Decentralized energy system offer fast and low-risk way to test energy transition pathways at local scale. The technology variety and increased role of user preferences call for a systematic design process in close collaboration with prosumers. We propose a novel methodology to design local energy systems that are technically robust and socially supported – the Participatory Approach to Community Energy Design. The methodology is applied to a neighborhood in the Netherlands. Among four alternative designs, a biogas-fueled and a smart grid systems consistently outperformed the alternatives, regardless of changing the user preferences.
Free Piston linear Generator becomes a new solution and device for energy conversion highly integrated engine and linear machine due to its potential application on hybrid vehicles. This paper investigated the starting process of an opposed-piston free-piston linear generator (OPFPLG), and a prototype was built to carry out the experimental research of the startup process. The prototype adopts a piston synchronization mechanism and a pipeline connecting two bounce chambers to improve the self-balance performance of the system. The linear machine is used to start the engine because of its flexibility and controllability. The control strategies combining mechanical resonance and synchronization control methods were applied on the prototype for starting operation, and the test data collected for further analysis. When the linear motor’s thrust force was 240N, the maximum pressure in combustion cylinder achieved was beyond 11.8 bar with a compression ratio of 12:1, indicating that the mixture was ready for ignition. The system frequency was up to 14Hz, and the piston amplitude was about 56.5mm with a synchronization error of the opposed pistons less than 1.5mm. Especially, the piston synchronization error of the inner and outer dead center was nearly zero. Both the variation of synchronization error and the cyclic fluctuation of starting process were demonstrated with different synchronization control methods. The piston sync error of the dual current command control mode was found to be lower than that of the master-slave mode, and the cyclical fluctuation was smaller. The dual current command control method will be implemented to the prototype to start and maintain the piston motion synchronization during the starting process of the OPFPLG system.
Fossil fuels are the primary energy source because of their (1) low cost, (2) ease of storage, (3) low-cost transport and (4) economic dispatchability. Because the capital cost of power plants, furnaces, and boilers is small relative to the cost of the fuel, it is economic to meet variable energy demand by operating fossil plants at part load. Nuclear, wind, solar and hydrogen production plants have high capital cost; thus, operating these facilities at half capacity can almost double energy costs. A low-carbon system is defined that enables high-capital-cost low-operating-cost technologies to operate at high capacity while providing variable heat, hydrogen and electricity to the customer. This minimizes total costs. In the U.S., over 80% of all energy used is in the form of heat; thus, heat production and storage is central to a low-carbon economy. Nuclear power is the primary low-carbon low-cost heat producing technology.
Abstract—Apart from improving our quality of life, knowledge, and our development in general, the Industrial Revolution and the inadequate system of values and priorities that followed disturbed natural and energy balances to the point that it jeopardizes life continuation on Earth. The new direction and the change of the approach in handling our resources were necessary, united under the introduction of renewable and sustainable energy. The transformation of the energy sector requires a very complex analysis, different perspective, and philosophy from the one we currently use.
This article aims to propose a novel understanding of renewable energy and energy in general, by introducing a new technological merger between electricity generation and water filtration technologies, with far better financial, environmental and sustainability benefits from presently known technologies.
Unconventional shale gas production in the United States has been largely improved due to development of hydraulic fracturing technology. However, the acquisition of freshwater and management of flowback and produced (FP) water associated with hydraulic fracturing operation becomes one of the greatest challenges in shale gas development. Thus, it requires a better understanding of the quantity of injected water and produced FP water as well as their relationship of shale wells to help expand and upgrade the existing water network and shale gas network. We collected water-use and monthly FP water production volume data for each shale gas well available in the Eagle Ford and Marcellus shale regions from multiple database sources. Then, water recovery ratios of these wells were calculated to study their spatiotemporal variation among counties over multiple time periods. To evaluate how the water recovery ratio may affect shale gas development, a shale gas supply chain network (SGSCN) optimization model from the literature was utilized to perform two case studies in the Marcellus region. In conclusion, significantly different SGSCN configurations are required for economically desirable, and practically feasible management of wells with different water recovery ratios.
