scholarly journals A Quadratically Constrained Optimization Problem for Determining the Optimal Nominal Power of a PV System in Net-Metering Model: A Case Study for Croatia

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1746
Author(s):  
Luka Budin ◽  
Goran Grdenić ◽  
Marko Delimar
Keyword(s):  
Optimization Problem ◽  
Net Present Value ◽  
Electrical Energy ◽  
Electricity Production ◽  
Discrete Optimization Problem ◽  
Pv System ◽  
Net Metering ◽  
Quadratically Constrained ◽  
The Impact

The world’s demand for electrical energy is increasing rapidly while the use of fossil fuels is getting limited more and more by energy policies and the need for reducing the impact of climate change. New sources of energy are required to fulfill the world’s demand for electricity and they are currently found in renewable sources of energy, especially in solar and wind power. Choosing the optimal PV nominal power minimizes the unnecessary surplus of electrical energy that is exported to the grid and thus is not making any impact on the grid more than necessary. Oversizing the PV system according to the Croatian net-metering model results in switching the calculation of the costs to the prosumer model which results in a decrease of the project’s net present value (NPV) and an increase in the payback period (PP). This paper focuses on formulating and solving the optimization problem for determining the optimal nominal power of a grid-connected PV system with a case study for Croatia using multiple scenarios in the variability of electricity production and consumption. In this paper, PV systems are simulated in the power range that corresponds to a typical annual high-tariff consumption in Croatian households. Choosing the optimal power of the PV system maximizes the investor’s NPV of the project as well as savings on the electricity costs. The PP is also minimized and is determined by the PV production, household consumption, discount rate, and geographic location. The optimization problem is classified as a quadratically constrained discrete optimization problem, where the value of the optimal PV power is not a continuous variable because the PV power changes with a step of one PV panel power. Modeling and simulations are implemented in Python using the Gurobi optimization solver.

scholarly journals Photovoltaic Systems and Net Metering in Greece

2018 ◽  
Vol 8 (4) ◽  
pp. 3168-3171
Author(s):  
F. Mavromatakis ◽  
G. Viskadouros ◽  
H. Haritaki ◽  
G. Xanthos
Keyword(s):  
Net Present Value ◽  
Electricity Consumption ◽  
Electrical Energy ◽  
Internal Rate Of Return ◽  
Pv System ◽  
Local Loads ◽  
Electricity Bill ◽  
Net Metering ◽  
Cost Of Energy ◽  
Electrical Consumption

The latest measure for the development of photovoltaics in Greece utilizes the net-metering scheme. Under this scheme the energy produced by a PV system may be either consumed by the local loads or be injected to the grid. The final cost reported in an electricity bill depends upon the energy produced by the PV system, the energy absorbed from the grid and the energy injected to the grid. Consequently, the actual electricity consumption profile is important to estimate the benefit from the use of this renewable energy source. The state latest statistics in Greece for households reveal that the typical electrical consumption is 3750 kWh while 10244 kWh are consumed in the form of thermal energy. We adopt in our calculations the above amount of electrical energy but assume four different scenarios. These different hourly profiles are examined to study the effects of synchronization upon the final cost of energy. The above scenarios are applied to areas in different climate zones in Greece (Heraklion, Athens and Thessaloniki) to examine the dependence of the hourly profiles and the solar potential upon the financial data with respect to internal rate of return, payback times, net present value and the levelized cost of energy. These parameters are affected by the initial system cost and the financial parameters.

scholarly journals Marine current energy assessment and the hydrodynamic design of the hydrokinetic turbine for the Moroccan Mediterranean Coast

2021 ◽  
pp. 014459872098662
Author(s):  
Salma Hazim ◽  
Abdelouahab Salih ◽  
Mourad Taha Janan ◽  
Ahmed El Ouatouati ◽  
Abdellatif Ghennioui
Keyword(s):  
Electrical Energy ◽  
Mediterranean Coast ◽  
Electricity Production ◽  
Blade Element Theory ◽  
Hydrokinetic Turbine ◽  
Marine Current ◽  
Current Resource ◽  
Suitable Area ◽  
The Impact ◽  
Current Energy

