The Old Way

Before batteries and software, this is how we kept the lights on. It cost over EUR 10 billion per year.

Peaker Plants

A peaker plant is a gas turbine that exists for one purpose: to fire up during rare demand spikes. Think of it like keeping a taxi running 24 hours a day, engine idling, burning fuel, just in case someone needs a ride. Most of the time, nobody does.

These plants sit idle roughly 95% of the year. In the US alone, peaker plants account for 19% of total generation capacity but produce only 3% of electricity. They run fewer than 1,500 hours per year — some as few as 250. Yet grid operators keep them on standby because when demand spikes, nothing else can respond fast enough.

The cost of maintaining this insurance policy is staggering. Peaker electricity costs EUR 150--250 per MWh — two to three times more expensive than baseload gas. Across Europe, the total bill for peaker capacity reaches an estimated EUR 6.5 billion every year, paid by consumers whether the plants run or not.

Spinning Reserves

Spinning reserves are generators that run continuously, synchronized with the grid, burning fuel but producing nothing useful. They exist purely as a safety margin — ready to ramp up within seconds if another generator trips offline or demand surges unexpectedly.

Imagine leaving your car engine running in the driveway all day, every day, just so you can pull out instantly if you need to. That is what spinning reserves are: thousands of generators across Europe running at partial load, wasting fuel, so the grid has a buffer.

The standard margin is roughly 15% of all generation capacity. That means at any given moment, about one in seven generators on the grid is burning fuel to produce nothing. The fuel waste alone is estimated at EUR 1--3 billion per year, but you will never see it on your electricity bill — it is hidden in wholesale prices, buried in the cost of "keeping the lights on."

Grid Congestion

The European transmission grid has bottlenecks — places where the wires simply cannot carry enough power from where it is generated to where it is needed. When wind farms in northern Germany produce more electricity than the north-south transmission lines can handle, grid operators face an absurd situation: they pay the wind farms to stop generating, then pay gas plants in the south to start up instead. Same power delivered. Twice the cost.

Imagine a highway with a traffic jam. Instead of waiting, you pay a helicopter to fly the cargo to the other side. That is congestion management — an expensive workaround for infrastructure that has not kept up with how the grid actually works.

In 2023, managing grid congestion across the EU cost EUR 4.2 billion. Germany alone accounted for EUR 3.3 billion of that, driven by its north-south bottleneck. Remedial action volumes rose 14.5%, reaching 57 TWh of redispatched electricity. And the problem is getting worse: as more renewables come online in locations far from demand centers, congestion costs keep climbing.

Curtailment

Curtailment is when the grid literally throws away free, clean energy because the wires cannot carry it. Too much sun in Bavaria? Turn off the solar panels. Too much wind in Schleswig-Holstein? Shut down the turbines. The energy is there, the demand is there, but the grid between them is full.

In Germany alone, over 10 TWh of renewable electricity was curtailed in 2023 — enough to power roughly 2.7 million homes for an entire year. That is clean energy, already generated, with zero fuel cost, dumped because the system was not designed to handle it.

And it is not just a German problem. Across Europe, grid congestion curtailed over 12 TWh of renewable electricity in 2023, causing an additional 4.2 million tons of CO2 emissions as fossil plants ran instead. Every megawatt-hour of curtailed wind or solar is a megawatt-hour that a gas plant had to produce in its place.

Real Incidents

The old system does not just cost money. When it fails, the consequences are measured in lives lost and millions of people left in the dark. Here are three incidents where the traditional grid failed catastrophically.