Energy monitoring guide
Solar, DG and grid monitoring: every source against the plant load.
Most plants now run on more than one source: grid supply, rooftop solar and a DG set for outages. Each has its own meter or display, and none of them shows the whole picture. Monitoring all three against the plant load shows what each source really costs and delivers.
What to meter
Put a meter on each source and tag it: the grid incomer, the solar inverter output, the DG output. Load feeders are tagged as loads. Then the system knows which readings to add up as supply and which as consumption, and never counts the same unit twice.
The daily views that matter
- Solar generation today, this month, and per kWp of panels installed.
- Share of solar used on site and how much was exported. Exported units often earn less than imported units cost, depending on your state’s solar rules.
- Generation against the weather, so a low day caused by cloud is not mistaken for a fault.
- Dust loss: an estimate of generation lost to dirty panels, so cleaning is planned by data, not by calendar.
- Grid-off hours, when a grid-tied inverter stops with the grid and solar is lost.
- DG units generated, and DG load hour by hour.
Energy balance
An energy balance chart shows, hour by hour, grid import and solar and DG used on site stacked against the plant load, with export below the line. It answers the questions owners ask: how much did solar save today, how much did we export, and how long did the DG run.
DG cost per unit
DG cost per unit = diesel price per litre ÷ units generated per litre
At an illustrative ₹90 per litre and 3.2 units per litre, each DG unit costs about ₹28, several times a grid unit. Units per litre fall when a DG runs lightly loaded, so a large DG carrying a small load costs more per unit still. Your DG’s own fuel log and its metered units give your real figure.
Why solar inverters trip
- Grid outage: a grid-tied inverter must stop when the grid goes, by design.
- High voltage: at midday, export can push voltage at the inverter above its limit.
- Running on DG: most grid-tied inverters do not run with a DG unless a controller limits them.
- Insulation or earth faults, often after rain or panel washing.
Any of these show as solar dropping to zero while the sun is up. An alert on that pattern catches a tripped inverter the same day, instead of at month end.
Solar, DG and grid in KONDUKTOR® EMS
- Each meter tagged as Grid, Solar, DG or Load, with sources kept out of load totals.
- Solar generation, yield per kWp, share used on site, export, dust loss and grid-off hours.
- An energy balance chart of every source against the plant load.
- An inverter-trip alert that can be switched on per site.
Automatic limits on solar and DG through Modbus I/O cards, such as holding solar below the load while the DG runs, are engineered for your plant as part of your project.
Common questions
Can one system monitor solar, DG and grid together?+
Yes, if each source has a meter the system can read. Tag each meter as Grid, Solar, DG or Load, and the dashboard shows every source against the plant load without counting any unit twice.
How do you calculate DG cost per unit?+
Divide the diesel price per litre by the units the DG generates per litre. At an illustrative ₹90 per litre and 3.2 units per litre, that is about ₹28 per unit. Light loading lowers units per litre and raises the cost.
Why does our solar inverter trip?+
Most often because the grid went off, since a grid-tied inverter must stop with it. Other causes are high voltage at the inverter during midday export, running on DG without a controller, and insulation faults after rain or washing.
See solar, DG and grid in one view.
Book a live demo and see every source against the plant load on meters like yours.