The EPA conducted a case study of the energy consumption of the BuffetAsia restaurant chain at its three locations in Las Vegas, which installed solar water heating systems to help defray the costs of washing as many as 20,000 dinner plates each day.
The restaurants will save more than $300 each month on their energy bill. The total cost for the project was $26,295. However, a $7,500 rebate from the local utility company reduced the owner’s final invoice to $18,795.
Solar water heating systems can use either flat plate collectors (large shallow boxes) or long, cylindrical vacuum tube collectors. Each approach offers advantages, although flat plates have a much longer history. The BuffetAsia restaurants used the vacuum tube collectors. The system heats the restaurants’ potable water and delivers it to a hot water storage tank near the kitchen.
Because of seasonal changes throughout the year, solar water heating technology employs various systems to detect potential freezing during cold months or overheating during the summer months. The BuffetAsia design uses sensors to measure the water temperature, which activate water flow control mechanisms to provide protection against both freezing and overheating.