RWEI 2011 - Wind Energy Transmission

Transmission 101: 

Transmission 101 RWEI Meeting Washington, DC 10/26/2011 Presenter: Tom Mousseau

Introduction: 

Introduction Who is EnerNex? EnerNex is a research, engineering, and consulting firm specializing in the development and application of new electric power technologies. Our focus is to aid in the understanding and solution of electric power related issues, as well as, the development of technology and expertise that will ultimately improve the operation and reliability of electric power systems.

Objective: 

Objective What makes up the electric power transmission system grid in 20 minutes or less (allow for questions) System fundamentals Terms and definitions Limits of the transmission system (grid)

Electricity Production: 

Electricity Production

Definitions: 

Definitions Voltage: Voltage is electric potential or potential difference expressed in volts (V). Current: Rate of flow of electric charge expressed in amperes (A). Power: Rate electricity is converted to energy. Measured in Watts (W). Energy: The amount of work done in a period of time. Measured in Watt-hours ( Wh ).

Traditional Transmission Expansion: How we got the grid we have: 

Traditional Transmission Expansion: How we got the grid we have Established rationale for transmission expansion Connect generation to load Maintain system reliability Economic energy exchanges with neighbors Perspective Initially on an individual company basis Interconnections with neighbors increased scope Emergence of wholesale energy markets has lead to a regional view Is the regional view adequate for remote renewable resources?

Why is Transmission an Issue for Wind?: 

Why is Transmission an Issue for Wind? Current situation: Installed U.S. wind generation capacity ~40 GW <3% of annual U.S. electric energy use Transmission is already a limitation on wind development in many regions of the country ERCOT MISO: Dakotas, Minnesota, Iowa Inter-Mountain West and Desert Southwest Development still continuing, but congestion and curtailment are facts of life

How?: 

How? Power flows according to the laws of physics following the path of least resistance It is more efficient to move long distances at high (69kV -345kV) and extra high voltage (345 kV +) The grid is "networked", such that there are many physical paths between any two points Grid must be operated to withstand loss of any element, therefore the need for redundancy In sparely populated areas, the grid is many times weak. Here the limits on power flow are usually not the "wires", but the need to maintain system stability following the loss of an element, or the shock of disruptions like short-circuits.

Constrained Generation LMP: 

Constrained Generation LMP

Economic Sources and Sinks: 

Economic Sources and Sinks

Lots of wind, Lots of load, Lots of distance: 

Lots of wind, Lots of load, Lots of distance Best Onshore Wind Resources Highest Load

Going Forward: 

Going Forward Further substantial wind energy development and transmission are tightly linked Regional transmission can support additional development in near term Aggressive wind development requires a broader view

What does 20% Wind Energy Look Like?: 

What does 20% Wind Energy Look Like? 5-10 GW

Evaluating Transmission Requirements: 

Evaluating Transmission Requirements Transmission need identified through economics-based planning methodology Whole interconnection considered, rather than regions Connect energy “sources with sinks” The resulting conceptual transmission overlays consist of multiple 800kV HVDC and EHV AC lines

Innovative Approaches to Breaking the Transmission Logjam: 

Innovative Approaches to Breaking the Transmission Logjam Achieving 20% energy penetration across the Eastern Interconnect will require very substantial wind development and therefore significant grid expansion. Transmission is stymied in many regions due to cost allocation, cost recovery, siting and permitting, and NIMBY issues Identify renewable energy zones Build transmission in advance of need Transmission lead times are 7-10 years Wind plant lead times are 1-2 years Break out of traditional cost recovery methods Socialize the cost Pay for lines with LMP differences Let TSO recover cost in rates until wind plants come If you love wind, you gotta at least like transmission!