Residential Energy Storage Control Device for Solar Arbitrage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The misalignment between solar energy production and consumer demand in residential settings leads to inefficiencies, with excess solar energy often being curtailed or not reimbursed, necessitating a solution to shift energy usage to peak demand hours when grid electricity is more expensive.

Innovation Solution

A control device manages electric power flow using a bidirectional inverter to optimize energy storage by charging during pre-event periods and discharging during demand-response periods, leveraging renewable energy sources and grid conditions to maximize solar self-consumption and minimize grid electricity usage during peak hours.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If solar energy is produced during daytime hours, then renewable energy generation is maximized, but energy demand occurs later in the evening when solar production is ramping down

Engineering Contradiction:
Improvesolar energy generationVSAvoidtime misalignment between supply and demand
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The system performs preliminary action by charging the battery storage during daytime hours when solar energy is abundant and electricity rates are lower. The control device monitors solar production and grid pricing, storing excess energy before the evening peak demand period, thus preparing energy in advance for when it is most needed and most expensive.

Inventive Principle:
Principle #10Preliminary action

2Loss of energy

If excess solar energy is fed into the grid, then renewable energy is utilized, but reimbursement is reduced or eliminated under new regulations

Engineering Contradiction:
Improveexcess solar energy utilizationVSAvoideconomic return from energy feed-in
Core Design Contradiction:
Loss of energyVSQuantity of substance

Solution Approach 1:

The system converts the previously harmful curtailment of excess solar energy into a beneficial storage opportunity. Instead of wasting excess daytime solar production or receiving reduced reimbursement, the system captures this excess energy in the battery, transforming it into a valuable resource that can be discharged during peak pricing periods to maximize economic return.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system changes the temporal parameter of energy utilization by storing energy when it is abundant and inexpensive, then releasing it when demand and pricing are high. This parameter transformation from immediate feed-in to delayed discharge converts the economic disadvantage of reduced feed-in reimbursement into advantage through arbitrage of time-based pricing differences.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If battery storage is charged during pre-event periods, then energy is available for peak demand, but charging time is limited before peak pricing intervals

Engineering Contradiction:
Improveenergy availability during peak demandVSAvoidcharging duration before peak period
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The control device dynamically adjusts the charging rate and power flow based on real-time conditions including state of charge, solar availability, and time remaining until peak pricing. The system optimizes the charging profile by varying power levels throughout the pre-event period, maximizing energy capture within the limited time window while respecting battery capabilities and grid conditions.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively increases the use of renewable energy onsite, reduces electricity bills, and ensures the energy storage is fully charged before peak pricing intervals, thereby optimizing energy usage and cost savings.

Implementation Method 1

A control device manages electric power flow using a bidirectional inverter to optimize energy storage

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3624293B1Method and control device for operating a stationary, electric energy storage that is provided for an electric consumption unit, like, e.g., a household
Publication Date: 2021.11.03 BAYERISCHE MOTOREN WERKE AG
  • EP3624293B1 patent drawingFigure 1
  • EP3624293B1 patent drawingFigure 2
  • EP3624293B1 patent drawingFigure 3

AI summary

The invention concerns a method for operating an electric energy storage (12) that is provided for an electric consumption unit (11), wherein the electric consumption unit (11) is additionally coupled to an electric power grid (13). The method is characterized in that the control device (22) performs the following steps of a) providing different operation logics (25) for controlling the power flow (BP) as a function of the state of charge (SOC) and of a total unit load (THL), b) observing a status signal (S, DR) that is signaling the present and/or the next supply condition of the grid (13), c) selecting one of the operation logics (25) as an active operation logic depending on a current value of the status signal (S, DR), and d) operating the power converter (21) according to the active operation logic.