Buying guide
EMS vs SCADA vs BMS: three systems, three different jobs.
A SCADA runs the process. A BMS runs the building. KONDUKTOR® EMS runs your energy: it shows what the power costs and why, then controls chosen loads to bring that cost down. All three can read a meter, which is why they get confused. Here is how to tell which one your plant needs.
Here, EMS means energy monitoring and control in a plant, not a utility grid EMS or a battery EMS.
Side by side
| Question | KONDUKTOR® EMS | SCADA | BMS |
|---|---|---|---|
| Main job | Show energy use, demand and cost, and control the loads behind them | Supervise and control a process or network | Run building services: air-conditioning, lighting, pumps |
| Main user | Plant head, maintenance, accounts | Process operators in a control room | Facility managers |
| Connects to | Energy meters, Modbus I/O cards and solar inverters | PLCs, RTUs, drives and instruments | Building controllers and sensors |
| Controls equipment? | Yes: by demand limit, TOD zone, solar and DG limits, idle time and schedule | Yes | Yes, by schedule and setpoint |
| Control driven by your bill? | Yes: it acts on the running MD against Contract Demand and on your TOD zones | Only if an integrator programs it, and again at each tariff order | Only if someone programs it |
| What you look at | Load profile, Maximum Demand, power factor, cost by panel | Mimic screens, alarms, process trends | Temperatures, schedules, equipment status |
| Reads your bill lines? | Yes, that is its point: MD against Contract Demand, kVAh, TOD zones | Only if someone programs it | Only if someone programs it |
| Typical setup | Meters on RS-485, a gateway and Modbus I/O cards. No server PC, no PLC programming | Control panels, PLC programming, servers, an integrator | Controllers across the building, a server, an integrator |
Which one do you need
- SCADA if you have to run a process: start and stop, interlocks, recipes, a control room.
- BMS if you run a building: a hotel, hospital or office, with air-conditioning, lifts and lighting to schedule.
- KONDUKTOR® EMS if the bill is the problem: MD crossing Contract Demand, power factor penalties, idle machines left running, or nobody can say which section uses what. It shows the cause, then holds demand and cuts waste by itself.
Many plants end up with an EMS beside one of the others, because each answers a different question.
If you already have SCADA or a BMS
It may already read your meters. Ask whether it can do these seven things:
- Hold your tariff, and change when the tariff order changes.
- Split units into your TOD zones.
- Work out billing demand against Contract Demand.
- Work out power factor the way your bill does.
- Keep 15-minute demand data for months, ready to open.
- Set its figure beside the DISCOM’s bill and show the gap.
- Hold back chosen loads by itself as demand nears your limit, and restore them in steps, with no new programming when the tariff changes.
If the answer is yes to all seven, you may not need another system. If not, the gap is what an EMS fills.
Where KONDUKTOR® EMS goes further than SCADA
A SCADA switches what it has been programmed to switch. Unless someone has programmed your tariff into it, it does not know what that switching does to your bill. KONDUKTOR® EMS starts from the bill. It tracks the running demand interval against Contract Demand, the TOD zone you are in and what each machine is doing, then acts on the loads you choose:
- Maximum Demand: sheds non-essential loads in your priority order before demand crosses the limit, then brings them back in steps.
- TOD zones: moves loads that can wait out of peak-rate hours.
- Solar and DG: throttles inverter kW over Modbus to hold export at your limit, down to zero export, where the inverter allows it, and keeps solar below the load while the DG runs.
- Idle machines: switches off machines left running outside shift.
- Shifts and holidays: runs chosen loads to your schedule.
All of it runs over standard Modbus, with I/O cards for the switching: no PLC programming, no server PC and no integrator to call back at each tariff order.
We set the loads, priorities and limits for your plant as part of your project. Control works alongside your protection relays, not in place of them. It fails safe if communication is lost, keeps a manual override, logs every action, and only an Admin can change the rules.
Process control stays with your PLCs and SCADA: interlocks, recipes, start and stop sequences. KONDUKTOR® EMS works beside them and, as part of your project, can pass readings on to your SCADA or BMS over Modbus TCP, or over MQTT to your own broker.
Comparing with a demand controller instead? See MD controller vs energy monitoring.
Common questions
Can SCADA do the job of an EMS?+
It can show meter values, and an integrator can program tariff logic into it. That is engineering you pay for and maintain, because TOD zones, rates and billing demand rules change with tariff orders. Ask it the seven questions on this page.
Is a BMS enough for a factory?+
Rarely. A BMS looks after building services. Production machines, feeders and the demand and power factor lines of the bill are usually outside what it watches.
Does an EMS control machines?+
Many EMS products only monitor and alert. KONDUKTOR® EMS also controls: it holds back chosen loads near the demand limit, moves them out of peak TOD hours, limits solar and DG, and switches off idle machines through Modbus I/O cards, engineered for your plant as part of your project.
Is KONDUKTOR® EMS better than SCADA?+
For energy and the bill, yes. It knows your tariff, Contract Demand and TOD zones, and as part of your project it controls loads by them with no PLC programming. A SCADA does that only if someone programs and maintains it. For running a process, with interlocks and recipes, keep your SCADA and PLCs.
Can an EMS and SCADA read the same meters?+
Yes, but not as two masters on one RS-485 line, because Modbus RTU allows one master per line. Use the meter’s second port or a separate line.
Not sure which one you need? Start with the bill.
Send us a bill for a free check, or see a live demo on meters like yours.