Use-Cases for Distributed Photovoltaic and Storage Systems

EPRI (Electric Power Research Institute, Palo Alto, USA) has been active in the research and development of the electrical power delivery systems. Just remember the projects UCA 1.0 (Utility Communication Architecture) and UCA 2.0. Both projects have contributed to the IEC TC 57 (Power System Management) and influenced several crucial standard series like the CIM, IEC 60870-6 TASE.2 and IEC 61850.

The work on the “Utility Communication Architecture” is going on in various IEC TC 57 projects and EPRI is still contributing to this process (especially to the definition of IEC 6185-90-7 - Object models for photovoltaic, storage, and other DER inverters). A very interesting EPRI report looks into the “Uses for Distributed Photovoltaic and Storage Systems”. The report lists and discusses briefly the following use-cases:

• Energy Generation
• Local Energy Storage to Compensate for Photovoltaic Intermittency
• Use of Energy Storage for Arbitrage Benefit
• Use of Local Energy Storage to Maximize Photovoltaic Generation Value
• Energy Storage for Customer or Community Backup Power
• Energy Storage to Reduce or Limit Peak Loading on the Utility System
• Energy Storage for Load Following
• Energy Storage to Reduce Customer Peak Demand
• Energy Storage for Local Power Quality Control
• System Stabilization – Transient Watt Modulation with Line Frequency
• System Stabilization - Transient Watt Modulation with Line Voltage
• Var Production for Voltage Regulation
• Var Production for Voltage Stabilization
• Var Production for Power Factor Management
• Var Compensation for Intermittent Generation
• Connect/Disconnect from Grid – Non Islanding
• Connect/Disconnect from Grid – Islanding
• On/Off Control of PV and/or Storage Inverter
• Adjusting Maximum Generation Level
• Metering Energy from Photovoltaic or Storage Device
• State Monitoring
• Event Reporting by Exception
• Event Logging

Click HERE for the 44 page report on use cases.
Click HERE for an overview about IEC 61850-90-7.

In an up-to-date publication of the German VDI nachrichten it is reported about storage possibilities on 2011-10-28 that:

• The capacity of all German pumped-storage hydropower plants would provide power for 1 hour.
• The capacity of 42 million German cars would last for 24 hours.
• The capacity of the German oil and gas storages would last at least for 2 months.
• The storage of “Wind or PV Power” (Converting Electricity to Natural Gas) is also an option.

Click HERE for an R&D report on Converting Electricity to Natural Gas.

Whatever the energy Mix will be – there is a crucial need for information and communication systems supporting the future power delivery system!

The good news is that there is no need to develop standards for information and communication systems from scratch! There are sufficient standards available, implemented and tested so that the power industry can straight use them: IEC 60870-6 TASE.2, CIM, IEC 61850, IEC 61400-25, …