Tag Archives: Solar energy


In my last year of college I started working in solar energy research, processing large amounts of data of global, diffuse and direct solar radiation. The processing of this information was very difficult, considering that a year of measurements means more than 500,000 data measured every minute. For each data had to calculate the position of the sun and do quality control of measurements, it was impossible to do it in Excel due to long processing times and freezes. It was then that I began to process information with Fortran, everything was much faster, did not fall and was able to process lots of information quickly. The problem was that was not possible to generate graphics and that was critical for me.

This is how I reach DISLIN, a library to generate incredible graphics from Fortran, very easy to use and export to all formats. With the time I even use Dislin to generate Graphics Users Interface (GUI) for Fortran software.

Below are images with more than 200,000 points that was realized in a couple of seconds with Fortran and DISLIN.

Rotating Shadowband Radionometer (RSR)

Rotating Shadowband Radionometer (RSR) are a cheap and precise way to measure the solar energy resource (global, diffuse and direct radiation) with a silicon photodiode radiometer and a shadow band.

This system was developed by Dr. Edward Kern, MIT professor who I personally met few years ago, who founded in 2003 Irradiance, Inc. the company which manufacture the Rotating Shadowband Radionometers (RSR2).

Rotating Shadowband Radionometer (RSR2)

Rotating Shadowband Radionometer (RSR2),Image from Irradiance

The Irradiance RSR2 head unit uses a rotating curved band and a single, fast-response, photodiode sensor to measure global and diffuse sunlight. Direct sunlight is calculated by Irradiance’s computer program onboard the Campbell Scientific data logger. It includes a head unit, motor controller, temperature/relative humidity sensor, data logger, PV/battery power supply, cellular modem for remote data access, and stable, light-weight tripod. Continue reading