Technology Forecasting Offers A Window Into PV Technology Trends


It can be argued that understanding trends in the efficiency of photovoltaic cells is instrumental to understanding the future economics of solar energy. While unequivocally true, this view often carries the implication that one can do little more than track such developments after the fact.

Most people have heard of Moore's Law, which describes the exponential growth in computing power over time, but few know that Moore's Law is merely a singular application of a broad class of growth models that apply to technological advancement in general.

Is there a Moore's Law for energy in general and PV in particular? There is. The problem is there are many laws because there are many technologies vying for a place at the bar.
The first order of business is to adequately define the technologies of interest – think silicon versus cadmium-telluride versus copper indium gallium diselenide versus organic PV verses etc. Then, you need to select the appropriate metrics that will enable you to assess the expected performance of these technologies over time.

Few people are equipped to do both. Fewer still know how to apply such models to the vast quantity of technology trend data that has become available in PV, wind energy, energy storage and a host of technologies of interest to energy planners, utilities, developers, manufacturers, researchers, research and development managers, strategic planners, venture capitalists and investors in emerging technologies.

The specialized field of technological forecasting – which is an important input to strategic technology planning and technology intelligence – is devoted to studying the dynamics of technological advancement. Its practitioners have honed practical, analytical approaches for assessing the likely trajectories of specific technologies.

Technological forecasting consists of numerous extrapolative and normative techniques for predicting the direction and rate of technological advancement in a given field and also for assessing emerging technologies. Importantly, these approaches are perfectly appropriate for analyzing advances in renewable and alternative energy technologies, and the growth in PV cell efficiencies offers an ideal application.

Particular varieties of silicon and thin-film dominate the landscape now, but for how long? The history of technological advances is replete with competing technologies vying for dominance in the marketplace, and the current energy arena is no different. For example, perovskites have recently garnered much attention in the press and appear to be on a steep upward trajectory. How do we assess their potential in comparison, not to where the incumbents are today, but to where they will be in the future?
But, there is more to it than simply turning such technology assessments into a data-dredging exercise. It is common to consult with individual experts, but, unfortunately, their biases often limit – albeit unintentionally – their ability to provide an objective picture of technological advancement in a given field. More worrisome, perhaps, would be relying on overpriced reports from the big market research houses whose generally optimistic growth projections are typically unsubstantiated.

Fortunately, more rigorous approaches for aggregating the diverse opinions and experiences of multiple experts are available to help arrive at a more complete picture of future advances in technologies of interest. Combining these qualitative approaches with the aforementioned trend analyses can equip technology planners with a fairly robust suite of methods to analyze emerging technologies and plan technology investments.

It is incumbent on those who are making and managing investments in new technology, as well as those who are at the heart of contributing to such innovations, to have at least some understanding of the dynamics of technological advancement to help guide their decision-making. The tools to achieve this are available. It is not so much that a given forecast must be proved accurate, but it is the learning gained from engaging in the exercise that enables better decision-making.

In order to perform a useful technology forecast, consider the following guidelines:

  1. Determine the technological performance parameters that can help you describe technological advancement. For PV, cell efficiencies are a good place to start but there are others. The corollaries for wind energy would be rotor diameter, hub height and turbine nameplate capacities. Just keep in mind that sales growth is NOT a technological performance parameter.
  2. Obtain trend data on the metrics of interest, but be careful not to mix different technologies. For example, if looking at trends in the speed of aircraft, do not mix propeller-driven aircraft with jet aircraft, as they are fundamentally different technologies and this will only make a mess of your analysis. Be careful not to mix polysilicon with monosilicon installations.
  3. Understand where you are on the s-curve of the technology you are researching. There is always some physical limitation to the performance of every technology. Are you close to it? Know how and when to apply the proper growth models (Gompertz, Pearl-Reed, Fisher-Pry, etc.) to complete your analysis.
  4. If looking at the substitution of an emerging technology for an incumbent one, consider that such substitutions often take longer than expected – in spite of what you may read in the press about paradigms shifting. When transitioning from an old technology to a new technology, at what point will the capability of the new technology surpass that of the old one? Must it do so? It is not uncommon for such pressure to motivate improvements in the incumbent technology.
  5. The use of such analyses in planning your technology strategy is only a starting point. You have to work to understand what the data is telling you.

Most importantly, understand that trend is not destiny.

On Nov. 13-14, Technology/Engineering Management International in Golden, Colo., is holding a two-day workshop on renewable and alternative energy technologies and methods for characterizing and forecasting technological advancement. For information on the workshop, click here.

Richard P. Mignogna is principal consultant with Renewable & Alternative Energy Management LLC, a Golden, Colo.-based consultancy specializing in renewable energy technology and policy. Mignogna has served on the staff of the Colorado Public Utilities Commission and is a lecturer in the global energy management graduate program at the University of Colorado at Denver. Reach him by email at

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