How do solar panels work?

         In a world where sustainable energy solutions are becoming increasingly important, harnessing the potential of solar power has emerged as a viable option. However, there are still many misconceptions about how a solar panel works and how sunlight energy systems perform under different conditions. 

To make an informed decision about whether solar power is an option for you, it’s important that you understand how it actually works.

In this article, we will delve into the mechanics of solar panels, shedding light on how they work and addressing common queries about their performance and accessibility under various conditions.

How do Solar Panels Work?

         A solar panel, also known as a photovoltaic (PV) panel, is an innovative device that converts sunlight into electricity through a process called the photovoltaic effect. This technology is a cornerstone of sustainable energy systems, enabling homes and businesses to generate clean, renewable power. 

Solar panel technology may seem highly technical and complex, and to a degree, it is. However, all you really need to know is that a solar panel transforms energy from one state to another, i.e., from solar energy to usable electrical energy.

The process can be summarised in the following steps:

           1. Sunlight activates the panel

When sunlight, which consists of photons, strikes the surface of the solar panel, it excites the electrons within the semiconductor wafer material, usually made of silicon.

Of course, the more sunpower reaches your panels; the more excitement is generated. Many factors influence the activation level, including roof orientation, weather conditions, etc.

           2. The panels convert the energy to DC current

This excitement prompts the electrons to start moving, creating a flow of direct current (DC) electricity. The panels are designed with plates and circuits that capture this current, transforming it into a usable electrical charge.

           3. The inverter converts the electricity from DC to AC

To power your home's appliances and electronics, the DC electricity is passed through a solar inverter. The inverter converts the DC electricity into alternating current (AC), which is the standard form of electricity used in homes.

       
       There are three main types of inverters used in residential solar systems today:

• String Inverters:

          * Converts DC electricity from panels into AC for your home.

          * Economical choice but affected by shading and panel mismatch, impacting overall system efficiency.

• Micro Inverters:

          * Installed on each panel to optimise energy production individually.

          * Resilient to shading and offers higher efficiency, but comes at a higher cost due to per-panel installation.

• Power Optimisers:

           * Installed on each panel to maximise energy harvest, improving shading tolerance.

           * Offers a balance between micro inverters and string inverters, boosting panel performance without complete panel- level conversion.

 
         4. Transformed electricity powers your home

      The outcome is that the converted AC electricity is then ready to power your home's electrical systems, reducing your reliance on traditional energy sources. If you install a hybrid inverter system with a battery, it will also help you avoid power outages.

         5. A net meter measures usage

       A net meter tracks both the power your panels produce and the power your home consumes. Any excess energy generated by your solar panels can be fed into the grid, potentially resulting in energy bill savings.

In the UK, this mechanism is known as the Smart Export Guarantee (SEG). Under the SEG, energy suppliers with over 150,000 customers are required to offer payments to eligible households and businesses for the surplus electricity resources they export back to the grid. These payments are made on a per-kilowatt-hour basis. 

That means if you generate more electricity than you use and send it to the grid, you can receive compensation from your energy supply company. Suppliers set their own tariffs, which generally range from 2p/kWh to 15p/kWh.

Another way to reduce your utility bills through solar is to use it to power your electricity needs during peak-times. In the UK, some suppliers offer plans where you pay more for electricity during peak hours (daytime) and less during off-peak hours (nighttime). In this case, you can use a solar system to power your needs during the day while relying on grid energy at night.

Do Solar Panels Work in Winter?

          One of the most common concerns among would-be adopters pertains to the performance of solar panels during the winter. While it is true that solar panels are influenced by sunlight availability, they still generate electricity even on cloudy or overcast days. 

During winter, the reduced daylight hours might lead to lower energy production, but technological advancements have made modern panels more efficient in capturing diffuse sunlight.

As the UK lies relatively far from the equator, the difference in daylight hours is significant. At its peak in June, you can expect over 16 hours of sunlight on average, while there is less than half that in December.

Do Solar Panels Work on Cloudy Days?

           Yes, a solar panel is capable of generating electricity on cloudy days as well. Although their output might be lower compared to bright, sunny days, they still harness available light to produce power. The only time you can’t generate any power is at night.

Many factors influence how much efficiency panels lose under cloudy conditions, but it typically various between 50-70%. In most cases, this decrease in performance can easily be offset by a backup battery storage system to store power.

This underscores solar energy systems' viability, versatility, and reliability even in less-than-ideal weather conditions.

At What Temperature Do Solar Panels Work Best?

          Solar panels operate most efficiently when they are cool. Contrary to common perception, extremely warm temperatures can actually decrease their efficiency, which is why panels sometimes perform best in the morning or late afternoon.

Solar panels have a temperature coefficient that represents how their efficiency changes with temperature variations. The temperature coefficient is usually expressed as a percentage per degree Celsius (or Fahrenheit). Solar panels have a negative temperature coefficient, meaning that as the temperature increases, the panel's efficiency decreases

Excessively hot conditions can also result in heat-related stress from the continuous expansion and contraction due to temperature changes.

Solar panels are typically rated to work in the range between 25 and 75 degrees Celsius. However, the standard test condition (STC) for PV panels is defined as 25℃, and this is generally considered the “ideal” operating temperature.

How Long Do Solar Panels Last For?

         The lifespan of solar panels is an important consideration for any potential adopter. Typically, solar panels can last around 30 years or more. While their efficiency may decrease slightly over time, modern panels are designed to maintain a high output even after decades of use. 

Many panels come with warranties ensuring their performance does not drop below a certain level within the warranty period, which can be as long as 20-25 years. Typically, you can expect a loss of about 0.5% to 1% per year, which means a solar panel will only lose roughly 12.5-30% of output power over its lifespan. 

Proper maintenance and environmental conditions have the biggest impact on how much efficiency solar panels retain.

Conclusion

       Understanding how a solar panel works and how it performs under various conditions is crucial for making informed decisions about integrating solar energy production into your home or business. These remarkable devices not only provide greener energy solutions than fuel, coal, or gas but also offer long-term financial benefits. 

With the ability to generate electricity even in winter and on cloudy days, solar panels have become a reliable and efficient solution for sustainable energy production. Embrace the power of solar technology and pave the way for a cleaner and more sustainable future for our earth.