How the UK and its Residents Can Guard Against Blackouts in the Future with Solar Panels

Earlier in 2025 we saw headlines warning us that the UK was close to suffering blackouts alongside concerns that the country was relying more heavily on weather dependent energy generation. 

Blackouts, or unplanned power cuts are not only inconvenient but can be potentially life-threatening. In April, Spain and Portugal experienced nationwide blackouts that lasted around 10 hours, as a massive voltage surge left tens of thousands of people stranded on public transport systems, caused car crashes as traffic lights shut down, and left emergency services uncontactable. Understandably people in the UK were worried that a similar blackout could happen here. 

However, the chance of blackouts in the UK is relatively small. The government’s National Risk Register estimates that there’s a 1-5% chance of a national or regional grid failure in the next five years. 

What Causes a Blackout

Blackouts are caused by significant changes in frequency.

Electrical frequency is the number of times per second that an alternating current (AC) moves back and forth. This is what gives AC its name, as it alternates between positive and negative voltage.

In the UK, our AC electricity travels through this cycle 50 times per second, so our frequency is 50 hertz (Hz). All electrical items in the UK are designed to work at 50Hz and will stop functioning if the frequency spikes or dips more than a little bit. This makes things difficult since the frequency changes nearly every second.

When demand rises compared to supply, the frequency ticks upwards, and when the supply increases above demand, the frequency drops. The reason for this is that the nation’s frequency is directly related to how fast its grid connected generator turbines are spinning.

If demand exceeds supply, energy companies must increase their output which basically means making their turbines spin faster. If this doesn’t have the desired effect on the frequency, then the grid will use its battery storage reserves. If there isn’t enough energy stored to make up the difference, there is only one solution to finding balance and that is to reduce supply by cutting off power in selected areas for a set time. If that doesn’t work, blackouts are inevitable. Usually, because most of the process is automated, problematic shifts in frequency can be fixed very quickly, within milliseconds. 

Solar panel systems have solar panel limiters also called solar export limiters which is a component that prevents a solar PV system from sending more electricity to the national grid than the local infrastructure can handle or a distributor permits. It works by monitoring power flow and sending a signal to the solar inverters to reduce or "clip" power production when the combined self-consumption and export would exceed a predetermined limit, to ensure grid stability and protect distribution networks from overload.

Blackouts can happen unexpectedly because of a significant imbalance between supply and demand resulting in the power station tripping. This is when a plant disconnects from the network and therefore stops transmitting electricity.

There are many reasons why a system might trip, including faulty equipment, extreme weather, and human error when running or maintaining the network or a combination of these factors.

One power station tripping won’t normally cause a blackout as NESO has built-in automatic processes and battery storage that will kick in when needed. It takes at least two power stations to trip at the same time to cause a blackout as in this case the grid may not have enough reserve power to balance the frequency. However, this rarely happens. 

The publicly owned National Energy System Operator (NESO), which runs Britain’s electricity transmission system, is legally obliged to keep the frequency to within 1% of 50Hz – so between 49.5Hz and 50.5Hz. As the margins are so fine, NESO has set its own internal target of 0.4% – or 0.2Hz – to be safe.

How Can You Protect Against Blackouts with Solar Panels?

The best way you can protect yourself against blackouts is to have a source of power you can use if the grid goes down. 

Unfortunately, most solar & battery systems are tied to the grid and so will automatically shut down during a power outage for safety reasons, so they don’t export to the grid and electrocute any engineers working on the power lines.

One way to avoid being affected by power outages is to go fully off-grid. Alternatively, you can have a solar panel and battery system normally connected to the grid that continues to provide power during a blackout, but your system will need to be specifically configured for this backup capability. This involves installing a solar battery with backup power functionality and a relay to temporarily disconnect your home from the grid in a process known as “islanding”. This backup power is referred to as an emergency power supply (EPS). To ensure true backup functionality, special EPS inverters with transfer switches are required. 

Your system will automatically switch to the stored battery energy when the grid loses power. To keep solar panels charging batteries during a power cut, an EPS solar setup (backup gateway) is required. An EPS inverter with transfer relay switches that can disconnect the solar system from the grid in an outage is essential. It then creates a mini grid within the home, with the panels charging batteries directly. This specialised inverter converts the battery’s DC power into usable AC electricity for the home’s circuits. If there’s enough sunlight the solar panels can continue to charge the batteries even during a blackout, providing a continuous power supply. 

Although this is an expensive option for most UK households it can be useful if you regularly suffer blackouts or have vital medical equipment that requires a constant source of electricity.

