SDP

A service data point is a physical location on an electrical distribution network where consumption data is collected, typically through a meter or sensor. It represents the boundary between a utility's delivery responsibility and a customer's internal installation. Every building connected to a grid has at least one SDP, sometimes more if there are multiple supply feeds or separately metered systems within the same site.

The SDP serves as the official reference point for billing and network management. Meter readings taken at the SDP determine what a customer pays and provide the utility with visibility into load patterns, demand spikes, and system imbalances. In modern networks, SDPs transmit data continuously or at regular intervals through automated meter reading systems, smart meters, or dedicated data loggers. This removes guesswork from consumption records and enables demand-side response schemes where network operators can incentivize reduced usage during peak periods.

The technical challenge with SDPs lies in their accuracy and security. Meters must stay calibrated within tolerance bands set by regulation, typically 0.5% to 2% depending on voltage class and type. Tampering or meter bypass defeats both commercial and operational purposes, so utilities protect the SDP with seals, enclosures, and audit trails. In industrial settings with multiple production lines or buildings on a single contract, placement of the SDP becomes strategic: putting it upstream captures all consumption, but placing it downstream of a large motor or transformer load can obscure real demand patterns.

SDP in modern grids and microgeneration

The rise of distributed generation has complicated the SDP's role. A factory with rooftop solar or a home with a battery now needs an SDP that can measure flow in both directions: import from the grid and export back to it. Bidirectional meters at the SDP record net consumption, and in some tariff schemes, export of excess power is credited at a lower rate than import. The SDP remains the point where these cross-currents are officially reconciled.

SDPs are identified by unique reference numbers within each utility's territory, often printed on the building itself or in connection agreements. In countries with competitive energy markets, the SDP code is portable: it ties the connection to the physical location, not the supplier, so switching retailers does not change the SDP number. This standardization is why SDPs appear on every invoice and in every network fault report.