SolarAnywhere® Research
Insight into the state-of-the-art methods of SolarAnywhere technologiesClean Power Research produces primary research in a number of categories. A Research Timeline and the Research Archive are available on CleanPower.com. Additional product information is available in SolarAnywhere Validation & Product Resources, which includes articles, whitepapers and webinars.
Solar Prediction
Developers, utilities and independent system operators depend on accurate time-series solar irradiance data for project siting, planning and operations. Groundbreaking solar prediction research quantifies the accuracy of PV output modeling, solar irradiance data and irradiance forecasting, as well as describing methods for modeling high-speed PV output variability.
Accuracy of Satellite-Derived Solar Irradiance Data, Solar Irradiance Forecasts & PV Performance Models
This research provides government researchers, utilities, independent system operators and developers information on PV power output models and methods of calculating and quantifying the accuracy of satellite-derived solar irradiance data for specific applications.
Enhancing Temporal Variability of 5-minute Satellite-Derived Solar Irradiance Data
Satellite-derived solar irradiance data are known to underestimate temporal variability compared to point measurements because of their pixel-averaging nature. In this study, we apply an algorithm imposing random noise to enhance the temporal variability of 5-minute...
A Review of Solar Forecasting, Its Dependence on Atmospheric Sciences and Implications for Grid Integration: Towards Carbon Neutrality
The ability to forecast solar irradiance plays an indispensable role in solar power forecasting, which constitutes an essential step in planning and operating power systems under high penetration of solar power generation. Since solar radiation is an atmospheric...
Investigations of Site-Specific, Long Term Average Albedo Determination for Accurate Bifacial System Energy Modeling
As interest in bifacial PV modules grows, there is a need to quantify the impact of additional energy generation for financing solar projects. A critical parameter for accurately modeling rear-side irradiation in bifacial modules is albedo. This paper identifies...
Improved PV System Modeling with ML-Based Power Model: Case Study of a Commercial Building
Solar PV system specifications are critical to accurately modeling PV system production (along with high-quality weather data and PV production models), but are not always readily available. This paper describes how it's possible to infer system specifications and...
Improved model of solar resource variability based on regional aggregation and climate zones
This paper provides the results of using an alternative method to calculate annual insolation probability of exceedance statistics (PXX), which are critical measurements for assessing long-term energy yield and valuation of PV systems. This method aggregates...
Day-Ahead Irradiance Forecast Variability Characterization Using Satellite Data
This article calculates day-head forecast variability as function of historical clearness index based on intraday irradiance variability. In this paper we address the use of satellite data as a proxy for ground data to determine the clearness index of a day, and...
Solar Energy Forecast Validation for Extended Areas & Economic Impact of Forecast Accuracy
This article evaluates the accuracy of solar forecast models, including SolarAnywhere®, as a function of geographic footprint ranging from a single point, to regions spanning several hundred kilometers. The forecast time horizons range from one-hour ahead, to two-days...
Satellite-to-Irradiance Modeling – A New Version of the SUNY Model
This article presents and validates the latest version of the SUNY model for using satellite imagery to calculate irradiance. The new version includes an improved treatment of clear sky, the ingestion of now-casting numerical weather predictions, and a more effective...
CEC PIER Project: Demonstration and Validation of PV Output Variability Modeling Approach
The California Energy Commission’s Public Interest Energy Research (CEC PIER) program awarded Clean Power Research a contract to evaluate satellite-derived irradiance and simulated PV fleet performance accuracy for PV resource management in the CAISO control area....
Operational Improvements in the Performance of the SUNY Satellite-to-Solar Irradiance Model Using Satellite Infrared Channels
This paper summarizes operational improvements to the existing SUNY satellite-to-solar irradiance model used to generate SolarAnywhere® Data. Through incorporation of geostationary satellite infrared (IR) channels, this improved model addresses limitations of previous...
Solar Monitoring, Forecasting and Variability Assessment at SMUD
This paper summarizes the deployment of a 71 station solar monitoring network in Sacramento, Calif., and its use in validating solar forecasts and solar resource variability for high penetrations of solar on the Sacramento Municipal Utility District (SMUD) grid. The...
