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January 2014


More Flexible Coal Plants Can Play a Part in 21st Century Power Systems


The branding identifier for the 21st Century Power Partnership.

Globally, new economic and political circumstances are reshaping power systems in favor of those that operate with greater flexibility and efficiency and incorporate renewable energy and demand response (DR). Coal, which is widely perceived to provide only baseload power generation, remains a critical component in most power systems, and a new study shows that coal generation plants can be modified to fit within the new power sector and be a part of a cleaner energy system.

The report, Flexible Coal: Evolution from Baseload to Peaking Plant, by Jaquelin Cochran and Debra Lew of the National Renewable Energy Laboratory (NREL) and Nikhil Kumar of Intertek, summarizes the findings from a coal generating station that has been modified to operate more flexibly, with the ability to cycle on and off daily and run at low generation levels. The report was prepared for the 21st Century Power Partnership, which aims to accelerate the global transformation of power systems.

"This study proves that coal can be part of a power system with high levels of renewable energy," said NREL's Cochran, a lead author of the report. "Coal plants can be modified to respond to the changing output of renewable energy and run at low levels when renewable electricity generation is high but demand is low, such as at night. There is a cost to this flexibility, but these costs can be minimized with strategic modifications and maintenance."

Subscriber-based Greenwire quoted Cochran in an article about the report.


simuwatt Solar Reduces PV System Design Costs


A photo of an iPad with the simuwatt software being displayed.

Photo from Matt Brown, concept3D

The simuwatt® Solar software package—developed by Denver-based software developer concept3D in partnership with NREL and backed by the U.S. Department of Energy's (DOE's) SunShot Initiative—is a mobile tablet application that improves the speed and accuracy of commercial rooftop solar photovoltaic (PV) sales, design, and permitting processes.

The mobile and cloud-based application uses 3D modeling for site survey, shade, production and economic analysis, permitting, bid preparation and preliminary system design in one visit. It is the first product to streamline the entire process, from sales to engineering, to permitting in a single application.

simuwatt Solar is backed by a community-driven library of equipment (e.g., solar panels, racking systems, inverters, and combiner boxes) for use in designing rooftop systems—called the "simuwatt Library."

simuwatt Solar relies on several datasets to optimize the configuration of a rooftop PV system, including incentives from DSIRE, and uses NREL's System Advisor Model (SAM) as an analysis engine.

Also in development is the simuwatt Energy Auditor software package, which allows users to gather key building information rapidly and find potential energy savings.

For more information on simuwatt, visit the simuwatt website; for more information on simuwatt Energy Auditor, read NREL's news release and fact sheet.

Renewable Energy World posted an article about simuwatt Solar; Reuters, Clean Technica, and ThomasNet News posted articles about simuwatt Energy Auditor.


How Are Utilities Incorporating Solar Generation in Resource Planning?


Today's utility planners have a different market and economic context than their predecessors, including planning for the growth of renewable energy. State and federal support policies, solar PV price declines, and the introduction of new business models for solar PV "ownership" are leading to increasing interest in solar technologies, especially PV.

Using interviews and a questionnaire, Treatment of Solar Generation in Electric Utility Resource Planning—by Joyce McLaren and Karlynn Cory of NREL and John Sterling and Mike Taylor of Solar Electric Power Association (SEPA)—begins a discussion about how solar technologies are considered in the resource planning process.

The authors will share the findings from this report in a free webinar on January 14, 2014, at noon MST. Register here.

Specifically, this webinar will provide an overview of:

  • How utilities conduct resource planning activities
  • The benefits and challenges of incorporating solar generation into resource planning processes
  • Potential analysis options for more accurately incorporating solar generation into utility long-term planning processes
  • Utility analysis needs that would better inform solar supply planning.

Karlynn Cory recently presented another related webinar, Treatment of Solar in Utility Resource Planning, which was facilitated by SEPA. View the webinar recording and slides.


NREL Analysis and Analysts in the News


Kate Young and the Geothermal Regulatory Roadmapping team, including Kermit Witherbee, Aaron Levine, and Jon Weers, won a Special Recognition Award from the Geothermal Energy Association for their outstanding geothermal work over the past year, including working with federal, state, and local agencies to produce a guide to help agencies, industries, and policymakers understand regulatory processes and timelines and to identify potential areas of concern. Altenergymag.com and Renewable Energy Focus reported on the awards.

Business Energy and Forbes posted articles about Doug Arent's interview on NPR's All Things Considered titled "Slashing Fossil Fuel Consumption Comes With a Price."

