Definitive Solar Institute

A community for solar development professionals.

The Definitive Solar Institute - Advancing the Solar Profession

Members of the Definitive Solar Institute seek to learn:

  • How do you develop solar projects with long-term financial success?
  • What are the best solar technology products in the market - today and tomorrow?

If you are searching for these answers - whether from the perspective of technology, finance, or policy, then you should subscribe to our FREE email list to receive updates from the Definitive Solar Institute here:

About the Definitive Solar Institute

Our online reference center and resource guide is for solar development and installation professionals who make system component design recommendations and purchasing decisions in the commercial and utility scale market.

  • PSI Ratings - Unbiased Ratings for Solar PV modules
  • Webinars - Browse our list of online events for solar professionals
  • Resource Guide - Find organizations in the solar industry, and compare products by category
  • Whitepapers - Download whitepapers from industry experts


  • Bi-Partisan Support Driving Solar Energy Development By: Michael Gorton, Chief Executive Officer / Chairman, Principal Solar; Mark Victor Hansen, Founder and Co-creator, Chicken Soup for the Soul; and Laura Carabello, Founder and Principal, CPR Strategic Marketing Communications

    Over the last two decades, photovoltaic (PV) solar energy has experienced one of the most remarkable growth curves in the U.S. technology sector. Over this period the cost of solar generation has decreased dramatically, and the amount installed has increased exponentially. Many have tied this success to public incentives and subsides. In the U.S., Democrats have supported development and growth while Republicans have generally ignored or even opposed the entrée of PV. Some believe that once supporting policies end, the demise of the solar industry will follow. The observed trends do not support this belief. This whitepaper is focused o... More »

    Bi-Partisan Support Driving Solar Energy...
  • The Road To Change: Electric Vehicles Power the Future for Everyone By: Mark Victor Hansen, Founder and Co-creator, Chicken Soup for the Soul and Michael Gorton, Chief Executive Officer / Chairman, Principal Solar

    The EV industry is on the precipice of a significant growth spurt. New battery technologies coupled with innovations in the electric motor will drive this growth from inside the EV sector. Pressure from environmental groups, along with pricing, supply and demand of petroleum, will drive that growth from the traditional vehicle sector. The EV will prevail because it is already more efficient, cleaner and more durable than traditional transportation. Most importantly, within the next five years, the EV will likely reach a point where it is cheaper than the internal combustion engine. EVs operate for one-quarter the cost of gasoline cars, especi... More »

    The Road To Change: Electric Vehicles Po...
  • Investing in the Power of the Sun - The Capitalist Case for Solar Energy By: Michael Gorton, Chief Executive Officer / Chairman, Principal Solar and Dan Bedell, Executive Vice President - Marketing & Corporate Development, Principal Solar

    This paper examines the recent past and potential future of photovoltaic (PV) solar in terms of how it has compared with traditional generation and how, even without government subsidies, solar utility scale projects will reach a price per KWh that will be at - or less than - traditional generation, possibly as soon as 2014. Now is the time for traditional conservative thinking to re-examine the facts about solar energy and explore its potential for not only delivering more efficient and less costly power, but also for creating jobs and opportunities that jump-start economic growth. This jump-start would be possible because electricity drives... More »

    Investing in the Power of the Sun - The...
  • Solar Industry Goes Mainstream: Revolutionary PV Module Rating System Empowers Solar Professionals By: Ken Allen, COO, Principal Solar; Rick Borry, CTO, Principal Solar; Dan Bedell, Executive Vice President - Marketing & Corporate Development, Principal Solar; Kirk Blankenship, Institute Development, Principal Solar Institute; and Matthew Thompson, Executive Director, Principal Solar Institute

    The Principal Solar Institute (PSI) has launched the PSI PV Module Rating, the industry's first and only comprehensive, independent rating standard for comparing PV modules. The rating method is constructed without bias: PSI has no affiliation with any PV module manufacturer and no interest in promoting one over another. The ratings are designed to allow large-scale solar consumers to make informed, intelligent comparisons and decisions when selecting PV modules. The PSI PV Module Rating is a comparative number that can be used with pricing information to provide power plant designers, buyers and financiers with a consistent basis for choosin... More »

