nasa-gesdisc/es-publications-researchareas huggingface dataset:
GEOSPATIAL ASSESSMENT FOR PLANNING A SMART ENERGY CITY USING ROOFTOP SOLAR PHOTOVOLTAIC IN BANDUNG CITY, INDONESIA. (2021)

Abstract. Increasing the production of clean and environmentally friendly energy has become one of the world agendas as a strategic effort in dealing with long-term climate change. Seeing the potential of the energy produced, the ease in the installation process, with the small risk of harm generated, solar energy has received significant attention from many countries in the world. The potential for solar energy in Indonesia alone reaches 207 GWp, but only 145.81 MWp has been utilized. Currently, the Indonesian government has set a target to build a Solar Power Plant capacity in 2025 of 6.5 GWh. Urban areas are areas with higher energy demand than rural areas, but the availability of vacant land in urban areas is very minimal for installing solar power plants. Therefore, rooftop solar PV(Photovoltaic) can be a solution in dense areas such as cities. Good planning by looking at the potential resources and energy needs in spatial is needed to manage and utilize energy optimally and sustainably in urban areas. This study aims to develop a geospatial assessment for plan smart energy city that uses rooftop solar PV's potential energy in every building that is effective and efficient. The novelty in the analysis of the distribution of the potential for rooftop solar PV development in urban areas integrates meteorological and spatial aspects and socio-economic aspects. Integration of multi-dynamic spatial data uses in determining the rooftop solar PV construction location, such as meteorological data for solar energy potential, increasing energy needs of each building, and socio-economy data. The data source used comes from statistical data and remote sensing data. The analysis will be carried out temporally (2008, 2013, and 2018) to see the pattern of changes in aspects used in a certain period so that the development plan can be carried out more optimally. This research's output is the formation of a priority analysis of solar PV rooftop construction in urban areas, especially the city of Bandung. The result of energy can also produce by the construction of rooftop solar PV in a potential area. This research is expected to be utilized by policymakers to develop renewable energy in the city of Bandung and increase community participation in switching to renewable energy.

Research areas: Energy Production/Use
Global atlas of closed-loop pumped hydro energy storage (2020)

The difficulty of finding suitable sites for dams on rivers, including the associated environmental challenges, has caused many analysts to assume that pumped hydro energy storage has limited further opportunities to support variable renewable generation. Closed-loop, off-river pumped hydro energy storage overcomes many of the barriers. Small (square km) upper reservoirs are typically located in hilly country away from rivers, and water is circulated indefinitely between an upper and lower reservoir. GIS analysis of high resolution global digital elevation models was used to determine economically feasible closed-loop scheme locations outside protected and urban areas. This search identified 616,000 potential storage sites with an enormous combined storage potential of 23,000 TWh. This is two orders of magnitude more than required to support large fractions of renewable electricity, allowing flexible site selection. Importantly, the resource is widely distributed to effectively support large-scale solar and wind deployment for electrical grid decarbonization.

Research areas: Energy Production/Use
Direct impact of solar farm deployment on surface longwave radiation (2021)

Abstract
            
              Motivated by a previous study of using the Moderate Resolution Imaging Spectroradiometers (MODIS) observations to quantify changes in surface shortwave spectral reflectances caused by six solar farms in the southwest United States, here we used a similar method to study the longwave effects of the same six solar farms, with emphases on surface emissivities and land surface temperature (LST). Two MODIS surface products were examined: one relying on generalized split-window algorithm while assuming emissivities from land cover classifications (MYD11A2), the other based on Temperature Emissivity Separation algorithm capable of dynamically retrieving emissivities (MYD21A2). Both products suggest that, compared to adjacent regions without changes before and after solar farm constructions, the solar farm sites have reduced outgoing radiances in three MODIS infrared window channels. Such reduction in upward longwave radiation is consistent with previous
              in situ
              measurements. The MYD11A2 results show constant emissivities before and after solar farm constructions because its land type classification algorithm is not aware of the presence of solar farms. The estimated daytime and nighttime LST reduction due to solar farm deployment are 14K and 0.20.9K, respectively. The MYD21A2 results indicate a decrease in Band 31 (10.7811.28
              
              m) emissivity up to 0.01 and little change in Band 32 (11.7712.27
              
              m) emissivity. The LST decreases in the MYD21A2 is slightly smaller than its counterpart in the MYD11A2. Laboratory and
              in situ
              measurements indicate the longwave emissivity of solar panels can be as low as 0.83, considerably smaller than MODIS retrieved surface emissivity over the solar farm sites. The contribution of exposed and shaded ground within the solar farm to the upward longwave radiation needs to be considered to fully explain the results. A synthesis of MODIS observations and published
              in situ
              measurements is presented. Implication for parameterizing such solar farm longwave effect in the climate models is also discussed.

