June/July 2012 Newsletter
The Energy Analysis at NREL newsletter highlights all the analysis activities in renewable energy and energy efficiency technologies going on at the laboratory. Features include news and events, new website areas, updates to our models and tools, and our latest publications. You can subscribe to this newsletter using our simple online form, and you can also unsubscribe online.
NREL Report: Renewable Electricity Futures Study
The Renewable Electricity Futures Study (RE Futures) is an initial investigation of the extent to which renewable energy supply can meet the electricity demands of the continental United States over the next several decades. This study explores the implications and challenges of very high renewable electricity generation levels—from 30% up to 90%, focusing on 80%, of all U.S. electricity generation from renewable technologies—in 2050. At such high levels of renewable electricity generation, the unique characteristics of some renewable resources, specifically geographical distribution and variability and uncertainty in output, pose challenges to the operability of the nation's electric system.
RE Futures provides initial answers to important questions about the integration of high penetrations of renewable electricity technologies from a national perspective, focusing on key technical implications. The study explores electricity grid integration using models with unprecedented geographic and time resolution for the continental United States to assess whether the U.S. power system can supply electricity to meet customer demand on an hourly basis with high levels of renewable electricity, including variable wind and solar generation.
RE Futures, funded by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy, is a collaboration with more than 110 contributors from 35 organizations including national laboratories, industry, universities, and non-governmental organizations.
LCA Harmonization Project
The Journal of Industrial Ecology published a special issue titled "Meta-Analysis of Life Cycle Assessments" showcasing seven NREL articles on life cycle assessment (LCA) harmonization. Garvin Heath and Margaret Mann led this NREL project, which included systematic review of estimates of life cycle GHG emissions from electricity generation technologies published between 1970 and 2010. LCAs consider emissions from all stages in the life cycle of an electricity generation technology, from component manufacturing to operation of the generation facility to its decommissioning, and include acquisition, processing, and transport of any required fuels. For selected technologies, a meta-analytical procedure called "harmonization" was applied to adjust estimates so that they were methodologically more consistent and therefore more comparable. This was done to reduce variability and clarify central tendency in the estimate of life cycle GHG emissions so that more robust decisions can be made and other analyses relying on such estimates can be strengthened.
To coincide with the special issue of the magazine, NREL launched a new project page on NREL.gov and an LCA application on OpenEI. The application allows for a customized visualization of summary statistics and the underlying published estimates collected for each technology, as well as companion harmonized estimates.
NREL's harmonization work has been featured in several recent publications and blogs, including Energy Central Professional, Eco-Business, Energy-Enviro Finland, ThomasNet News, Earth Techling, and Jonathan Koomey's blog. NREL has also been contacted by the Environment & Energy Policy committee for the Japan Association of Corporate Executives and DNV (Det Norske Veritas) KEMA for assistance with interpretation of the analysis and results for their organizations and contexts.
Authors: Laura Vimmerstedt and Brian Bush, NREL; Steve Peterson, Peterson Group
The Energy Independence and Security Act of 2007 targets use of 36 billion gallons of biofuels per year by 2022. Achieving this may require substantial changes to current transportation fuel systems for distribution, dispensing, and use in vehicles. DOE and NREL designed a system dynamics approach to help focus government action by determining what supply chain changes would have the greatest potential to accelerate biofuels deployment. The Biomass Scenario Model (BSM) represents the primary system effects and dependencies in the biomass-to-biofuels supply chain. The model provides a framework for developing scenarios and conducting biofuels policy analysis. This paper focuses on the downstream portion of the supply chain—represented in the distribution logistics, dispensing station, and fuel utilization—and vehicle modules of the BSM.
NREL Report: Biomass Resource Allocation among Competing End Uses
Authors: Emily Newes, Brian Bush, Daniel Inman, Yolanda Lin, Trieu Mai, Andrew Martinez, David Mulcahy, Walter Short, Travis Simpkins, and Caroline Uriarte, NREL; Corey Peck, Lexidyne, LLC
The Biomass Scenario Model (BSM), a system dynamics model, facilitates understanding of policies and their potential effects on the U.S. biofuels industry. However, BSM does not currently have the capability to account for allocation of biomass resources among the various end uses. This report provides a more holistic understanding of the dynamics surrounding the allocation of biomass among competing uses by (1) highlighting the methods used in existing models' treatments of competition for biomass resources; (2) identifying coverage and gaps in industry data regarding the competing end uses; and (3) exploring options for developing models of biomass allocation that could be integrated with the BSM.
Authors: Mackay Miller, Phil Voss, Adam Warren, Ian Baring-Gould, and Misty Conrad, NREL
NREL partners with island communities around the world to address the technical, policy, social, and economic hurdles to deploying energy efficiency and renewable energy technologies (RET) on small, islanded systems. The lessons learned from these partnerships are briefly summarized in this document with the goal of supporting the International Renewable Energy Agency in the development of specific near-term and longer-term strategies for island RET deployment.
