Load management techniques

Load management is the planned control of when and how much electrical load an industry draws, so that the maximum demand and peak-hour consumption are reduced and the load curve is flattened, without lowering production. It lowers demand charges, time-of-day energy cost and losses, and helps the utility too.

Load management techniques

1. Peak clipping (shaving): reduce or switch off non-essential loads during peak hours (e.g. 17:00–23:00 in Nepal's NEA time-of-day tariff) using a maximum demand controller.
2. Load shifting: move flexible loads – water pumping, batch furnaces, charging, grinding – to off-peak or night hours where the tariff is lower.
3. Valley filling: add useful loads in off-peak hours (thermal storage, ice making, battery charging).
4. Staggering / rescheduling of operations: stagger the starting of large motors, shift timings and lunch breaks so that large loads do not run together.
5. Maximum demand controller (MDC): monitors demand continuously and automatically trips selected low-priority loads when demand approaches a set limit.
6. Power factor improvement: capacitor banks reduce kVA demand for the same kW.
7. Use of storage: thermal storage, compressed air receivers, water tanks, batteries to supply part of peak demand.
8. Captive / standby generation during peak hours if cheaper than grid peak tariff.
9. Efficient equipment and VFDs: reduce the load itself (soft start reduces starting peaks).

kW │   ___peak (clip)
   │  /   \        shifted
   │ /     \___    loads
   │/  valley  \__/‾‾‾ (fill)
   └───────────────────── hours