Energy Storage Dispatch for Online Peak-Demand Reduction

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Solution Overview

Problem

Large-load consumers face significant challenges in reducing peak-demand charges, which account for a large portion of their electricity bills, due to the volatility of small-scale demands and self-owned renewable generations.

Innovation Solution

An optimal online algorithm is developed to maximize peak-demand reduction using energy storage, achieving the best possible competitive ratio among all online algorithms by solving a linear number of linear-fractional problems and extending to an adaptive algorithm for improved average-case performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If time-of-use pricing strategies are used to promote load shifting to off-peak hours, then off-peak energy consumption increases, but rebound peaks occur that increase peak-demand charges

Engineering Contradiction:
Improveoff-peak energy consumptionVSAvoidpeak-demand charge
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The system performs preliminary actions by charging energy storage devices during off-peak hours before the peak-demand period arrives. This pre-positioning of energy allows the system to discharge during peak periods, preventing rebound peaks while maintaining off-peak consumption benefits.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Energy storage devices serve as an intermediary between the grid and the consumer's load. They buffer the timing mismatch between off-peak charging and peak-period discharge, enabling load shifting without creating rebound peaks on the grid.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If energy storage is used to reduce peak-demand charge, then peak-demand reduction is achieved, but future demand volatility and uncertainty make optimal decisions difficult

Engineering Contradiction:
Improvepeak-demand reductionVSAvoidfuture demand information
Core Design Contradiction:
PowerVSLoss of information

Solution Approach 1:

The system performs preliminary charging actions during off-peak hours based on current information, preparing energy storage devices for potential peak-period discharge. This allows the system to act proactively without knowing future demand patterns.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The energy storage system serves itself by automatically charging during off-peak periods and discharging during peak periods based on price signals, without requiring perfect future information or complex external control.

Inventive Principle:
Principle #25Self-service

3Use of energy by moving object

If self-owned renewable generations are used to reduce energy purchased from grid, then green energy consumption increases, but net demand curve becomes more fluctuating and peak-demand charge is not reduced

Engineering Contradiction:
Improverenewable energy consumptionVSAvoidnet demand curve stability
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

Energy storage devices act as an intermediary that smooths the fluctuating output from renewable generators. By charging during high renewable generation periods and discharging during low generation or high demand periods, they stabilize the net demand curve while maintaining renewable energy consumption benefits.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system provides beforehand cushioning by storing excess renewable energy when generation is high, creating a buffer that compensates for periods when renewable generation is low or demand is high, thus stabilizing the net demand curve.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

The algorithm effectively reduces peak-demand charges by strategically utilizing energy storage, achieving peak reductions comparable to optimal offline solutions with perfect information, while outperforming other alternatives.

Implementation Method 1

an electricity storage device to reduce the use of a mains electricity grid during peak cost charging periods

Methodology Applied
Scientific EffectEnergy storage: Accumulator (energy)

Data Source

PatentUS12243113B2Methods for online peak demand reduction of large load users with energy storage discharge
Publication Date: 2025.03.04 CITY UNIVERSITY OF HONG KONG
  • US12243113B2 patent drawing
  • US12243113B2 patent drawing
  • US12243113B2 patent drawing

AI summary

A method of managing real-time electrical energy storage management from an electricity storage device to maximise the reduction of the use of a mains electricity grid during peak cost charging periods on the mains electricity grid, including: calculating an ideal offline use of the electricity storage device using ideal predicted parameters; calculate a plurality of electrical storage device storage and electrical discharge models using a plurality of algorithms based on recorded data; calculate the competitive ratio for each of the algorithms and the ideal offline use; and use power from the electricity storage device based on an optimal competitive ratio.