Nate Blair

U.S. Renewable Energy Technical Potentials: A GIS-Based Analysis

This report presents the state-level results of a spatial analysis effort calculating energy technical potential, reported in square kilometers of available land, megawatts of capacity, and gigawatt-hours of generation, for six different renewable technologies. For this analysis, the system specific power density (or equivalent), efficiency (capacity factor), and land-use constraints were identified for each technology using independent research, published research, and professional contacts. This report also presents technical potential findings from previous reports.

Solar Advisor Model User Guide for Version 2.0

The Solar Advisor Model (SAM) provides a consistent framework for analyzing and comparing power system costs and performance across the range of solar technologies and markets, from photovoltaic systems for residential and commercial markets to concentrating solar power and large photovoltaic systems for utility markets. This manual describes Version 2.0 of the software, which can model photovoltaic and concentrating solar power technologies for electric applications for several markets. The current version of the Solar Advisor Model does not model solar heating and lighting technologies.

2015 Standard Scenarios Annual Report: U.S. Electric Sector Scenario Exploration

This report is one of several products resulting from an initial effort to provide a consistent set of technology cost and performance data and to define a conceptual and consistent scenario framework that can be used in the National Renewable Energy Laboratory’s (NREL’s) future analyses. The long-term objective of this effort is to identify a range of possible futures of the U.S. electricity sector in which to consider specific energy system issues through (1) defining a set of prospective scenarios that bound ranges of key technology, market, and policy assumptions and (2) assessing these scenarios in NREL’s market models to understand the range of resulting outcomes, including energy technology deployment and production, energy prices, and carbon dioxide (CO2) emissions.

Validation of multiple tools for flat plate photovoltaic modeling against measured data

In this validation study, comprehensive analysis is performed on nine photovoltaic systems for which NREL could obtain detailed performance data and specifications, including three utility-scale systems and six commercial-scale systems. Multiple photovoltaic performance modeling tools were used to model these nine systems, and the error of each tool was analyzed compared to quality-controlled measured performance data. This study shows that, excluding identified outliers, all tools achieve annual errors within ±8% and hourly root mean squared errors less than 7% for all systems. Finally, the acceptability of this range of annual error is discussed with regard to irradiance data uncertainty and the use of default loss assumptions, and two avenues are proposed to reduce photovoltaic modeling error.

System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report

The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic 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. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.

Power system modeling of 20% wind-generated electricity by 2030

The Wind Energy Deployment System model was used to estimate the costs and benefits associated with producing 20% of the nationpsilas electricity from wind technology by 2030. This generation capacity expansion model selects from electricity generation technologies that include pulverized coal plants, combined cycle natural gas plants, combustion turbine natural gas plants, nuclear plants, and wind technology to meet projected demand in future years. Technology cost and performance projections, as well as transmission operation and expansion costs, are assumed. This study demonstrates that producing 20% of the nationpsilas projected electricity demand in 2030 from wind technology is technically feasible, not cost-prohibitive, and provides benefits in the forms of carbon emission reductions, natural gas price reductions, and water savings.

Renewable Energy and Efficiency Modeling Analysis Partnership: An Analysis of How Different Energy Models Addressed a Common High Renewable Energy Penetration Scenario in 2025

Energy system modeling can be intentionally or unintentionally misused by decision-makers. This report describes how both can be minimized through careful use of models and thorough understanding of their underlying approaches and assumptions. The analysis summarized here assesses the impact that model and data choices have on forecasting energy systems by comparing seven different electric-sector models. This analysis was coordinated by the Renewable Energy and Efficiency Modeling Analysis Partnership (REMAP), a collaboration among governmental, academic, and nongovernmental participants.

