Electrical Tariffs and Metering

Vocabulary practice flashcards covering electricity tariffs, metering structures, maximum demand, billing calculations, and power factor correction principles.

Semi-State Bodies

Organizations established by the Irish Government combining the efficiencies of private enterprise with retained state majority shareholding to determine company policy.

ESB (Electricity Supply Board)

A major Irish semi-state body that was historically granted statutory monopoly rights to sell electricity in Ireland prior to market deregulation starting in 2000.

Commission for Regulation of Utilities (CRU)

The regulatory authority that reviewed and approved ESB Customer Supply tariffs from 2001 to 2010 to foster competition and protect consumers.

Electric Ireland

The rebranded identity of ESB Customer Supply and ESB Independent Energy, established in 2011 after domestic market deregulation criteria were satisfied.

Calorific Value

The total quantity of heat energy released during the complete combustion of a specified amount of fuel; also called heat value or heating value.

Peat (Turf)

A primary indigenous fuel formerly utilised by the ESB to foster regional employment in the Midlands, discontinued due to low calorific value and high smoke emissions.

Ardnacrusha

The ESB's first hydroelectric generating station, opened on the River Shannon in 1947 to harness renewable water energy.

Daily Load Curve

A graph illustrating the variations in national electricity demand across the hours of an average working day, used by the Load Dispatch Office for system forecasting.

Base Load

The minimum level of electrical demand continuous over 24 hours, serviced by the most cost-effective generating units to provide the cheapest electricity.

Pumped Storage

A generation method that uses surplus, low-cost off-peak night electricity to pump water to an elevated reservoir, releasing it during peak hours to drive turbines.

Turlough Hill

The site of Ireland's pumped storage hydroelectric generating facility located in County Wicklow.

Active Power ($kW$)

The true, tangible electrical power that performs physical work and heat, also called wattful or in-phase energy, calculated as kW = V \times I \times \forcecos(\theta).

Reactive Power ($kVAr$)

The wattless component of electrical power required to sustain alternating electromagnetic fields in inductive loads, calculated as kVAr = V \times I \times \forcesin(\theta).

Apparent Power ($kVA$)

The total vector resultant of active power and reactive power supplied to an alternating current circuit, given by kVA = \forcesqrt{kW^2 + kVAr^2}.

Power Factor

The ratio of active power ($kW$) to apparent power ($kVA$), describing electrical efficiency where values below $0.95$ attract supplier surcharges in Ireland.

Meter Point Reference Number (MPRN)

A unique reference number that identifies an individual electricity connection point to the ESB Network.

Meter Reading Codes (A, C, E)

Billing indicators identifying whether the calculation was based on an ESBN actual read (A), a customer-submitted read (C), or an estimated read (E).

Public Service Obligation (PSO) Levy

A government levy charged to final electricity customers to recover additional generation costs associated with indigenous, sustainable, and renewable energy.

Standing Charge

A fixed daily charge on an electricity account that covers continuous customer and network access costs irrespective of electricity consumption.

Demand Costs

Tariff cost components reflecting the capital expenditure required to construct, maintain, and operate generation, transmission, and distribution assets.

Energy Costs

Tariff cost components directly attributable to the cost of purchasing primary fuels used in electricity generation.

Customer Costs

Tariff cost components covering administration, metering, customer billing, and local network operations.

Magnitude of Load

The mathematical summation of the rated electrical capacities of all connected devices within an electrical installation.

Maximum Demand

The highest average load demand established over a rolling 15-minute integration period, used to calculate commercial billing parameters.

Demand Charge

A commercial tariff charge applied to demand exceeding $30\,kW$ between 17:00 and 19:00 on weekdays from 1 November to the end of February.

Winter Demand Reduction Incentive (WDRI)

An incentive scheme during November/December and January/February limiting the maximum demand evaluation window to 17:00–19:00 on weekdays.

50% Rule

A billing rule establishing that the billed maximum demand is the greater of the period's measured MD or 50% of the peak MD billed across the previous five periods.

Diversity Factor

The ratio of actual maximum operating load to total connected load ($\text{Diversity Factor} = \frac{\text{Actual maximum load}}{\text{Total connected load}}$), having a value less than 1.

Load Factor

The relationship expressing the magnitude and duration of the actual load consumed compared to the magnitude and duration of the total available supply.

Maximum Import Capacity (MIC)

The agreed capacity limit in $kVA$ contracted with the electricity network operator, serving as the basis for the capacity charge.

Capacitive kVA

The required rating of corrective static capacitors in $kVAr$, calculated by the equation \text{Capacitive } kVA = kW \times (\forcetan(\phi_1) - \forcetan(\phi_2)).

Smart Meter

An advanced digital meter providing detailed interval consumption data, two-way utility communication, and enabling real-time tariff pricing.

Current Transformer (CT) Multiplier

The scaling factor given by the primary to secondary turns ratio of a CT (such as $\frac{1000}{5} = 200$) used to determine primary line current from meter readings.