High‐frequency standard deviation of the capacity factor of renewable energy facilities: Part 1—Solar photovoltaic

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Alberto Boretti
Keyword(s):  
Renewable Energy ◽  
Standard Deviation ◽  
High Frequency ◽  
Frequency Standard ◽  
Capacity Factor ◽  
Solar Photovoltaic

scholarly journals Capacity factors of solar photovoltaic energy facilities in California, annual mean and variability

2020 ◽  
Vol 181 ◽  
pp. 02004
Author(s):  
Alberto Boretti ◽  
Stefania Castelletto ◽  
Wael Al-Kouz ◽  
Jamal Nayfeh
Keyword(s):  
Energy Storage ◽  
High Frequency ◽  
Energy Production ◽  
Low Frequency ◽  
Average Energy ◽  
Capacity Factor ◽  
Solar Photovoltaic ◽  
Cost Penalty ◽  
The Individual ◽  
Annual Capacity

The capacity factors of the largest solar photovoltaic (PV) energy facilities of California are computed, based on a low-frequency monthly statistic that is covering the last few years. While the best-performing facilities achieve annual capacity factors of about 32-33%, the average annual capacity factor is less than 30%, at about 26-27%. The scattered information on costs suggests a cost penalty of 35% for a capacity factor gain of 10%. Higher frequency data of 1-minute or less for every facility connected to the same grid and the grid average energy supply are needed to define the energy storage indispensable to cover a given demand. The individual facility energy production requires to account for a cost associated with an energy storage allowance to every producer of intermittent and unpredictable electricity, with this amount inversely proportional to the annual average capacity factor and directly proportional to the standard deviation of the high-frequency capacity factors.

Reliability of the Minimum Masking Level as Outcome Variable in Tinnitus Clinical Research

2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  
Keyword(s):  
Standard Deviation ◽  
High Frequency ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Outcome Variable ◽  
Reliable Estimate ◽  
Moderate Correlation ◽  
Trained Subjects ◽  
The Relationship ◽  
Minimum Intensity

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.

scholarly journals Environmental Impact and Levelised Cost of Energy Analysis of Solar Photovoltaic Systems in Selected Asia Pacific Region: A Cradle-to-Grave Approach

2021 ◽  
Vol 13 (1) ◽  
pp. 396
Author(s):  
Norasikin Ahmad Ludin ◽  
Nurfarhana Alyssa Ahmad Affandi ◽  
Kathleen Purvis-Roberts ◽  
Azah Ahmad ◽  
Mohd Adib Ibrahim ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Renewable Energy ◽  
Life Cycle ◽  
Environmental Impact ◽  
Degradation Rate ◽  
Economic Feasibility ◽  
Asia Pacific ◽  
Solar Photovoltaic ◽  
Economic Output ◽  
Cost Of Energy

Sustainability has been greatly impacted by the reality of budgets and available resources as a targeted range of carbon emission reduction greatly increases due to climate change. This study analyses the technical and economic feasibility for three types of solar photovoltaic (PV) renewable energy (RE) systems; (i) solar stand-alone, a non-grid-connected building rooftop-mounted structure, (ii) solar rooftop, a grid-connected building rooftop-mounted structure, (iii) solar farm, a grid-connected land-mounted structure in three tropical climate regions. Technical scientific and economic tools, including life cycle assessment (LCA) and life cycle cost assessment (LCCA) with an integrated framework from a Malaysian case study were applied to similar climatic regions, Thailand, and Indonesia. The short-term, future scaled-up scenario was defined using a proxy technology and estimated data. Environmental locations for this scenario were identified, the environmental impacts were compared, and the techno-economic output were analysed. The scope of this study is cradle-to-grave. Levelised cost of energy (LCOE) was greatly affected due to PV performance degradation rate, especially the critical shading issues for large-scale installations. Despite the land use impact, increased CO2 emissions accumulate over time with regard to energy mix of the country, which requires the need for long-term procurement of both carbon and investment return. With regards to profitably, grid-connected roof-mounted systems achieve the lowest LCOE as compared to other types of installation, ranging from 0.0491 USD/kWh to 0.0605 USD/kWh under a 6% discounted rate. A simple payback (SPB) time between 7–10 years on average depends on annual power generated by the system with estimated energy payback of 0.40–0.55 years for common polycrystalline photovoltaic technology. Thus, maintaining the whole system by ensuring a low degradation rate of 0.2% over a long period of time is essential to generate benefits for both investors and the environment. Emerging technologies are progressing at an exponential rate in order to fill the gap of establishing renewable energy as an attractive business plan. Life cycle assessment is considered an excellent tool to assess the environmental impact of renewable energy.

