Power and renewables

Solar energy assessment validation

Is it time for PPA 2.0? Why we need to future-proof energy funding

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Rounak Kharait

Rounak Kharait

Director, Solar Energy Assessments

DNV’s approach to improving the accuracy of our solar energy assessments

Solar projects of all sizes have generally produced less than their long-term energy forecasts. Numerous studies* have demonstrated that project underperformance is an industry-wide problem, including one that shows nearly half of project years are not hitting their 1-year P90 and P50 gaps of >7%. Unfortunately, DNV’s own solar energy assessments are not immune to this problem. In 2019, DNV published a white paper illustrating a 3.1% shortfall in our own energy assessments. What will DNV do about it?

Energy assessment validation - image

The following will go through the road map on our approach to how we are addressing this industry-wide problem. With over 150 years as a trusted independent advisory, DNV is uniquely positioned to lead the industry to more accurate energy assessments and provides the largest solar validation in the industry. Our team of leading experts have virtually eliminated the energy assessment gap in the wind industry and will bring this expertise to solar.

Over the remainder of 2021, DNV will be opining on our current hypotheses in bridging the gap:

  1. Sub-hourly clipping loss
  2. Terrain adjustment
  3. Wind stow

Join us on the journey! Throughout the year, we will present and discuss the latest methodology refinements.

Contact us:

Rounak Kharait

Rounak Kharait

Director, Solar Energy Assessments

Download the 2019 Energy Assessment Validation Study

2019 Energy Assessment Validation Study

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Agenda

Hear from DNV on energy assessment validation

Part 1 

2021 Activities

 

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Session

Energy Assessment Validation - The Ins and Outs of Degradation

During this webinar, our panel of experts discussed the best data and strategies to implement to facilitate data-driven decisions. This session focused on applying a statistical approach to estimate the impact of degradation and degradation uncertainty on the project downside stress cases.

Speaker

Rounak Kharait

Director - Solar Energy Assessments, DNV

Jeff Newmiller

Principal Engineer - Solar EA, DNV

Jon Previtali

Director - Technology and Technical Services, Wells Fargo

Henry Hieslmair

Principal Engineer - Solar Technology, DNV

MinWah Leung

Senior Engineer - Solar Technology, DNV

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Session

Maximum Likelihood Estimation Approach for Determining Most Representative Solar Resource Dataset for U.S.

Presentation at the 48th IEEE Photovoltaic Specialists Virtual Conference

Speaker

Rounak Kharait

Director - Solar Energy Assessments, DNV

Jeff Newmiller

Principal Engineer - Solar EA, DNV

Cegeon Chan

Head of Department - Energy Analytics, DNV

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Session

Tracker Terrain Loss Part II

Presentation at the 48th IEEE Photovoltaic Specialists Virtual Conference

Speaker

Mark Mikofski

SolarFarmer Modeling Specialist, DNV

Mike Hamer

Senior Developer - Software Development, DNV

Anja Neubert

Senior Engineer - Software, Tools & Products, DNV

MinWah Leung

Senior Engineer - Solar Technology, DNV

Abhishek Parikh

Energy Analyst - Solar, DNV

Rounak Kharait

Director - Solar Energy Assessments, DNV

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Session

Comparison of Predicted PV System Performance with Surfrad vs. TMY

Presentation at the 48th IEEE Photovoltaic Specialists Virtual Conference

Speaker

Mark Mikofski

SolarFarmer Modeling Specialist, DNV

Rounak Kharait

Director - Solar Energy Assessments, DNV

View the presentation

Session

Validation of Subhourly Clipping Loss Errorcorrections

Presentation at the 48th IEEE Photovoltaic Specialists Virtual Conference

Speaker

Abhishek Parikh

Energy Analyst - Solar, DNV

Kirsten Perry

Kevin Anderson

William Hobbs

Rounak Kharait

Director - Solar Energy Assessments, DNV

Mark Mikofski

SolarFarmer Modeling Specialist, DNV

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Session

Mind the gap - Addressing solar energy production shortfalls

In the solar industry, there is a growing awareness that pre-construction energy assessments in recent years have overstated the expected production from projects in comparison to actual production. The underperformance of these projects represents a risk to the long-term health of the industry, as project stakeholders fail to achieve the expected return on investment. Through the course of our efforts to validate our modeling tools and methodologies, we have identified the key drivers for such underperformance and how to address this. During this session, our leading experts will provide insights into:  

  • Key drivers of underperformance, including: sub-hourly inverter clipping losses, wind stow losses and the losses due to complex terrain
  • Techniques to ensure these factors are modeled to yield the most accurate energy assessment possible
  • The impacts on project finance transactions

Speaker

Cegeon Chan

Vice President, Energy Analytics and Measurements - DNV

Chris Frantz

Managing Director, Operations - Excelsior Energy Capital

Rounak Kharait

Director, Solar Energy Assessments - DNV

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Session

Mind the Gap: Validating and Advancing the State-of-the-Art for Solar Energy Assessments

Webinar with SEIA 

There is increasing awareness in the solar industry that energy assessments in recent years have, on average, overstated expected production from solar projects on a preconstruction basis. Accurate and certain energy assessments give confidence to stakeholders in projected production and return on investment for solar projects, ultimately leading to lower cost of capital and increased competitiveness for solar. DNV therefore considers it essential for Independent Engineers to conduct rigorous, transparent validation and advancement of their methodologies.   In this webinar, DNV will provide insight into its own solar energy assessment validation process and resulting methodology refinements, including:

  • Empirical observations on actual solar project performance vs. expectations;
  • Causes for energy production shortfalls;
  • History, process, and current results of DNV’s validation efforts;
  • Our leading-edge techniques for addressing losses due to sub-hourly inverter clipping, wind stow, and complex terrain; and
  • Approach and timeline for completion of DNV’s current validation cycle, implementation of methodology refinements, and next steps.
Accurate and certain energy assessments are essential to a thriving and sustainable solar industry. Come learn how DNV is validating and advancing its methodology to lead the way!

Solar Measurements and its impact of long-term Weather Selection

The use of on-site meteorological data to create “tuned” satellite weather files for solar energy assessments has become more common as projects have ballooned in capacity. On-site data intuitively provides confidence in the local irradiance. But does that confidence hold up to rigorous statistical evaluation? In this webinar, DNV’s experts will discuss methodology to leverage on-site measurements for the most accurate weather file selection while reducing overall uncertainty in the energy assessment process, covering:

  • The hidden pitfalls of defaulting to on-site measurements as the single source of truth for irradiance.
  • Advanced statistical methods for minimizing overall uncertainty by using multiple available weather files.
  • The value of on-site measurements when utilized appropriately to minimize uncertainty and boost project economics.

Resources you may be interested in

Solar Energy Assessment

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Solar Risk Assessment 2020

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Solar Leadership Webinar Series

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More Than The Sun: A Solar Report Series

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