Cost and Performance Solar Analysis Model for All Solar Technologies

A comprehensive solar technology systems analysis model is being developed at NREL to support program planning for the U.S. Department of Energy’s Solar Energy Technologies Program (SETP). This new model will calculate the costs, finances and performance of current solar technologies including solar heat (typically solar domestic hot water), concentrating solar power, photovoltaics (PV) and solar hybrid lighting. The primary function of the model is to allow users to investigate the impact of variations in physical, cost, and financial parameters to better understand their impact on key figures of merit. Although a variety of models already exist to examine various issues with each individual technology, this model, when fully implemented in the future, will have the capability to analyze and compare different solar technologies (utility-scale PV vs. CSP for example) within the same interface while making use of similar cost and financing assumptions. A central idea for this model is to have a user-friendly interface while at the same time having a detailed, accurate analysis for each of the technologies. The underlying performance engine, which is hidden from the user, is TRNSYS, which already contains an extensive library of solar technology models. There are built-in cost models or the user can access their own spreadsheet-based cost model. The financial model is an extension of an existing validated finance model. This paper will discuss the goals and implementation of the model and present several sample results for interesting sensitivities.Copyright

Correlations Between Geographically Dispersed Concentrating Solar Power and Demand in the United States

Correlations between the electricity generated by concentrating solar thermal power (CSP) plants, as well as cross-correlations between CSP, wind power and electricity demand, have significant impacts on decisions for how much and where to build utility-scale CSP capacity, the optimal amount of thermal storage in the CSP plants, reserve capacity needed to back-up the system, as well as the expected levels of curtailed renewable power. Accurately estimating these correlations is vital to performing detailed analyses of high renewable penetration scenarios. This study quantifies the degree of correlation between geographically dispersed CSP, as well as the correlation between CSP and wind power, and CSP and electricity demand in 356 discrete regions in the contiguous US. Correlations are calculated using hourly data on an annual basis. Maps of the correlations will be presented to illustrate the degree of correlation between solar power and the demand it is serving, as well as the synergies between the negatively-correlated wind power and solar power serving the same region.Copyright

Current and Future Economics of Parabolic Trough Technology

Solar energy is the largest energy resource on the planet. Unfortunately, it is largely untapped at present, in part because sunlight is a very diffuse energy source. Concentrating solar power (CSP) systems use low cost reflectors to concentrate the sun’s energy to allow it to be used more effectively. Concentrating solar power systems are also well suited for large solar power plants that can be connected into the existing utility infrastructure. These two facts mean that CSP systems can be used to make a meaningful difference in energy supply in a relatively short period. CSP plants are best suited for the arid climates in the Southwestern United States, Northern Mexico, and many desert regions around the globe. A recent Western Governors’ Association siting study [1] found that the solar potential in the U.S. Southwest is at least 4 times the total U.S. electric demand even after eliminating urban areas, environmentally sensitive areas, and all regions with a ground slope greater than 1%.While it is currently not practical to power the whole county from the desert southwest, only a small portion of this area is needed to make a substantial contribution to future U.S. electric needs. Many of the best sites are near existing high-voltage transmission lines and close to major power load centers in the Southwest (Los Angeles, Las Vegas, and Phoenix). In addition, the power provided by CSP technologies has strong coincidence with peak electric demand, especially in the Southwest where peak demand corresponds in large part to air conditioning loads. Parabolic troughs currently represent the most cost-effective CSP technology for developing large utility-scale solar electric power systems. These systems are also one of the most mature solar technologies, with commercial utility-scale plants that have been operating for over 20 years. In addition, substantial improvements have been made to the technology in recent years including improved efficiency and the addition of thermal energy storage. The main issue for parabolic trough technology is that the cost of electricity is still higher than the cost of electricity from conventional natural gas-fired power plants. Although higher natural gas prices are helping to substantially reduce the difference between the cost of electricity from solar and natural gas plants, in the near-term increased incentives such as the 30% Investment Tax Credit (ITC) are needed to make CSP technology approach competitiveness with natural gas power on a financial basis. In the longer term, additional reductions in the cost of the technology will be necessary. This paper looks at the near-term potential for parabolic trough technology to compete with conventional fossil power resources in the firm, intermediate load power market and at the longer term potential to compete in the baseload power market. The paper will consider the potential impact of a reduced carbon emissions future.Copyright