    Solar Industry Goes Mainstream: Revoluti...
  • Next Generation Vehicles: Addressing Air Quality, Fuel and Efficiency By: Margaret Keliher, Board of Directors, Principal Solar and Michael Gorton, Chief Executive Officer / Chairman, Principal Solar

    One hundred years ago, the automobile began showing up on the streets of our country. Many experts at the time opined that it was nothing more than a novelty. The horse, after all, had been the primary transportation source for thousands of years. Now, the car is mainstream and everything else is novelty - not to be taken seriously. The problem is that the internal combustion engine has not changed significantly since its introduction. It has been a great resource, yet it also has its weaknesses. The number one man-made contributor to dirty air is the automobile. Couple that with rising gas prices and national security issues associated with... More »

    Next Generation Vehicles: Addressing Air...
  • Feed-In Tariffs: The Proven Road Not Taken... Why Not? By: Peter Lynch, CEO, Salem Financial, Inc.

    Feed-in tariffs (FIT) are a policy mechanism designed to accelerate investment in renewable energy technologies. Producers of renewable energy are paid a set rate for the electricity they produce, usually differentiated according to the technology used (wind, solar, biomass, et.al.) and the size of the installation. Over the past decade, the FIT is credited for the rapid deployment of wind and solar power among world renewable energy leaders Denmark, Germany and Spain. This paper will examine the FIT within the context of real-world experiences, and make a case that the U.S. needs a nationwide FIT to kick-start the renewable energy industry,... More »

    Feed-In Tariffs: The Proven Road Not Tak...
  • Technological Niches: Concentrated Solar Thermal vs. Photovoltaic Solar By: Rick Borry, CTO, Principal Solar and Brett Gage, Research Intern, Principal Solar

    Concentrated solar thermal and photovoltaic solar technologies have evolved independently for decades, and both are approaching "grid-parity" power prices in many applications today. This paper will explore the different situations where each technology succeeds or fails in today's electric power generation marketplace, specifically excluding non-electric applications such as solar hot water heating. As of 2012, PV has come to dominate all smaller-scale solar electricity applications, while retaining the majority market share even in commercial and utility-scale applications. CSP retains a strong niche at the utility-scale and in combined hea... More »

    Technological Niches: Concentrated Solar...
  • Solutions for the Texas Energy Shortage By: Ron Seidel, Principal, RBS Energy Consulting

    In the summer of 2011, Texas experienced extremely low reserve margin periods throughout the state…causing average wholesale electricity prices to skyrocket to more than twice their normal level. Given that Texas is expected to add another 14 million to its population between 2010 and 2030,1 these shortages raise alarms about the state’s ability to meet future energy demand. Success will depend upon finding the most effective way to incent the development of more capacity. Unlike many other states, Texas has had a competitive retail market for electricity since 2001, replacing the traditional cost of a service-based regulated ma... More »

    Solutions for the Texas Energy Shortage
  • Navigating by the Sun: U.S. Department of Defense Takes Aggressive Lead as Early Adopters of Solar Energy By: Brig Gen (ret) Becky Halstead, CEO / Founder, STEADFAST Leadership and Michael Gorton, Chief Executive Officer / Chairman, Principal Solar

    The U.S. Department of Defense (DoD) has a long-standing tradition of accelerating technological innovation, serving as early adopters and impacting the broader commercial market in such areas as aviation, computing and global positioning systems (GPS). For the past several years, the DoD has been playing this same role in the renewable energy space. In fact, The Pew Charitable Trusts reports that the DoD clean energy investments increased 300 percent between 2006 and 2009, from $400 million to $1.2 billion. Projections for 2030 are set to eclipse $10 billion annually,1 with an overall target of obtaining 25 percent of the DoD's energy from r... More »

    Navigating by the Sun: U.S. Department o...
  • Energy Efficiency & Sustainability in Organic Food Supply By: Jim Keyes, Chairman, Key Development LLC; Michael Martin, EVP, Business Development, Principal Solar; and Brett Gage, Research Intern, Principal Solar

    Over the past few decades, the organic food industry has gained increasing attention among various sectors of the population. Consumers and suppliers, alike, have facilitated this growth by appealing to a health and wellness conscience that grew out of the 20th century. With the growth of the organic food industry is a parallel trend of social responsibility showing that consumers across all sectors are not only demanding great products at affordable prices, but also understanding that their products were produced with minimal harm to the environment. Examining the food industry, ONE OF THE BIGGEST QUESTIONS presented to suppliers is how to b... More »

