VRE Tutorial: Lessons Learned from Grid Integration of Variable Renewable Energies

Lunch

Lecture 1 (45 min.)
Lessons Learned from Grid Integration of VRE: System Integration from TenneT’s Perspective
Mart van der Meijden (TenneT TSO / Delft University of Technology, Netherlands)

Many of us are working very motivated on a reliable, affordable and carbon free energy system. The carbon free ambition is leading to to a fast growing amount of variable renewable Energy (VRE) sources with different availability characteristics than the traditional fossil fuel powered electricity generators. This offers new challenges for the planning and control of the system and grid operators. In addition transition of the electrical system alone is not enough to reach the goal of a carbon free energy system.  Co-operation with the industry, heat and transportation sector is important and even so is the understanding of the impact of upcoming new technologies on the system integration. During this lecture different examples with impact on planning and control from a TSO perspective will be discussed.

Discussion &  Short Break (15 min)

Lecture 2 (45 min.)
Lessons learned from Grid Integration of VRE: Activities in 20 Countries
Thomas Ackermann (Energynautics, Germany)

Thomas Ackermann will share his experiences of 25 years of world-wide work in the area of grid integration of renewables and electric vehicles. The presentation will give an overview of challenges and lessons learned.

Discussion &  Short Break (15 min)

Coffee Break

Lecture 3 (45 min.)
Lessons Learned from Grid Integration of VRE: Resource Adequacy and System Balancing
Debra Lew (ESIG, USA)

Variable renewable energy resources create challenges for utilities to meet resource adequacy requirements because VRE may not be coincident with system peak demand and VRE output during system peak periods varies inter-annually. We discuss how methods for determining resource adequacy may need to be modified to consider high penetrations of VRE. High penetrations of VRE can contribute significant variability and uncertainty to the system operators‘ responsibility of balancing the system. In this lecture, we cover many mitigation options for system balancing and considerations that each utility must undertake to determine what makes the most sense for their system. 

Discussion &  Short Break (15 min)

Lecture 4 (45 min.)
Lessons Learned from Grid Integration of VRE: Introduction to Grid Forming Inverters from the Power System Perspective
Julia Matevosyan (ESIG, USA)

In order to maintain reliability in girds with high shared of inverter-based resources (IBRs), the role of this resources needs to evolve. Some of the grid services currently (or formerly) provided by conventional synchronous power plants need to be provided by IBRs. IBRs are already required to have the capability to provide some of these grid services, but advanced controls will be needed to enable them to provide the full range of necessary grid services in a high-renewables grid. The tutorial will provide introduction to new advanced inverter controls, termed grid forming. We will discuss differences and similarities with between capabilities of and limitations of existing conventional inverters termed grid following vs grid forming inverters. System operators and planners, equipment owners, and manufacturers face a circular problem: Which comes first, the requirement for a capability or the capability itself? How do grid operators know what performance or capability is possible from new equipment, and therefore what they could conceivably require? How can they go about evaluating the costs and benefits of having such equipment on the grid? And what drives manufacturers to invest in new technology without it being mandated for interconnection to the grid or otherwise incentivized by the market? The tutorial will introduce a framework which may help to solve this circular problem as well as will talk about “early adopters”, i.e. existing grid forming projects around the world and emerging technical specifications for grid forming inverters.

Discussion (15 min)

Coffee Break

Lecture 5 (45 min.)
Lessons Learned from Grid Integration of VRE:  Frequency Control and System Stability
Nicholas Miller (HickoryLedge, USA)

The dynamic performance of interconnected power systems, especially the transient response to grid disturbances, is substantially changed by the substitution of inverter-based variable renewable resources (IBVRE) for traditional synchronous generation. Ability to maintain frequency control following loss of major generation units or interconnectors is strongly influenced by reduced synchronous inertia and rapidly responding IBVRE. Transient stability, particularly first swing stability between importing and exporting systems can be radically altered by IBVRE. This lecture will explore lessons learned in large-scale integration studies, including opportunities to improve utilization of transmission infrastructure beyond levels possible today with predominantly synchronous generation.

Discussion (15 min)