Battery Storage for Resilient Homes

Abstract

Small-scale battery energy storage systems (BESS), especially for behind-the-meter applications, are still relatively expensive, but we show that it can be a potent solution to render homes resilient to storm related power outages. We present a stochastic programming model formulation to optimize PV/BESS explicitly accounting for resilience benefits these investments entail, over and above their ability to reduce cost of supply. The stochastic optimization considers uncertainties around storm related grid supply failures as well as variability of solar PV. The model includes an embedded Monte Carlo simulation module that considers storm related outage risks using climate model reanalysis data. It is a least-cost planning framework that optimizes selection of BESS, solar PV, grid supply, and diesel generator, from a homeowner's perspective. We present two case studies with low and high storm risks that demonstrate how different risk exposures can impact on the selection of alternative options to build resilience. Duals, or shadow prices, of demand-supply constraints from the model for both normal days and for storm related contingencies, provide interesting insights into the marginal cost of supply that can inform innovative pricing schemes to promote customer level resilience measures. The case study results reveal significant merits of BESS, in combination with PV, to enhance resilience. We find that in low-risk areas like Bethesda, MD, incremental PV and BESS required for a more resilient system can add $79 (4%) to expected annual electricity costs for a typical household, and a considerably higher $208 (10.6%) in Miami, FL which is at a much greater risk. These options are, however, 27% (in Bethesda) and 20% (in Florida) less expensive than the conventional solution of installing a diesel generator. These results provide insights into the value of BESS as part of a resilient and clean energy solution for households.

Planning for a Resilient Home Electricity Supply System

“…The tradeoff between cost of supply and resilience at a household level supply system has not been explored in the literature to date. An extension to the planning model is proposed to build resilience standard and used data from our previous analysis [19] to construct cases that can quantify this trade-off.…”

“…This work also demonstrated how roof-top solar PV and BESS can form part of an effective resilience solution even in locations like Miami that are prone to severe cyclones. The present work further extends the analysis in [19] to form resilience constraints and implement the planning framework.…”

“…Moreno, Panteli and others [17] more recently have further reiterated the need for planning models to make the transition from a relatively simple and one-dimensional reliability criterion to multi-dimensional resilience standards. There have also been case studies that incorporate resilience considerations in practical systems including flooding risks in Bangladesh [10], impact of storms on the British transmission network [18] and impact of cyclones on household level supply in Florida [19]. It is recognized that resilience needs to be built throughout the supply chain and measures may include a vast range of options from change of power plant siting in Bangladesh [10] down to strengthening of distribution network using microgrids and distributed energy resources.…”

“…As roof-top solar PV, BESS and smart meters enable behind-the-meter resources that can more than adequately equip households to deal with power outages, there is a need to go beyond microgrids and plan for household level electricity supply. Our previous work [19] has demonstrated that planning analysis can be extended to distributed energy resources to develop an optimal supply mix for a household that may include solar PV, BESS and diesel back-up to complement grid supply. This work also demonstrated how roof-top solar PV and BESS can form part of an effective resilience solution even in locations like Miami that are prone to severe cyclones.…”

“…Figure 1 shows different phases of a system following a disaster including the response, recovery and transition phase until normal operation is restored. Resilience focuses on all of these phases [15][16][17][18][19]33] including the initial depth of the outage, what back-up measures are in place to sustain critical operation/load, what responses can be taken to restore supply, etc. Resilience is about the entire process and how the system should be designed to render it reliable.…”