Europe is building renewable energy faster than ever.
Solar panels are appearing on rooftops, warehouses, and utility-scale farms. Offshore wind capacity continues expanding. Governments are pushing electrification to reduce dependence on imported fossil fuels.
Yet something strange keeps happening.
On particularly sunny or windy days, some renewable power plants are told to reduce output or shut down completely.
The reason is not that Europe suddenly has too much clean energy.
The real problem is that the electricity system cannot always move, store, or use that clean power when and where it is produced.
This process is called renewable curtailment, and it is becoming one of the biggest challenges facing Europe’s energy transition.
The International Energy Agency says growing wind and solar generation is creating periods when electricity supply exceeds what the grid can absorb, particularly during low-demand hours.
Why Would Anyone Turn Off Free Solar or Wind Power?
Electricity grids have one fundamental requirement:
Supply and demand must remain balanced almost every second.
Imagine Germany produces 50 gigawatts of electricity at noon.
Consumers and businesses are using only 45 gigawatts.
Something has to happen to the extra five gigawatts.
It can be exported.
Stored in batteries.
Used by flexible industrial consumers.
Or generators can be asked to reduce production.
If none of the first three options is available in sufficient quantity, renewable output may have to be curtailed.
This is not because solar or wind suddenly became undesirable.
It is because the electricity system has nowhere useful to send the power.
The IEA says negative electricity prices and renewable curtailment are increasingly signals that power systems do not yet have enough flexibility.
Solar Creates an Especially Difficult Midday Problem
Solar generation follows a predictable pattern.
Output climbs during the morning.
Peaks around midday.
Then falls toward evening.
The problem is that electricity demand does not always follow the same pattern.
On a sunny spring Sunday, factories may be operating at reduced capacity, offices may be closed, and household demand may be relatively modest.
Yet millions of solar panels can simultaneously produce enormous amounts of electricity.
This creates what energy analysts often call the duck curve.
Power demand from traditional generators falls sharply during the middle of the day as solar output rises.
Then the sun sets.
Solar production collapses while household electricity demand rises during the evening.
The grid suddenly needs large amounts of replacement power.
The European Commission said this summer that high solar output significantly reduced electricity prices during central daytime hours, but emphasized that more storage is needed so surplus daytime electricity can be shifted into the evening peak.
That is one of the clearest explanations of the problem.
Europe does not necessarily have too much solar.
It has too much solar at noon and not enough stored solar at 8 p.m.
Wind Has a Similar Problem, but It Is Less Predictable
Wind generation creates the same basic challenge.
When strong weather systems cross the North Sea, turbines in the United Kingdom, Germany, Denmark, the Netherlands, and surrounding countries can produce enormous quantities of electricity simultaneously.
The challenge is location.
Some of Europe’s best wind resources are far from major population centers.
Offshore wind farms may generate power hundreds of kilometers from factories and cities.
If transmission lines cannot carry all that electricity south or inland, operators may have to reduce turbine output.
This is known as grid congestion.
The electricity exists.
Customers need electricity.
But there is not enough transmission capacity connecting the two.
The European Network of Transmission System Operators for Electricity, ENTSO-E, says congestion is increasing in frequency, scale, and complexity as renewable deployment grows.
Europe Built Renewables Faster Than It Built the Grid
This may be the biggest underlying problem.
A solar farm can sometimes be developed within a few years.
A wind farm can also be constructed relatively quickly once permits are secured.
A major high-voltage transmission line is different.
The IEA says renewable projects can often be completed within roughly one to five years, while major grid infrastructure can take five to 15 years to plan, permit, and build.
That creates a timing mismatch.
Developers keep adding generation.
The wires needed to transport that electricity arrive much later.
Eventually the grid becomes the bottleneck.
The European Commission says grid-connection queues now exist in at least 16 EU countries, while around 120 gigawatts of mature renewable projects could face delayed access by 2030 if grid problems are not addressed.
That is an extraordinary amount of clean-energy capacity potentially waiting for cables.
Negative Electricity Prices Are Becoming More Common
Electricity prices can sometimes fall below zero.
That sounds impossible.
Why would a power producer pay someone to take electricity?
Because shutting down generation is not always simple.
Some generators have technical reasons to remain online.
Others receive subsidies or contractual payments that allow them to continue making money even when wholesale prices turn negative.