Predicting Short-term Variability of High Penetration PV
This article evaluates the ability of three operational satellite models (SolarAnywhere® Standard, Enhanced, and High Resolution) to predict ground-based measured irradiance conditions. Results suggest that the performance of satellite-based monitoring approaches that...
Reporting of Irradiance Model Relative Errors
Metrics used in assessing irradiance model accuracy such as Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) are precisely defined. Their relative (%) counterpart, however, can be subject to interpretation and may cover a wide range of values for a given...
Evaluating Irradiance Accuracy Using California ISO Data: Lessons Learned
This presentation provides the results of a study evaluating the short, medium and long-term accuracy of irradiance data derived from satellite imagery to measured data from CAISO. The research was presented at a Utility Variable-Generation Integration Group (UVIG)...
Validation of Short & Medium Term Operational Solar Radiation Forecasts in the U.S.
This paper presents a validation of the short- and medium-term global irradiance forecasts that are produced as part of the U.S. SolarAnywhere (2010) data set. Download PDF >>>
Validation of PV Performance Models Using Satellite-based Irradiance Measurements: A Case Study
This paper presents a study of how PV performance model results are affected when satellite-based weather data is used in place of ground-based measurements. Download PDF >>>
Field Validation of the Clean Power Estimator’s Obstruction Analysis Algorithm
This paper validates the Clean Power Estimator obstruction analysis algorithm based on results produced by the Solar Pathfinder™. Download PDF >>>
Validation of a Simplified PV Simulation Engine
This paper describes and validates a simple PV simulation model capable of predicting average PV output as a function of array geometry (slope and azimuth) and location. Download PDF >>>
Combining Solar Satellite & Ground Data to Reduce Solar Project Uncertainty
These papers highlight the benefit of combining high-quality solar ground data with satellite derived solar irradiance data to reduce solar project uncertainty.
Importance of Input Data and Uncertainty Associated with Tuning Satellite to Ground Solar Irradiation
Although the uncertainty of satellite data such as SolarAnywhere® Data has been shown to be low, it can be challenging to determine the uncertainty of satellite data that has been corrected using ground data. This paper explores the limitations of traditional...
On the Ability of Ground Based Global Horizontal Irradiance Measurements to Reduce Error in Satellite Derived Plane of Array Irradiance data for Fixed Tilt Photovoltaic Power Plants
This paper quantifies the residual errors in plane of array irradiance (POAI) at locations where ground-measured GHI and POAI instruments are installed. Reductions in error to the modeled PAOI are observed when using satellite derived GHI that has been tuned with...
Combining Satellite and Ground Data: What Works & What Doesn’t
In this presentation, you'll learn about which type of solar irradiance data—typical year, ground or satellite—is appropriate for each stage of solar project development. The presentation then discusses the value of combining satellite and ground and data for...
Reducing Solar Project Uncertainty with an Optimized Resource Assessment Tuning Methodology
This paper describes procedures suitable for the optimal combination of ground-based and satellite-based irradiance data to reduce the overall uncertainty of the solar resource assessment. It presents a case study depicting the application of these approaches, and...
Determining the Value of Photovoltaic (PV) Solar Power Using Solar Prediction & Data Modeling
Solar developers and utility planners are often faced with the task of determining the solar energy output & economic value of one or more PV systems. This research offers insights into the solar energy value assessment process.
Nonparametric Temporal Downscaling of GHI Clear-sky Indices Using Gaussian Copula
Small-scale variabilities of solar irradiance are important for many applications. Downscaling approaches need to be developed where only the averaged state of solar irradiance is known. In this study, we investigate the use of copula for temporally downscaling GHI...
Solar Energy Forecast Validation for Extended Areas & Economic Impact of Forecast Accuracy
This article evaluates the accuracy of solar forecast models, including SolarAnywhere®, as a function of geographic footprint ranging from a single point, to regions spanning several hundred kilometers. The forecast time horizons range from one-hour ahead, to two-days...
