In the US, Stanford University in California has developed a central energy facility (CEF) with the help of Johnson Controls, which has seen the university improve building efficiency – reducing its water and energy use through various storage and smart technologies.
The facility is reported to perform in any weather condition, featuring technology that improves the operational efficiencies of the HVAC systems in the building. The central plant system is a key component of the Stanford Energy System Innovations (SESI) featuring heat recovery chillers, hot and cold water thermal energy storage and an intelligent technology system that uses weather and electricity pricing forecasts to optimize operations.
Building efficiency through smart tech
According to PR Newswire, Johnson Controls partnered with a global multi industrial company, Affiliated Engineers Inc., to assist Stanford engineers deliver a custom heat-recovery process that is 70% more efficient than the cogeneration process Stanford used since 1987.
The York heat-recovery chillers provided by the Wisconsin-based company is said to meet more than 90 percent of campus heating demands by “capturing almost two-thirds of the waste heat generated by the campus cooling system to produce hot water for the heating system.”
Says Trent Nevill, vice president and general manager, Johnson Controls Building Efficiency, said: “Nothing goes to waste inside this facility. We are recycling heat that is typically released by cooling towers and putting it to good use to keep students and staff comfortable.
“All this is accomplished while helping Stanford reduce its carbon emissions by 50% compared to levels during the 1990s.”
Apart from its Metasys building automation system, Johnson Controls developed an enterprise optimization system – a predictive control software system created to optimise cost and energy use, based on a 10 day weather forecast and future grid electricity prices.
The enterprise optimization system is able to predict hourly campus heating and cooling needs and then use that data to evaluate the best route to run the heat recovery, heating, and cooling equipment inside.
The software also determines how much hot and cold water to store in the facility’s water thermal storage tanks for future use.
Nevill added: “There’s a great comparison to autopilot technology on an aircraft. The system continuously monitors plant equipment, predicts campus energy loads and grid electricity prices, and steers the system to optimal efficiency.”