Distributed Generation

Advanced Renewable Tariffs for Wisconsin Analysis and Case Study

"Advanced Renewable Tariffs for Wisconsin: Analysis and Case Study" was prepared by the University of Wisconsin Madison Energy Analysis & Policy Certificate Capstone Project.

ART is a policy which aims to encourage customer-sited development of renewable energy. An ART is unique because a regular customer becomes the producer (who we will refer to as a Renewable Power Producer (RPP)), and the electric utility becomes the customer. This is different than net metering and a RPS; net metering is essentially running the kWh meter backwards-thus, the value for a kWh of renewable electricity is equal to the retail rate-while a RPS establishes a quantity obligation.

There are many ways to establish energy payments for an ART. The various methods are primarily based on:

  1. Generation cost, which provides a payment based on the cost of the technology
  2. Avoided cost, which sets the payment based on displacing fossil fuel-based generation
  3. Premium rates, which establish energy payment at a specified level above the retail rate for electricity

This analysis uses a generation cost approach-generation cost is the most common form and is consistent with the Governor‘s Task Force on Global Warming-to determine energy payments for each renewable technology.

Minnesota Transmisson Study Suggests Grid Upgrades for Renewable Energy

A new study released by the Minnesota Office of Energy Security shows that the state's power grid could accomodate 600 megawatts of new renewable energy capacity by making upgrades to electric transmission systems. A previous study had shown that another 600 MW could be added to the existing tranmission grid without impacting it's performance.

"Dispersed Renewable Generation Transmission Study Phase II" completes a two-part study chartered by the Minnesota legislature as part of the Minnesota NextGen Energy Act passed in 2007. The act calls for 25 percent of the total energy used in the state to be derived from renewable energy resources by the year 2025. In order to meet that goal, dispersed generation of the grid would allow many distributed power generators, such as wind farms, to add significant energy capacity to the system. Together, the combined studies created complex computer models designed to add 1200 MW of dispersed capacity by the year 2013.

Phase I, completed in June 2008, identified locations in the state transmission grid where a total of 600 MW of renewable energy projects could be developed with little or no changes required to the existing grid infrastructure. Although the study noted that dispersed generation can have impacts on the electric grid, it concluded that the majority of the 600 MW could be sited without disruptions at locations in southern Minnesota. In fact, in 2008 the state added 454 MW of commercial wind power with the vast majority sited in southwestern Minnesota.

Proposed DRG Phase II Sites

Phase II of the study sought an additional 600 MW and found that there were limited locations in the state that could accommodate 10-40 MW generation projects without incurring some amount of transmission investment. So, the study team focused on sites that could potentially accommodate generation with only minor transmission investments, not the construction of new high-voltage transmission routes. The total cost of the transmission upgrades were estimated to be $121 million. In comparsion, the CapX 2020 project for constructing three new high-voltage transmission lines across the state is estimated to cost $1.7 billion.

As a result of the studies, the Minnesota Office of Energy Security concluded that achieving the renewable energy goal calls for a dual strategy of:

  • Using our existing transmission infrastructure more efficiently, through increased energy conservation and efficiency, demand response, emerging efficiency technologies and dispersed renewable generation where it can be interconnected reliably, and
  • Significantly increasing high-voltage transmission capacity in the state.

The studies and explanatory recorded webinars are available from the Minnesota Office of Energy Security on the link below.

Tom Wind (Wind Utility Consulting) acting as a consultant to Windustry served as a member of the Technical Review Committee for both studies.

Green Power Express

ITC Holdings Corp. has worked to develop the Green Power Express, a network of transmission lines that would facilitate the movement of 12,000 MW of power from the wind-abundant areas in the Dakotas, Minnesota and Iowa to Midwest load centers, such as Chicago, southeastern Wisconsin, Minneapolis and other states that demand clean, renewable energy.

This new project addresses the recognized lack of electric transmission infrastructure needed to integrate renewable wind energy.

The Green Power Express could be a step to modernize the overburdened, aging electricity grid by building a high-voltage backbone to meet America's renewable energy goals and eliminate costly inefficiencies in the grid. Once built the Green Power Express transmission project will traverse portions of North Dakota, South Dakota, Minnesota, Iowa, Wisconsin, Illinois and Indiana and will ultimately include approximately 3,000 miles of extra high-voltage (765kV) transmission. The entire project is currently estimated to cost of approximately $10 to 12 billion.

"The Green Power Express will create the much-needed link between the renewable energy-rich regions of the Midwest and high-demand population centers," said Joseph L. Welch, chairman, president and CEO of ITC. "The Green Power Express is in many ways the true definition of a 'smart grid'."

Due to the size and scope of this project along with the various state and federal approvals that will be required, ITC is aggressively targeting to have the Green Power Express in service by 2020.

Read more about the Green Power Express.

Distributed Generation Tariff Development

http://www.newrules.org/dgtariff/

The Minnesota state legislature, recognizing that distributed generation will play an integral roll in our energy future required that a standardized set of rules, procedures, and technical criteria for interconnection of distributed generation within the state.  To find out more about the ongoing process visit the site listed above which has links to distributed generation rule making and resource planning in other states as well. 

Community Based Energy Development Transmission Study: West Central (Minnesota) Transmission Planning Zone

 

The Minnesota Department of Commerce is interested in  promoting Community Based Energy Development (C-BED)  projects in the state of Minnesota.  The Department has  encouraged the CapX utilities to undertake a study of the West Central Transmission Planning Zone to determine if C-BED  projects can be interconnected the the transmission system utilizing existing transmission and distribution infrastructure.  The CapX C-BED Interim Report was released in June 2006.  You can also view a PDF of the West Central C-BED map and  Southeast C-BED map here.  The C-BED 800 MW generation map and C-BED 1400 MW generation map are also available for download.

Distributed Generation

The concept of distributed wind generation has been around since the 1970's and is just now gaining acceptance in the utility sector.  Traditionally most forms of generation have been located at some distance from load centers.  Energy from these generation plants had to be transmitted to large load centers like Minneapolis and Chicago via high voltage transmission lines.  With recent increases in energy demand of large cities and new load centers popping up in areas where there once was no demand for electricity, system planners are looking to distributed generation as a way to quench the energy thirst of 21st century society with smaller dispersed power plants that can supply energy directly to load centers without the construction of new multi-million dollar transmission lines.

Distributed wind generation, wind farms of just one or several wind turbines, have several advantages over traditional large wind farms:

* distributed wind, in many cases, has a lower cost to integrate into the existing grid than large wind farms,

* new turbine technology can add voltage and reactive power support to distribution feeders far from substations, improving system reliability and power quality,

* distributed wind generation, in many cases, can supply power much closer to electrical loads than conventional power plants significantly reducing electrical losses as well as lessening constraints on congested power lines,

* distributed wind generation is a way for community stake holders to control electrical generation, allowing communities to keep energy dollars local and to take control their energy future.

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