Forecasting the Mix of World Energy Needs by mid-21st Century

The logistic function is used to forecast energy consumed worldwide. The logistic substitution model is used to describe the energy mix since 1965 presenting a picture significantly different from the one covering the previous 100 years. In the new picture the share of heavy pollutants, i.e. coal plus oil, keeps declining systematically in favor of natural gas and renewables (wind, geothermal, solar, biomass, and waste), the share of which grows rapidly. The shares of these three energy sources are poised to reach around 30% each by mid-21st century. Nuclear and hydroelectric energy, both with rather stable shares, are responsible for the remaining 10%, which goes mostly to hydroelectric; Zooming into the composition of renewables we find that today’s dominant wind power is about to begin losing share to solar energy, which will overtake wind after 2024 and account for more than 90% of all renewables by mid-21st century, by which time geothermal, biomass, and other sources of energy will have dropped to insignificant levels. Forecasts in exajoules are given for all energy sources up to 2050.

The current state and prospects for the development of Russian Federation green energy exports

Renewable energy is obtained from sustainable sources, which in particular include solar and wind energy, geothermal and hydroelectric energy, biomass, tidal energy. The Russian Federation has a significant potential for the development of “green” energy, is among the leaders in terms of export potential in this area. The article considers the export potential of fuel wood pellets. The European sales market, problems and prospects of entering it were studied as priority areas. The purpose of this study is to assess the export potential of the Russian Federation for “green” energy products, using the example of the group of HS 4401310000 Wood pellets. Within the framework of the study, the following tasks were solved: the importance of export relations in the framework of the development of “green” energy directions was studied, the market of wood pellets of the Russian Federation was studied and the export potential of the country for this group of goods was determined. As a result of the conducted research, the authors concluded that the development of the export of wood fuel pellets is of high importance for strengthening the country’s position in the market of foreign trade in renewable energy sources.

Symmetric and Asymmetric Impacts of Commercial Energy Distribution from Key Sources on Economic Progress in Pakistan

This paper aims to determine the interaction of commercial energy distribution, including the installed capacity of hydroelectric energy, hydroelectric energy generation, the installed capacity of thermal energy, thermal energy generation, the installed capacity of nuclear energy, and nuclear energy generation, with economic progress in Pakistan over the 1970–2019 period. Both linear and non-linear autoregressive distributed lag models were used to ascertain the symmetric and asymmetric short- and long-run effects. The findings from the linear autoregressive distributed lag model analysis revealed evidence that increases in the installed capacity of nuclear energy, alongside higher levels of hydroelectric energy generation and thermal energy generation, have positively affected economic growth in the short run, while a greater installed capacity of nuclear energy has positively affected economic growth in the long run. The findings from the non-linear autoregressive distributed lag model analysis showed that negative shocks to installed capacities related to hydroelectric, thermal, and nuclear energy reduced economic growth, while positive shocks to hydroelectric energy generation and the installed capacity of nuclear energy boosted economic growth in the short run. Furthermore, in the long run, negative shocks to the installed capacities of hydroelectric and thermal energy reduced economic growth, negative shocks to the installed capacity of nuclear energy enhanced economic growth, and positive shocks to hydroelectric energy generation and the installed capacity of nuclear energy have stimulated economic growth in Pakistan.

Experimental Study on Hydroelectric Energy Harvester Based on a Hybrid Qiqi and Turbine Structure

The Qiqi structure design can automatically upset and spill its content once it arrives at limit capacity under vertical water flow excitation. Considering this function, the Qiqi structure has been utilized for small hydroelectric energy harvesting lately. To investigate the tradeoff between the Qiqi structure and the turbine structure for small hydroelectric energy harvesting, an energy harvester based on a hybrid Qiqi and turbine structure is proposed for vertical water flow hydroelectric applications. The hybrid structure is composed of a rectangular Qiqi structure, with two blades inserted on both sides. Self-tipping function of the hybrid Qiqi structure and working principle of the structure is investigated in detail. The proposed structure has both the advantages of low flow velocity energy harvesting of the Qiqi structure and high flow velocity energy harvesting of the turbine structure. A hydroelectric energy harvesting application using the hybrid structure is given to demonstrate that the hybrid structure had a higher rotational speed than the Qiqi structure under vertical low water flow excitation and was able to work at relatively high flow rates. Thus, the investigated hybrid structure can help small rotational hydropower achieve better energy harvesting performance and work at wide-range flow rates under vertical ultra-low water flow applications. At 600 mL/min, 902 μJ of electrical energy was charged by the investigated structure, which is six times higher than that using the Qiqi structure alone.

