What DSM is; effective DSM techniques

Demand side management (DSM) is the planning, implementation and monitoring of utility activities that encourage consumers to change the amount and time pattern of their electricity use, so that the load curve takes a desired shape. It works on the consumer side of the meter instead of building new generation.

Objectives

• Reduce peak demand and defer new power plants and lines.
• Improve load factor and use of existing plant.
• Reduce cost of supply and consumer bills; reduce losses and emissions.

Load-shape techniques (the six basic DSM objectives)

 Peak clipping     Valley filling    Load shifting
  __/--\__          __/~~\__          __/--\__
 /  cut   \        /fill    \        /  move  \
            Strategic conservation  Strategic load growth
            Flexible load shape

1. Peak clipping: reduce load during peak hours, e.g. utility switching off water heaters or pumps by direct load control.
2. Valley filling: build up load in off-peak hours, e.g. EV charging, storage heating, irrigation pumping at night.
3. Load shifting: move loads from peak to off-peak time, e.g. industries running heavy furnaces or crushers at night under time-of-day tariff.
4. Strategic conservation: reduce overall energy use by efficient equipment, e.g. LED lamps, efficient motors, insulation.
5. Strategic load growth: planned increase in sales, e.g. electric cooking, electric vehicles, replacing diesel and LPG with hydro power.
6. Flexible load shape: interruptible/curtailable supply contracts; consumers accept limited reliability in return for lower tariffs.

Means of achieving effective DSM

1. Tariff-based methods: time-of-day (ToD) tariff, seasonal tariff, demand charges in kVA, pf penalties, real-time pricing.
2. Energy efficiency programmes: efficient lighting (CFL to LED), high-efficiency motors and VFDs, energy audits, appliance labelling.
3. Direct load control and interruptible loads: utility remotely switches selected loads during peaks.
4. Demand response and smart metering: consumers reduce load on signals or price; smart meters and automation make it easy.
5. Power factor correction: capacitors reduce kVA demand and losses.
6. Energy storage: batteries, thermal storage and pumped storage charge off-peak and discharge at peak.
7. Consumer awareness and incentives: rebates, subsidies and education campaigns.

Effective DSM needs good load research, attractive incentives, reliable metering and monitoring of results.