Research Timeline

Research Timeline

A chronological listing of more than two decades of Clean Power Research published research.

2022

Impact of PV/Wind Forecast Accuracy and National Transmission Grid Reinforcement on the Italian Electric System

The high share of PV energy requires greater system flexibility to address the increased demand/supply imbalance...

IRENA SolarCity

This project combines ultra-high-resolution (0.5 meter or 1 meter) Digital Elevation Model (DEM) data and 3D vector...

IEA Task 16-3.5 Report: Firm Power Generation

Grid-connected solar power generation, either dispersed or centralized, has developed and grown at the margin of a...

Inferring PV system specifications from net loads and reconstructing gross loads

The US Energy Information Administration (EIA) estimates that residential PV systems accounted for 61 percent of total...

Inferring PV system specifications from net load

The increasing penetration of grid-connected solar photovoltaics has challenged the existing method of planning and...

Firm PV Power generation for Switzerland

We investigate whether photovoltaics (PV) can effectively and economically contribute to a massively renewable energy...

Firm PV Power Generation in Switzerland

We investigate whether PV can effectively and economically contribute to a massively renewable energy (RE) power...

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...

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...

Update 2022 – A Fundamental Look at Supply Side Energy Reserves for the Planet

Energy on our planet is central to the functioning of our ecosystem and modern human society. This work attempts to...

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...

2021

IMPLICIT STORAGE – Optimally Achieving Lowest-Cost 100% Renewable Power generation

Implicit storage – aka overbuilt and operationally curtailed variable renewable energy (RE) resources – is a...

Quantifying the Solar Impacts of Wildfire Smoke in Western North America

2020 was the most active wildfire season in recent history. This study leverages solar models to quantify the solar...

Least-Cost Firm PV Power Generation: Dynamic Curtailment vs. Inverter-Limited Curtailment

Overbuilding and dynamic curtailment are increasingly acknowledged as central to cost-optimally transforming...

Residual Load Imbalance Mitigation Strategy via Flexible PV Ancillary Services: The Italian Case Study

Large share of solar energy imposes a higher system flexibility to resolve the increased demand/supply imbalance due...

Ultra-High Photovoltaic Penetration: Where to Deploy

While it is widely known that the solar resource is sufficient to meet the world’s energy demand many times over, the...

Making the Cut with a Carbon Elimination Price: The Missing Piece to Bill Gates’ How to Avoid a Climate Disaster Book

In the book How to Avoid a Climate Disaster, Bill Gates begins to address the issue of how much it will cost to...

Italian Protocol for Massive Solar Integration: From Solar Imbalance Regulation to Firm 24/365 Solar Generation

This article describes a progressive strategy to achieve 100% penetration of intermittent renewables at minimal cost....

2020

Observed Recent Trends in the Solar Resource across North America: Changing Cloud-cover, AOD and the Implications for PV Yield

In years recent to 2020, low solar-resource in the Eastern U.S. was observed in the SolarAnywhere® dataset. This paper...

From Firm Solar Power Forecasts to Firm Solar Power Generation an Effective Path to Ultra-High Renewable Penetration a New York Case Study

We introduce firm solar forecasts as a strategy to operate optimally overbuilt solar power plants in conjunction with...

The Value of PV Power Forecast and the Paradox of the “Single Pricing” Scheme: The Italian Case Study

One of the major problem of photovoltaic grid integration is limiting the solar-induced imbalances since these can...

Verification of Deterministic Solar Forecasts

The field of energy forecasting has attracted many researchers from different fields (e.g., meteorology, data...

Italian Protocol for Massive Solar Integration: Imbalance Mitigation Strategies

This article proposes two strategies for the mitigation of power imbalances and related costs resulting from...

2019

Perfect Operational Solar Forecasts: A Scalable Strategy toward Firm Power Generation

We present the perfect forecast concept as both an effective forecast validation metric and an operational strategy to...

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...

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...

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...

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...

Advancing the Science of Behind-the-Meter PV Forecasting

This presentation discusses how probabilistic forecasting enables electric utilities and grid operators to reduce...

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...

Solar+ Homes: If an Integrated Approach Works in a Retrofit Application, New Homes Will Be Even Better

This presentation demonstrates the effectiveness of an integrated approach to electrification of existing and new...

Value of Solar+Storage in Guam

This report presents the results of a distributed-solar valuation performed for the island of Guam. The study used...

Montana Solar Market Assessment

As part of the U.S. Department of Energy’s SunShot Initiative, the Montana Energy Office (MEO) of the Montana...

A Radical Idea to Get a High-Renewable Electric Grid: Build Way More Solar and Wind Than Needed

The famous inventor Edwin Land said, “It’s not that we need new ideas, but we need to stop having old ideas.” He...

Can We Gauge Forecasts Using Satellite-Derived Solar Irradiance?

Satellite-derived irradiance data, as an alternative to ground-based measurements, offer a unique opportunity to...

Overbuilding & Curtailment: The Cost-Effective Enablers of Firm PV Generation

Current thinking considers that PV output curtailment is a last resort measure to be avoided. In this article, we...

2016

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...

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...

2015

Maine Distributed Solar Valuation Study

In support of the Maine Public Utilities Commission's work in 2014-15 to determine the value of distributed solar...

Valuation of Solar + Storage in Hawaii: Methodology

Clean Power Research was engaged by the Interstate Renewable Energy Council, Inc. (IREC) to develop a methodology that...

