"Bulk power" is electricity delivered by a utility in a well-established manner allowing for satisfactory performance of conventional lighting and motor loads. Utility systems providing bulk power are designed to minimize costs while maintaining reasonable levels of reliability. As a result, bulk power is often referred to as "utility-grade" power (analogous to tap water).
Bulk power also refers to the power supplied inside customer-owned facilities, which contains internally created power quality disturbances and problems. In fact, studies done by the Electric Power Research Institute (EPRI) indicate that four out of five power quality problems are due to faulty wiring and grounding inside customer-owned facilities.
In contrast, "premium power" is electricity delivered to sensitive electronic loads requiring higher reliability and power quality than conventional loads. Premium power can be customized to match the operating requirements of the equipment in question and is commonly referred to as "computer-grade" power. Ideally, premium power will consist of continuous, regulated voltage free from disturbances.
In general, CenterPoint Energy cannot provide premium power. To obtain this level of service, customers must enhance or upgrade their existing electrical facilities by installing power conditioners and applying other power quality solutions specifically selected to meet their requirements.
CenterPoint Energy’s Tariff states it is the customer's responsibility to install the necessary protective equipment to limit adverse effects on equipment from voltage fluctuations, waveform distortion and single-phasing events. The concept of bulk power vs. premium power helps explain the responsibilities of CenterPoint Energy and our customers.