Introduction to Hybrid Power Systems and Case Studies

Session 1 (120 min.)
Introduction to Hybrid Power Systems
Dr. Thomas Ackermann, Peter-Philipp Schierhorn (both Energynautics, Germany)

Energynautics CEO Dr. Thomas Ackermann and senior engineer Peter-Philipp Schierhorn will provide an introduction to the world of hybrid power systems, focusing especially on small power systems on islands or in remote areas. This session intends to give an insight into the current state of small power systems, which are typically still mainly powered by diesel generators, and the challenges and opportunities of supplementing or replacing conventional generation with renewables in such systems.

Energynautics have collected significant experience in analyzing island power systems over the past years, ranging from microgrids in the Bahamas powered by a single generator across multi-MW systems with multiple diesel power plants in Galapagos and the Seychelles to even larger island systems including small coal power plants in Indonesia. The session is targeted at participants from the renewable energy community with and without experience in hybrid power systems and will connect the theoretical foundation on small power systems with real world experience from various projects. Typical challenges of VRE integration into small power systems, such as frequency control, the accessibility of generator flexibility and the techno-economic potential of battery energy storage will be elaborated on and illustrated using real operational examples. A side focus will be on the challenges of getting hybrid power system development started in developing countries, as most small power systems worldwide fall into this category.

This session is intended to provide the technical background and an overview of hybrid power system development in different areas of the world. The application of this information will then be demonstrated by the following presenters focusing on individual projects in the respective systems.

Short Break

Session 2 (60 min.)
Case Studies from Hybrid Power Systems:
Design considerations for PV-Battery Hybrid Systems
Johannes Weide (SMA Sunbelt Energy GmbH, Germany)

The focus of this session is the robust design of PV-Battery systems in Genset based island grids. The integration of PV into genset based energy systems faces several challenges from reverse current protection of gensets to the minimum spinning reserve required for PV power fluctuations. A decently sized battery system can solve these problems and even improve the grid stability with its fast and accurate provision of active and reactive power. The right sizing of the battery system under technical and economical aspects is a multidimensional problem. A proven sizing approach that considers the technical and commercial aspects will be discussed in this session.

Short Break

Session 3 (60 min.)
Retaining Operational Flexibility and Assigning Risk with Innovative PPAs: Hawai’i’s Experience with Wind and Hybrid Solar PV and Energy Storage Projects
Nicholas W Miller (HickoryLedge, USA)

Most island systems depend on power purchase agreements (PPAs) rather than clearing markets for supply of power from variable energy resources (VERs), such as solar PV and wind, to the grid. Traditional PPAs, of typically 20 years duration, are based on energy delivered to the grid have serious deficiencies when VERs become a major contributor to the overall energy supply of a host power system. The key stakeholders in the State of Hawai’i have introduced a new PPA structure that provides substantial benefits for all key stakeholders, including investors, the grid operator, end-users and rate-payers. The lecture examines the motivations for the new structures, including consequences of more traditional PPAs and structure of the new PPAs, addressing risk allocation and management elements.

Closing