2014 Value of Solar at Austin Energy

This report and presentation summarizes a Value of Solar® study conducted for Austin Energy in the fall of 2013....

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...

Behind-the-Meter PV Fleet Forecasting

Grid-connected PV in the U.S. has grown substantially over the past several years and grid operators are increasingly...

The Value of Distributed Solar Electric Generation to San Antonio

This Value of Solar® study was prepared for Solar San Antonio under a Department of Energy SunShot Initiative grant....

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...

Integrating PV into Utility Planning and Operation Tools

This presentation describes how SolarAnywhere® FleetView™ is being used to cost-effectively forecast power output of...

Net Metering: Quantifying Benefits and Sharing Costs

This presentation covers two methods of valuing solar that are currently being considered as alternatives to net...

The Value of Distributed Solar Electric Generation to New Jersey and Pennsylvania

This Value of Solar® study was prepared for the Mid-Atlantic Solar Energy Industries Association (MSEIA) and the...

Behind-the-Meter PV Fleet Forecasting

Learn how SolarAnywhere® FleetView™ can be used for behind-the-meter PV fleet forecasting. Presented at the Utility...

Photovoltaic Incentive Design Handbook

This handbook will help agencies and utilities select, design, and implement incentive programs that best meet...

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...

Reporting of Irradiance Model Relative Errors

Metrics used in assessing irradiance model accuracy such as Root Mean Square Error (RMSE) and Mean Absolute Error...

Predicting Short-term Variability of High Penetration PV

This article evaluates the ability of three operational satellite models (SolarAnywhere® Standard, Enhanced, and High...

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...

Solar Power Generation in the US: Too Expensive or a Bargain?

This article identifies the combined value that solar electric power plants deliver to utilities’ rate payers and...

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...

2011

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...

Modeling PV Fleet Output Variability

This paper introduces a novel approach to estimating the maximum short‐term output variability that an arbitrary fleet...

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...

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...

2010

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...

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...

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...

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...

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...

Weather Adjusted Performance Guarantees

This paper describes how to generate more accurate Weather-Adjusted Performance Guarantees for PV systems using a...

Market Transformation Benefits of a PV Incentive Program

Real-life example of the economics of implementing a PV incentive program Download PDF >>>

Quantifying the Cost of High Photovoltaic Penetration

Calculating the cost of energy storage to provide firm capacity on a power grid with high PV penetration. Download PDF...

The CA Net Energy Metering Report: Approach, Results & Implications

The steps required to compute the costs and benefits of electric rates that use net energy metering. Download PDF...

2009

Evaluating PV Fleet Output Variability

This presentation describes methods for evaluating the power output variability of PV fleets, and how that information...

Quantifying PV Power Output Variability

This paper presents a new approach to rigorously quantify power output variability from a fleet of PV systems, ranging...

2008

Solar Sustained Vehicles: A Consumer’s Solution to Protection in an Age of Oil Dependence, Economic Uncertainty, & Global Warming

A consumer’s view of the fuel saving benefits of Solar Sustained Vehicles. 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...

Expected Performance Based Buydown (EPBB) Incentive Structure: Rationale & Implications

Rationale for using an up-front incentive payment structure Download PDF >>>

Incentive Structure Alternatives

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The Value of Distributed Photovoltaics to Austin Energy & the City of Austin

Quantifies the comprehensive value of distributed PV to Austin Energy. Download PDF >>>

Maximizing the Value of Customer-Sited PV Systems Using Storage & Controls

Enhancing the load management and outage protection attributes of PV to increase the value of customer-sited PV...

Economic Benefits of Performance-Based Incentives

Compares the economic consequences of performance-based and buy-down PV incentives Download PDF >>>

Quick Review of Basic Economics

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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...

Are Photovoltaic Systems Worth More to Residential Consumers on Net Metered Time-of-Use Rates?

Examination of the value of PV to residential customers under Time-of-Use rates. Download PDF >>>

Distributed Photovoltaics in New Jersey

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A Simple Method for Consumers to Address Uncertainty When Purchasing Photovoltaics

Should consumers invest in PV now, or wait? Download PDF >>>

Maximizing PV peak shaving with solar load control: validation of a web-based economic evaluation tool

Calculating the value of solar load control for commercial applications using Clean Power Estimator. 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...

Estimator Documentation

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1999

Clean Distributed Resources in the U.S. Residential Market

Examines how PV combined with energy efficiency and cogeneration fuel cells can satisfy the energy needs of the U.S....

Keep the Door Open for Micro-Grids

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A Micro-Grid with PV, Fuel Cells and Energy Efficiency

This article provides an evaluation of the economic potential of a micro-grid composed of PV, fuel cells and energy...

1997

Distributed Generation & Micro-Grids

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Credit Ratings & Photovoltaic Investments

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Integrating Renewable Energy Technologies in the Electric Supply Industry: A Risk Management Approach

Identifies the renewable energy technology risks to utilities, and how to mitigate those risks Download PDF...

Managing Risk Using Renewable Energy Technologies

Explains how owning renewable energy technologies can mitigate risk faced by the electric utility industry Download...

Blog

2024 Solar Risk Assessment report: Data-driven insights address emerging risks
2024 Solar Risk Assessment report: Data-driven insights address emerging risks

This sixth annual Solar Risk Assessment (SRA) report is now available, offering deep insights into extreme weather and operational risk, and for the first time, battery energy storage system (BESS) risk. The report is published by kWh Analytics and features articles from more than a dozen industry leaders. This year’s report includes strategies for addressing […]

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