Research areas: Sun-Earth Interactions
Determination of the Suitable Areas for The Investment of the Wind Energy Plants (WEP) in Osmaniye Using Analytical Hierarchy Process (AHP) and … (2020)

Renewable energy sources are considered as clean energy sources. They have a much lower environmental impact than other energy sources. Among the renewable energy sources, the wind is an important energy source. In many countries the wind power production is so popular and many alternative research techniques related to wind energy are applied. Wind energy comes to the forefront today due to the increasing population of countries and the increase in energy needs. In our country the studies about the renewable energy has evolved rapidly over the past decade. The cost of initial installation of Wind Energy Plants (WEP) is high and they can only be installed if certain conditions are met. Site selection for wind turbine installation is not a technical process only, also a complex process is necessary for involving social, economic, physical and environmental sanctions. Therefore, site selection of wind energy plants is a very complex spatial decision problem for decision makers. For the different site selection studies multi criteria evaluation methods are often used. In the study, potential WEP investment areas of Osmaniye province were determined by using, Geographical Information Systems (GIS), Analytic Hierarchy Process (AHP) method and remote sensing. The criteria selected according to the general characteristics of the study area were combined with ArcGIS software using the weight values obtained with AHP and suitable areas for the WEP installation were determined. The land suitability index maps for the WEP siting is created in the ArcGIS program. The weighted Sum analysis of the Spatial Analyst Tool is used for this purpose. According to the results, 14.30% of the study area are suitable, 15.84% are moderate suitable and 69.86% are not suitable for wind energy plant siting

Research areas: Energy Production/Use
Impact of Prospective Climate Change Scenarios upon Hydropower Potential of Ethiopia in GERD and GIBE Dams (2021)

Ethiopia is growing fast, and the country has a dire need of energy. To avoid environmental damages, however, Ethiopia is looking for green energy polices, including hydropower exploitation, with large water availability (i.e., the Blue Nile, the greatest tributary of Nile river). Besides other dams on the Omo river, the GIBE family, Ethiopia is now building the largest hydropower plant of Africa, the GERD (Grand Ethiopian Renaissance Dam), on the Blue Nile river, leading to tensions between Ethiopia, and Egypt, due to potentially conflictive water management. In addition, present and prospective climate change may affect reservoirs operation, and this thereby is relevant for downstream water users, population, and environment. Here, we evaluated water management for the GERD, and GIBE III dams, under present, and future hydrological conditions until 2100. We used two models, namely, Poli-Hydro and Poli-Power, to describe (i) hydrological budget, and flow routing and (ii) optimal/maximum hydropower production from the two dams, under unconstrained (i.e., no release downstream besides MIF) and constrained (i.e., with fair release downstream) simulation. We then used climate change scenarios from the reports CMIP5/6 of the Intergovernmental Panel on Climate Change (IPCC) until 2100, to assess future hydropower production. Our results demonstrate that the filling phase of the GERD, particularly critical, have optimal filling time of 5 years or so. Stream flows at GERD could be greater than the present ones (control run CR) at half century (20502059), but there could be large decrease at the end of century (20902099). Energy production at half century may increase, and then decrease until the end of century. In GIBE III discharges would increase both at half century, and at the end of century, and so would energy production. Constrained, and unconstrained simulation provide in practice similar results, suggesting potential for shared water management in both plants.

Research areas: Energy Production/Use
Meteorological assessment of coupled wind–solar power generation regimes in Spain (2022)