Meanwhile, solar and wind production can remain extremely high.
The result is an electricity market temporarily saying:
Please use more power.
The IEA says negative wholesale electricity prices have become increasingly common across European markets.
In 2025, countries including Germany, France, the Netherlands, and Spain experienced negative pricing during around 6% of wholesale hours, roughly double the frequency seen in some markets a few years earlier.
The trend became even stronger in Spain during the first half of 2026.
Negative prices occurred during approximately 17% of hours, up from about 10% the previous year.
That does not mean electricity is becoming worthless.
It means the timing of generation and demand is increasingly mismatched.
Then Prices Can Explode a Few Hours Later
The strange part is what can happen after sunset.
Solar output disappears.
Demand rises.
Other generators must suddenly replace the lost production.
Electricity that was nearly worthless at 2 p.m. can become extremely expensive at 8 p.m.
During Europe’s June 2026 heatwaves, the IEA says the difference between midday lows and evening electricity-price peaks reached as much as $600 per megawatt-hour in several markets.
That is not primarily a renewable-energy failure.
It is a flexibility failure.
Europe has large amounts of inexpensive daytime electricity.
It needs better ways to move that electricity through time.
This is where batteries become extremely important.
Batteries Could Solve a Large Part of the Problem
The logic of battery storage is simple.
When solar output is enormous and prices are low:
Charge the battery.
When the sun goes down and prices rise:
Discharge the battery.
That converts excess renewable electricity into evening electricity instead of wasting it.
Battery economics have improved dramatically as manufacturing costs fall.
The Financial Times recently reported that combined solar-and-battery projects are becoming an increasingly important business model because operators can store surplus solar energy and sell it when electricity is more valuable.
This does not eliminate every grid problem.
A battery designed to store four hours of electricity cannot solve a week-long period of low wind.
But it can solve a huge portion of daily solar imbalance.
Batteries Need to Be Built Much Faster
Europe is adding storage, but renewable capacity is still expanding rapidly.
Every additional gigawatt of solar makes midday electricity cheaper.
That is excellent if storage and flexible demand increase alongside it.
It becomes problematic if they do not.
The European Commission explicitly identified storage as critical during this summer’s heatwave, noting that surplus solar generation during central daytime hours needs to be shifted into the evening consumption peak.
That is why future renewable projects may increasingly look different.
Instead of:
Solar farm
the business model may become:
Solar farm + battery
and eventually:
Solar + battery + flexible industrial demand.
Electric Cars Could Become Part of the Solution
Europe has millions of increasingly large batteries already being deployed.
They just happen to have wheels.
Electric vehicles can charge during periods of abundant renewable electricity.
If electricity prices are low at noon, smart chargers can encourage drivers to charge then instead of during the evening peak.
Eventually, vehicle-to-grid technology could allow some EVs to send electricity back into the grid when demand is high.
Imagine ten million cars each contributing only a few kilowatt-hours.
Together, they could represent enormous distributed storage capacity.
The challenge is coordinating them.
Electricity tariffs need to reward flexible charging.
Vehicles and chargers need compatible software.
Drivers need incentives.
But technically, the opportunity is significant.
Heat Pumps Can Also Shift Demand
Home heating is another potential source of flexibility.
Modern heat pumps can operate when electricity is plentiful and reduce consumption when the grid is stressed.
Buildings themselves can act as a form of thermal storage.
Heat a well-insulated home slightly earlier.
Reduce the heat pump later when electricity prices rise.
The homeowner may barely notice.
At national scale, millions of small adjustments can reduce the need for renewable curtailment.
This idea is known as demand response.
Instead of forcing electricity supply to follow demand constantly, some demand begins following electricity supply.
The IEA identifies flexible loads and demand response as major tools for integrating larger shares of wind and solar.
Industry Could Use Electricity When It Is Cheapest
Large industrial consumers may be even more useful.
Hydrogen production is one obvious example.
Electrolyzers use electricity to split water into hydrogen and oxygen.
They do not necessarily need to operate at exactly the same power level every hour.
When renewable electricity is abundant and cheap:
Produce more hydrogen.
When electricity becomes scarce and expensive:
Reduce production.
Data centers may also provide some flexibility by shifting certain computing workloads between times or locations.
Steel plants, refrigeration warehouses, water systems, and other industrial processes can sometimes adjust electricity usage without shutting down completely.
