A review of the water and energy sectors and the use of a nexus approach in Abu Dhabi

Rapid population increase coupled with urbanization and industrialization has resulted in shortages of water in the Middle East. This situation is further exacerbated by global climate change due to greenhouse gas emissions. Recent research advocates that solutions to the global water security and scarcity crisis must involve water–energy nexus approaches. This means adopting policies and strategies that harmonize these inter-related sectors to minimize environmental impact while maximizing human benefit. In the case of Abu Dhabi, when designing and locating oil/gas refineries and associated power generation facilities, previous relevant decisions were based on simple economic and geographical grounds, such as nearness to oil rigs, pipelines, existing industries and port facilities, etc. The subsequent design and location of water abstraction and treatment works operated by the waste heat from these refining and/or power generation processes was catered for as an afterthought, meaning that there is now a mismatch between the water and energy supplies and demands. This review study was carried out to show how Abu Dhabi is trying now to integrate its water–energy sectors using a nexus approach so that future water/power infrastructure is designed optimally and operated in harmony, especially in regard to future demand. Based upon this review work, some recommendations are made for designers and policy makers alike to bolster the nexus approach that Abu Dhabi is pursuing

Load Matching and Grid Interaction of Net Zero Energy Buildings

“Net Zero Energy Building” has become a prominent wording to describe the synergy of energy efficient building and renewable energy utilization to reach a balanced energy budget over a yearly cycle. Taking into account the energy exchange with a grid infrastructure overcomes the limitations of seasonal energy storage on-site. Even though the wording “Net Zero Energy Building” focuses on the annual energy balance, large differences may occur between solution sets in the amount of grid interaction needed to reach the goal. The paper reports on the analysis of example buildings concerning the load matching and grid interaction. Indices to describe both issues are proposed and foreseen as part of a harmonized definition framework. The work is part of subtask A of the IEA SHCP Task40/ECBCS Annex 52: “Towards Net Zero Energy Solar Buildings”

U.S. Department of Energy Commercial Reference Building Models of the National Building Stock

The U.S. Department of Energy (DOE) Building Technologies Program has set the aggressive goal of producing marketable net-zero energy buildings by 2025. This goal will require collaboration between the DOE laboratories and the building industry. We developed standard or reference energy models for the most common commercial buildings to serve as starting points for energy efficiency research. These models represent fairly realistic buildings and typical construction practices. Fifteen commercial building types and one multifamily residential building were determined by consensus between DOE, the National Renewable Energy Laboratory, Pacific Northwest National Laboratory, and Lawrence Berkeley National Laboratory, and represent approximately two-thirds of the commercial building stock

Controlling Capital Costs in High Performance Office Buildings: A Review of Best Practices for Overcoming Cost Barriers Preprint Controlling Capital Costs in High Performance Office Buildings: A Review of Best Practices for Overcoming Cost Barriers

ABSTRACT First costs, or capital costs, for energy efficiency strategies in office buildings are often a primary barrier to realizing high-performance buildings with 50% or greater energy savings. Historically, the industry has been unable to reach deep energy savings because of a reliance on energy cost savings and simple payback analysis alone to justify investments. A more comprehensive and integrated cost justification and capital cost control approach is needed. By implementing innovative procurement and delivery strategies, integrated design principles and cost tradeoffs, life cycle cost justifications, and streamlined construction methods, first cost barriers can be overcome. It is now possible to attain marketable, high-performance office buildings that achieve LEED Platinum and reach net zero energy goals at competitive whole building first costs, as illustrated by the U.S. Department of Energy's and National Renewable Energy Laboratory's latest high-performance office building, the Research Support Facility (RSF) on the National Renewable Energy Laboratory campus in Golden, Colorado. The RSF is a recently completed 220,000-ft 2 headquarters and administrative office building with a corporatescale data center. The RSF reached these goals while maintaining a firm fixed price budget at competitive whole-building capital construction costs (move-in ready) of $259/ft 2 . This paper presents a set of 15 best practices for owners, designers, and construction teams to reach highperformance goals while maintaining a competitive budget. They are based on the recent experiences of the owner and design-build team for the RSF, which show that achieving this outcome requires each key integrated team member to understand their opportunities to control capital costs

Supervisory control for intelligent building systems

The objective of an office building is to provide optimum comfort that enables the occupants to attain maximum productivity. To meet this objective, a heating, ventilating, and air-conditioning (HVAC) system provides climate control; however, with an energy cost to the building owner. From an economic point of view it is important to minimize energy consumption while maximizing comfort. A three-level hierarchical control system composed of a supervisor, coordinators, and local controllers was formulated to meet this objective such that the building control system learns the characteristics of the building and determines the best control strategy. This intelligent building system (IBS) contains local controllers that control the equipment, a supervisor that monitors predicted disturbances to anticipate control actions, and coordinators that modify the supervisor\u27s decisions to compensate for unexpected real-time disturbances. The supervisor provides an optimistic plant to operate the building using past information to predict the performance of the building. This level can learn the building dynamics and formulate a model from generic units or building blocks. These generic units are simple models that can be identified with data from the building and its HVAC system. Since comfort is needed only when the building is occupied, a technique was developed to predict occupancy using motion sensors. This technique requires no prior knowledge and with sufficient data can create a probability of occupancy. To minimize energy cost while maintaining comfort, a cost function was formulated. This functional relates comfort and energy costs into a unified performance index. An experimental test bed, composed of three offices, was used to verify portions of the supervisory control. Motion data was converted into probability of occupancy profiles, weather forecasts were collected, and the building model was identified. Predicted building block coefficients and occupancy profiles showed good correlation with the actual data. This information, with the performance index, was used to determine analytically optimal time dependent set points for a room

Reducing Plug and Process Loads for a Large Scale, Low Energy Office Building: NREL's Research Support Facility

The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LL