Solar panels and what effects them.

Solar panels have a long way to go to be perfect, out side of the lab, they may yield around 21% of the suns power, and so that makes some sense that 1200W per square meter of sun power…. ( thats about 228 watts per square meter). therefore your average panels being 1.33245 m2 or around 304 watts.

You would think a sunny day would be great for solar but that would be wrong, Solar panels work worse in the sun as they heat up.

The main reason solar panels produce less power when they’re hot is due to the increased electrical resistance of the materials within the panel.

Here’s a breakdown of the process:

1. Sunlight Absorption: Solar panels convert sunlight into electricity through photovoltaic cells. These cells are typically made of silicon.  
2. Heat Generation: While converting sunlight into electricity, some of the energy is inevitably transformed into heat. This is a natural byproduct of the process.  
3. Increased Resistance: As the temperature of the solar panel rises, the electrical resistance of the silicon increases. This means that it becomes more difficult for electricity to flow through the panel.  
4. Reduced Efficiency: Higher resistance leads to a decrease in the amount of electricity that can be generated, resulting in lower overall output.  

To summarise:

• Higher temperatures increase the electrical resistance of the panel’s materials.
• Increased resistance hinders the flow of electricity, reducing output.  

It’s important to note that while heat negatively impacts solar panel efficiency, it doesn’t mean they stop working entirely in hot conditions. The reduction in output is generally gradual.  

solar panels are dark, and I’m sure we are aware of the dark car seat, or the black something left out in the sun and the heat that occurs, this is how the panels heat up and much the same action is used for water heating (solar thermal).

Mitigation of heat has been seen in some countries who use irrigation pipes to sprinkle water over the panels, less effective was a underside heat channel used to heat water from the heat of the solar panel.

Dirt and maintenance

Solar panel glass tend to collect dirt, this thin film reduces the effectiveness of the solar panel to produce energy. after long dry periods, dust gathers on the panels which you can see in light rain shower as they move the dust and dirt across the panels. The water spray not only cools the panels, but they are also there to clean the solar panels.

Generally, cleaning your solar panels once a year is sufficient. However, this can vary depending on your location and environment.  Most of the time, you do not need to do anything extensive to clean your solar panels. That is because the rain will likely take care of most concerns. The rain can typically remove about 95% of any buildup of dust, pollen, dirt, or debris on the surface, making it very easy for you not to have to do anything about the process.

Here’s a breakdown:

• Low-maintenance areas: If you live in an area with minimal dust, pollen, or bird droppings, annual cleaning is usually enough.
• High-maintenance areas: If your solar panels are exposed to heavy pollution, industrial areas, or frequent bird activity, you might need to clean them more often, perhaps every 3-6 months.

Signs that your panels might need cleaning:

• Visible dirt or debris on the panels
• A noticeable decrease in energy production

Important note: Overcleaning can actually harm your panels. Using harsh chemicals or excessive pressure can damage the surface.

Aging solar panels.

We all get old and solar panels are not immune to getting old either, they tend to have a life span of 25 years, where they may become 80% of their former selves. and decline slowly over time. if you were to buy a solar panel then it will last your life time, but may only provide 50% of its rated power.
However, solar panels are in development pretty much constantly, and while todays panels may be efficient to around 22% the labs and future of solar should see 36% effective solar panels. The time maybe to upgrade the panels where they are more effective, as you lose 20% and could gain 10% that would mean that replacement could see gains of 30% or more.
You only have to look at panels around 250w from 10 years ago, for the same size you now have 410watt solar panels.
you could replace the panels covering the same space and have 30% more power. ( see retro fitting Fit system)

Solar panel fires…

Having solar panels can seem like a risk, where we see solar panel roof fires. the fires are usually caused by a fault in the connections, this can be resolved with a AFD. (Arch Fault Detection) the second fire fault is at the DC isolator. All of these issues should have been detected with good maintenance. Most people do not know they need to cycle the isolators as part of the maintenance as it cleans the contactors. Resistance testing the cables may reveal faults in the cables, as well as temperature viewing of the panels and the connections can also detect problems.

Leading Causes of Fires in Home Solar Installations

While solar panels are generally safe, fires can occur due to several factors. Here are the primary causes:  

Installation Errors

• Improper wiring: Incorrectly connected or damaged wiring can lead to overheating and sparks.
• Faulty components: Using low-quality or defective parts can increase the risk of fire.   Are solar panels a fire hazard? | Fire Protection Association www.thefpa.co.uk
• Penetration of roof: Incorrectly sealing the roof where wires or pipes pass through can allow moisture to enter, causing electrical issues.

System Issues

• Electrical arcing: This can happen due to faulty components or poor installation and can ignite nearby materials.   A Consumer’s Guide to Fire Safety with Solar Systems – Department of Energy www.energy.gov
• Overheating: While rare, overheating can occur under specific conditions and lead to fires.
• Hot spots: These can develop in panels due to shading or damage and can cause localised overheating.   Hotspot Effect – ChemiTek www.chemitek.pt

External Factors

• Lightning strikes: Direct hits or nearby strikes can damage the system and cause fires.
• Extreme weather: High winds or hail can damage panels and wiring, leading to potential fire hazards.
• Animal interference: Birds or rodents can damage wiring or build nests, creating fire risks.