Solar energy is full of myths and misconceptions, particularly about how well it works under certain conditions. This has caused confusion among homeowners about the reliability of solar energy, especially during power outages or cloudy weather. In this blog, we’ll address some of the myths by explaining how solar panels work, how efficient they are in various weather conditions, and how different solar system configurations affect power availability during outages.
How solar panels work: The basics
Solar panels convert sunlight into electricity through the photovoltaic (PV) effect. When sunlight hits the solar cells, it excites electrons, generating a flow of electricity. The energy produced is direct current (DC), which is converted into alternating current (AC) by an inverter, making it usable for your home.
This process still works even in cloudy conditions. Since the panels don’t rely on direct sunlight but on visible light, they can generate electricity from ambient light. However, the system configuration—whether it includes battery backup or is grid-tied only—greatly impacts whether your solar system continues providing power during grid outages.
Myth: Solar panels work during power outages
Fact: Most solar panels do not work during power outages unless they’re paired with a battery backup system.
This myth is based on the assumption that, as long as the sun is shining, a solar system should continue to generate electricity even if the grid goes down. While it may seem logical that solar panels would function independently of the grid during a sunny power outage, most solar systems are designed to shut down when the grid goes offline for safety reasons, including protecting utility workers who may be working on lines to restore power.
However, Enphase IQ8 Series Microinverters don’t need an Enphase IQ battery as part of the system to keep panels working because they have their own backup system called Sunlight Backup. When paired with an Enphase IQ System Controller, this technology makes IQ8s grid independent, which means you can have power during the daylight hours of a grid outage to keep your essential loads powered.
While Sunlight Backup offers a limited backup option, a battery backup system, such as the Enphase IQ Battery, provides a more reliable and comprehensive solution. With a battery, homeowners can store excess solar energy generated during the day and use it even after the sun sets. This ensures round-the-clock energy security, keeping critical appliances running regardless of the time of day or weather conditions.
Want to learn more? Contact us to find the best backup solution for your needs.
Myth: Solar panels don’t work on cloudy or rainy days
Fact: Solar panels still generate electricity on cloudy or rainy days, though at reduced efficiency.
Solar panels work in different weather conditions, including overcast and rainy days. While they don’t produce as much energy in cloudy weather, they continue to generate electricity by capturing diffuse sunlight. Depending on the density of the clouds, the output may be reduced by 20-80%, but power generation doesn’t stop completely. You may still be able to power your home partially or fully, depending on your consumption, even on cloudy days.
Cooler temperatures, which often accompany cloudy or rainy weather, can even improve solar panel efficiency, as excessive heat can reduce their output. According to the National Renewable Energy Laboratory (NREL), solar panels can still perform at 10-25% efficiency on cloudy days compared to sunny days.
Myth: Solar panels require constant maintenance
Fact: Solar panels are low-maintenance and typically only require periodic cleaning and inspection.
One of the greatest benefits of solar panels is they’re low maintenance. Solar panels are designed and tested to withstand harsh weather conditions like rain, hail, and snow. Maintenance usually involves periodically cleaning off dust or debris and occasionally inspecting for wear or damage.
Many solar panels come with warranties that last 20-25 years, further reducing long-term concerns about maintenance. Routine cleaning to ensure maximum efficiency and periodic checks are all that’s needed to keep a solar system operating smoothly. Systems like those from Enphase allow you to monitor your system at the panel level so if there’s an issue, you’ll know quickly.
The importance of solar system configuration for outages
The effectiveness of your solar system during a power outage largely depends on its configuration. Here are four main solar system configurations and their impact on power availability during outages:
1. Grid-tied Solar Only system (without batteries):
- Connected to the utility grid, with no battery storage.
- Shuts down during power outages.
2. Grid-tied Solar Plus Battery without backup:
- Connected to the grid but includes battery storage.
- Shuts down during power outages.
- Battery storage is used for optimal savings.
