Integrated control of dynamic facades and distributed energy resources for energy cost minimization in commercial buildings

Abstract

Controllable window, shading, and daylighting technologies provide an interesting opportunity to manage end use demands on distributed energy resources (DER) in ways that both complements the peak output profile of solar photovoltaic (PV) electricity generation and counteracts the peak demands on the utility grid produced by daytime commercial activities. The objective of this study is to explore whether dynamic facade technologies can play an enabling role in supporting a desired level of electricity service at either minimum operating cost or minimum carbon footprint through optimized integrated control with distributed energy resources. A proof-of-concept control system was developed by approximating nonlinearities as piecewise-linear and determining the control state of both the demand and supply side components through global optimization. Annual simulations of a south-facing office zone with switchable electrochromic windows, solar photovoltaic electricity generation, and battery storage indicated that with optimized integrated demand-supply side controls, the utility grid load profile could be lowered to nearly zero demand (5 W/m 2 ) during the daytime when energy costs are highest. A full-scale outdoor field test in Berkeley, California verified this performance, demonstrating that during a week of sunny winter weather, electricity bills could be reduced by 63% compared to heuristic control of electrochromic windows without the photovoltaics and electrical storage. In both the simulated and measured cases, the photovoltaic system was sized to meet the peak perimeter zone load and the electrical storage was sized to be fully discharged by the end of the peak day. Technical and market challenges for achieving reliable optimal control for widespread applications are discussed.

Office buildings with electrochromic windows: A sensitivity analysis of design parameters on energy performance, and thermal and visual comfort

“…While total energy savings, peak load reductions and visual/thermal comfort indicators were assessed in this paper, further studies using a similar approach should include additional relevant decision making information regarding SW. Among other, future studies should include the relative effect of overhang designs [41], active load management window strategies [42], integrated control strategies [43] and should consider the economic challenges related to the integration of smart windows.…”

Literature review - Energy saving potential of user-centered integrated lighting solutions

“…; and technology limits such as switching speed, and limits on actuation, among others. Model predictive controls are applied in cases, where optimization includes forecasted lag effect of thermal mass on various loads (Lee, Gehbauer, Coffey, McNeil, Stadler and Marnay, 2015;Gehbauer, Blum, Wang and Lee, 2020). Reinforcement learning can provide low cost alternatives, capable of adapting to building operations, over the life of its installation (Gehbauer, Rippl and Lee, 2021).…”

Techno-economic feasibility of trigeneration systems with Thermal storage: The impact of the load size and spark spread rates

“…It is written and executed in GAMS and uses Mixed Integer Linear Programming (MILP) to minimize either the annual total energy cost, or the CO2 emissions, or both. DER-CAM has been used as a simulation tool for a number of publications for different purposes: assessing the feasibility of distributed energy generation [42], [43]; combining the distributed generation with energy conservation measures [44]; analyzing the performance of the electrical distribution circuit for microgrids [45]; and even studying the integration of communication technologies and information models for the integration and interoperability of distributed energy generation systems [46]. and cut the search when it reaches a MIP gap of 5%.…”