The Buzz about Solar Forecasting

Installed solar generation capacity is growing worldwide and this movement’s effect on load forecasts is significant. Energy service providers and electricity market operators are striving to understand how solar generation impacts their short- and long-term load forecasts. Itron is at the forefront of developing statistical modeling approaches to address this problem. I’ve written a white paper titled “Forecast Practitioner’s Handbook: Incorporating the Impact of Embedded Solar Generation into a Short-term Load-Forecasting Model” which describes a statistical modeling framework to incorporate the load impact of embedded solar generation.

When we talk about solar generation, we must differentiate utility solar installations, where the electricity generated feeds directly into the grid, from non-utility installations (also referred to as embedded solar generation, i.e., rooftop solar), where generation offsets on-site consumption. Both pose unique forecasting challenges. Utility solar installations impact the measurements of net load, which is defined as load minus utility solar generation. In this case, accurate forecasts of utility solar generation are required to forecast net load. Embedded generation directly impacts measurements of load since this generation occurs behind the meter. As a result, embedded generation impacts how we model load. The joint impact of utility and non-utility solar installations is increased volatility of net load. This, in turn, has added complexity to near-term forecasting of ramping regulation requirements.

There are a number of initiatives underway – the Department of Energy’s Sunshot Initiative being the most active - that focus on utility solar generation forecasting. The primary focus of these initiatives is developing tools that provide accurate utility solar generation forecasts. Further, these initiatives have been applied to the area of forecasting embedded solar generation. Clearly, these initiatives are delivering high value to the industry. Unfortunately, the impact of embedded solar generation on loads and consequently on load forecasting has received little to no attention. The purpose of Dr. Monforte’s white paper is to provide guidance on how to incorporate the impact of embedded solar generation in a load forecast.

As you think about forecasting the impact of embedded solar generation into your forecast, you need to make assumptions about:

(a) solar insolation, which is how much sunlight hits the panels on any given day of the year and time of day,
(b) the average operating efficiency of the solar panel population,
(c) average cloud cover, and if you are generating a long-term forecast,
(d) the growth of the embedded solar generation in your service area.

The white paper breaks these pieces down into manageable tasks and begins with an example that illustrates the impact embedded solar generation can have on existing load forecasting models. This is followed by an overview of the language of solar generation and a presentation of practical steps to develop engineering-based explanatory variables that capture the load impact of embedded solar generation. The modeling constructs presented in the paper can be used in both short- and long-term load forecast models.

My white paper can be downloaded from Itron’s website. Click here to download.

12th Annual Energy Forecasting Meeting

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It’s been a couple weeks since the 12th Annual Energy Forecasting Meeting taking place April 2-3, 2014.

As I reflect on the two days spent discussing energy trends, weather normalization, and forecasting challenges, I realize how quickly memories are pushed into the recesses of my mind in the face of life’s busyness and new challenges. To counteract this effect, I find that recalling meeting highlights keeps the material fresh.

When David Simons walked by my office this morning, I asked him what his meeting highlights were. You’ll remember David as one of our bright young analysts who gave the presentation on quantile regression. He mentioned the following:

  • I enjoyed how Martin Holdrich demonstrated the impact of age groups on the economy. There’s nothing like data to reinforce intuition. This is clearly something we need to consider in the forecasting process.
  • Jeff Johnson’s presentation on long-term weather drivers was a great way to understand weather trends and their uncertainty. Coupled with the other weather normal presentations and the round table discussion, weather normalization is clearly a challenge—especially in the face of this cold winter.
  • I don’t know if anyone views light bulbs like Stuart McMenamin does. But, the price point, payback, and quality of light argue that LEDs are here to stay.
  • I found Abdul Razack’s “thinking outside the box” approach to visualizing data very refreshing. It was great to see the multitude of ways we can depict data to help us seek out and understand relationships among variables.
  • And, who didn’t like, or need, Sunny Grigorova’s demonstration of simple stretches and exercises in the afternoon. That session was a great reminder of the importance of moving our bodies to improve our health and wellness while we’re in the workplace.

Each of David’s observations brought me back to Las Vegas and dredged up vivid pictures from each presentation. While I wish I could summarize each presentation here (they were all so excellent!), I encourage you to take a moment to recall something you learned at the meeting. Share your highlight with the rest of the group by leaving a comment!

12th Annual Energy Forecasting Meeting Approaches

Next week Itron hosts the 12th Annual Energy Forecasting Meeting at the Venetian Hotel in Las Vegas. On April 2-3, 2014, over 50 forecasters from across North America will gather to discuss changes in the energy efficiency, economic drivers, weather normalization practices and forecast model development.

We have a full agenda that includes presentations by the following companies:

  • Alberta Electric System Operator
  • American Electric Power
  • Central Electric Power Cooperative
  • Energy Information Administration
  • Kansas City Power & Light
  • NV Energy
  • Opower
  • Otter Tail Power
  • San Diego Gas & Electric
  • Schneider Electric (formerly DTN)
  • Woods & Poole Economics

In addition, Itron will be presenting on the Weather Normalization and Forecast Outlook survey results, Industrial Intensities, SAE model updates and quantile regression along with conducting two one-day hands on workshops prior to the meeting on Tuesday, April 1.

Be prepared for challenging three days of learning and networking. We look forward to seeing you!

Click here to learn more about this event.

Free Itron Forecasting Brown Bag Seminars

Itron is proud to continue hosting the popular hour-long internet seminars covering a range of forecasting topics. Itron is always at the forefront of the energy forecasting field. We are helping our customers around the world understand the complexities of energy forecasting and talking about the latest forecasting issues and solutions. Take advantage of Itron’s expertise and experience to gain insightful knowledge and help you to improve your forecasts.

Participation is free, but prior registration is required. Each seminar lasts approximately one hour, allowing 45 minutes for the presentation and 15 minutes for questions. Seminars begin at noon Pacific-time, and if you can’t attend a seminar or missed one, don’t worry, your registration ensures that a link to the recording will be sent to you automatically approximately one week after the seminar date.

Our first seminar of the year is next Tuesday, March 25. "The Frontier of Short-term Load Forecasting" seminar presents three areas of research designed to improve forecast accuracy:

  1. Treatment of weather
  2. Model cascade
  3. Inclusion of embedded solar generation

Click here to register for this event.

Remaining 2014 Topics

  • 2013 Weather Normalization Trend Survey
  • 2014 Forecast Accuracy Benchmarking Survey and Energy Trends
  • Using AMI Data to Enhance Daily Tracking Processes

Click here to read more about these topics.


Welcome to Itron’s Forecasting Blog dedicated to energy forecasting related discussions and ideas. For over 30 years, Itron has worked with electric and natural gas clients across North America, Europe and Australia to improve the precision of both short- and long-term forecasting models. With the hours our staff of economists and analysts log on planes, in hotels, and behind computer screens, we’ve had significant time to consider how to solve some of the toughest problems in predicting the future of energy consumption. Our experience and proven results are a true reflection of Itron’s commitment to innovate and keep our fingers on the pulse of the energy industry.

In this blog, we plan to share our reflections on energy industry trends, insights into forecast methods as well as useful tricks in Itron’s forecasting software. The contents of this blog are intended to spark conversation–not a monologue. We invite you to ponder the topics presented and to share your insights as well. Please be considerate and professional when posting.

We hope to hear from you soon.

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