That's the actual question behind "when is the best time to charge" — and it's what the widget above answers. If the signal reads low, you're already in one of the cheapest hours of the day: charging now is the right call. If it reads high, waiting even a few hours for the next cheap window can meaningfully lower the cost of a full charge.
The gap is usually bigger than people expect. The difference between the cheapest and most expensive hour of the day is commonly 3–10 times, and during extreme demand or renewable oversupply it can exceed 100 times. For a full EV charge, waiting a few hours can easily save several euros or dollars in a single session — for free, with no manual math.
Night charging is a decent default because demand drops when homes and businesses are quiet. But electricity prices are set by supply and demand in real time, not by the clock — and that plays out differently market by market:
This is exactly the gap a live signal closes: instead of assuming last night's pattern repeats, you check what today's day-ahead market actually published.
General tendencies, not today's actual price. Always check the live signal for the exact window.
| Market | Typical pattern | Notes |
|---|---|---|
| Nordics (FI, SE, NO, DK) | Overnight, 01:00–06:00 | Strong day/night split; wind can shift the cheapest window to daytime |
| Germany | Overnight or midday solar dip | High solar penetration can make early afternoon cheaper than night on sunny days |
| UK (Octopus Agile) | 00:30–04:30, half-hourly | Half-hour resolution — the cheapest 30-minute slot can differ from the cheapest hour |
| California (CAISO) | Midday solar dip, 10:00–15:00 | Solar oversupply often makes midday cheaper than night — opposite of the usual pattern |
| Texas (ERCOT, HB_WEST) | Windy nights, highly variable | Wind zone prices can go negative during oversupply — most volatile market covered |
| Australia / New Zealand | No public day-ahead data | Real-time spot price is available; a 24h ranked forecast is not published |
The whole point of a live signal is that software can watch it for you.
Instead of remembering to look this up each evening, your charger, home automation system, or AI assistant can check the live signal automatically and act on it — start charging when it's cheap, hold off when it isn't.
One call returns the ranked cheapest hours for the next 24h, plus a ready-to-use signal. Free, no API key.
curl "https://elecz.com/signal/cheapest-hours?zone=FI"
{
"mcpServers": {
"elecz": { "url": "https://elecz.com/mcp" }
}
}
Full parameters, response fields, and integration examples: Cheapest Hours API · Electricity Price API overview · Electricity Price MCP server · Full documentation.
Any flexible electricity use benefits from the same live cheapest-hours signal.
next_cheap_hour from the API.current_hour_signal without custom logic. See Electricity Price MCP.GET https://elecz.com/signal/cheapest-hours?zone=YOUR_ZONE — free, no API key. Or connect an AI assistant via MCP at https://elecz.com/mcp and just ask it.cheapest_hours signal applies to any flexible load, including industrial and commercial buildings. See the full cheapest hours API for response fields and integration examples with Home Assistant and n8n.Same live data, different questions.
Free. No API key. 40 countries. Works via MCP or REST.