Optimal greenhouse lighting scheduling using canopy light distribution model: A simulation study on tomatoes

2019 ◽  
Vol 52 (2) ◽  
pp. 233-246
Author(s):  
L Xu ◽  
R Wei ◽  
L Xu
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Optimal Solution ◽  
Light Distribution ◽  
Distribution Model ◽  
Decision Variable ◽  
Threshold Control ◽  
Greenhouse Crops ◽  
The Status ◽  
Led Lights

Light is considered the most important environmental factor for greenhouse crops, and lack of lighting limits the productivity of greenhouses. Many studies have focused on improving the energy efficiency of lighting in agriculture. In this study, LED lights were mounted in the top, middle and bottom of the plant canopy to provide additional photosynthetically active radiation. Assuming that 100% of the predicted outdoor radiation is available, the canopy light distribution model was used to determine the relationship between the light energy consumption and the optimal yield. Decision-making on lighting scheduling may be considered as a constrained optimisation, and the status of the LEDs in a period acts as the decision variable. Besides, there are two objective functions: one is the energy consumed by the LED device; the other is the expected yield calculated by the crop model of tomatoes. The optimal solution of the multi-objective optimisation is not unique but corresponds to an infinite number of yield/energy combinations. Farmers can select these combinations according to additional restrictions such as energy efficiency ratio or photoperiod. The yield of our strategy was increased by 12.3% under the constraint of equal energy consumption compared to the greenhouse threshold control strategy. Given the same output as the constraint, the energy consumption was reduced by 30.1%.

scholarly journals Energy Use Efficiency Past-to-Future Evaluation: An International Comparison

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3804 ◽  
Author(s):  
Chia-Nan Wang ◽  
Thi-Duong Nguyen ◽  
Min-Chun Yu
Keyword(s):  
United States ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Demand ◽  
Energy Use ◽  
The United States ◽  
Total Energy Consumption ◽  
The Future ◽  
The Status ◽  
Energy Efficiency Evaluation

Despite the many benefits that energy consumption brings to the economy, consuming energy also leads nations to expend more resources on environmental pollution. Therefore, energy efficiency has been proposed as a solution to improve national economic competitiveness and sustainability. However, the growth in energy demand is accelerating while policy efforts to boost energy efficiency are slowing. To solve this problem, the efficiency gains in countries where energy consumption efficiency is of the greatest concern such as China, India, the United States, and Europe, especially, emerging economies, is central. Additionally, governments must take greater policy actions. Therefore, this paper studied 25 countries from Asia, the Americas, and Europe to develop a method combining the grey method (GM) and data envelopment analysis (DEA) slack-based measure model (SMB) to measure and forecast the energy efficiency, so that detailed energy efficiency evaluation can be made from the past to the future; moreover, this method can be extended to more countries around the world. The results of this study reveal that European countries have a higher energy efficiency than countries in Americas (except the United States) and Asian countries. Our findings also show that an excess of total energy consumption is the main reason causing the energy inefficiency in most countries. This study contributes to policymaking and strategy makers by sharing the understanding of the status of energy efficiency and providing insights for the future.

scholarly journals Intelligent power management at waterworks (case of Water Supply Branch of State Unitary Enterprise St. Petersburg Vodokanal)

2020 ◽  
Vol 2020 (4) ◽  
pp. 7-14
Author(s):  
Valery Glebovich Larionov ◽  
Marina Gennad'evna Treyman
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Water Supply ◽  
Energy Saving ◽  
Electricity Consumption ◽  
Optimal Solution ◽  
The State ◽  
Energy Resources ◽  
Resource Saving ◽  
Software Products

The article gives the analysis of resource saving and energy efficiency of the enterprises of water supply and waste water services of the State Unitary Enterprise “St. Petersburg Vodokanal”. There has been evaluated the consumption of electrical energy by the enterprise. The main methods of energy resources management (creating a system of rational consumption and saving of energy resources, using energy-efficient materials, equipment and technologies, identifying the potential of energy-saving measures at operating facilities) have been determined. The priority directions for reducing the production energy intensity in the water supply processes have been defined. An algorithm is proposed that includes the processes of collecting, modeling, structuring information, as well as developing an optimal solution for an enterprise. A model for optimizing work in water supply processes is presented, software products are considered that allow to control the processes of energy saving and energy efficiency. The most promising software products for their introducing them into practice of the enterprise have been identified, including General Electric Intelligent Platforms CSense. A plan for the sequential implementation of the software product into operation at the enterprise is presented. The dynamics of electricity consumption at the enterprise, the structure of energy consumption are illustrated. It is noted that the most significant contribution to the amount of energy consumption is made by the technological processes of water intake and supply. It has been substantiated that the most energy-consuming process for the enterprise (Water Supply Branch of the State Unitary Enterprise St. Petersburg Vodokanal) is replacement or maintenance of pumping equipment. The components of energy conservation of the enterprise under study are the partial regulation and automation of processes.