Off-Shore Wind and Grid-Connected PV: High Penetration Peak Shaving for New York City
This article presents an experimental evaluation of the combined effective capacity of off-shore wind and PV generation using the city of New York as a test case. Download PDF >>>
Valuing a Portfolio of PV Investments
This presentation describes the importance of PV output variability as a factor in calculating the value of a fleet of PV systems. The research was presented at Solar Power International in October, 2010. Download PDF >>>
Weather Adjusted Performance Guarantees
This paper describes how to generate more accurate Weather-Adjusted Performance Guarantees for PV systems using a baseline dataset of monthly system production estimates coupled with a location-specific monthly solar resource index. Download PDF
Shining on the Big Apple: Satisfying New York City’s Peak Electrical Needs with PV
This presentation describes how measured data was used to evaluate the potential of PV to satisfy the electrical needs of New York City (NYC) during peak load conditions. The study concluded that 2 GW of PV would have been well-matched to NYC’s electrical needs on...
Forecasting Solar Irradiance With High-Penetration Distributed Photovoltaics (PV)
The intermittent nature of solar energy using PV requires utilities and independent system operators to adapt their planning, scheduling and operating strategies to maintain grid reliability and get the most value out of installed PV resources. These papers describe projects that use advanced methodologies to forecast high-penetration PV fleet solar energy output, and integrate solar energy forecasts into grid system operations.
Extending Fleet Forecasting Capability into the Probabilistic Realm
This presentation demonstrates how a new approach to PV fleet forecasting can address the problem of artificially high fleet variability when plants share the same solar resource data. The presentation was given at the ESIG 2018 Forecasting Workshop, June 19-21, 2018,...
EPIC Solar Forecasting Task 3 Final Report: Grid-Connected and Embedded PV Fleet Forecasting Accuracy
This report, prepared with an Electric Program Investment Charge (EPIC) fund, describes new methods for improving production forecasts of behind-the-meter and grid-connected PV systems by incorporating real-world effects of PV module age and soiling. The report also...
EPIC Solar Forecasting Task 2 Final Report: Data Forecasting Accuracy
This report, prepared with an Electric Program Investment Charge (EPIC) fund, describes the results of research to determine whether real-time data could be used to supplement forecasts generated using PV system hardware specifications and forecasted...
Advancing the Science of Behind-the-Meter PV Forecasting
This presentation discusses how probabilistic forecasting enables electric utilities and grid operators to reduce their operational costs by risk adjusting expected solar production. This presentation was given at the 2018 EPIC Symposium on February 7, 2018. Download...
Integration of Behind-the-Meter PV Fleet Forecasts into Utility Grid System Operations
This paper describes a study, funded by the U.S. Department of Energy, to evaluate new, state-of-the-art solar irradiance forecasting models, and integrate behind-the-meter PV forecasts into the California Independent System Operator's (ISO) load forecasts. This work...
CSI RD&D Solicitation 3 Final Webinar: Integrating PV into Utility Planning and Operation Tools
Clean Power Research received a California Solar Initiative (CSI) Research, Development, Demonstration and Deployment Program (RD&D) Solicitation 3 grant for a project titled, “Integrating PV into Utility Planning and Operation Tools.” This webinar presentation...
Behind-the-Meter PV Fleet Forecasting: Results for 130,000 PV Systems in California
Lean how SolarAnywhere® FleetView® is being integrated into CAISO planning and operations tools to provide power output forecasts of the more than 130,000 PV systems within the CAISO territory. Presented at the SEPA Utility Solar Conference, held April 16-17, 2013 in...
Integrating PV into Utility Planning and Operation Tools
Clean Power Research received a California Solar Initiative (CSI) Research, Development, Demonstration and Deployment Program (RD&D) Solicitation 3 grant for a project titled, “Integrating PV into Utility Planning and Operation Tools.” The report and presentation...
Forecasting Output for 130,000 PV Systems in California
Lean how SolarAnywhere® FleetView® is being integrated into CAISO planning and operations tools to provide power output forecasts of the more than 130,000 PV systems within the CAISO territory. The presentation was given at the Utility Wind Integration Group’s...
