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Smart Scheduling

Power Profiler does more than pick the cheapest hour. It knows exactly how your appliance uses power throughout its cycle, and it uses that knowledge to find the absolute cheapest window — minute by minute, matched against energy prices.

This page explains the three layers of scheduling: standalone (price-only), solar-aware, and capacity-aware (multiple appliances).

Finding the cheapest window

You tell the scheduler when your appliance needs to be done. That can be a relative deadline ("run within the next 8 hours") or an absolute one ("finish before 07:00"). The scheduler then figures out the best time to start.

Here is how it works:

  1. Your power profile — The app already knows your appliance's consumption pattern from recorded cycles. A washing machine, for example, might use ~2000 W for 15 minutes (heating), then ~300 W for 60 minutes (washing and rinsing), then ~400 W for 15 minutes (spinning). That's roughly 90 minutes total.

  2. Sliding the profile across the timeline — For every possible start time between now and the deadline, the app overlays the power profile on the energy prices. It multiplies each minute's power consumption by that minute's price to calculate the total cost for that window.

  3. The cheapest one wins — The start time with the lowest total cost is selected.

This approach is more accurate than simply looking for the cheapest hour. Because your appliance's power consumption changes throughout the cycle, the optimal window often overlaps both cheap and expensive hours. A flat "cheapest hour" approach would miss these nuances.

Shadow prices

Day-ahead energy prices for the Netherlands are published between 13:00 and 15:00 CET. But what if you schedule at 22:00 with a 12-hour deadline? Some of those hours don't have real prices yet.

The app fills the gaps with shadow prices — historical averages it has learned for each hour of the day. This means scheduling works even before tomorrow's prices are published.

Shadow prices are a fallback

Shadow prices are less accurate than real prices. They represent what prices typically look like at each hour. Once real prices arrive, the app re-evaluates and may update the schedule.

Re-evaluation

When new day-ahead prices arrive, the app automatically re-evaluates all active schedules. If the new optimal start time differs by more than 1 minute from the current one, the schedule is silently updated. You'll see the new time on the device dashboard.

This means you can schedule at any time of day without worrying about whether prices are available yet. The scheduler always uses the best information it has, and updates when better information arrives.

Standalone scheduling diagram

Scheduling with solar

Note

You don't need to change your flows or scheduling logic. When a PV Profiler is configured, the scheduler automatically uses effective prices instead of grid prices.

What are effective prices?

Without solar panels, the price per kWh is straightforward: whatever your energy provider charges.

With solar, it gets more interesting. During hours when your panels produce more than your household uses, you have a surplus. That surplus gets exported to the grid at your feed-in tariff — typically around EUR 0.07/kWh in the Netherlands.

So what does it "cost" to run an appliance during surplus hours? Not the grid price — you're using your own solar energy. The cost is the feed-in revenue you're giving up by consuming the energy yourself instead of exporting it. That's your feed-in tariff.

If the feed-in tariff is EUR 0.07/kWh and the grid price at that hour is EUR 0.25/kWh, you save EUR 0.18/kWh by using your own solar instead of buying from the grid.

How it affects scheduling

The scheduler replaces the grid price with the effective price during surplus hours:

  • Surplus hours — effective price = feed-in tariff (e.g., EUR 0.07/kWh)
  • Non-surplus hours — effective price = grid price (e.g., EUR 0.25/kWh)

Since the feed-in tariff is typically much lower than the grid price, surplus hours appear as the cheapest slots on the timeline. The scheduler naturally moves your appliance into the solar window.

Exception: negative prices

If the grid price drops below the feed-in tariff (which can happen during negative pricing events), the grid price is used as the effective price. It's cheaper to buy from the grid than to use your own solar in that case.

Solar scheduling diagram

Capacity-aware scheduling

The problem

Imagine you have a washing machine and a dryer, both scheduled with Power Profiler. Without coordination, both appliances would pick the same optimal window — likely the same solar surplus hours. But there's only enough surplus power for one of them. The other would end up drawing from the grid anyway, defeating the purpose.

The solution

Power Profiler schedules appliances one at a time, ordered by deadline urgency (earliest deadline first):

  1. The first appliance is scheduled normally and "reserves" its expected power consumption from the available capacity.
  2. The next appliance sees the reduced remaining capacity. If the surplus window no longer has enough headroom, it picks the next best option — often a cheap grid hour later in the day.
  3. This continues for each additional appliance.

The result: appliances are spread across the best available windows instead of competing for the same one.

Example

Consider this scenario:

  • Solar surplus: ~2000 W available from 11:00 to 15:00
  • Washing machine (deadline: 16:00): scheduled at 11:00, reserves ~1500 W average
  • Dryer (deadline: 20:00): sees only ~500 W remaining surplus at 11:00–15:00 — not enough for a 2000 W dryer

The dryer skips the surplus window and picks a cheap grid hour in the evening instead. Both appliances run at the lowest possible cost given the available capacity.

Capacity-aware scheduling diagram

Next steps:

  • Virtual Energy Provider — central dashboard showing effective prices, surplus, and flow triggers for solar automation
  • Flow Examples — concrete flows for scheduling with and without solar