EME 810
Solar Resource Assessment and Economics

8.7 Discussion Activity 8.1


Relations in Time and Space

You have been reading about the relations between time and space, and you have read about different time horizons of interest to the solar energy and electric grid fields. Now, let us apply that knowledge to Table 8.2 from the Chpater by Coimbra, Kleissl, and Marquez (2013).

Table 8.3 Characteristics of Solar Forecasting Techniques and Inputs
(adapted from Table 8.2 of Kleissl, 2013)
Technique Sampling Rate Spatial Resolution Spatial Extent Suitable Forecast Horizon Application
Persistence High 1 point 1 point Minutes Baseline
Sky-Imagery 30 sec 10-100 m 2-5 m radius Tens of minutes Short-term ramps, regulation
GOES Satellite Data 15 min 1000 m U.S.A. 5 hours Load following
NAM weather model 3600 sec 12 km U.S.A. 10 days Unit commitment

Questions to discuss:

  1. Based on the FRYB (Fujita-Rayl-Young-Brownson) relation of 17 m/s and the given "Sampling Rate" for each method (in Table 8.3), what is the characteristic meteorological distance scale being sampled (easy conversion)? How do those distances compare to the "Spatial Resolution" scales provided in the table?

  1. Now take a moment to read up on the Nyquist-Shannon Sampling Theorem, where you will focus on the Nyquist rate. Do all of the systems listed in the table meet the Nyquist sampling rate, and if so, for what minimum resolution?

This discussion will take place in the Lesson 8 Discussion Activity 8.2 Forum in Canvas.

Grading Criteria

Discussions will be graded on the quality of your post and the thoughtful contributions you make to your classmates' posts. Please see the Discussion Expectations and Rubric under Orientation/Resources.


Typically initial posts are due in the middle of the study week (Sunday), and comments and replies are due by the end of the study week (Wednesday). Please see the Canvas calendar for specific due dates.