SolarAnywhere® Research

Insight into the state-of-the-art methods of SolarAnywhere technologies
Clean 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...

Detecting Calibration Drift at Ground Truth Stations: A Demonstration of Satellite Irradiance Models’ Accuracy
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...

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...

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 >>>

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 >>>

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.
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...

Experience in California with Behind-the-Meter PV Forecasts

SolarAnywhere® FleetView® is generating behind-the-meter PV forecasts in California, enabling utilities and ISOs to better integrate distributed solar. This presentation was given at the Utility Wind Integration Group’s 2014 Forecasting Workshop, held February 26,...

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...

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.
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...

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...

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 >>>

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