A Novel Approach of Energy Efficiency Based on Multiple Data Collector Placement for Wireless Seismic Sensor Network

2016 ◽  
Vol 13 (10) ◽  
pp. 6834-6843
Author(s):  
Xunqian Tong ◽  
Gengfa Fang ◽  
Jun Lin
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Simulation Analysis ◽  
Optimal Solution ◽  
Theoretic Approach ◽  
Total Energy Consumption ◽  
Data Collector ◽  
Multiple Data ◽  
Novel Approach ◽  
Battery Capacity

Since the geological environments are highly unpredictable and the battery capacity of seismometer nodes in the wireless seismic sensor networks (WSSN) is constraint, the lifetime of the network that using conventional single data collector may be dramatically reduced. Even with the most energy-efficient algorithm that deploys multiple data collectors, it is still too difficult to satisfy the system requirement in terms of energy consumption. In this paper, we therefore propose an optimal solution that uses multiple data collectors to minimize the total energy consumption of data transmissions in WSSN. The aim of this work is not only to determine how many data collectors are required, but also to find out how to place them in an effective way, so that the energy efficiency of the system can be further enhanced. In so doing, an optimal solution that is based on the placement of multiple data collectors is proposed. A two-step approach is adopted, in which the number of required data collectors is firstly calculated based on a graph theoretic approach and then the placement of the data collectors are further optimized according to maximize the network lifetime. The simulation analysis shows that with a given number of seismometer nodes, using the proposed algorithm, an optimal value can always be found to extend the WSSN lifetime. As the number of seismometer nodes are selected to be 200, 500, 800 and 1000, the lifetime of the WSSN can be improved by 176%, 236.8%, 408.4% and 575%, respectively.

Parameterization of a light distribution model for green cell growth of microalgae: Haematococcus pluvialis cultured under red LED lights

2017 ◽  
Vol 23 ◽  
pp. 20-27 ◽  
Author(s):  
Xin Gao ◽  
Xinyu Wang ◽  
Haijun Li ◽  
Sanja Roje ◽  
Shyam S. Sablani ◽  
...  
Keyword(s):  
Cell Growth ◽  
Haematococcus Pluvialis ◽  
Light Distribution ◽  
Distribution Model ◽  
Green Cell ◽  
Red Led ◽  
Led Lights

scholarly journals Evaluasi Penggunaan Listrik dengan Metode Konservasi Energi untuk Efisiensi Energi di Gedung FKIP UNTIRTA

2020 ◽  
Vol 12 (1) ◽  
pp. 11-21
Author(s):  
Fahrizal Tunjung Kresnadi
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Electrical Energy ◽  
Energy Audit ◽  
Building Area ◽  
Led Lights ◽  
Consumption Intensity ◽  
Area Data

Knowing the level of intensity of energy consumption (IKE) in the FKIP Untirta building using the energy audit method for achieving energy efficiency. The data used in data collection in the form of electricity usage data, building area data and observations made by researchers. Analysis of the data used in this study is to use the formula of energy consumption intensity. The results showed the IKE value of the CB FKIP Untirta building was 254.5 kWh/m2. With these results, it can be seen that the IKE value in the CB FKIP Untirta building is still inefficient. This is based on ASEAN-USAID parameters which range at 240 kWh/m2. Based on electrical energy consumption in the CB FKIP Untirta building there is an opportunity for energy saving or energy saving solutions that are replacing TL lamps with Led lights or by replacing TL lamps that are smaller watts and in terms of air conditioning or air conditioning load replacing R32 refrigerant with R32 refrigerant mixture and The R290 has proven to be quite efficient in terms of savings and energy efficiency. And the duration of use of electrical energy.

