What Happens to Solar Panels During a Power Outage?

Last month parts of Spain, including the Costa del Sol, experienced widespread power outages that left many homes without electricity for hours. While these situations are rare, they raise an important question for homeowners who rely on renewable energy:

Do solar panels still work when the power goes out?

The short answer is: it depends on your setup. In this blog, we’ll explain how solar energy systems respond during outages, what options are available if you want energy security, and why Marbella’s sunny climate makes backup solutions even more effective.

Grid-Tied Systems: What Most Homes Have

Most solar panel systems in Spain—including those installed by SolarMind—are grid-tied. That means your solar system is connected to the national power grid, allowing you to:

• Draw electricity from the grid when your panels aren’t producing (e.g. at night)

• Send excess solar energy back to the grid, often in exchange for credit (via net metering or compensation schemes)

However, the downside of a grid-tied system is this:

If the grid goes down, your solar panels automatically shut off.

This isn’t a flaw—it’s a safety feature. When the power grid fails, any solar system that’s still feeding electricity into the wires could pose a danger to repair crews working to restore power. So by law, grid-tied inverters are designed to switch off during outages.

So What Happens During a Power Cut?

If you have a standard solar system without a battery, your home will lose power just like your neighbors—even if the sun is shining.

That’s because your solar energy can’t be used independently from the grid unless it’s stored somewhere else first. This surprises many people, but it’s one of the most important things to understand about solar energy systems.

Want Power During Outages? Add a Battery

If you want to keep the lights on when the grid fails, you need a solar battery storage system—like the ones SolarMind installs.

Here’s how it works:

• During the day, your solar panels power your home and charge your battery

• At night or during outages, the battery supplies stored energy to keep your home running

• Smart systems can automatically disconnect from the grid when an outage is detected (this is called "islanding") and continue powering essential loads

Modern batteries like the Tesla Powerwall or Sonnen are designed for exactly this kind of scenario. They respond instantly and silently, giving you uninterrupted energy even when the neighborhood is dark.

What Can You Power with a Battery?

It depends on the size of your battery and your daily consumption, but typically, a home battery can run:

• Refrigerator and freezer

• Wi-Fi router and communication devices

• Lights in key rooms

• Charging points for phones/laptops

• Medical equipment or home security systems

You can even choose to scale your storage system to include air conditioning or EV charging, though this increases cost and capacity requirements.

Tip: SolarMind can help you design a custom system that prioritizes your essential appliances during an outage.

Hybrid Inverter Systems: The Middle Ground

Some homeowners choose to install hybrid inverters, which can switch between grid-tied and off-grid modes when combined with battery storage. These systems offer the flexibility of both worlds:

• You can export excess energy when the grid is running

• You can go into "island mode" and use your own power during a blackout

These setups are becoming increasingly popular in regions like Marbella, where solar production is high, but grid instability is becoming more noticeable.

Solar and Backup Generators

Another option some homeowners consider is combining solar with a backup generator. This is less common in urban areas but might be useful for rural properties.

A hybrid solar + generator system works well if:

• You want backup during prolonged outages

• You have very high energy needs

• You want redundancy alongside a solar battery

However, generators rely on fuel, require maintenance, and aren’t as eco-friendly. That’s why most Marbella residents prefer solar + battery as a cleaner, quieter solution.

Why It Matters in Spain (Especially Marbella)

While Spain has one of Europe’s strongest energy networks, recent outages show that no system is 100% reliable—especially with rising demand and climate-related stress on infrastructure.

In sunny regions like Marbella, where solar panels can produce energy nearly every day of the year, a battery backup system makes even more sense. It allows you to fully benefit from your investment in solar—even when the grid fails.

Is It Worth It to Add a Battery?

It depends on your lifestyle and priorities. If you:

• Work from home

• Have medical or safety equipment that needs power

• Want peace of mind during outages

• Want to increase your energy independence

…then a solar battery is a smart upgrade. It not only keeps your home running, but also improves your solar system’s self-consumption and long-term savings.

Take Control with SolarMind

At SolarMind, we don’t just install panels—we help you build energy independence. From smart solar design to battery integration and hybrid inverters, we offer custom solutions for homeowners who want more control, more resilience, and more savings.

Want to stay powered—even when the grid goes down?

Contact us today for a free consultation and see how solar + battery can work for your home in Marbella.