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What happened to all the solar thermal systems from 30-40 years ago?
I bought some old Solaron collectors from Fort Hays State University in Kansas. The person who was put in charge of selling them did not know much about the original system, but he did tell me that the system never worked properly because the building did not have enough load for the system. I can't find much more info about the installation, just a short story in the school's paper which said they had been removed so repairs could be made to the roof, and that they had not been operational for several years. There were 200 collectors offered for sale (I bought 20 of them) so this must have been large and expensive system. The building they were originally installed on (Rarick Hall) was built in 1981, I presume they were installed at that time. The people at Fort Hays provided a copy of the Solaron brochure with specs and installation guidelines dated 1979. On the front page there are pictures of two other installations, so I did some research on them.
US Post Office, Ridley Park PA. 2205 sf collector area for space heating and cooling. This building was completed in 1976. The building was featured in Kaiman Lee's Encyclopedia of energy-efficient building design: 391 practical case studies. The solar panels provided 20% of the post office's heating and cooling energy needs. They were removed in 1990 for unknown reason.
Navy Pier Administration Building, Chicago IL. 7344 sf collector area for space heating. This system was also featured in Kaiman Lee's Encyclopedia of energy-efficient building design and was in the planning stages when the book was printed. In 1977 the system cost $320,000. I cannot find any info about how long this system was operational, but looking at the building on Google Earth I do not see any collectors on the roof. I suspect they were removed during a $200 million renovation in the 1990s.
So all this has me wondering, How many of these solar thermal systems from the 70's-80's are still operating, and what are the reasons for the ones that are not. I suspect low fuel prices in the late 80's-90s put a lot of systems out of service. It doesn't seem like the collectors have changed much since then, maybe the control technology wasn't adequate?