Viable residential DC microgrids combined with household smart AC and DC loads for underserved communities

Abstract

The availability of fossil fuels in the future and the environmental effects such as the carbon footprint of the existing methodologies to produce electricity is an increasing area of concern. In rural areas of under-developed parts of the world, the problem is lack of access to electrification. DC microgrids have become a proven solution to electrification in these areas with demonstrated exceptional quality of power, high reliability, efficiency, and simplified integration between renewable energy sources (principally solar PV) and energy storage. In the United States, a different problem occurs that can be addressed with the same DC microgrid approach that is finding success internationally. In disinvested, underserved communities of with high unemployment and low wages, households contribute a significant portion of their income toward the fixed cost of their electrical utility connection, which by law must be supplied to every household. This paper analyzes a residential DC microgrid in an urban, underserved area that enables the sharing of renewable and stored energy resources between dwellings. The goal of the residential DC microgrid is to drive down to fixed costs of utility-provided electricity to all participants, such that the percentage of utility cost to total household income comes can be made comparable to that of more advantaged communities. A group of renovated dwellings constitute the community which the DC microgrid would serve. The distributed installation of solar panels and battery storage among dwelling locations are optimized based upon varying consumption patterns. Also, consumption patterns during different seasons of the year are considered. Electrical distribution architectures within the dwellings are based upon conventional AC. Each dwelling has a DC interface to the residential microgrid and progressive insertion of DC loads, with associated household DC distribution, is considered.