Integration of Variable Energy Resources (VER)

On june 22, FERC released a final rule in the integration of Variable Energy Resources (VER) rulemaking proceeding. The final rule requires VER generators to provide transmission owners with specific meteorological and forced outages information  in order to support power production forecasting and to reach the goal of remove barriers to VER integration.This article offers a simple overview about the new rule, its implications and consequences for US enery industry.


More specifically this new rule requires 2 reforms:

- Pro forma Open Access Transmission Tariff (OATT): Before June 22 final rule, under OATT Schedule 9, generation imbalance charges are assessed against generators, including VERs, as a penalty for deviations between the scheduled delivery of energy from generator and the amount of energy actually generated. When generation output changed within a givenhour, generators lacked the ability to minimize related penalty imbalance charges. FERC considered this unreasonable, so allowed a 15-minute scheduling.

- Pro forma Large Generator Interconnetion Agreement (LGIA): Prior to June 22 final rule, public utility transmission providers had a limited ability to develop and deploy power production forecasts to more efficiently manage operating costs related to integrating VERs that are interconnecting to their systems. LGIA  has been modified to require new interconnection customers with VER generating facilities to provide meteorological and force outaged information to the transmission providers for power production forecast purposes.

Since the amount of VERs is increasing rapidly becoming a significant component of the US energy supply portfolio, FERC recognized a reform is needed in order to conveniently integrate VERs into the system.

15-Minute Intra-Hour Sheduling

Although according to this new rule transmission providers must offer a 15-minute scheduling to all transmission customers, it only requires transmission providers to offer 15-minute scheduling to give all transmission customers the option of using the more frequent transmission scheduling intervals within each operating hour. This acction will be useful to correct an existing deficiency by providing customers an opportunity to adjust their transmission schedules to reflect generated output.

The implementation of intra-hour scheduling will provide VERs and other transmission customes the flexibility to adjust their transmission schedules and minimize their exposure to imbalance charges.

Data Reporting for Power Production Forecasting

June 22 final rule requires meteorological and forced outage information. This data must be consistent and will provide public utility transmission providers with advanced knowledge of system conditions needed to managed the variability of VER generation.

What kind of information must be provided by generators?

Wind generators must provide, at least, site-specific meteorological data including:

- Temperature

- Wind Speed

- Wind Direction

- Atmospheric Pressure

Solar generators must provide, at least, site-specific meteorological information including:

- Temperature

-Atmospheric pressure

- Irradiance

 The importance of an accurate Energy Forecast

June 22 final rule establishes a new opportunity for VER integration while provides flexibility to energy system. Since interconnection customers are required to provide utility transmission customers with meteorological data, it becomes specially positive for creating accurate and reliable energy forecasts in order to more efficiently manage energy, integrate VERs and minimize imbalace charges.

Therefore, utility transmission customers will have to analyze data provided by interconnection customers and to develop accurate energy forecasts in order to manage energy and ensuring VER integration.

Wheather Intelligent System for Energy (WISE) is a web-based tool developed by Gnarum that automatically processes meteorological information and generates 15-minute accurate energy forecasts up to 7 days ahead for any type of renewable energy technology.

This tool offers automatic reports to continuousy evaluate the quality of generated forecasts and it is very convenient in order to manage energy efficiency, as well as energy trading in electricity markets.





Morgan Lewis (2010): FERC Proposes New Rules to Integrate Variable Energy Resources

Morgan Lewis(2012): Integrating VER webinar

Troutmann Sanders (2012): FERC Issues Final Rule in Integration of Variable Energy Resources Rulemaking Proceeding



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