Grid only

One meter and nothing else. Every published property still has a value here, which makes this the simplest place to see what the engine does at the edges: a single source, a house that draws nothing, and a sensor that has dropped out.

What this case shows

• With no local device, the whole gross power is the unmetered home base load.
• A sink with one available source has a provenance row of exactly one.
• Marginal and levelized cost agree while the grid is the only source.
• An unavailable meter collapses everything derived from it to nothing, while a total over an empty device set (no PV, no battery) stays zero.

Each snapshot below is one set of readings on this wiring, drawn as a flow chart — how to read it.

Import only

Grid only · snapshot 01

The house runs on the grid alone; every watt is unmetered base load.

Reading	W	Of gross	Share	Made of
Gross power	1200 W	1		grid 1200 W
Grid import	1200 W	1		grid 1200 W
Grid export	0 W	0		nothing exported
PV production	0 W	0		no PV system
Charging power	0 W	0		no battery charging
Discharging power	0 W	0		no battery discharging
Standby power	0 W	0		no standby draw
Self-consumption	1200 W	1		grid 1200 W
Metering imbalanceok	0 W	0		readings reconcile exactly
Home base load	1200 W	1		unmetered remainder of consumption

Ribbon widths are watts in every view. Hover, focus or tap a ribbon to see the sensor behind it.

Grid idle

Grid only · snapshot 02

The meter reads exactly 0 W: gross power is zero and every ratio has to survive it. A connected meter reading zero is not an absent one. The grid is idle — in no flow group — but keeps its key in every per-source map: its watts, shares and ratios read 0, and its price reads nothing at all, because nothing was delivered to put a price on. The blended price of electricity is blank for the same reason.

Every reading is 0 W, so nothing flows in this snapshot.

Reading	W	Of gross	Share	Made of
Gross power	0 W	—		no source delivers anything
Grid import	0 W	—		nothing drawn from the grid
Grid export	0 W	—		nothing exported
PV production	0 W	—		no PV system
Charging power	0 W	—		no battery charging
Discharging power	0 W	—		no battery discharging
Standby power	0 W	—		no standby draw
Self-consumption	0 W	—		nothing consumed
Metering imbalanceok	0 W	—		readings reconcile exactly
Home base load	0 W	—		unmetered remainder of consumption

Idle: grid · 0 WRibbon widths are watts in every view. Hover, focus or tap a ribbon to see the sensor behind it.

Grid unavailable

Grid only · snapshot 03

The grid sensor has dropped out. Everything derived from the meter collapses to nothing, while a total over an empty device set — no PV, no battery — is still a confident zero. Where a value is grid-derived (gross power, consumption, the ratios, the provenance maps, every cost rate) the engine publishes nothing at all rather than a stale or invented figure. Where a value is a structural sum over devices that do not exist here (production, charging, discharging, standby) it stays 0: the missing meter says nothing about PV that is not installed.

grid has no reading, so the engine publishes no flows for this snapshot.

Reading	W	Of gross	Share	Made of
Gross power	unavailable	—		not published: a reading is unavailable
Grid import	unavailable	—		not published: a reading is unavailable
Grid export	unavailable	—		not published: a reading is unavailable
PV production	0 W	—		no PV system
Charging power	0 W	—		no battery charging
Discharging power	0 W	—		no battery discharging
Standby power	0 W	—		no standby draw
Self-consumption	unavailable	—		not published: a reading is unavailable
Metering imbalance	unavailable	—		not published: a reading is unavailable
Home base load	unavailable	—		not published: a reading is unavailable

Ribbon widths are watts in every view. Hover, focus or tap a ribbon to see the sensor behind it.

Why this case exists

Every case needs something to be read against, and for a long time that job was done by a four-adapter house. It should not have been. A single grid meter is enough to give every property in the catalog a value — all four layers of it, provenance and money included — which makes this the simplest place to see what the engine does when there is nothing to be clever about.

Every answer here can be checked in your head: one source means a provenance row of exactly 1, no local generation means marginal and levelized cost agree, and nothing is saved because there was nothing to save it against. Read the bigger houses against it.

The third snapshot is the one worth arguing with. When the only meter drops out, almost everything correctly reports nothing at all — and one rate reports zero instead.