The more flexible demand becomes, the less frequently renewable generators need to be switched off.
Europe Also Needs More Transmission Lines
Storage moves electricity through time.
Transmission moves electricity through space.
Both are necessary.
Northern Europe has enormous wind resources.
Southern Europe has exceptional solar resources.
Industrial demand is concentrated elsewhere.
A stronger European grid would allow surplus electricity in one region to flow toward another.
The European Commission now describes electricity networks as one of the central constraints on European energy security and competitiveness. Its May 2026 analysis warned that inadequate grid capacity is already slowing renewable projects and industrial electrification.
European Commission overview of Europe’s grid strategy
New transmission lines are expensive.
They also face political resistance.
Nobody objects to a renewable project in theory.
People can become much less enthusiastic when a new high-voltage power line is proposed through their community.
That makes permitting one of the biggest obstacles.
Cross-Border Connections Matter Too
Europe has one advantage compared with many electricity systems.
Countries are heavily interconnected.
France can send electricity to Germany.
Norway can export hydropower.
Denmark can export wind.
Spain can exchange electricity with France and Portugal.
The European Commission said those cross-border connections played an important role in maintaining electricity reliability during the extreme weather conditions of summer 2026.
Interconnectors effectively allow countries to share renewable resources.
A windy Denmark can export electricity to Germany.
A cloudy Germany can import from somewhere else.
The larger the connected system, the easier it becomes to balance variable renewable energy.
But existing interconnectors also have capacity limits.
Europe needs more of them.
Norway Was Once Called Europe’s “Green Battery”
Norway has enormous hydropower reservoirs.
That makes the country particularly useful for balancing renewable electricity.
When Europe has too much wind:
Norway can reduce hydropower generation and import electricity.
When Europe needs power:
Norwegian hydro plants can increase production and export it.
This resembles a giant natural battery.
But the politics have become complicated.
Norway’s energy minister recently said the idea of Norway simply functioning as Europe’s “green battery” is outdated, partly because electricity exports can create domestic price volatility.
That illustrates another problem.
Technical solutions often create political consequences.
A highly integrated European electricity market is efficient.
But voters may object if cross-border trading raises local electricity prices.
Pumped Hydro Can Store Huge Amounts of Energy
Batteries are not the only storage technology.
Pumped-storage hydropower has been used for decades.
When electricity is cheap, water is pumped uphill into a reservoir.
When electricity becomes expensive, the water is released through turbines.
Electricity is effectively stored as gravitational energy.
Pumped hydro can store much larger quantities of energy than many battery projects and can discharge for longer periods.
The limitation is geography.
Suitable reservoirs and elevation differences are required.
Environmental permitting can also be difficult.
Still, countries with appropriate geography can use pumped hydro as another important balancing tool.
Hydrogen Could Help With Longer-Term Storage
Lithium batteries work extremely well for storing electricity for several hours.
Seasonal storage is harder.
Europe may sometimes experience multiple days with little wind during winter.
This phenomenon is sometimes called Dunkelflaute, meaning periods that are both dark and relatively windless.
Huge batteries capable of powering entire countries for a week would be extraordinarily expensive.
Hydrogen could potentially help.
Excess renewable electricity can produce hydrogen.
That hydrogen can be stored for longer periods.
Later, it can be used in industry, fuel cells, or power generation.
The process loses more energy than battery storage, so it is not ideal for daily cycling.
But for very long-duration storage, lower efficiency may be acceptable.
Better Electricity Pricing Could Help
Europe’s electricity market was largely designed before solar and wind became dominant sources of new generation.
As renewable penetration rises, pricing systems need to provide stronger incentives for flexibility.
Consumers should ideally pay less when electricity is abundant.
And more when electricity is scarce.
Smart meters make this possible.
A household could charge an EV or run a washing machine when electricity prices fall.
Industrial users could automatically modify consumption.
Battery operators could charge when prices turn negative and sell power later.
ENTSO-E argues that market design needs to reflect the physical reality of where grid congestion occurs and provide better signals about where new generation, storage, and electricity demand should be located.
That could reduce the need for expensive grid interventions.
Location Matters More Than Many Renewable Developers Expected
A solar farm does not necessarily belong wherever land is cheapest.
It belongs where the grid can actually use the electricity.
