Bosch Building Grid Technologies was awarded a $3 million, grant from the U.S. Department of Defense’s (DoD) Environmental Security Technology Certification Program (ESTCP)

Project located at Ft. Bragg Hercules Fitness Center which is also an emergency shelter. The project installation included:

  • Replacement of 400W AC metal halide high-bay lights with 250W DC induction lights. The DC lighting was installed by reusing the existing AC lighting wiring infrastructure in the building.
  • Installation of DC Power-Server (AC/DC rectifier) to supplement power from the utility grid to the DC loads when the power from the PV system is insufficient. The Power-Server has two 15kW rectifier stages of which one stage is needed to run all the DC fans and lighting loads. Should that rectifier fail, the second one immediately takes over to keep the lights and fans operational, providing fault-tolerance.
  • A 15kW rooftop solar array for the core DC system from which the power is routed to the Power Server.
  • Additionally, the Bosch Energy Management Gateway performs overall system energy management. It provides maximum power point tracking algorithms that keep the PV System operating at the highest possible efficiency regardless of weather and load conditions. It also optimizes the use of solar vs. grid power and provide controls for the DC loads During grid outages, the PV system stays operational as there is no inverter connecting it to the utility grid, that needs to be disconnected for saftey. As the PV system is connected directly to the lighting and ventilation loads, this enables a very cost effective “islanding” strategy without requiring transfer switches or grid-forming inverters.
As part of the second-phase of the demonstration, a 100 kWh Lithium-Ion energy storage system was added to the building to provide back-up power during evening and/or night time grid outages or to supplement the PV power. As a result, the reliance on other backup power sources such as diesel generators is eliminated or significantly reduced.