Generating electricity through renewable energies is growing increasingly to reduce the huge demand on electricity and the impact of fossil energies on the environment, the most common sources forms used are: the wind, the sun, the photovoltaic and the thermal, without forgetting hydropower by the bays of dams. Fortunately, 70% of our planet is covered by the seas and oceans, this area constitutes a huge potential for electricity production to be exploited. The scientific advances of recent years allow a better exploitation of these resources especially the marine current due to its reliability and predictability. The marine current energy is extracted using a hydrokinetic turbine (HKT) which transform the kinetic energy of water into an electrical energy. The exploitation of this resource needs in the first step the assessment of marine currents in the study area for implementing the HKT, and the second step is designing an adequate technology. The main goal of this study is the assessment of the marine current resource on the Moroccan Mediterranean coast to evaluate the suitable area to implement the HKT, and to determine the marine current speed intensities at different depths. As well as, to estimate an average potential existing in the site. Moreover, we will conduct a study based on the results of the assessment that was made to design a horizontal axis marine current turbine (HAMCT). Two hydrofoil profile were considered to design a HAMCT using the Blade Element Theory (BEM) and calculating their performances adapted to the site conditions Naca4415 and s8052. In addition, a comparison was made between this two HAMCT hydrofoil profile for deciding the best one for implementing in the studied area.

Impact of Rooftop PV Shading on Net Electrical Energy Demand of Buildings in Pakistan

2021 ◽  
Vol 3 (1) ◽  
pp. 45-49
Author(s):  
Muhammad Umar Maqbool ◽  
Arslan Dawood Butt ◽  
Abdul Rauf Bhatti ◽  
Yawar Ali Sheikh ◽  
Muhammad Waleed Asif
Keyword(s):  
Energy Demand ◽  
Heat Load ◽  
Layer Structure ◽  
Electrical Energy ◽  
Position Angle ◽  
Net Energy ◽  
Ambient Conditions ◽  
Pv System ◽  
Roof Structure ◽  
The Impact

This work performs a quantitative assessment of the impact of rooftop PV installation on building’s net energy demand using model of roof structure and steady state thermal simulations. For this purpose, roof structure typically used in Faisalabad, Pakistan is modeled with and without the shading effect due to a 395 W commercial rooftop PV setup. The simulated parameters include the impact of PV module’s dimensions, mounting position/angle alongside roof size and ambient conditions on heat load of air-conditioning system to maintain a temperature of 25 °C within building’s top floor. During the daylight hours of July, the heat load added by the roof on average reduces from 150.87 BTU/h/m2 without PV to 118.16 BTU/h/m2 with PV structure. This 20.05% reduction in energy demand has been achieved with July’s maximum daytime solar and infrared irradiances of 792.2 W/m2 and 466 W/m2 recorded at an average ambient temperature of 35.5 °C and wind speed of 2.75 m/s. This study provides valuable data on optimization of roof layer structure during building’s construction in anticipation of PV system installation at a later stage. Also developed techniques/methods to reduce building’s energy budget due to PV installation, can be valuable input for construction industry as well.

Simulating the impact of coal seam gas water production on aquifers

2012 ◽  
Vol 52 (1) ◽  
pp. 545 ◽  
Author(s):  
Julian Strand ◽  
Reem Freij-Ayoub ◽  
Shakil Ahmed
Keyword(s):  
Coal Seam ◽  
Electricity Production ◽  
Water Production ◽  
Hypothetical Case ◽  
Coal Seam Gas ◽  
Coal Resources ◽  
Victorian Department ◽  
Gippsland Basin ◽  
The Impact

Derived from a larger scale project, which studied geomechanical issues associated with coal seam gas (CSG) production, this paper investigates a hypothetical case study based on the Latrobe Valley, Gippsland Basin, Victoria. The paper focuses on examining aquifer water management associated with CSG production-related water extraction. As such, the paper limits itself to determining the volume of water production from a hypothetical case study area in the Latrobe Valley. A simplistic property model and methane production strategy has been used. The impact of extraction of this water on the hydraulic head in aquifers underlying the produced seams is quantified. The Latrobe Valley Depression contains 129,000 million tonnes of coal resources and is one of the world’s largest, and lowest cost, energy sources. Most of Victoria’s electricity is generated using coal from the Loy Yang, Morwell and Yallourn mines. In addition to these massive operations, significant additional coal resources are available and unallocated at this time. Opportunities exist for the continued usage of these resources for electricity production, gasification, liquefaction and other coal conversion processes, as well as solid fuel for industrial, domestic and other uses. The existence of data from the Victorian Department of Primary Industries 2003 coal resource model was the main reason for the selection of the case study, and their data was used to form a model of the stratigraphy of the Latrobe Valley. Aquifer models were simulated in MODFLOW, based on extraction figures modelled in the CSG simulator COMET3.

scholarly journals Investigation of the Multi-Point Injection of Green Hydrogen from Curtailed Renewable Power into a Gas Network

