How EV Fleet Depots Turn Day-Ahead and Intraday Electricity Prices Into Savings

Do you know what your electricity actually cost, hour by hour, last week? Not the number on the monthly bill. The real, day-ahead and live wholesale price. If you actually look at it, you'll be surprised.

Almost every day, the price hits the floor

Look at the rhythm. Day-ahead market prices peak in the morning and evening at €150–200/MWh, then fall in the middle of the day. Down to zero every day. And on a couple of days even below it. The pattern repeats day after day.

The midday collapse is solar. When the sun is up, the grid fills with renewable power. Supply overwhelms demand, and the price drops. Literally every day electricity is (almost) free around midday.

And then there are days like Easter

Now look at what happened in Germany over Easter 2026. The price didn't just touch zero. It went deeply negative, hour after hour across the holiday weekend, bottoming around −€130/MWh. A negative price means exactly what it sounds like: the market is paying consumers to take electricity off its hands. On the intraday market it was even more extreme: the price hit -€324/MWh at 15:00.

Day-ahead market vs. intraday market: 

• Think of the day-ahead market as a single, daily auction for planning the next day. Once a day buyers and sellers submit bids for every slice of the next day based on a forecast.
• Forecasts are never perfect. The intraday market is continuous trading and all market players rebalance their positions. Most flexibility has been used up day-ahead, so intraday prices tend to swing even harder.

Why so extreme negative prices? Factories and offices were closed for the holiday, so demand cratered. The weather was sunny, so solar surged. With far more power than the grid could absorb, producers would rather pay you to consume than shut their plants down. A fleet charging that weekend wasn't just fuelling for free. It was getting paid to fuel up.

Negative prices are more common than you might think. In 2025, Germany had negative prices on the day-ahead market in 573 out of a total of 8,760 hours. That's 6.5% of the year - and 25% more than in 2024, so the trend is clear.

The grid literally pays people to use its electricity during 6.5% of the year.

Dr.-Ing. Jonas Schlund, CPO at Ampcontrol

It's only free if you're flexible

A fleet's energy need is fixed. Every vehicle requires a set number of kWh to run its routes. But when that energy is delivered is flexible. Vehicles idle for predictable windows overnight and between shifts.

That flexibility is the entire opportunity. Plug in at 6pm and charge at full power, and you're buying at the top of the curve. Park that same charging in the midday or overnight trough, and you're buying at the bottom. Or you're even getting paid for fueling. Same energy. Wildly different cost.

"But I can't charge my trucks midday - they're on-route"! We hear that a lot. Well, there's a simple solution. Add battery energy storage (BESS) to your depot. It charges during the cheap hours, then feeds your trucks whenever they're back. Our TCO analyses consistently show that the economic benefit of BESS is even larger than adding solar panels. You can run your own truck TCO analysis with our free tool here.

Four ways depots turn the spread into margin

1. Load shifting: charge in the cheap hours while still guaranteeing every vehicle is ready at departure. This is an optimization problem, not a timer: it has to respect each vehicle's energy need and schedule (see AutoScheduler), not just "charge at night."
2. Demand-charge management: cap simultaneous charging so the 15-minute peak stays low. Often the largest lever to save on costs.
3. On-site battery and solar: use a BESS to store cheap or solar-generated power and discharge it when prices spike; self-consume solar to skip retail rates entirely. The depot stops being a passive load and becomes an active energy asset.
4. Grid-service revenue: stack demand response and utility flexibility programs on top of market activities. Many built on standards like IEEE 2030.5/CSIP. A controllable depot can get directly paid to adjust its load during grid stress.

The bottom line

The cheap energy is already on the grid. It shows up almost every day, in broad daylight. On some days, the grid will pay you to take it.