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REPLACE_AFTER_DEPLOY

Bart Kardol

Riding the
Duck Curve

☀️ Mother's Day, 10 May 2026

Solar panels are producing.
The grid says: no thanks.

Day-ahead purchase price, 15-minute resolution.

Agenda

Three parts

1 · Grid mechanics

Why prices go negative

2 · The NL duck curve

Real data from 2015 to 2026

3 · Riding it

What the smart products actually do

Part 1 · no energy degree required

Grid mechanics

How power actually gets traded

Three markets, one delivery hour

Merit order, in one sentence

Cheapest generation runs first

Solar and wind bid near €0. No fuel cost, so they're always first in line.

Illustrative

How about negative prices?

When supply keeps showing up anyway

Inflexible generation & Subsidised renewables.

Illustrative

Forecasts are wrong sometimes

The market never really closes

A cloud rolls in, a turbine trips. Intraday keeps trading right up to gate closure.

Zoomed in: intraday trading after day-ahead closes

50.00 Hz, or the grid gets nervous

Frequency is the grid's heartbeat

Supply must match demand every instant, not on average.

Duration vs. magnitude

8 Jan 2021 & Jan–Mar 2018 · ENTSO-E

The reserves that catch what forecasting can't

Balancing happens in seconds, not hours

Three layers of reserve capacity keep frequency at 50.00 Hz.

The other release valve

Local congestion: the grid's other "no thanks"

Price isn't the only lever. A congested local grid can just tell a device to stop.

A physical limit, not a price signal

Part 2 · the data, not the story

The NL duck curve

What we're about to look at

Actual Total Load, not a model

ENTSO-E

Grid-metered demand, published

15 min

Resolution

2015–2026

Twelve years, no stock art

Every month · business-day average per year, 2015–2026

The midday shape, month by month

2022, business-day average per month

The valley is a summer phenomenon

The lighter stripe down the middle is the duck's belly.

Pale = low load, saturated = high.

Quantifying the dip

Up to a fifth of midday demand, gone

27%

March, the sharpest dip of the year

~18–20%

Typical for April through September

6–10%

December and January, barely a dip

2022, business-day average · midday min vs. morning/evening

The compensation model is changing underneath this

Saldering is packing its bags

€0.28–0.35

Today, per kWh exported · full retail rate

→

1 January 2027

€0.04–0.08

From 2027, per kWh exported · near wholesale

Eerste Kamer approval 17 Dec 2024

Two curves, colliding

Put together, that's the meltdown

~18–20%

Midday demand, hidden behind rooftop solar

-75%

Export pay, once saldering ends in 2027

Part 3 · the payoff

Turning grid chaos
into a good month

One shared move, three products

Grid signal → device steering → financial outcome

Signal

Price, congestion, own production

Steer

A connected device

Outcome

Money back, not a penalty

Same spine, three apps

What the customer actually opens

The same signal → steer → outcome loop, live on a phone.

🔌 Smart Charging

🔋 Home Battery

☀️ Solar Curtailment

Essent Solar app Slim Terugleveren screen showing feed-in curtailment, euros earned, and kWh dimmed

March 2022 · actual vs. Smart illustrative

The valley these products are built for

Actual load, unsteered

Illustrative, steered

Smart Charging · 11:00–15:00

Home Battery · 15:00–21:00

Solar · not pictured

Solid: measured. Dashed: illustrative, with steering.

The grid is asking
you to move demand.

Ride the duck. Don't get run over by it.

Questions?

Riding the Duck Curve · Bart Kardol

Riding theDuck Curve

Solar panels are producing.The grid says: no thanks.