Metering, consumption, and grid flow

SolarSENS uses power and energy values to answer two related questions: how electricity is flowing during an interval, and how much electricity accumulated over a day or month. Keeping those dimensions separate is essential when comparing solar generation, facility demand, grid import, and grid export.

Keep power and energy separate

Value	Dimension and period	What it describes
Plant or inverter power	Power for an interval	The combined generation rate from the plant’s inverters.
Grid Power	Power for an interval	The grid-side power series produced from eligible meter data. Its direction depends on the plant’s meter configuration.
Consumption Load	Five-minute power	Facility load power derived from plant inverter power and Grid Power.
Grid Import and Grid Export	Daily or monthly energy	Positive accumulated energy amounts for the two grid directions.
Load Energy	Daily or monthly energy	Facility energy calculated from yield, grid import, and grid export.

The displayed unit confirms the dimension in a particular view. Power is commonly shown in kW, while accumulated energy is commonly shown in kWh. Check the unit and period before comparing the numerical values.

flowchart LR
  subgraph P[Interval power]
    I[Plant inverter power] --> C[Consumption Load power]
    G[Grid Power] --> C
  end
  subgraph E[Daily or monthly energy]
    Y[Yield energy] --> L[Load Energy]
    GI[Grid Import energy] --> L
    GE[Grid Export energy] -->|subtract| L
  end

These are separate calculation branches: SolarSENS calculates daily and monthly Load Energy from yield and grid energy, not by integrating the five-minute Consumption Load series.

Interval load power

For the analytical interval series, SolarSENS combines plant inverter power with grid power:

\text{Consumption Load} = \text{Plant Inverter Power} + \text{Grid Power}

Inverter readings are combined for the plant, and eligible grid-meter readings are aligned into five-minute intervals. The resulting Consumption Load answers a power question: how much facility demand was present during that interval.

This series needs suitable inverter and grid-meter inputs. If one input is unavailable, Consumption Load is unavailable rather than zero.

Daily and monthly grid energy

Import and export meters normally provide cumulative energy counters. For each eligible meter, SolarSENS takes the difference between that meter’s highest and lowest eligible cumulative reading within the selected plant reporting day. It then sums those per-meter results to produce the plant total. This within-day calculation is different from reviewing the difference between two consecutive displayed meter readings.

Grid Import and Grid Export are retained as positive energy amounts. SolarSENS calculates daily Load Energy as:

\text{Load Energy} = \text{Daily Yield} + \text{Grid Import} - \text{Grid Export}

For example, if Daily Yield is 80 kWh, Grid Import is 30 kWh, and Grid Export is 10 kWh:

80 + 30 - 10 = 100\ \text{kWh of Load Energy}

This example illustrates the daily energy identity only; it is not a settlement calculation.

Monthly Load Energy uses the same identity after the daily components have been combined for the month.

Stored direction and chart direction

Grid Import and Grid Export are stored and returned as positive energy amounts. A chart can draw export below the horizontal axis to make its direction easier to scan. That visual transformation does not make the underlying export amount negative.

The sign of interval Grid Power depends on the plant’s meter telemetry and configuration, so its convention can vary by plant. Use daily or monthly Grid Import and Grid Export when you need an explicit direction.

Why meter configuration matters

The calculated series depends on the right meters, mapped fields, multipliers, and import/export direction. Configuration changes affect interpretation, not the physical meter. Have an authorized operator verify a changed direction or multiplier against a trusted reading. See Data freshness and corrections when a value is blank, zero, stale, or corrected.