Solar panels 101
Solar panels are the most important part of a solar power system since they produce the electricity that eventually finds it’s way to your laptop, lights and television.
In this basic introduction, we look at how this happens.
How do solar panels work?
Solar panels convert sunlight into electricity through a process called the photovoltaic effect.
In this process, sunlight charges the electrons in a solar panel, creating an electrical current that can then power an electrical appliance.
What are solar panels made of?
A panel comprises 60-72 solar cells. Solar cells create electricity when exposed to light. Each cell produces about 3 volts of power.
90% of solar cells are made from silicon. Silicon absorbs light and can conduct electricity.
Solar panel efficiency
Efficiency is a measure of how much of the sun’s potential energy a panel will convert into solar power.
Most panels have an efficiency rating of between 15-23%.
You shouldn’t worry too much about panel efficiency.
High-efficiency panels only matter where you have a small space to work with. They do however cost more.
Less efficient panels cost less and will reduce the overall cost of your system.
How long does a solar panel last?
Most manufacturers guarantee their panels will be at least 80% efficient for 25 years.
That’s not to say the panels will break down after 25 years.
They will keep working, but with reduced power output.
A 300-watt panel, for example, would still produce 240 watts of output at the 25-year mark.
Batteries and inverters have a shorter lifespan. Typically, inverters have a 10-20-year lifespan.
Batteries may last between 3-7, or 10-15 years depending on how you maintain them and what batteries you use.
Are solar panels worth it?
If you’re trying to get away from blackouts, outages or load shedding, then a solar power system is your best bet.
In the long run, they’re a cheaper back-up power supply than diesel generators.
In a future post, we will look at the pros and cons of solar versus other alternative back-up solutions.
Do solar panels work in a blackout or load shedding?
Yes, you can still get power from solar even during load shedding or a blackout. However, this depends on your system design. Solar system design depends on what you need.
A solar system can be designed to supplement or replace grid supplied electricity or as a backup in the event there is no electricity from your utility.
You can read more on solar system designs here.
Solar panel FAQs
These are some common questions people ask about solar panels.
Will solar panels work on cloudy days?
Yes, solar will still produce energy under cloudy conditions, although at lower levels than on a clear day. Solar cells produce energy from a broad spectrum of light.
Even if you can’t see the sun, sunlight is still reaching your panels.
Will solar panels work in winter?
Yes, solar cells will still produce energy in winter, although at lower levels since the sun is not at its peak position and the days are shorter.
How many solar panels do I need to power my home?
This depends on how much power you need. The more appliances you have, the more power you use, and therefore the more panels you will need.
Can solar panels work at night?
No, the solar cells we have produce energy from the spectrum of light from the sun.
Combined with batteries, however, a solar system can provide electricity at night.
There is research into solar cells that produce electricity at night.
Do they need maintenance?
Solar panels don’t need a lot if any maintenance. Rainwater can keep them clean. In a dry year, you can take a garden hose and hose them down.
Now you know far more about solar panels than the average person.
If you think you’re up for the challenge, test your knowledge of solar by taking our Solar 101 quiz.