REopt Helps Optimize Telecommunications Power for Verizon Wireless

NREL is helping Verizon Wireless design an all-DC solution for the telecommunication company’s facilities. Photo from Verizon Wireless

Verizon Wireless and NREL are working to develop and validate a new telecommunications facility power system design that incorporates photovoltaics (PV) and batteries. The power system, which was modeled using NREL’s REopt^® model and OpenStudio^® software, will ease utility interconnection by connecting solar PV to the network equipment’s DC bus and batteries, increase resilience by allowing PV to contribute—and cooling to continue—during a power outage, lower costs with day-to-day utility cost savings, and increase efficiency through reduced part count and fewer power conversions from DC to AC.

Telecommunications network equipment uses DC power rather than conventional AC power, so the system design employs new DC cooling systems. To validate the DC power system configuration, researchers conducted testing in NREL’s Energy Systems Integration Facility environmental chamber at temperatures as low as ‑40°C and as high as 55°C. The thermal and electrical performance of the optimal power system configurations were tested to confirm that the cooling systems can maintain required temperatures, the controls correctly prioritize PV power and optimize battery dispatch, and the computer models are calibrated.

OpenStudio and REopt modeling extrapolated results to 17 climate zones, four different power levels, and with or without PV as a shade canopy over the equipment. This modeling produced recommendations for types of cooling systems that minimize total costs and the amount of PV and battery storage that should be used.

These results serve as a guide that provides site-specific recommendations for the design of new sites and refurbishment of existing sites. The power system topology that NREL suggests will be a new approach to powering telecommunications facilities. An all-DC facility is a sustainable and reliable solution to powering Verizon Wireless’s many existing and forthcoming sites.