"The two reports, along with previous reports, provide a comprehensive look at the full cost of installing solar, while delineating and quantifying the various contributors to that final cost."
- Barry Friedman

The NREL analyst was quoted in PV Magazine's article "Soft Costs Account for Most of PV Residential Installation Costs." The two reports are: Benchmarking Non-Hardware Balance-of-System (Soft) Costs for U.S. Photovoltaic Systems, Using a Bottom-up Approach and Installer Survey — Second Edition and Financing, Overhead, and Profit: An In-depth Discussion of Costs Associated with Third-party Financing of Residential and Commercial Photovoltaic Systems. The Energy Collective and CleanTechnica also posted articles on the reports.

GreenTech Solar and PV Magazine quoted Rachel Gelman about the 2012 Renewable Energy Data Book.

A blog from The Hill quoted Trieu Mai about renewable energy on the grid.

PV Insider and subscriber-based DebtWire quoted Michael Mendelsohn in an article on securitization. Michael Mendelsohn also recently spoke at the Novogradac Financing Renewable Energy Conference about securitization.

MIT News quoted Doug Arent in an article discussing a journal article on emissions policies.

Subscriber-based ClimateWire quoted Doug Arent in their article "COAL: The Odds Against Getting Int'l Financing for Coal-Fired Power Plants Rise Sharply."


Recent Publications


Journal Article: "Demand Response for Ancillary Services"
Journal: IEEE Transactions on Smart Grid
Authors: Ookie Ma, DOE; Nasr Alkadi, Oak Ridge National Laboratory (ORNL); Peter Cappers, Lawrence Berkeley National Laboratory (LBNL); Paul Denholm, NREL; Junqiao Dudley and Sasank Goli, LBNL; Marissa Hummon, NREL; Sila Kiliccote, Jason MacDonald, Nance Matson, Daniel Olsen, Cody Rose, and Michael D. Sohn, LBNL; Michael Starke, ORNL; Brendan Kirby, consultant; and Mark O'Malley, University College Dublin

This journal article describes and implements a methodology to construct detailed temporal and spatial representations of DR resources and to incorporate those resources into power system models. It also outlines ways to evaluate barriers to implementation.


Journal Article: "Envisioning a Renewable Electricity Future for the United States"
Journal: Energy
Authors: Trieu Mai, David Mulcahy, and Maureen Hand, NREL; Samuel F. Baldwin, DOE

This paper presents high renewable electricity penetration scenarios in the United States using detailed capacity expansion modeling that is designed to properly account for the variability and uncertainty of wind and solar resources.


Journal Article: "A Dynamic Programming Approach to Estimate the Capacity Value of Energy Storage"
Journal: IEEE Transactions on Power Systems
Authors: Ramteen Sioshansi and Seyed Hossein Madaeni, The Ohio State University; Paul Denholm, NREL

This paper presents a method to estimate the capacity value of storage. This method uses a dynamic program to model the effect of power system outages on the operation and state of charge of storage in subsequent periods.


NREL Report: System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report
Authors: Janine Freeman, Jonathan Whitmore, Leah Kaffine, Nate Blair, and Aron P. Dobos, NREL

This report provides detailed validation of SAM flat plate PV performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size.


NREL Report: Grid Integration of Aggregated Demand Response, Part 2: Modeling Demand Response in a Production Cost Model
Authors: Marissa Hummon, David Palchak, Paul Denholm, and Jennie Jorgenson, NREL; Daniel J. Olsen, Sila Kiliccote, Nance Matson, Michael Sohn, Cody Rose, Junqiao Dudley, and Sasank Goli, Lawrence Berkeley National Laboratory; Ookie Ma, U.S. Department of Energy

This study is a multi-national-laboratory effort to assess the potential value of DR and energy storage to electricity systems with different penetration levels of variable renewable resources and to improve our understanding of associated markets and institutions. This report describes the implementation of DR resources in the commercial production cost model PLEXOS.


NREL Report: Wind Resource Assessment Report: Mille Lacs Indian Reservation, Minnesota
Author: Tony Jimenez, NREL

The U.S. Environmental Protection Agency (EPA) launched the RE-Powering America's Land initiative to encourage development of renewable energy on potentially contaminated land and mine sites. EPA collaborated with NREL and the Mille Lacs Band of Chippewa Indians to evaluate the wind resource and examine the feasibility of a wind project at a contaminated site located on the Mille Lacs Indian Reservation in Minnesota.


