materials, and take necessary precautions to prevent accidents and ensure the safety of individuals and the environment.

How to Use the DC Electricity Generated From Solar Panels:

The direct current (DC) electricity that’s generated from low voltage or DIY / project solar panels needs to be converted to a usable form of electricity… at least for most common applications, and especially if you want to power household devices or charge electronic gadgets (which typically run on alternating current (AC)). Here’s how the conversion process typically works:

1. DC Output: The solar panel generates DC electricity when exposed to sunlight. This electricity flows through the wiring and connectors of the solar panel system.
2. Charge Controller (if applicable): In some DIY solar panel setups, especially those that involve battery charging, a charge controller is used to regulate the charging process. (don’t go attaching solar panels directly to Li-Ion batteries guys) The charge controller ensures that the batteries receive the appropriate voltage and current to prevent overcharging and optimize battery performance and lifespan.
3. Inverter (if AC power is needed): To convert the DC electricity from the solar panel into usable AC electricity, an inverter is required. The inverter takes the DC electricity as input and outputs AC electricity at the appropriate voltage and frequency for powering household appliances or other AC-powered devices.
4. Conversion Process: Inside the inverter, the DC electricity undergoes a transformation process known as inversion. This process involves converting the DC electricity into AC electricity by rapidly switching the direction of the current, typically at a frequency of 50 or 60 hertz (Hz) to match the standard frequency of AC power grids.
5. Voltage Regulation: The inverter also ensures that the output AC voltage remains within the desired range, typically 110V or 220V depending on the local electrical standards. This ensures compatibility with the devices or appliances being powered.
6. Output Connection: The converted AC electricity from the inverter is then made available for use through standard electrical outlets or connectors. Users can plug in their devices, appliances, or other electrical loads directly into these outlets to receive power from the solar panel system.

Why Can’t Solar Panels Be Directly Connected To Things?

Solar panels cannot be directly connected to certain devices or systems without proper consideration of voltage, current, and compatibility due to several reasons:

1. Voltage Matching: Solar panels produce direct current (DC) electricity, and the voltage they generate depends on factors such as the intensity of sunlight and the characteristics of the solar panel itself. The voltage produced by solar panels may not match the voltage requirements of the devices or systems they are intended to power. Connecting a device directly to a solar panel without voltage matching can result in either insufficient power delivery or damage to the device due to overvoltage.
2. Current Regulation: Solar panels can produce varying levels of current depending on factors such as sunlight intensity, temperature, and shading. Connecting devices directly to solar panels without proper current regulation can result in fluctuating power delivery, which may be harmful to sensitive electronic components.
3. Energy Storage: Solar panels only generate electricity when exposed to sunlight, and their output can fluctuate throughout the day. Many devices and systems require a continuous and stable power supply, which may not be possible with solar panels alone. Additional components such as batteries or grid-tie inverters are often needed to store excess energy or provide consistent power output when sunlight is not available.
4. Compatibility: Some devices or systems may not be compatible with the electrical characteristics of solar panels. For example, devices designed for alternating current (AC) power may not function properly when connected directly to solar panels, which produce DC electricity. In such cases, an inverter is needed to convert the DC electricity from the solar panels into AC electricity compatible with the device or system.
5. Safety Considerations: Directly connecting devices to solar panels without proper voltage and current regulation can pose safety hazards, such as electrical shock or damage to the device. Components such as fuses, circuit breakers, and surge protectors are often required to ensure safe operation and protect against overvoltage or overcurrent conditions.

Overall, while solar panels are a renewable and sustainable source of electricity, their integration with devices and systems requires careful consideration of electrical compatibility, voltage matching, current regulation, energy storage, and safety considerations to ensure optimal performance and safety.