Home Battery System Research Articles

Air quality as a game-changer: Pathways towards large-scale vehicle electrification in Australia

This paper presents an integrated analysis of the costs and benefits of carefully constructed scenarios for the electrification of transport in Australia. Scenarios were constructed to responsively meet increased electricity demand, whilst maximising emission reduction, household finances and public health benefits. The scenarios bundle several technologies, including charging infrastructure, electric vehicles, home battery systems, and renewable energy. The fastest, mission-style, adoption scenario can reduce emissions by 9% of the 2030 carbon budget and reduce the loss of life by 24,000 by 2042. In all scenarios, government expenditure is dwarfed by the estimated public benefits, and households are nearly always better off in the medium to long term. Demonstrating the feasibility and advantages of surface transportation electrification in Australia, which presents cross-sections of rural and urban infrastructure, traffic and a large, socially and politically diverse population, provides broadly applicable evidence of the feasibility of electrification in other jurisdictions.

Considerations on the impact of battery ageing estimation in the optimal sizing of solar home battery systems

The exponential reduction in cost of photovoltaic panels and the forecasts projecting a similar behaviour for battery-based energy storage systems are driving increasing attention on residential energy systems based on photovoltaic (PV) panels and batteries. Such systems, if combined with demand electrification, could help decarbonising the sector and foster the adoption of distributed energy systems. In this work, a modular tool for the techno economic analysis of smart energy systems is applied to a case study in the residential sector. The considered system is composed by PV panels, battery, heat pump and air conditioning system. The tool integrates a method for the estimation of cyclic and calendric ageing of the battery. The effects of varying battery capacity and its maximum depth of discharge on its lifetime have been investigated. An optimization algorithm has been employed to find the battery capacity that maximizes net present value (NPV) for given battery prices and PV panels areas. Results have highlighted the impact of using ageing models on the economics of residential energy systems, suggesting that discontinuities might arise in the functions to be optimized, hence requiring more robust optimization algorithms. Results also suggest that not accounting for battery aging could lead to incorrect predictions regarding the economics of the system. The breakeven price for the introduction of batteries in residential energy systems is lower when using ageing algorithms, while, at the same time, higher optimal capacities have been obtained for lower battery prices.

Community-scale interaction of energy efficiency and demand flexibility in residential buildings

Demand-side management (DSM) strategies, including energy efficiency (EE) and demand flexibility (DF), contribute to cost-effective operation of the electricity grid. From a system-level perspective, such programs reduce costs, enhance reliability, and reduce network issues. Similarly, DSM programs help participating customers reduce utility bills while maintaining occupant comfort. Understanding the relationship between EE and DF is key to realizing the full potential of DSM programs. In this study, we modeled an all-electric residential community based on a 498-home community that is planned for construction in Fort Collins, Colorado in the United States. We used this community model to study the relationship between different EE measures, including building envelope upgrades and smart appliances, and DF enabled by a home energy management system (HEMS) responding to a time-varying tariff. Various EE levels in the homes – code-minimum, zero energy ready, and even higher levels of envelope efficiency – were simulated. DF is enabled by the HEMS, which coordinates behind-the-meter resources, including flexible building loads, PV, and home battery systems, to minimize utility bills while maintaining occupant comfort. When comparing to the code-minimum homes, EE upgrades alone reduce HVAC energy use during peak hours by up to 50% and the HVAC utility bill by up to $312/year. With the addition of HEMS, the average daily peak demand can be reduced by up to 0.58 MW or 1.2 kW/home in the higher envelope efficiency homes. The combination of EE upgrades, HEMS, and home battery systems is expected to save homeowners up to $590/year while increasing community load flexibility. However, HEMS and home battery systems are less effective in increasing the DF in the more efficient homes due to the lower load.

Prototype Evaluation of Grid‐Connected Bidirectional Power Conversion System for Storage Battery Systems with Bidirectional Switch Circuit Topology

SUMMARYIn recent years, various storage battery systems, such as home battery system, V2H/V2G system, and UPS system, have spread rapidly all over the world. We propose a new power conversion system for use in the previously‐stated storage battery systems. This paper describes operation analysis of this system for bi‐directional power conversion with fundamental grid‐interconnection. Good output follow‐up controllability characteristics of the proposed system are shown through experimental results.

Quantifying self-consumption linked to solar home battery systems: Statistical analysis and economic assessment

The recent development of new and innovative home battery systems has been seen by many as a catalyst for a solar energy revolution, and has created high expectations in the sector. Many observers have predicted an uptake of combined PV/battery units which could ultimately disconnect from the grid and lead to autonomous homes or micro-grids. However, most of the comments in social media, blogs or press articles lack proper cost evaluation and realistic simulations. We aim to bridge this gap by simulating self-consumption in various EU countries, for various household profiles, with or without battery. Results indicate that (1) self-consumption is a non-linear, almost asymptotic function of PV and battery sizes. Achieving 100% self-consumption (i.e. allowing for full off-grid operation) is not realistic for the studied countries without excessively oversizing the PV system and/or the battery; (2) although falling fast, the cost of domestic Li-Ion storage is most likely still too high for a large-scale market uptake in Europe; (3) home battery profitability and future uptake depend mainly on the indirect subsidies for self-consumption provided by the structure of retail prices; (4) the self-sufficiency rate varies widely between households. For a given household, the volume of self-consumption cannot be predicted in a deterministic way. Along with these results, this study also provides a database of synthetic household profiles, a simulation tool for the prediction of self-consumption and a method for the optimal sizing of such systems.

The impact of residential photovoltaic power on electricity sales revenues in Cape Town, South Africa

In South Africa, electricity is provided as a public service by municipalities. The combination of (a) rising electricity rates, (b) decreasing photovoltaic technology costs, and (c) a progressive tariff system (under which wealthier households support low tariff rates for indigent residents) leads to incentives for high-income households to cover part of their electricity demand by self-produced photovoltaic (solar) electricity. This development is simulated with hourly load profiles and radiation data, and an optimization model for a case study in Cape Town through the year 2030. Results indicate that the majority of higher-income residents are incentivized to invest in photovoltaic power production by 2020 and additionally use home battery systems by 2028. This leads to a steadily increasing gap between revenues and expenditure needs in the budget of the municipality. The budget gap can be reduced by replacing the energy-based tariff with a revenue-neutral fixed network-connection fee implementation of which is particularly effective in reducing incentives to invest in storage.