The same applies to data centers and battery projects.
Suppose northern Germany already has enormous wind output and limited southbound transmission capacity.
Building another wind farm there may increase congestion.
Building an energy-intensive factory, battery, electrolyzer, or data center nearby could absorb some of that electricity locally.
This is why European regulators are increasingly discussing locational incentives.
Instead of treating every grid connection as equivalent, electricity markets could encourage generators and large consumers to locate where they help the system most.
The European Commission is also promoting flexible connection agreements that allow projects to connect sooner if they accept temporary limits during congested periods.
Curtailment Is Not Always a Disaster
It is important not to treat every curtailed megawatt-hour as evidence of policy failure.
Some curtailment can actually be economically sensible.
Imagine spending €1 billion on transmission lines solely to transport electricity during five extremely windy hours each year.
It might be cheaper simply to shut down a few turbines during those rare periods.
Electricity systems have always maintained spare capacity and occasionally wasted potential energy.
The objective should therefore not necessarily be:
Zero curtailment.
It should be:
Avoid unnecessary curtailment when storing, moving, or using the electricity would cost less.
That is an important distinction.
More Renewable Energy Can Actually Make Electricity Cheaper
Negative prices sometimes produce headlines suggesting renewable power is destabilizing markets.
There is another interpretation.
Solar and wind have near-zero fuel cost.
Once built, producing another unit of electricity costs very little.
That pushes wholesale electricity prices downward when renewable generation is abundant.
Consumers can ultimately benefit if electricity markets and retail pricing allow those savings to reach them.
The problem is not cheap electricity.
Cheap electricity is good.
The problem is that today’s grid is not flexible enough to take full advantage of those low-cost periods.
Storage, smart charging, flexible industry, and better transmission can convert temporary oversupply into an economic advantage.
Europe’s Energy Crisis Is Accelerating Renewable Investment
Europe also has another reason to solve this problem quickly.
Energy security.
The continuing U.S.-Iran conflict and disruption to global fossil-fuel flows have reinforced Europe’s desire to reduce dependence on imported oil and gas.
Reuters reported this week that countries across Europe and Asia are accelerating renewable investment as geopolitical disruptions increase the risks associated with fossil-fuel imports.
That means renewable capacity will continue growing.
Grid flexibility will have to grow with it.
Otherwise, Europe could simultaneously experience:
Too much solar at noon.
Too little electricity during the evening.
High power prices during shortages.
Negative prices during surpluses.
And renewable plants being switched off.
That sounds contradictory.
It is actually one problem:
Timing and infrastructure.
The Fix Is Not One Technology
There is no single solution.
Europe needs more batteries.
More transmission lines.
More cross-border interconnectors.
More pumped hydro where geography permits.
More flexible EV charging.
More responsive industrial electricity demand.
Smarter pricing.
Better grid planning.
Faster permitting.
Potentially more hydrogen for long-duration storage.
And improved digital control of distributed solar generation.
The IEA estimates that global grid investment needs to increase by roughly 50% by 2030 from today’s approximately $400 billion annual level if electricity networks are going to keep pace with demand and renewable deployment.
Europe will need to contribute heavily to that investment.
Solar and Wind Aren’t Being Turned Off Because They Failed
This is the most important point.
A wind farm being curtailed does not mean wind power does not work.
A solar farm being disconnected does not mean solar power was a bad investment.
Quite the opposite.
They are sometimes being switched off because they are producing more electricity than the existing system can intelligently handle at that moment.
Europe has become extremely good at building renewable generation.
Now it needs to become equally good at building the infrastructure around it.
The next phase of the energy transition is therefore less glamorous than giant offshore turbines or enormous solar farms.
It is transmission cables.
Batteries.
Transformers.
Smart meters.
Interconnectors.
Grid software.
Flexible factories.
And better electricity-market rules.
Those systems determine whether a megawatt of wind or solar power becomes useful electricity—or gets thrown away.
Europe’s renewable-energy problem is no longer simply:
“Can we produce enough clean electricity?”
Increasingly, the question is:
“Can we move and store it fast enough to use everything we produce?”
Until the answer becomes yes, there will continue to be days when Europe has enough sunshine and wind to produce enormous amounts of cheap electricity—and still tells some of its cleanest power plants to switch off.
Read the IEA’s latest analysis of electricity-system flexibility