Air dehumidification through cooling is an energy-intensive process, which consumes about 20-40% of the overall energy for air-conditioning. Liquid desiccant dehumidification can separate dehumidification from space cooling and has potential to improve the cooling efficiency and reduce the overall energy consumption for air-conditioning. However, the drawbacks such as liquid carryover and corrosion, membrane contamination and blocking, limit its application. To eliminate these problems, a new dehumidifier using nonporous membrane and ionic liquid desiccant (ILD) was developed. The dehumidification performance of the new dehumidifier was characterized through a series of lab tests. Test results indicate that the new dehumidifier can achieve a moisture removal rate up to 180.3 g/h and a dehumidification effectiveness up to 12.7%. A parametric study found that the dehumidification performance is sensitive to the flowrates of the air and the ILD solution. A higher mass flow ratio between the ILD solution and the air could result in better dehumidification performance.
The traditional energy management system of hybrid electric vehicle did not take into account the future driving information. To realize the further energy optimization, the Bi-level energy management strategy in connected environment is studied in this paper. The upper controller is to predict the optimal velocity. Firstly, the target velocity range is first calculated based on the signal phase and timing (SPAT) information. Then the optimization function is designed to obtain the optimal acceleration. The lower controller is designed to follow the optimal acceleration and to save energy by optimizing the power split between the engine and motor under the condition of meeting the physical constraints. The rule-based and fuzzy logic controller based on genetic algorithm are adopted in this paper. Simulation results indicate that optimizing vehicle velocity trajectory in connected environment can effectively reduce fuel consumption and pollutant emission. Meanwhile, compared with Rule-based strategy, the fuzzy logic controller based on genetic algorithm contributes to realize the superior fuel economy performance and lower emissions.
Vehicle energy management is the core technology of hybrid vehicles, which determines the fuel economy and emission performance of the vehicle. At present, most of the common energy management is based on known operating conditions, without considering actual road traffic information, which makes vehicles unable to achieve optimal energy management. With the development of GPS and ITS, future traffic information can be obtained in advance. In the paper, a hierarchical energy control method for hybrid electric vehicles is proposed. Model predictive control algorithm is utilized to predict the optimal vehicle velocity in the upper controller. The lower controller is designed to follow the optimal velocity, and uses the neural network control algorithm to optimize the power distribution between the engine and the motor to reduce fuel consumption. Compared with the traditional energy management strategy, the proposed method can prevent the vehicle from stopping at the red light, thereby reducing the fuel consumption of the vehicle to achieve the purpose of saving fuel consumption.
Access to deep energy resources (geothermal energy, hydrocarbons) from deep reservoirs will play a fundamental role over the next decades. However, drilling of deep wells to extract deep geo-resources is extremely expensive. As a fact, drilling deep wells into hard, crystalline rocks represents a major challenge for conventional rotary drilling systems, featuring high rates of drill bit wear and requiring frequent drill bit replacements, low penetration rates and poor process efficiency. Therefore, with the aim of improving the overall economics to access deep geo-resources in hard rocks, in this work, we focus on two novel drilling methods, namely: the Combined Thermo-Mechanical Drilling (CTMD) and the Plasma-Pulse Geo-Drilling (PPGD) technologies. The goal of this research and development project is the effective reduction of the costs of drilling in general and particularly regarding accessing and using deep geothermal energy, oil or gas resources. In this work, we present these two novel drilling technologies and focus on evaluating the process efficiency and the drilling performance of these methods, compared to conventional rotary drilling.
It was predicted in 2012 that the global demand for energy over a period of 28years (2012-2040) will increase by 48%. This will raise the total global energy consumption from 549 quadrillion British thermal units (Btu) in 2012 to 815 quadrillion Btu by 2040. As a strategic player in the energy mix, a reduction in the emission of CO2 to the environment from the natural gas network will result in environmental and cost savings. Although several researchers have alluded various opportunities associated with renewable energy feedstocks and have examined various strategies for optimized energy supply, the possible structural adjustments to gas infrastructure to align with future policies on climate will bring about a sustainable strategy for future economic growth. The motive of work is to investigate the problem associated with exogenous interruptions to a gas network resulting in loss of gas to the environment. The research also proposed a mitigation strategy for gas loss and emission reduction. To achieve this, a mixed integer linear programming (MILP) optimization model is developed that establishes a strategy for loss reduction in gas supply chain. Data from real case study have been accessed which enhances the applicability of the proposed model which was run on the GAMS 26.14 software using the CPLEX solver 12 in an intel ® core ™ i7 and a zero-optimality gap within reasonable solution time. The result obtained revealed a reduction from 555.1million kg of CO2 to 8.06 million kg of CO2 after optimization while still delivering on projected throughput. The proposed methodology can help natural gas operators to optimize performance considering disruption time estimation.