Discrimination between schools and submerged trees in reservoirs: A preliminary approach using narrowband and broadband acoustics

With a growing demand for hydroelectric energy, the number of reservoirs is dramatically increasing worldwide. These new water bodies also present an opportunity for the development of fishing activities. However, these reservoirs are commonly impounded on uncut forests, resulting in many immersed trees. These trees hinder fish assessments by disrupting both gill netting and acoustic sampling. Immersed trees can easily be confused with fish schools on echograms. To overcome this issue, we developed a method to discriminate fish schools from immersed trees. A random forest algorithm was used to classify echo-traces at 120 and 200 kHz, recorded by an EK80 (SIMRAD) in narrowband (Continuous Wave) and in broadband mode (Frequency Modulated). We obtained a good discrimination rate between trees and schools, especially in broadband (90 % ratio of good classification). We demonstrate that it is possible to discriminate fish schools from immersed trees and thus facilitate the use of fisheries acoustics in reservoirs.

Snow Cover Variability in the Greater Alpine Region in the MODIS Era (2000–2019)

Snow cover is particularly important in the Alps for tourism and the production of hydroelectric energy. In this study, we investigate the spatiotemporal variability in three snow cover metrics, i.e., the length of season (LOS), start of season (SOS) and end of season (EOS), obtained by gap-filling of MOD10A1 and MYD10A1, daily snow cover products of MODIS (Moderate-resolution Imaging Spectroradiometer). We analyze the period 2000–2019, evaluate snow cover patterns in the greater Alpine region (GAR) as a whole and further subdivide it into four subregions based on geographical and climate divides to investigate the drivers of local variability. We found differences both in space and time, with the northeastern region having generally the highest LOS (74 ± 4 days), compared to the southern regions, which exhibit a much shorter snow duration (48/49 ± 2 days). Spatially, the variability in LOS and the other metrics is clearly related to elevation (r2 = 0.85 for the LOS), while other topographic (slope, aspect and shading) and geographic variables (latitude and longitude) play a less important role at the MODIS scale. A high interannual variability was also observed from 2000 to 2019, as the average LOS in the GAR ranged between 41 and 85 days. As a result of high variability, no significant trends in snow cover metrics were seen over the GAR when considering all grid cells. Considering 500-m elevation bands and subregions, as well as individual grid points, we observed significant negative trends above 3000 m a.s.l., with an average of −17 days per decade. While some trends appeared to be caused by glacierized areas, removing grid cells covered by glaciers leads to an even higher frequency of grid cells with significant trends above 3000 m a.s.l., reaching 100% at 4000 m a.s.l. Trends are however to be considered with caution because of the limited length of the observation period.

Mine Water for the Generation and Storage of Renewable Energy: A Hybrid Hydro–Wind System

Mine water is normally considered as waste that has to be managed. However, new applications are increasingly being sought for the water that floods mining voids, especially in relation to its use as an energy resource. The worldwide energy market, within the current transition framework, is searching for creative approaches to produce and store clean energy. In particular, underground pumped hydroelectric energy storage systems (UPHS) constitute efficient and flexible alternatives to deal with intermittent renewable energy sources. In this work, a UPHS is designed using the mine water and the voids of a closed coal mine in Asturias (North-west Spain) as a lower reservoir. Moreover, this system is combined with a wind energy generation facility and the efficiency of the hybrid system is evaluated. With an investment cost of EUR 193 M, a 40 MW UPHES joined to a 60 MW wind farm would generate benefits of about EUR 54 M in 40 years. The reduction in CO2 emissions (29,000 equivalent tons per year) and the social benefits in a traditional mining area are other intangible advantages of this system.