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6047 ◽  
Author(s):  
Ali Ekhtiari ◽  
Damian Flynn ◽  
Eoin Syron
Keyword(s):  
Green Energy ◽  
Active Management ◽  
Electricity Production ◽  
Renewable Electricity ◽  
Gas Network ◽  
Network Location ◽  
Network Parameters ◽  
Renewable Power ◽  
The Impact

Renewable electricity can be converted into hydrogen via electrolysis also known as power-to-H2 (P2H), which, when injected in the gas network pipelines provides a potential solution for the storage and transport of this green energy. Because of the variable renewable electricity production, the electricity end-user’s demand for “power when required”, distribution, and transmission power grid constrains the availability of renewable energy for P2H can be difficult to predict. The evaluation of any potential P2H investment while taking into account this consideration, should also examine the effects of incorporating the produced green hydrogen in the gas network. Parameters, including pipeline pressure drop, flowrate, velocity, and, most importantly, composition and calorific content, are crucial for gas network management. A simplified representation of the Irish gas transmission network is created and used as a case study to investigate the impact on gas network operation, of hydrogen generated from curtailed wind power. The variability in wind speed and gas network demands that occur over a 24 h period and with network location are all incorporated into a case study to determine how the inclusion of green hydrogen will affect gas network parameters. This work demonstrates that when using only curtailed renewable electricity during a period with excess renewable power generation, despite using multiple injection points, significant variation in gas quality can occur in the gas network. Hydrogen concentrations of up to 15.8% occur, which exceed the recommended permitted limits for the blending of hydrogen in a natural gas network. These results highlight the importance of modelling both the gas and electricity systems when investigating any potential P2H installation. It is concluded that, for gas networks that decarbonise through the inclusion of blended hydrogen, active management of gas quality is required for all but the smallest of installations.

A bioeconomic approach to assess the impact of an alien invasive insect on timber supply and harvesting: a case study with Sirex noctilio in eastern Canada

2009 ◽  
Vol 39 (1) ◽  
pp. 154-168 ◽  
Author(s):  
Denys Yemshanov ◽  
Daniel W. McKenney ◽  
Peter de Groot ◽  
Dennis Haugen ◽  
Derek Sidders ◽  
...  
Keyword(s):  
Net Present Value ◽  
Eastern Canada ◽  
Sirex Noctilio ◽  
Timber Supply ◽  
Allocation Model ◽  
Policy Makers ◽  
Potential Losses ◽  
Alien Insect ◽  
The Impact

This study presents a model that assesses the potential impact of a new alien insect species, Sirex noctilio Fabricius, on pine timber supply and harvest activities in eastern Canada. We integrate the spread of S. noctilio with a broad-scale growth and harvest allocation model. Projections of pine mortality range between 25 × 106 and 115 × 106 m3 over 20 years depending on S. noctilio spread and impact assumptions. Our model suggests Ontario could experience the highest, most immediate losses (78% of the potential losses across eastern Canada), with Quebec sustaining most of the rest of the losses over the next 20 years. Potential losses of $86 to $254 million per year are simulated after 20 years. The net present value of total harvest losses after 28 years of outbreak ranges between $0.7 to $2.1 billion. Adaptation policies decrease short-term losses by 46%–55% and delay larger harvest failures by 9–11 years. Without harvest adaptation, failures to maintain annual allowable cut levels may occur once the total area infested exceeds 15 × 106 ha. While better understanding and representing S. noctilio behaviour will involve a significant effort, there is a strong demand by policy makers for this kind of information.

Online Electrovalency Formulating and Influence Factors Analysing of Photovoltaic Generation

2012 ◽  
Vol 512-515 ◽  
pp. 113-118
Author(s):  
Qian Feng ◽  
Pei Kun Zhao ◽  
Hui Wei Shi ◽  
Jiong Zhu ◽  
Jie Lei Tu
Keyword(s):  
Net Present Value ◽  
Financial Analysis ◽  
Unit Cost ◽  
Influence Factors ◽  
Pv System ◽  
World Energy ◽  
Generating Capacity ◽  
And Performance ◽  
Important Position ◽  
The Impact

Photovaltaic power generation in the future world energy consumption will occupy an important position, not only to partially replace conventional energy sources, and will become the main energy supply. But at present, compared with conventional energy generation, photovoltaic electricity does not have a competitive advantage. So develop a reasonable electrovalency is the key to promote the healthy development of China’s photovoltaic industry. This paper use the net present value method of financial analysis to learn the generating capacity and investment cost of PV system combined with system’s characteristics and performance, discuss the unit cost of PV power and analyzed the impact of PV electricity price factors.

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