If an EPS solar system is sized properly it can power a home’s essential circuits from battery reserves during a blackout. Lights, fridge, freezer, internet, and other critical loads can stay on uninterrupted. Dedicated backup loads allow the battery system to efficiently power only the most critical appliances and devices which avoids overtaxing the system. EPS solar systems need to be designed carefully but can provide peace of mind.

As we become more reliant on renewable energy, battery energy storage systems (BESS) will be key to ensuring we have a consistent and dependable power supply. BESS can help to lower energy costs, increase grid stability, and enhance energy security. 

To further enhance the UK’s energy storage, we need to invest in diverse storage technologies like batteries, pumped hydro, and emerging long-duration energy storage (LDES) methods like liquid air or compressed air, improve grid connectivity, reduce power demand through energy efficiency, foster public and private collaboration for investment, deal with the skills shortfall by growing the energy workforce and build community support by addressing safety concerns and highlighting local benefits. It’s also important that the government play their part by implementing supportive policies and market reforms to provide a stable platform for investment in flexible energy solutions. 

To ensure that new, renewable and storage projects can be smoothly connected to the national grid it’s widely understood that the grid connection queue needs reform. There was an extraordinary surge in the queue last year with over 1,700 applications submitted. The total capacity which has doubled to over 700GW has far exceeded the energy system’s projected demands for both 2030 and even 2050 creating a growing bottleneck in energy development. 

The National Energy System Operator (NESO) and Ofgem have been working hard to address this, but more can be done by moving faster and more collaboratively. One thing that can be done, is to prioritise projects that are actually going to be built, and NESO are doing their best to achieve this.

Although grid modernisation requires huge capital investment, much can be done in the short-term by leveraging existing infrastructure or making use of available connection capacity. 

One way of maximising efficiency and reducing transmission loss of renewable energy projects is to implement projects that co-locate renewable generation with storage facilities. 

Because wind and solar farms don’t have any spinning parts that create inertia it means that as we move to a more renewable-heavy electricity network, we will see larger changes in frequency. 

Fortunately, there is a way to avoid this problem if wind and solar forms use grid forming technology that creates synthetic inertia. It does this by releasing electricity in a controlled way, instead of just feeding it straight into the network as it’s generated.

This is still a new development which NESO is working to make easier and more appealing to renewable generators. If a future with more blackouts is to be avoided this technology needs to be embraced.

The global energy storage industry is on the cusp of making big changes as it gears up to meet the ambitious global target of 1,500GW of installed storage capacity by 2030 in the Green Energy Storage and Grids Pledge. The storage industry is forecast to experience an annual growth rate of more than 20% through to 2030 according to Bloomberg NEF. Although this is an excellent rate of growth, it won’t be enough to meet the target above or global system needs. We will need to scale up in the coming years which is a huge challenge for the industry. 

Basically, there are three challenges that we face when accelerating BESS installation, technical challenges, financial challenges, and human challenges. The past has seen us be very adept at dealing with the first two. We can also be very good at the third, but these challenges often take us more time to address as we grapple with policy direction, regulatory complexities, and the vital requirements to engage with communities. Unfortunately, we don’t have the luxury of time as we work towards our goal of having a cheaper, more sustainable, and more secure energy system. 

Over the next 25 years the energy sector will need to recruit hundreds of thousands of skilled professionals to support the essential functions relating to design, construction and operation of the energy infrastructure. Currently, the demand for skilled professionals far outpaces the supply. To bridge this gap, we need to develop comprehensive training programmes and initiatives aimed at equipping new and existing talent with the necessary skills and knowledge. Industry partnerships, along with government-backed education and apprenticeship schemes will be vital to ensuring that both the current and next generation of energy professionals are ready to meet the needs of a rapidly evolving sector.

In future decades we need to see government agencies and industry leaders collaborating to shape policies and reforms that provide a stable, transparent, and competitive market for investing in renewables and storage. We also need to see the different stakeholders from asset owners to government agencies working together to drive investment and deliver benefits for all.

There needs to be more investment in energy efficiency measures such as improving insulation and the uptake of new technologies like heat pumps to reduce energy demand and to make the energy system more affordable and secure.

We need to look at ways of making energy storage more accessible and affordable perhaps through introducing schemes such as "energy-storage-as-a-service" as the costs are prohibitive for most people now.

There’s work to be done in addressing public concerns about the safety of new battery storage projects. The benefits of energy storage need to be explained to local communities to build trust in the technology. 

Blackouts don’t happen as often as they did in the past as NESO has worked to improve its network and power cut prevention schemes.

Of course, major blackouts still occur from time to time but they’re usually due to serious weather events which are harder to guard against. 

Currently, it’s not usually cost-effective to protect against blackouts with a solar and battery system. The increasingly renewable-heavy nature of the grid could lead to more power cuts, but it is hoped that the spread of grid forming should stop this outcome.