Bosch has developed and demonstrated a novel direct current (DC) microgrid system that maximizes the efficiency of locally generated photovoltaic energy while offering high reliability, safety, redundancy, and reduced cost compared to equivalent alternating current (AC) systems. Several demonstration projects validating the system feasibility and expected efficiency gains have been completed and additional ones are in progress. This paper gives an overview of the Bosch DC microgrid system and presents key results from a large simulation study done to estimate the energy savings of the Bosch DC microgrid over conventional AC systems. The study examined the system performance in locations across the United States for several commercial building types and operating profiles. It found that the Bosch DC microgrid uses generated PV energy 6%-8% more efficiently than traditional AC systems.

NREL prints on paper that contains recycled content.

Cooktop: intermittent ignition, open burner Oven: electric glo-bar ignition, self cleaning Cooktop: 40.0% Oven: 5.8% Cooktop: pilot lights Oven: pilot light, not self-cleaning, standard door seals, standard vent rate, standard insulation Cooktop: 18.8% Oven: 3.5% Table 44. Default Electric Oven/Cooktop Characteristics Equipment Characteristics EF Cooktop: reflective pans, flat coil elements Oven: self-cleaning, improved door seals Cooktop: 77.7% Oven: 10.2% Cooktop: solid disc elements Oven: not self-cleaning, improved door seals, reduced vent rate, high density insulation Cooktop: 74.2% Oven: 12.1% Cooktop: nonreflective pans, rounded coil elements Oven: not self-cleaning, standard door seals, standard vent rate, standard insulation Cooktop: 73.7% Oven: 10.9%

Buildings consume 75% of US electricity and could be a primary demand-side management resource for the rapidly changing electric grid. We assess the technical potential grid resource from best-available building efficiency and flexibility measures in 2030 and 2050 and find that such measures could avoid up to nearly one-third of annual fossil-fired generation and one-half of fossil-fired capacity additions after 2020. Our results quantify the role that building technologies can play in the future of the US electricity system.

No abstract