Behind-the-Meter PV Fleet Forecasting
Learn how SolarAnywhere® FleetView® can be used for behind-the-meter PV fleet forecasting. Presented at the Utility Wind Integration Group (UVIG) Fall Technical Workshop, held Oct. 23-25, 2012 in Omaha, Nebraska. Download PDF >>>
Solar Monitoring, Forecasting and Variability Assessment at SMUD
This paper summarizes the deployment of a 71 station solar monitoring network in Sacramento, Calif., and its use in validating solar forecasts and solar resource variability for high penetrations of solar on the Sacramento Municipal Utility District (SMUD) grid. The...
Photovoltaic (PV) Solar Energy Output Variability Methodologies
These papers present methodologies for cost-effectively predicting the solar power output variability of high-penetration PV fleets.
Spatial and Temporal Variability of Solar Energy
This paper summarizes and analyzes recent research by the authors and others to understand, characterize, and model solar resource variability. This research shows that understanding solar energy variability requires a definition of the temporal and spatial context...
CSI RD&D Solicitation 1 Final Webinar: Advanced Modeling and Verification for High Penetration PV
In April 2010, Clean Power Research received a California Solar Initiative (CSI) Research, Development, Demonstration and Deployment Program (RD&D) Solicitation 1 grant for a project titled, “Advanced Modeling and Verification for High Penetration PV.” The project...
Determining Storage Reserves for Regulating Solar Variability
This paper describes the initial validation of a method of quantifying PV variability by using satellite-derived solar data. The validation was performed using a network of high-speed solar irradiance data loggers in and around Napa, California. Download PDF...
Modeling PV Fleet Output Variability
This paper introduces a novel approach to estimating the maximum short‐term output variability that an arbitrary fleet of PV systems places on any considered power grid. A clear understanding of variability will make it possible for utilities and control system...
Short-term Irradiance Variability: Station Pair Correlation as a Function of Distance
This article focuses on station pairs, and investigates the correlation of their short-term variability as a function of their distance. Download PDF >>>
PV Power Output Variability: Calculation of Correlation Coefficients Using Satellite Insolation Data
This paper describes analytical methods and tools to quantify PV fleet output variability that can be used by utility planners and operators to analyze how short-term PV system output changes may affect utility system stability. This paper analyzes the correlation...
Parameterization of Site-specific Short-term Irradiance Variability
This article presents a set of empirical models capable of extracting metrics quantifying the short‐term variability of solar resources based upon site/time specific satellite‐derived hourly irradiance data. Download PDF >>>
PV Power Output Variability: Correlation Coefficients
This paper introduces a novel approach to estimate the maximum short‐term output variability that a fleet of PV systems places on any considered power grid. Download PDF >>>
Evaluating PV Fleet Output Variability
This presentation describes methods for evaluating the power output variability of PV fleets, and how that information is useful for utilities in the planning and operation of distributed PV. The research was presented at PowerGen International in Dec. 2009. Download...
Quantifying PV Power Output Variability
This paper presents a new approach to rigorously quantify power output variability from a fleet of PV systems, ranging from a single central station to a set of distributed PV systems. Download PDF >>>
Blog
New SolarAnywhere® monitoring API (beta) joins across-the-board API performance enhancements
Clean Power Research® is excited to announce the public beta release of our new SolarAnywhere monitoring API, designed to provide you with scalable, seamless and efficient access to real-time data. This new, synchronous API supports fast and reliable data retrieval to...
Unlock the power of real-time solar data: New SolarAnywhere® dashboard
Clean Power Research® is excited to unlock the power of real-time solar data for more users with the launch of the SolarAnywhere® SystemCheck® Monitoring Dashboard. Users can now access and visualize SystemCheck real-time irradiance data directly from a user...
Enhancing precision with new SolarAnywhere® sub-hourly TMY data
Clean Power Research® is thrilled to announce the launch of SolarAnywhere® Sub-Hourly Typical Meteorological Year (TMY) irradiance and weather data! This feature provides SolarAnywhere customers with sub-hourly data, enhancing the precision of solar resource...
Reduce solar power forecast uncertainty with SolarAnywhere® Forecast
Solar forecasting solutions for the diverse needs of the solar power industry and utilities. SolarAnywhere Forecast is the solar industry’s leading irradiance forecast paired with trusted PV simulation.