  The current plan divides the UC Berkeley (UCB) campus energy system into five
nodes, where the Business and Law node was studied because of an open field
site for borehole installation. The Pacific Northwest National Laboratory's
Commercial Prototype Building Models were used to estimate heating and cooling
load requirements for UCB campus building types by considering model
characteristics (for example, high base load from hospitals, high DHW in
hotels) corresponding to the ASHRAE Standard 90.1-2013. Unscaled load profiles
were created from the EnergyPlus building energy simulation and scaled with
monitored peak load and annual energy use to generate the target node's hourly
heating and cooling load profiles. An optimization problem was solved to design
a hybrid GSHP system, where the objective function is the lifetime total cost
of the system, and the optimization variables are the portion of heating and
cooling loads covered by the GSHP system. Modelica models for air source and
ground source heat pump systems were built for detailed case studies based on
optimization results. In the Modelica model, the demand side is connected to
the radiators in the building to transfer heat, and the source side is
connected to GSHP, ASHP, or other heating and cooling facilities. The results
demonstrate that an appropriate hybrid GSHP system can help reduce both
borehole numbers and electricity consumption for the UCB campus site.