Analysis on the Status and Influencing Factors of Industrial Carbon Emissions in Northeast China

2013 ◽  
Vol 869-870 ◽  
pp. 866-869
Author(s):  
Shao Ping Li ◽  
Qian Wang ◽  
Yan Meng
Keyword(s):  
Energy Efficiency ◽  
Economic Development ◽  
Energy Consumption ◽  
Influencing Factors ◽  
Carbon Emissions ◽  
Northeast China ◽  
Pull Factors ◽  
Industrial Carbon ◽  
Small Impact ◽  
The Status

This paper calculates the carbon emissions in the three northeastern provinces from 1997 to 2011 by using carbon formula, and compares the differences of the carbon emissions among the three provinces. Based on the LMDI model, the paper reveals the influences of every factor on the industrial carbon emissions. The population, economic development and industrialization rate are the pull factors in the increasing industrial carbon emissions, and the economic development is the main reason, followed by industrialization rate, the population has the least impact. The energy efficiency and structure of energy consumption are the inhibitory factors in the increasing industrial carbon emissions, energy efficiency is the most important factor to reduce industrial carbon emissions, and structure of energy consumption has a small impact on the industrial carbon emissions.

The Existing Architecture Energy-Saving Technologies’ Application in the Residential Community’s Transformation

2011 ◽  
Vol 71-78 ◽  
pp. 82-86
Author(s):  
Li Ying Wang ◽  
Qiu Shi Hao
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Saving ◽  
Engineering Practice ◽  
Application Analysis ◽  
The Status ◽  
Common Problems

In this thesis, it starts from the status of China's energy consumption and energy efficiency application, analysis our country’s existing architecture common problems and causes, combined with engineering practice, put forward the technological measures to the existing architecture energy-saving’s transformation.

scholarly journals Influence of Cold Water Inlets and Obstacles on the Energy Efficiency of the Hot Water Production Process in a Hot Water Storage Tank

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6509
Author(s):  
Agnieszka Malec ◽  
Tomasz Cholewa ◽  
Alicja Siuta-Olcha
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Demand ◽  
Storage Tank ◽  
Cold Water ◽  
Optimal Solution ◽  
Hot Water ◽  
Domestic Hot Water ◽  
Water Storage Tank ◽  
Single Plate

Domestic hot water preparation is one of the main sources of energy consumption in households. One of the most important elements of domestic hot water (DHW) preparation installation is the storage tank. Its design can significantly affect the efficiency of the system and energy consumption for hot water preparation. This paper presents the results of an experimental study to examine seven different designs of the cold water inlet to the storage tank and the use of two types of obstacles inside this tank placed at three different heights. The number of stratification and the energy efficiency of the system for each variant were examined. Additionally, tests were carried out for different profiles of hot water consumption in order to examine the temperature changes in the DHW tank. A system with an inlet, as an elbow facing down with a single plate, turned out to be the most advantageous variant (3–8% increase in energy efficiency compared to the basic inlet variant). An analogous analysis of the use of obstacles inside the tank showed that the most optimal solution is to place the partition, which allows the water flow on the sides of the tank, in its lower parts (energy efficiency higher by up to 15% compared to the variant without a partition). These solutions showed the highest energy efficiency for DHW production and the lowest energy demand for hot water heating in the tank among all analyzed variants.

Optical Design of LED Street Lights

2011 ◽  
Vol 121-126 ◽  
pp. 1004-1008
Author(s):  
Ying Chao Xu ◽  
Wen Zhang Zhu ◽  
Hong Yi Lin ◽  
Fei Bing Xiong
Keyword(s):  
Energy Efficiency ◽  
High Power ◽  
Light Emitting Diode ◽  
Optical Design ◽  
Light Distribution ◽  
Operating Life ◽  
Light Emitting ◽  
The Status ◽  
Output Efficiency ◽  
Optics Design

High-power light emitting diode (LED) develops greatly owing to its energy efficiency, light mono-direction and long operating life. But it is critical to have a secondary optics design for the LED street light, for obtaining good output efficiency and light distribution pattern. This article introduces many advantages of LED as street lightings source, and also analyzes the status and features of LED lamps’ application as street lightings. This article mainly designs a secondary optical light distribution implement using Lighttools 7.1. This paper also gives an example of one kind of freeform surfaces lens which can realize rectangular light shape.

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