    Energy Efficiency & Sustainability i...
  • Interfacing with the Electrical Grid By: Ken Allen, COO, Principal Solar and Ron Seidel, Principal, RBS Energy Consulting

    "Interfacing with the Electrical Grid" outlines a new generation of power plants that will become increasingly dependent upon solar energy systems as a heat source, and the role federal, regional and state regulatory agencies will play in ensuring that connection, transmission and performance remains stable. More »

    Interfacing with the Electrical Grid
  • Navigating Environmental and Regulatory Issues to Reduce Risk By: Scott Deatherage, Partner, Gardere Wynne Sewell and Michael Gorton, Chief Executive Officer / Chairman, Principal Solar

    Understanding the full breadth of legal, regulatory and environmental issues associated with determining when and where to develop solar projects is critical to reducing risks and avoiding costly delays. "Solar Power Installations: Navigating Environmental Regulatory Issues to Reduce Risk" suggests the research, planning and design warranted to develop both private and public lands that will lead to the timely approval and construction of a project. More »

    Navigating Environmental and Regulatory...
  • Shining Light on Renewable Energy in Developing Countries By: Robert Freling, Executive Director, Solar Electric Light Fund and David Ramsour, Ph.D., Private Consultant, Researcher and Economist

    Many of the poorest countries in the world have the highest exposure to the sun. "Shining Light on Renewable Energy in Developing Countries" explores the opportunities for unprecedented investment in clean, renewable alternative energy systems that have the potential to not only enrich newly industrialized countries, but positively alter the quality of life for populations around the world. More »

    Shining Light on Renewable Energy in Dev...
  • Turning Green into Greener By: Wendell Brown, Inventor, Entrepreneur, Philanthropist and Michael Gorton, Chief Executive Officer / Chairman, Principal Solar

    This paper - which the authors nicknamed "Solar 101" - teaches the fundamentals of Solar energy. It is packed with current information and virtually everything you need to know about industry basics -- simplifying the complex science of solar energy and providing an understanding of grid parity. Discover how energy efficiency investments can provide up to one-half of the needed greenhouses gas emissions reductions most scientists say are needed between now and the year 2050. Such a gain in energy efficiency would mean reduced greenhouse gas emissions and lower energy bills for consumers and businesses alike. Readers will learn how power is pr... More »

    Turning Green into Greener
  • New PV and Natural Gas Electric Capacity - US

    This interesting graph shows the growth of utility-scale solar PV, as compared to natural gas. Download it now to see the details. You should also register for our free live/recoreded webinar: As Coal Dims, Will Solar Shine? Perspective on a Changing Electricity Industry Thursday, August 21, 2014 2:00pm - 3:00pm CDT More »

    New PV and Natural Gas Electric Capacity...
  • New PV compared to new coal plants in USA

    This graph dramatically shows the extinction of coal generation in the US. Solar continues to climb. Hear more about this at a free live/recorded webinar: As Coal Dims, Will Solar Shine? Perspective on a Changing Electricity Industry Feel free to download our analysis and use it in your presentations and discussions. More »

    New PV compared to new coal plants in US...
  • Texas and Germany: Energy Twins?

    There are surprising similarities in the way German and Texas think about their electricity markets. Both are fully deregulated and competitive. Both have large and growing amounts of wind and solar power. Both have economically-efficient “energy-only” markets, where power producers get paid for their energy, not for providing stand-by capacity. And both have questions about market structures and avoiding blackouts. Presented by The University of Texas Energy Institute, Cynthia and George Mitchell Foundation, Heinrich Böll Foundation, and CleanTX. Click the download button for more information and to register for this live ev... More »

    Texas and Germany: Energy Twins?
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Introduction to PSI Ratings
August 31, 2012 10:44pm


U.S. EIA Forecast for Solar
May 25, 2014 9:37am


Webinar Slides: PACE Comes To Texas
September 26, 2013 4:12pm


Solar Calculators
May 1, 2014 9:47pm


2014 SPI Poster
October 20, 2014 8:25am


EIA-860 Instructions
August 19, 2014 1:47pm


EIA-860 Survey Form
August 19, 2014 1:51pm


Webinar Proposal Form
November 18, 2011 11:24am

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