Authors: Ariel Esposito and Chad Augustine, NREL
Geopressured geothermal reservoirs are characterized by high temperatures and high pressures with correspondingly large quantities of dissolved methane. Due to these characteristics, the reservoirs provide two sources of energy: chemical energy from the recovered methane and thermal energy from the recovered high temperature fluid. Formations with the greatest potential for recoverable energy are located in the gulf coastal region of Texas and Louisiana. This study estimates the total recoverable onshore geopressured geothermal resource (defined as a brine reservoir with fluid temperature greater than 212°F and a pressure gradient greater than 0.7 psi/ft) for identified sites in Texas and Louisiana.
Authors: Colleen Porro and Chad Augustine, NREL
In this presentation, NREL provides an initial estimate of the geothermal resource in major U.S. sedimentary basins by (1) providing a preliminary review of major sedimentary basins in the United States; (2) delineating and mapping areal extent and depth contours of each basin in Geographic Information Systems (GIS); (3) estimating the temperature profile for each basin (assume single temperature gradient for each basin); (4) calculating basin volume as a function of temperature; and (5) converting volumes to heat in place and electricity generation potential.
Authors: Seyed Hossein Madaeni and Ramteen Sioshansi, The Ohio State University; Paul Denholm, NREL
This article estimates the capacity value of concentrating solar power (CSP) plants without thermal energy storage in the southwestern United States. The results show that CSP plants have capacity values that are between 45% and 95% of maximum capacity, depending on their location and configuration. The article also examines the sensitivity of the capacity value of CSP to a number of factors and shows that capacity-factor-based methods can provide reasonable approximations of reliability-based estimates.
Authors: Eric Lantz and Maureen Hand, NREL; Ryan Wiser, Lawrence Berkeley National Laboratory
Over the past 30 years, wind power has become a mainstream source of electricity generation around the world. However, the future of wind power will depend a great deal on the ability of the industry to continue to achieve cost of energy reductions. This report, developed as part of the International Energy Agency Wind Implementing Agreement Task 26, titled "The Cost of Wind Energy," reviews historical costs, evaluates near-term market trends, reviews the methods used to estimate long-term cost trajectories, and summarizes the range of costs projected for onshore wind energy across an array of forward-looking studies and scenarios. The authors also highlight the influence of high-level market variables on both past and future wind energy costs.
Authors: Paul Denholm, Sean Ong, and Chuck Booten, NREL
This paper describes a simple method to estimate hourly cooling demand from historical utility load data. It compares total hourly demand to demand on cool days and compares these estimates of total cooling demand to previous regional and national estimates. Load profiles generated from this method may be used to estimate the potential for aggregated demand response or load shifting via cold storage.
The Clean Energy Solutions Center, an initiative of the Clean Energy Ministerial and UN-Energy, helps governments design and adopt policies and programs that support the deployment of transformational low-carbon technologies. This fact sheet (published in English, French, and Spanish) highlights key Solutions Center offerings, including the 'ask an expert' policy design assistance offered at no cost to governments and technical assistance programs around the world.
Authors: Paul Schwabe and Michael Mendelsohn, NREL; Felix Mormann, Stanford Law School; Douglas J. Arent, JISEA
Financing renewable energy projects in the United States can be a complex process. Most equity investment in new renewable power production facilities is supported by tax credits and accelerated depreciation benefits and is constrained by the pool of potential investors that can fully use these tax benefits and are willing to engage in complex financial structures. For debt financing, non-government lending has largely been provided by foreign banks that may be under future lending constraints due to economic and regulatory conditions. To discuss renewable energy financing challenges and to identify new sources of capital to the U.S. market, two roundtable discussions were held with renewable energy and financing experts in April 2012. This report summarizes the key messages of those discussions and is designed to provide insights to the U.S. market and inform the international conversation on renewable energy financing innovations.
Authors: David Feldman, Michael Mendelsohn, and Jason Coughlin
Real estate investment trusts (REITs) may have the potential to lower the cost and increase the adoption of photovoltaic (PV) systems by offering an additional source of capital. This paper explains the fundamental physical characteristics of PV and compares them to the characteristics of 'real' property to help determine whether REITs can own PV systems.
