GIS-linked tidal range energy resource assessment

“Wind-shadowing” effects in the Gulf of Finland coastal zone are analyzed using high resolution Envisat Synthetic Aperture Radar (SAR) measurements and model simulations. These effects are related to the internal boundary layer (IBL) development due to abrupt change the surface roughness at the sea-land boundary. Inside the "shadow" areas the airflow accelerates and the surface wind stress increases with the fetch. Such features can be revealed in SAR images as dark areas adjacent to the coastal line. Quantitative description of these effects is important for offshore wind energy resource assessment. It is found that the surface wind stress scaled by its equilibrium value (far from the coast) is universal functions of the dimensionless fetch Xf/G. Wind stress reaches an equilibrium value at the distance Xf/G of about 0.4.

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HF Radars for Wave Energy Resource Assessment Offshore NW Spain

Remote Sensing ◽

10.3390/rs13112070 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2070

Author(s):

Ana Basañez ◽

Vicente Pérez-Muñuzuri

Keyword(s):

Wave Energy ◽

Numerical Models ◽

Wave Spectrum ◽

Energy Resource ◽

Electrical Energy ◽

Resource Assessment ◽

Electricity Production ◽

Statistical Validation ◽

Wave Energy Converters ◽

Energy Converters

Wave energy resource assessment is crucial for the development of the marine renewable industry. High-frequency radars (HF radars) have been demonstrated to be a useful wave measuring tool. Therefore, in this work, we evaluated the accuracy of two CODAR Seasonde HF radars for describing the wave energy resource of two offshore areas in the west Galician coast, Spain (Vilán and Silleiro capes). The resulting wave characterization was used to estimate the electricity production of two wave energy converters. Results were validated against wave data from two buoys and two numerical models (SIMAR, (Marine Simulation) and WaveWatch III). The statistical validation revealed that the radar of Silleiro cape significantly overestimates the wave power, mainly due to a large overestimation of the wave energy period. The effect of the radars’ data loss during low wave energy periods on the mean wave energy is partially compensated with the overestimation of wave height and energy period. The theoretical electrical energy production of the wave energy converters was also affected by these differences. Energy period estimation was found to be highly conditioned to the unimodal interpretation of the wave spectrum, and it is expected that new releases of the radar software will be able to characterize different sea states independently.

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Evaluation and re-understanding of the global natural gas hydrate resources

Petroleum Science ◽

10.1007/s12182-021-00568-9 ◽

2021 ◽

Vol 18 (2) ◽

pp. 323-338

Author(s):

Xiong-Qi Pang ◽

Zhuo-Heng Chen ◽

Cheng-Zao Jia ◽

En-Ze Wang ◽

He-Sheng Shi ◽

...

Keyword(s):

Natural Gas ◽

Gas Hydrate ◽

Oil And Gas ◽

Material Balance ◽

Energy Resource ◽

Resource Assessment ◽

Future Trend ◽

Natural Gas Hydrate ◽

The Future ◽

Recoverable Resources

AbstractNatural gas hydrate (NGH) has been widely considered as an alternative to conventional oil and gas resources in the future energy resource supply since Trofimuk’s first resource assessment in 1973. At least 29 global estimates have been published from various studies so far, among which 24 estimates are greater than the total conventional gas resources. If drawn in chronological order, the 29 historical resource estimates show a clear downward trend, reflecting the changes in our perception with respect to its resource potential with increasing our knowledge on the NGH with time. A time series of the 29 estimates was used to establish a statistical model for predict the future trend. The model produces an expected resource value of 41.46 × 1012 m3 at the year of 2050. The statistical trend projected future gas hydrate resource is only about 10% of total natural gas resource in conventional reservoir, consistent with estimates of global technically recoverable resources (TRR) in gas hydrate from Monte Carlo technique based on volumetric and material balance approaches. Considering the technical challenges and high cost in commercial production and the lack of competitive advantages compared with rapid growing unconventional and renewable resources, only those on the very top of the gas hydrate resource pyramid will be added to future energy supply. It is unlikely that the NGH will be the major energy source in the future.

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Proposal to Refine Solar Radiation of Typical Meteorological Year Database and Evaluation on the Influence of Air-Conditioning Load

Atmosphere ◽

10.3390/atmos12040524 ◽

2021 ◽

Vol 12 (4) ◽

pp. 524

Author(s):

Jihui Yuan ◽

Kazuo Emura ◽

Craig Farnham

Keyword(s):

Solar Radiation ◽

Air Conditioning ◽

Energy Savings ◽

Energy Resource ◽

Global Solar Radiation ◽

Resource Assessment ◽

Weather Data ◽

Diffuse Solar Radiation ◽

Chinese Standard ◽

The Impact

The Typical meteorological year (TMY) database is often used to calculate air-conditioning loads, and it directly affects the building energy savings design. Among four kinds of TMY databases in China—including Chinese Typical Year Weather (CTYW), International Weather for Energy Calculations (IWEC), Solar Wind Energy Resource Assessment (SWERA) and Chinese Standard Weather Data (CSWD)—only CSWD is measures solar radiation, and it is most used in China. However, the solar radiation of CSWD is a measured daily value, and its hourly value is separated by models. It is found that the cloud ratio (diffuse solar radiation divided by global solar radiation) of CSWD is not realistic in months of May, June and July while compared to the other sets of TMY databases. In order to obtain a more accurate cloud ratio of CSWD for air-conditioning load calculation, this study aims to propose a method of refining the cloud ratio of CSWD in Shanghai, China, using observed solar radiation and the Perez model which is a separation model of high accuracy. In addition, the impact of cloud ratio on air-conditioning load has also been discussed in this paper. It is shown that the cloud ratio can yield a significant impact on the air conditioning load.

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