AC Overbuild Add-On Using Storage to Smooth Grid Output
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Solution Overview
Problem
Legacy renewable power plants (LRPPs) have a low capacity factor, resulting in underutilization of interconnection infrastructure due to peak outputs being much higher than average outputs, leading to inefficient use of transmission capacity and increased requirements for new power plant interconnection infrastructure.
Innovation Solution
An add-on renewable power plant (ARPP) is connected to the LRPP interconnection infrastructure, featuring a renewable energy source (RES) and energy storage system (ESS) sized based on the LRPP's transmission capacity and power output profile, with a controller managing the combined output to match the transmission capacity and reduce variability, thereby complementing the LRPP output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the interconnection infrastructure is sized to match peak solar power output, then the transmission capacity is sufficient to handle peak loads, but the transmission capacity remains unused most of the time when power output is below peak levels
Solution Approach 1:
The energy storage system stores excess energy generated during peak production periods (when solar output is high) before it can be wasted, making it available for later use when demand exceeds generation capacity. This preliminary capture and storage of energy resolves the contradiction by ensuring capacity sufficiency during peaks while enabling utilization during off-peak periods.
Solution Approach 2:
The system changes the temporal distribution parameter of power delivery. Instead of delivering power only when generated (variable output), the ESS enables the system to deliver power at a more constant rate by transferring energy temporally from high-generation periods to low-generation periods, thus improving capacity utilization while maintaining reliability.
2Productivity
If a new renewable power plant is built to utilize existing interconnection infrastructure, then infrastructure utilization improves, but the variability of combined power output increases
Solution Approach 1:
The energy storage system acts as an intermediary buffer between the variable renewable energy sources and the transmission infrastructure. It absorbs the variability from multiple plants and releases power at a stabilized rate, enabling higher infrastructure utilization while maintaining output stability through its decoupling function.
Solution Approach 2:
The ESS provides beforehand cushioning by storing excess energy during high-generation periods to compensate for future deficits when generation is low. This cushioning effect smooths out the combined output variability of multiple renewable plants, allowing aggressive utilization of transmission capacity without proportionally increasing output instability.
Data Source
AI summary
An add-on renewable power plant (ARPP) may include a renewable energy source (RES) connected to a legacy renewable power plant (LRPP) interconnection infrastructure, where an output capacity of the RES is sized based on an LRPP transmission capacity and an LRPP power output profile, and an energy storage system (ESS) connected to the LRPP interconnection infrastructure, where a storage capacity of the ESS is sized based on the LRPP transmission capacity and the LRPP power output profile. The ARPP may also include a controller configured to control an ARPP output by controlling an RES output and an ESS charge/discharge such that a variability of an ARPP-LRPP combined power output has a lower variability than a variability of an LRPP output and control the ARPP output such that the ARPP-LRPP combined power output does not exceed a transmission capacity of the LRPP interconnection infrastructure.