Authors: Michael Mendelsohn, NREL; John Harper, Birch Tree Capital LLC
In the wake of the 2008–2009 financial crises, tax equity investors largely withdrew from the renewable energy market, resulting in stagnation of project development. In response, Congress established the Treasury grant program pursuant to Section 1603 of the American Recovery and Reinvestment Act (§1603 Program) to offer a cash payment in lieu of a production and investment tax credit. Drawing on insights offered by financial executives active in the renewable energy (RE) market during conference panel discussions and in presentations, direct interviews, and email correspondences, the authors address the potential project financing and market impacts from the expiration of the §1603 Program. With the expiration of the §1603 Program, smaller or less-established renewable power developers will have more difficulty attracting needed financial capital and completing their projects, development of projects relying on newer or 'innovative' technologies will likely slow as traditional tax equity investors are known to be highly averse to technology risk in the projects they fund, and, finally, projects relying on tax equity may be more expensive to develop due to higher transaction costs and potentially higher yields required to attract tax equity.
Journal Article: Enabling Technologies for High Penetration of Wind and Solar Energy
Author: Paul Denholm, NREL
High penetration of variable wind and solar electricity generation will require modifications to the electric power system. This work examines the impacts of variable generation, including uncertainty, ramp rate, ramp range, and potentially excess generation. Time-series simulations were performed in the Texas (ERCOT) grid where different mixes of wind, solar PV, and concentrating solar power provide up to 80% of the electric demand. Different enabling technologies were examined, including conventional generator flexibility, demand response, load shifting, and energy storage. A variety of combinations of these technologies enabled low levels of surplus or curtailed wind and solar generation depending on the desired penetration of renewable sources. At lower levels of penetration (up to about 30% on an energy basis) increasing flexible generation, combined with demand response, may be sufficient to accommodate variability and uncertainty. Introduction of load-shifting through real-time pricing or other market mechanisms further increases the penetration of variable generation. The limited time coincidence of wind and solar generation presents increasing challenges as these sources provide greater than 50% of total demand. System flexibility must be increased to the point of virtually eliminating must-run baseload generators during periods of high wind and solar generation. Energy storage also becomes increasingly important as lower cost flexibility options are exhausted. The study examines three classes of energy storage—electricity storage, including batteries and pumped hydro, hybrid storage (compressed-air energy storage), and thermal energy storage. Ignoring long-distance transmission options, a combination of load shifting and storage equal to about 12 hours of average demand may keep renewable energy curtailment below 10% in the simulated system.
Authors: David Hurlbut, Scott Haase, Craig Turchi, and Kari Burman, NREL
In January 2012, NREL delivered to the Department of the Interior the first part of a study on Navajo Generating Station (Navajo GS) and the likely impacts of BART compliance options. That document establishes a comprehensive baseline for the analysis of clean energy alternatives and their ability to achieve benefits similar to those that Navajo GS currently provides. This analysis is a supplement to that study. It provides a high-level examination of several clean energy alternatives, based on the previous analysis. Each has particular characteristics affecting its relevance as an alternative to Navajo GS. It is assumed that the development of any alternative resource (or portfolio of resources) to replace all or a portion of Navajo GS would occur at the end of a staged transition plan designed to reduce economic disruption. We assume that replacing the federal government's 24.3% share of Navajo GS would be a cooperative responsibility of both the U.S. Bureau of Reclamation (USBR) and the Central Arizona Water Conservation District (CAWCD).
NREL Report: 2010 Cost of Wind Energy Review
Authors: Suzanne Tegen, Maureen Hand, Ben Maples, Eric Lantz, Paul Schwabe, and Aaron Smith, NREL
This document provides a detailed description of NREL's levelized cost of wind energy equation, assumptions, and results in 2010, including historical cost trends and future projections for land-based and offshore utility-scale wind.
Lori Bird was quoted in a Power Magazine article titled "States Promote Clean Energy Programs."
The Clean Energy Solutions Center was highlighted in a ThinkProgress article titled "Connecting the Dots: The Clean Energy Solutions Center is Making a Difference for Policymakers" as well as in the Climate Spectator article "The World's Clean Energy Advance."
RenewableEnergyWorld.com republished a number of RE Finance blogs, including Bethany Speer's "Worth the Trouble: New Market Tax Credits" and "How the U.S. Geothermal Market Is and Is Not Growing"; Mike Mendelsohn's "Where Did All the Solar Go? Calculating Total U.S. Solar Energy Production"; Karlynn Cory's "Community Solar: Policies that Go the Distance" and "Pallets of PV: Communities Purchase Solar and Drive Down Costs Together"; Ryan Hubbell's "S & P Opines on Securitizing Distributed Generation"; and Travis Lowder's "An Intro to Building-Integrated Photovoltaics Pt. 2: Challenges," "Weather Derivatives as Insurance Products in the Wind Industry," and "Two New Reports on Utility-Scale Solar from NREL."
GreentechMedia reposted Karlynn Cory's blog titled "Bohr, Baby, Bohr! German Policies Support Enhanced Geothermal Drilling."
For the latest updates on information regarding energy analysis, visit the Energy Analysis website.