Commercial and industrial hot water requirements are today being economically met with a site-built large volume solar water heating system called the "shallow solar pond." The shallow solar pond (SSP), a horizonal intergral collector storage system, has proven to be a simple and reliable means of providing large quantities of inexpensive hot water to commercial and industrial facilities.Several ponds are now operational in the southeastern United States and the Caribbean. The existing ponds are providing hot water at costs between $8 and $10 per million Btu (MBtu). Economic analysis presented in this paper indicates a SSP located in Florida will deliver 0.20 to 0.30 MBtu per square foot annually at levelized costs of $4.22 per MBtu ($0.014/kWh).Units: Dual