Applications of optimal building energy system selection and operation

Abstract

Berkeley Lab has been developing the Distributed Energy Resources Customer Adoption Model (DER-CAM) for several years. Given load curves for energy services requirements in a building microgrid (µ⋅grid), fuel costs and other economic inputs, and a menu of available technologies, DER-CAM finds the optimum equipment fleet and its optimum operating schedule using a mixed integer linear programming approach. This capability is being applied using a software as a service (SaaS) model. Optimisation problems are set up on a Berkeley Lab server and clients can execute their jobs as needed, typically daily. The evolution of this approach is demonstrated by description of three ongoing projects. The first is a public access web site focused on solar photovoltaic generation and battery viability at large commercial and industrial customer sites. The second is a building CO2 emissions reduction operations problem for a University of California, Davis student dining hall for which potential investments are also considered. And the third, is both a battery selection problem and a rolling operating schedule problem for a large County Jail. Together these examples show that optimization of building µ⋅grid design and operation can be effectively achieved using SaaS.

Optimal deployment of thermal energy storage under diverse economic and climate conditions

“…As previous DER-CAM investigations have shown the tariff structure and in particular the rates imposed on power demands have a strong influence on the optimal behavior and configuration of DER installations [21][22][23] Tariffs with high on-peak energy rates and on-peak demand charges create opportunities for economic savings from load shifting. An investigation of a large religious building in Saudi Arabia found that the absence of tariff demand charges significantly reduced the economic feasibility of chilled water TES systems, despite a large disparity between on-peak and off-peak cooling consumption [24].…”

Regional analysis of building distributed energy costs and CO2 abatement: A U.S.–China comparison

“…DER-CAM has been in development by Lawrence Berkeley National Lab (LBNL) for over 10 years, and has been widely used to assess DER alternatives, to find optimal results, and for energy-economic assessments [6,7,8]. Figure 2 shows the energy flows modeled by DER-CAM.…”

“…Figure 12 illustrates the commercial building energy cost optimization results and their CO 2 abatement potential, expressed in terms of energy and emissions intensity. For each city, there is a baseline "Do-Nothing" case, which reflects an existing situation where electricity and natural gas are purchased from the local utilities, and buildings use electric chillers for cooling 7 Due to absence of more detailed data, this study assumes a static macrogrid marginal CO 2 emissions factor, which represents a fair approximation to reality. Marginal emissions from the grid vary slightly during the different seasons of the year and between day and night hours.…”

Sustaining Critical Social Services During Extended Regional Power Blackouts

“…As an example, the Santa Rita Jail of Alameda County, CA, has a peak electricity demand of around 3 MW and a capacity of 4,500 inmates. (49) The facility has a 1.2 MW PV system in addition to a relatively large (1-2 MW) battery installed onsite. Some correctional facilities such as the Worcester County Jail in Massachusetts are implementing small-scale wind generation to meet the energy demands of the facility as well as to provide power to neighboring loads by selling electricity back to the grid.…”