Emboldened with his success in concentrating collectors, Northrup turned his attention to achieving higher temperatures, with azimuth and elevation tracking mirrors "heliostats" focused on a central boiler – ie.
solar thermal power towers.
The most advanced power tower at the time was an experimental tower in France, the Solar furnace at Odeillo, in the Pyrenees Orientales, which like other power towers, had been used solely for scientific purposes.
Northrup attended a conference there in 1973 along with Professor Yellott and Floyd Blake, a former Martin Marietta senior aerospace engineer who had become interested in solar thermal research.

 This interest led to hiring Blake and 16 other ex-aerospace engineers, who set up a research center in Littleton, Colorado, near Denver.
The first Northrup, Inc. azimuth/elevation mirror array was built with Northrup, Inc funds and a grant from the State of Texas.
Designed by Blake’s team, the mirror array, dubbed "Northrup I", was assembled at the Northrup Energy manufacturing plant near Hutchins, Texas.
 It utilized multiple flat mirrors, with a weather-proof backing that became an industry standard.
Each mirror was angled to the anticipated focal length to the central tower.
Each moment of each year, each mirror had to be in a position to split the vectors between the mirror and the sun and the mirror and the target.
This required a large volume of calculations, special computers and gearing mechanisms which Northrup designed.
Team leader, Floyd Blake remembers, "Lynn climbed a ladder in front of the heliostats to take a picture of the sun reflected in them, then went up in a helicopter to be sure the heliostats were pointing correctly."

 Northrup, Inc. was soon an industry leader in pre-commercial and commercial power tower and heliostat installations, securing grants from  NASA Huntsville, Lawrence Livermore National Laboratory,  Sandia National Laboratories, the United States Department of Energy, and the Energy Research and Development Administration.
  Most of the heliostats, including the Northrup II, a commercial model, were developed under contract for the United States Department of Energy.
 The heliostats focused radiation from the sun to generate temperatures up to 2,000 degrees at the target.
 Northrup, Inc. joint-ventured with the Bechtel Corp., which was responsible for designing the heliostat's target, a steam boiler.
Emboldened with his success in concentrating collectors, Northrup turned his attention to achieving higher temperatures, with azimuth and elevation tracking mirrors "heliostats" focused on a central boiler – ie. solar thermal power towers. The most advanced power tower at the time was an experimental tower in France, the Solar furnace at Odeillo, in the Pyrenees Orientales, which like other power towers, had been used solely for scientific purposes. Northrup attended a conference there in 1973 along with Professor Yellott and Floyd Blake, a former Martin Marietta senior aerospace engineer who had become interested in solar thermal research.
 This interest led to hiring Blake and 16 other ex-aerospace engineers, who set up a research center in Littleton, Colorado, near Denver. The first Northrup, Inc. azimuth/elevation mirror array was built with Northrup, Inc funds and a grant from the State of Texas. Designed by Blake’s team, the mirror array, dubbed "Northrup I", was assembled at the Northrup Energy manufacturing plant near Hutchins, Texas.  It utilized multiple flat mirrors, with a weather-proof backing that became an industry standard. Each mirror was angled to the anticipated focal length to the central tower. Each moment of each year, each mirror had to be in a position to split the vectors between the mirror and the sun and the mirror and the target. This required a large volume of calculations, special computers and gearing mechanisms which Northrup designed. Team leader, Floyd Blake remembers, "Lynn climbed a ladder in front of the heliostats to take a picture of the sun reflected in them, then went up in a helicopter to be sure the heliostats were pointing correctly."
 Northrup, Inc. was soon an industry leader in pre-commercial and commercial power tower and heliostat installations, securing grants from  NASA Huntsville, Lawrence Livermore National Laboratory,  Sandia National Laboratories, the United States Department of Energy, and the Energy Research and Development Administration.   Most of the heliostats, including the Northrup II, a commercial model, were developed under contract for the United States Department of Energy.  The heliostats focused radiation from the sun to generate temperatures up to 2,000 degrees at the target.  Northrup, Inc. joint-ventured with the Bechtel Corp., which was responsible for designing the heliostat's target, a steam boiler.
Leonard L. Northrup Jr.