NREL Report: Estimating the Performance and Economic Value of Multiple Concentrating Solar Power Technologies in a Production Cost Model
Authors: Jennie Jorgenson, Paul Denholm, Mark Mehos, and Craig Turchi, NREL

This report uses an established concentrating solar power with thermal energy storage (CSP-TES) modeling framework in a commercially available production cost model to compare the dispatch and value of two CSP-TES technologies (molten salt towers and parabolic troughs) in a Colorado test system.


NREL Report: Wind Power Project Repowering: Financial Feasibility, Decision Drivers, and Supply Chain Effects
Authors: Eric Lantz, Michael Leventhal, and Ian Baring-Gould, NREL

This report is intended to inform policymakers and the business community regarding the history, opportunities, and challenges associated with wind power plant end-of-life actions, particularly repowering.


NREL Report: The Potential of Securitization in Solar PV Finance
Authors: Travis Lowder and Michael Mendelsohn, NREL

This report aims to demonstrate what volumes of solar deployment could be supported if the solar industry had access to the capital markets in the form of security issuance.


NREL Report: Solar Development on Contaminated and Disturbed Lands
Authors: Jordan Macknick, Courtney Lee, Gail Mosey, and Jenny Melius, NREL

This report examines the prospect of developing utility- and commercial-scale CSP and solar PV technologies on degraded and environmentally contaminated lands.


NREL Report: Overview of Opportunities for Co-Location of Solar Energy Technologies and Vegetation
Authors: Jordan Macknick, Brenda Beatty, and Graham Hill, NREL

This report outlines some of the impacts that large-scale solar facilities can have on the local environment, provides examples of installations where impacts have been minimized through co-location with vegetation, characterizes the types of co-location, and gives an overview of the potential benefits from co-location of solar energy projects and vegetation.


NREL Report: Estimating Rooftop Suitability for PV: A Review of Methods, Patents, and Validation Techniques
Author: Jenny Melius, Robert Margolis, and Sean Ong, NREL

This report reviews the literature and patents on methods for estimating rooftop area appropriate for PV, including constant-value methods, manual selection methods, and GIS-based methods. This report also presents NREL's proposed method for estimating suitable rooftop area for PV using Light Detection and Ranging (LiDAR) data in conjunction with a GIS model to predict areas with appropriate slope, orientation, and sunlight.


NREL Report: The Feasibility of Producing and Using Biomass-Based Diesel and Jet Fuel in the United States
Authors: Anelia Milbrandt, Christopher Kinchin, and Robert McCormick, NREL

The study summarizes the best available public data on the production, capacity, cost, market demand, and feedstock availability for the production of biomass-based diesel and jet fuel.


NREL Report: Effects of Deployment Investment on the Growth of the Biofuels Industry
Authors: Laura J. Vimmerstedt and Brian W. Bush, NREL

This report presents results from the Biomass Scenario Model—a system dynamics model of the biomass to biofuels system—that estimate effects of investments in biorefineries at different maturity levels and operational scales. The report discusses challenges in estimating effects of such investments and explores the interaction between this deployment investment and a volumetric production incentive.


Fact Sheet: NREL Develops OpenEI.org, a Public Website Where Energy Data can be Generated, Shared, and Compared
Author: Heather Lammers, NREL

This fact sheet highlights NREL's role in developing OpenEI.org, a public, open, data-sharing platform where consumers, analysts, industry experts, and energy decision makers can go to boost their energy IQs, search for energy data, share data, and get access to energy applications, and the impact OpenEI is having on energy decision making.


Fact Sheet: NREL Case Study Leads to International Partnership
Author: Ernest Tucker, NREL

This fact sheet describes how a case study, "Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience," led to the launch of the 21st Century Power Partnership.


Brochure: Introducing the Knowledge Management System
Author: Bethany Speer, NREL

This United Nations Energy Program brochure describes the Climate Technology Centre and Network's (CTCN) Knowledge Management System that will support delivery of the CTCN's core functions to developing country national designated entities, broader government decision makers, and other climate technology practitioners.


Clean Energy Finance: Challenges and Opportunities of Early-Stage Energy Investing
[Presentation] [Executive Summary]

This presentation provides an overview of the current state of clean energy finance across the entire spectrum, focusing on early stage investing, and it includes insights from investors across all investment classes.


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The National Renewable Energy Laboratory (NREL) aims to provide credible, objective data and insights that inform policy and investment decisions as energy efficient and renewable energy technologies advance from concept to commercial application. NREL analysis encompasses a broad range of scientific research and reporting activity in support of the U.S. Department of Energy's (DOE) Office of Energy Efficiency and Renewable Energy (EERE), NREL programs and initiatives, and the analysis community.