70% more efficient. First of its kind energy system. | aeieng.com | Based on the extent of heating and cooling demand overlap across its Palo Alto campus, Stanford University is completely transforming its district energy system from gas fired combined heat and power to electrically powered combined heat and cooling. As prime consultant and lead engineer for the Stanford Energy System Innovations (SESI) project, AEI designed and is now directing implementation of the project’s four central components: a new central plant, conversion of buildings to hot water, new hot water distribution system, and a new electrical substation. Projected to be 70% more efficient than the existing cogeneration and steam distribution process, and to reduce Stanford’s carbon emissions by 75% and potable water use by 60%, the new system will open Stanford’s energy supply platform to future technologies, allowing flexible management of the campus power portfolio. AEI advised Stanford with analysis of energy production options, evaluation of capital and operating costs, and assessment of financial and energy risk through 2050. SESI began operation in 2015.
Transcript
70% more efficient.
First of its kind energy system.
| aeieng.com |
Based on the extent of heating and cooling demand overlap across its Palo Alto campus,Stanford University is completely transforming its district energy system from gas fired combined heat and power to electrically powered combined heat and cooling. As prime consultant and lead engineer for the Stanford Energy System Innovations (SESI) project, AEI designed and is now directing implementation of the project’s four central components: a new central plant, conversion of buildings to hot water, new hot water distribution system, and a new electrical substation. Projected to be 70% more efficient than the existing cogeneration and steam distribution process, and to reduce Stanford’s carbon emissions by 75% and potable water use by 60%, the new system will open Stanford’s energy supply platform to future technologies, allowing flexible management of the campus power portfolio. AEI advised Stanford with analysis of energy production options, evaluation of capital and operating costs, and assessment of financial and energy risk through 2050. SESI began operation in 2015.
New Central Energy FacilityDesigned for a peak load of 28,000 tons of cooling and 350 mmbtu/hr heating, the Stanford Energy Center’s new combined heat and cooling system replaces a cogeneration system with heat recovery chillers that — along with standard chillers and gas-fired hot water generators — capitalize on daily heating and cooling overlap to heat the campus and university hospital with recovered energy. Two million gallons of hot water and ten million gallons of chilled water Thermal Energy Storage accommodate high demand periods and balancing of heating and cooling loads with the heat recovery chillers. Portions of the facility are regulated by OSHPD.
Campuswide Distribution and Building ConversionsNearly 200 campus buildings are being converted from steam to hot water. The new system will collect 70% of the waste heat from buildings through the chilled water loop and transfer it to a new hot water loop via new heat recovery chillers, meeting 80% of campus heating loads. Facilitated by temporary heat exchanger stations, over 20 miles of original campus piping is being replaced in phases with a highly insulated direct-buried, chemical-free hot water piping system conforming to European Standard EN253. By replacing steam heat delivery with a hot water loop, additional savings of 10% of the campus heating load will be realized through lower line losses.
New SubstationAEI is leading the design of the new 80MVA, N+1, 60kV-12.47 substation and the associated switchgear for all campus feeders. The existing 4.16kV switchgear will remain; associated modifications are designed to facilitate power conversion from the old substation with minimal downtime. A total of seven new pad mounted 12.47kV switchgear line-ups will be located throughout campus.
Substation
Central Energy Facility
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SESI Heat Recovery Plant Thermal OverlapStanford University
SESI Heat Recovery PlantHot Water & Chilled Water Production Source
