Central Plant Energy Storage Allocation for Demand Response and Equipment Life
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Solution Overview
Problem
Central plants face challenges in optimizing the allocation of resources across multiple subplants to minimize energy costs, particularly when considering electrical demand charges and the complexity of determining when and how to use different subplants effectively.
Innovation Solution
A controller is configured to optimize resource allocation by determining the optimal allocation of electrical energy storage and participation in incentive-based demand response programs, taking into account expected revenue, costs, capacity loss, equipment degradation, and equipment start/stop penalties, to maximize the economic value of operating the central plant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high efficiency equipment is used to reduce energy consumption, then energy efficiency is improved, but control complexity increases
Solution Approach 1:
The system dynamically changes operational parameters (equipment selection, load allocation, charge/discharge rates) based on varying conditions such as energy prices, demand charges, and equipment state. The optimization controller adjusts these parameters in real-time to minimize energy costs while managing control complexity through automated decision-making algorithms.
2Loss of energy
If electrical energy storage is allocated to generator subplants to minimize energy costs, then energy cost is reduced, but equipment degradation increases
Solution Approach 1:
The system performs preliminary actions by charging electrical energy storage during periods of low energy cost or low equipment stress, and discharging during high cost periods. The optimization controller predicts future energy prices and equipment degradation trends, allowing it to plan energy storage operations in advance that minimize both energy costs and equipment degradation over the optimization horizon.
Solution Approach 2:
The system dynamically adjusts the allocation of electrical energy storage to different subplants based on real-time conditions including energy prices, load demands, and equipment degradation rates. The optimization controller continuously recalculates the optimal charge/discharge rates and subplant allocation to balance energy cost reduction with equipment life preservation.
3Reliability
If equipment is operated frequently to meet building loads, then building service reliability is improved, but equipment start/stop penalties increase
Solution Approach 1:
The system maintains continuous useful action by keeping equipment operating at steady states rather than frequently starting and stopping. The optimization controller prioritizes maintaining equipment in operational states that meet building loads while minimizing transitions, as each start/stop cycle incurs penalties. Electrical energy storage is used to bridge periods where reducing equipment operation would save start/stop penalties while still meeting building demands.
Data Source
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AI summary
A central plant includes an electrical energy storage subplant configured to store electrical energy, a plurality of generator subplants configured to consume one or more input resources, including discharged electrical energy, and a controller. The controller is configured to determine, for each time step within a time horizon, an optimal allocation of the input resources. The controller is configured to determine optimal allocation of the output resources for each of the subplants in order to optimize a total monetary value of operating the central plant over the time horizon.