Optimal Power Dispatch in Energy Systems Considering Grid Constraints

Alejandro Rubio,Frank Schuldt,Peter Klement,Karsten von Maydell

doi:10.3390/en15010192

Abstract

As a consequence of the increasing share of renewable energies and sector coupling technologies, new approaches are needed for the study, planning, and control of modern energy systems. Such new structures may add extra stress to the electric grid, as is the case with heat pumps and electrical vehicles. Therefore, the optimal performance of the system must be estimated considering the constraints imposed by the different sectors. In this research, an energy system dispatch optimization model is employed. It includes an iterative approach for generating grid constraints, which is decoupled from the linear unit commitment problem. The dispatch of all energy carriers in the system is optimized while considering the physical electrical grid limits. From the considered scenarios, it was found that in a typical German neighborhood with 150 households, a PV penetration of ∼5 kWp per household can lead to curtailment of ∼60 MWh per year due to line loading. Furthermore, the proposed method eliminates grid violations due to the addition of new sectors and reduces the energy curtailment up to 45%. With the optimization of the heat pump operation, an increase of 7% of the self-consumption was achieved with similar results for the combination of battery systems and electrical vehicles. In conclusion, a safe and optimal operation of a complex energy system is fulfilled. Efficient control strategies and more accurate plant sizing could be derived from this work.

Highlights

IntroductionThere are several initiatives and international efforts to reduce the CO2 emissions in all energy sectors as part of the Paris agreement [1]
Even though this approach could be applied to any energy system, regardless of its dimension, this work is primarily intended for its implementation on mid and low voltage systems as described in
The main results obtained from the implementation of the electric grid constraints into the optimal operation of an energy system are presented

Summary

Introduction

There are several initiatives and international efforts to reduce the CO2 emissions in all energy sectors as part of the Paris agreement [1]. In Germany, the so-called “Energiewende” establishes the goals for the energy transformation towards a zero-emission national energy system [2]. A fundamental step to achieve such ambitious goals is the electrification of the residential heat and transport sectors that accounted in 2016 for ∼10%. ∼18.2% of the total emissions in Germany, respectively [3]. 50% of the district heating in Europe is expected, with approximately 30% of that demand being covered by heat pumps [4]. Combined heat and power is expected to serve as a bridge technology coupling electricity and heat sectors [5]. A fleet of around six million electrical vehicles is planned by the German government by 2030 [6]

Methods

Results

Discussion

Conclusion