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Based on an extensive literature review and research interviews of energy experts, this article asks: what are the remaining impediments to clean energy systems and how can a Post-Kyoto Protocol climate framework be designed to overcome them? The article begins by exploring commercially available 'clean' energy systems and practices relating to energy end-use and infrastructure, energy supply, carbon capture and storage, and non-CO2 related greenhouse gas emissions. The article then examines a selection of persistent financial, market, information and intellectual property barriers. Lastly, it articulates the implication of these barriers for the design of future national and international climate change policies.

Massive adoptions of combined heat and power (CHP) units necessitate the coordinated operation of power system and district heating system (DHS). Exploiting the reconfigurable property of district heating networks (DHNs) provides a cost-effective solution to enhance the flexibility of the power system by redistributing heat loads in DHS. In this paper, a unit commitment considering combined electricity and reconfigurable heating network (UC-CERHN) is proposed to coordinate the day-ahead scheduling of power system and DHS. The DHS is formulated as a nonlinear and mixed-integer model with considering the reconfigurable DHN. Also, an auxiliary energy flow variable is introduced in the formed DHS model to make the commitment problem tractable, where the computational burdens are significantly reduced. Extensive case studies are presented to validate the effectiveness of the approximated model and illustrate the potential benefits of the proposed method with respect to congestion management and wind power accommodation. (Corresponding author:Hongbin Sun)

SunPower Corp. describes its research to develop low-cost, next-generation SunPower modules with 30-year warranties and at least 50% higher energy production per area relative to today's typical multicrystalline Si modules.

Abstract As the adverse effects of global warming become increasingly apparent, the need for low-GWP solutions in the HVAC&R industry is its highest in decades. Alternative working fluids, including natural refrigerants such as Carbon Dioxide (CO2), and high efficiency systems are ways to mitigate the negative environmental impact of refrigeration systems. Researchers have focused on investigating several transcritical CO2 cycles for supermarket and transport applications. Yet, a systematic experimental comparison between multiple advanced cycle architectures is still lacking. To this end, a novel test stand capable of comparing two methods of expansion as well as open-economization at one or both evaporator pressure levels, allowing six cycle configurations that represent much of the state-of-the-art has been developed. Cycle designs, thermodynamic modeling for component sizing, and experimental validation of test stand operation and energy balances are discussed in-depth. Limitations and modifications to the test stand are discussed, as are next steps.

AbstractCompanies are forced by rising energy costs to seize control of their energy consumption to maintain contestability. There-fore, transparency over the companies’ energy flux along the production process is required. Energy data management software is helpful, but cost-intensive. Hence, especially small and medium sized enterprises (SME) spare this investment. In this paper, the requirements for an energy controlling infrastructure in SME are elaborated, followed by a deduced software-architecture which supports the respective controlling structure. Further, the prototypical realization of the corresponding tool “Green-Cockpit” will be presented. The free of cost, open source and web-based tool is designed to help companies monitor, interpret, analyze, plan and report their energy consumption. The Green Cockpit tool outperforms other energy management software at management disciplines with its ability to not only analyze energy consumption, but plan and control it additionally.

Over the past 30 years, wind power has become a mainstream source of electricity generation around the world. However, the future of wind power will depend a great deal on the ability of the industry to continue to achieve cost of energy reductions. In this summary report, developed as part of the International Energy Agency Wind Implementing Agreement Task 26, titled 'The Cost of Wind Energy,' we provide a review of historical costs, evaluate near-term market trends, review the methods used to estimate long-term cost trajectories, and summarize the range of costs projected for onshore wind energy across an array of forward-looking studies and scenarios. We also highlight the influence of high-level market variables on both past and future wind energy costs.

This report describes experimental studies performed at Carnegie Mellon University to study the parameters that affect the performance of plasma-assisted ammonia radical injection for NO{sub x} control from stationary combustion sources. First, the NO{sub x} reduction potential of hot ammonia injection was studied to determine whether the use of the plasma for radical generation was key to the high NO{sub x} reduction potential of the plasma deNO{sub x} process. It was found that while some of the NO{sub x} reduction in the plasma deNO{sub x} demonstration experiments could be attributed to the enhanced thermal breakdown of NH{sub 3} into NO{sub x} reducing radicals, the effect of using the plasma accounted for 15--35% absolute additional NO{sub x} reduction beyond any thermal benefit. This benefit of using the plasma increases with increased excess air and decreased flue gas temperature. With the benefit of using the plasma verified on the larger scale of a demonstration experiment, two additional experiments were performed to study the parameters that affect plasma deNO{sub x} performance on the local level. The opposed flow experiment failed to produce significant NO{sub x} reduction, although it did highlight some key aspects of plasma performance with ammonia injection. The reverse injection experiment successfully demonstrated the effects of NO-stream temperature, plasma power, and ammonia flow rate on plasma deNO{sub x} performance. Finally, a preliminary study of the chemical kinetics of the plasma deNO{sub x} system was performed. This study highlighted the importance of effective plasma temperature and the residence time of the reagent at that temperature to efficient radical generation.

Abstract A criterion, based on optimization principles, for determining the SAT setpoint in VAV systems is presented. It is generally accepted that conventional SAT reset controls (SATRC), bounded by either space humidity or ductwork size, will save cooling and/or heating energy. How-ever, the ventilation consequences and penalty resulting from increased fan power have generally been overlooked. Ventilation is impacted since changes in the SAT setpoint change the primary airflow rate and the operation of economizer cycles, i.e. the distribution of fresh outdoor air (OA). These changes may result in extra energy demand and ventilation inefficiency if the reset criterion is not appropriate. This optimization concept simultaneously reduces energy consumption and meets ventilation requirements. Simulation results illustrate that the use of the optimized SATRC saves more energy than a conventional one.