Most residential solar systems are grid-tied. These systems are designed to work alongside the utility grid. When your panels generate more electricity than your home uses, the excess is sent to the grid in exchange for credits (in regions with net metering). This setup allows you to draw electricity from the grid when your solar system isn’t producing enough, such as at night or during cloudy days.
However, in the event of a power outage, a grid-tied system without battery backup will automatically shut down. This is primarily a safety measure to prevent electricity from being sent back into the grid while utility workers are repairing the lines, avoiding the risk of electrocution.
As a result, if you only have a grid-tied solar system and the grid goes down, your home will be without power—even if the sun is shining.
3. Hybrid System (Grid-tied solar + battery backup)
- A combination of grid-tied and off-grid systems with battery backup.
- Can switch between drawing energy from the grid and using stored solar energy, providing flexibility and energy independence during outages.
To ensure your solar system continues to provide electricity during a power outage, you need to pair it with a battery backup system. These systems store excess energy generated during the day, which you can use at night or during an outage. When the grid goes down, a system with battery backup can automatically isolate itself from the grid and continue supplying power to your home.
Enphase and other leading solar technology companies offer integrated Solar Plus Storage systems that can be customized to meet your energy needs. For example, when configured for backup, the IQ Battery from Enphase provides enough power to run appliances like refrigerators, LED lights, routers, and sometimes even air conditioning units during an outage. This ensures uninterrupted service, even when the grid is down.
Solar Plus Storage with Enphase is unique because it’s an all-in-one approach to inverter technology, storage, and software. This allows it to seamlessly create a grid within your home to keep you operational during a blackout. The system can even prepare itself for a storm by charging the battery in advance through its innovative Storm Guard™ feature.
4. Off-Grid System:
- Completely independent of the grid and relies on solar power and batteries, often integrated with a home generator.
- Offers complete energy autonomy.
Debunking additional solar myths
Myth: Solar panels don’t work in cold weather
Fact: Solar panels are actually more efficient in cold temperatures. Solar cells are temperature-sensitive, and excessive heat can reduce their performance. During colder months, solar panels may produce even more energy on sunny days because they lose less energy as heat. As with cloudy days, if there’s a thin layer of snow on the panels, they’ll still produce some energy and potentially melt the snow as they heat up from sunlight. Heavier snow needs to be cleared off for panels to produce more efficiently.
Myth: Solar panels are too expensive
Fact: Solar panel costs have decreased significantly over the last 10 years, and various incentives make solar energy more affordable. Government and utility incentives like tax credits and rebates can significantly reduce overall system costs, making solar accessible for more homeowners. And over the course of their 25+ year lifespan, solar panels can provide significant savings on energy bills, further increasing their value.
Myth: Solar panels aren't environmentally friendly
Fact: Their carbon footprint is lower than traditional energy sources, and many are recyclable.
While there’s some environmental impact from manufacturing solar panels, it's generally lower than that of traditional energy sources like fossil fuels. Solar energy produces no emissions during operation and has a significantly smaller carbon footprint over its lifetime compared to fossil fuels. Additionally, many solar panels can be recycled at the end of their life cycle.
Conclusion
The misconception that solar panels stop working under different conditions like cloudy weather or outages is largely based on a misunderstanding of system configurations. While grid-tied systems without battery backup do shut down during outages, pairing your system with battery storage or opting for an off-grid solution can provide uninterrupted power. And all systems will keep producing on cloudy, rainy days. Solar energy remains one of the most reliable and eco-friendly energy sources you can have, debunking myths surrounding its efficiency and effectiveness in various weather conditions.
Frequently Asked Questions
How long do solar panels last?
Solar panels are typically warrantied for 20-25 years, covering both performance and durability. But they can keep producing for 30 or more years.
What is the cost of adding battery storage to a solar system?
The cost depends on the size and capacity of the battery system, but prices have decreased in recent years. Battery storage systems can range from $5,000 to $20,000 depending on the size and setup, but government and utility incentives can help lower that cost significantly.