New Photovoltaic Module Model And A Comparative Study of MPPT Control Techniques Based On Neural Networks

2021 ◽  
pp. 69-76
Author(s):  
Mourad Talbi ◽  
Nawel Mensia ◽  
Hatem Ezzaouia
Keyword(s):  
Renewable Energy ◽  
Comparative Study ◽  
Temporal Variations ◽  
Operating Conditions ◽  
Maximum Power ◽  
Energy Resources ◽  
Solar Photovoltaic ◽  
Maximum Power Point ◽  
Mppt Controller ◽  
Power Point

Nowadays, renewable energy resources play an important role in replacing conventional fossil fuel energy resources. Solar photovoltaic (PV) energy is a very promising renewable energy resource, which rapidly grew in the past few years. The main problem of the solar photovoltaic is with the variation of the operating conditions of the array, the voltage at which maximum power can be obtained from it likewise changes. In this paper, is first performed the modelling of a solar PV panel using MATLAB/Simulink. After that, a maximum power point tracking (MPPT) technique based on artificial neural network (ANN) is applied in order to control the DC-DC boost converter. This MPPT controller technique is evaluated and compared to the “perturb and observe” technique (P&O). The simulation results show that the proposed MPPT technique based on ANN gives faster response than the conventional P&O technique, under rapid variations of operating conditions. This comparative study is made in terms of temporal variations of the duty cycle (D), the output power ( out P ), the output current ( out I ), the efficiency, and the reference current ( ref I ). The efficiency, D, out P , and out I are the output of the boost DC-DC, and ref I is itsinput. The different temporal variations of the efficiency, D, ref I , out P , and out I (for the two cases: the first case, when T = 25°C and G =1000 W/m2 and the second case, when T and G are variables), show negligible oscillations around the maximum power point. The used MPPT controller based on ANN has a convergence time better than conventional P&O technique.

Estimation of Electrical-Wave Power in Merang Shore, Terengganu, Malaysia

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Jaswar Jaswar ◽  
C. L. Siow ◽  
A. Maimun ◽  
C. Guedes Soares
Keyword(s):  
Renewable Energy ◽  
Wave Energy ◽  
Electrical Power ◽  
Green Technology ◽  
Solar Photovoltaic ◽  
Oscillating Water Column ◽  
Mean Wave Period ◽  
Point Absorbers ◽  
The Mean ◽  
Wave Converter

Malaysian government introduced Small Renewable Energy Power (SREP) Program such as biomass, biogas, and municipal solid waste, solar photovoltaic and mini-hydroelectric facilities in 2001. In year 2010, the energy generated by biomass was achieved 18 MW and mini hydro also successes to generate around 23 MW. Green Technology and Water Malaysia are targeted by Ministry of Energy to achieve cumulative renewable energy capacity around 2080 MW at year 2020 and 21.4 GW at year 2050. This paper discusses the possibility to utilize ocean wave in Merang shore, Terengganu, Malaysia. The literature reviewed available technologies used to convert wave energy to electricity which are developing currently. The available technologies reviewed here are attenuator, overtopper, point absorbers, oscillating wave surge converter and oscillating water column. The work principle of the device was covered. Finally, the sea condition in Malaysia also studied to analyze the possibility to utilize the wave energy by using the available technologies. It is found that the mean wave height is 0.95 meter and the mean wave period is 3.5 second in the Merang shore, Terengganu, Malaysia. Attenuator type wave converter developed by Wave Star is considered as one of the possible devices to be installed at the location. From the calculation, it is obtained that the total rate electrical power possible to grid is 649 MWh a year if only one set of C5 Wave star device is installed on Merang shore, Terengganu.

scholarly journals The Dollar and Corporate Borrowing Costs

2021 ◽  
Vol 2021 (1312) ◽  
pp. 1-64
Author(s):  
Ralf R. Meisenzahl ◽  
◽  
Friederike Niepmann ◽  
Tim Schmidt-Eisenlohr ◽  
◽  
...  
Keyword(s):  
Standard Deviation ◽  
High Frequency ◽  
Standard Deviation Increase ◽  
Borrowing Costs ◽  
Corporate Borrowing ◽  
Loan Terms ◽  
Syndicated Loan ◽  
Loan Amount

We show that U.S. dollar movements affect syndicated loan terms for U.S. borrowers, even for those without trade exposure. We identify the effect of dollar movements using spread and loan amount adjustments during the syndication process. Using this high-frequency, within loan variation, we find that a one standard deviation increase in the dollar index increases spreads by up to 15 basis points and reduces loan amounts and underpricing by up to 2 percent and 7 basis points, respectively. These effects are concentrated in dollar appreciations. Our results suggest that global factors reflected in the dollar affect U.S. borrowing costs.

scholarly journals Challenges in Grid Integration of Renewable Energy Systems via Inverter: A Survey

2021 ◽  
Vol 7 (3) ◽  
pp. 30-33
Author(s):  
Sourabh Kedar ◽  
Mr. Santosh Singh Negi
Keyword(s):  
Renewable Energy ◽  
Reactive Power ◽  
Power Grids ◽  
Grid Integration ◽  
Solar Photovoltaic ◽  
Renewable Energy Systems ◽  
Pv Systems ◽  
The Past ◽  
Network Coordination ◽  
The Individual

Solar photovoltaic (PV) systems have mainly been used in the past decade. Inverter-powered photovoltaic grid topologies are widely used to meet electricity demand and to integrate forms of renewable energy into power grids. Meeting the growing demand for electricity is a major challenge today. This paper provides a detailed overview of the topological trend of inverters with connection to the photovoltaic grid, as well as the advantages, disadvantages and main characteristics of the individual inverters. For proper integration into a network, coordination between the supporting devices used for reactive power compensation and their optimal reactive power capacity for grid current stability is important.

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