Wind and solar power generation exhibit variability over a wide range of time scales. This intermittency is probably the most important drawback in terms of increasing the participation of these energies in the power systems. A proper distribution of wind and solar plants in a region has been reported to be a successful way to reduce the fluctuations in the aggregated-power supply. This reduction is enhanced when the allocation of the renewable power capacity makes use of the spatiotemporal variability of the wind and solar energy resources. Indeed, by exploiting the spatial and temporal complementarity of the wind and solar energy resources, below-normal power generation in some areas can be balanced with above-normal generation in other areas at given times, thereby reducing the fluctuations in the power generation. The main objective of this study is to assess the extent to which the wind and solar power generation is coupled in Spain on daily time scales, as well as to analyze their associated weather patterns. A byproduct of this study is the identification of coupled windsolar power generation modes exhibiting balancing. To this end, gridded daily solar and wind power generation time series, spanning a period of 10 years (200110) and covering Spain, are used as input of a clustering algorithm. As a result, coupled power regimes (CPRs) are obtained. For each of these CPRs, the spatial distribution of the wind and solar power generation and the associated synoptic weather patterns are evaluated. The CPRs are interpreted on the light of these weather patterns and the topographic features of the study region. The results reveal the existence of six-coupled modes for winter and four for the rest of the seasons, with only some of these modes being relevant regarding the balancing between the wind and solar power generation. A marked seasonality of the balancing strength as well as their spatial and temporal covering is observed. The most relevant balancing is detected during autumn, followed by winter, spring, and, lastly, summer. It is found that all the balancing modes, except the summer ones, are associated with the presence of a positive/negative (alternating) center of pressures anomalies located, roughly, over Ireland. The interaction of the resulting wind circulation with the existing topographical features explains the balancing patterns. The results reported in this study may have important consequences regarding the optimal spatial allocation of new renewable power plants over Spain. Nevertheless, the practical usefulness of the results implies the use of some daily energy storage system.

Research areas: Energy Production/Use
Effects of lockdown due to the COVID-19 pandemic on air quality at Latin America's largest open-pit coal mine (2021)

ABSTRACT Particulate matter (PM) is the main pollutant produced by open-pit mining operations, and its emission into the atmosphere is strongly associated with adverse health effects in the surrounding communities. The objective of this study was to evaluate the effects of the COVID-19-related lockdown on the PM concentrations in the North, Central, and South Zones of Cerrejon, Colombia, the largest open-pit coal mine in Latin America. To compare the levels before and during the emergency shutdown, we analyzed both the ground-based daily PM10 and PM2.5 data and the satellite (Terra/Aqua MODIS)-based daily aerosol optical depth (AOD) values from March 6 through April 13, 2020. The average PM10 concentrations in the North and South Zones, in contrast to those observed at other global monitoring sites, increased by 1338% and 47%, respectively, although they decreased by 2631% in the Central Zone, between the pre-lockdown and lockdown periods. Furthermore, during the latter, the daily PM2.5 levels in the South Zone rose by up to 43%, and we found higher AOD values ( 0.4) over the Central and South Zones as well as significant AOD-contributing loads upwind and downwind of the coal production pits. Finally, the increases in humidity and temperature ( 3.5% and  0.3 K, respectively), decrease in planetary boundary layer height ( 0.11 km), wind field variability, and rural biomass burning events shaped the spatial-temporal behavior of the PM in this region, and changes in meteorology and external sources nearly offset the reduction in emissions from mining activities. These results establish a baseline for developing future regulations and mitigation plans.

Research areas: Energy Production/Use, Air Quality
A solar energy desalination analysis tool, sedat, with data and models for selecting technologies and regions (2022)

There is interest for desalination technologies powered by solar energy as arid areas are typically bestowed with good solar potential. In response to a US DOE call for solar desalination analysis tools, we developed an open-source solar energy desalination analysis tool, sedat, for techno-economical evaluation of desalination technologies and selection of regions with the highest potential for using solar energy to power desalination plants. It is expected that this software will simplify the planning, design, and valuation of solar desalination systems in the U.S. and worldwide. Sedat uses Dash for integrating various layers of large volumes of GIS data with Python-based models of solar energy generation and desalination technologies. It derives time-series of energy generation and water production, with details of plant performance and suggestions for improving the solar-desalination coupling. This paper summarizes the various phases of the tools development, presents example results showing the potential, under multiple objectives, of solar desalination in parts of the U.S. southwest, and discusses method details that would be useful for future model development.

Research areas: Energy Production/Use
Potential assessment of photovoltaic power generation in China (2022)

Accurate assessment of the photovoltaic (PV) power generation potential in China is important for the reduction of carbon emission intensity and the achievement of the goal of Carbon Neutral. This study used a PV power generation potential assessment system based on Geographic Information Systems (GIS) and Multi-Criteria Decision Making (MCDM) methods to investigate the PV power generation potential in China. Firstly, the high spatial-temporal resolution and high-quality ERA5 data and related technical, geographic, and social factors were used to assess the theoretical power generation and land suitability of PV power generation. Then, the theoretical power generation and land suitability were comprehensively considered to evaluate the PV power generation potential of China in 2015. The results showed that the average suitability score of land in China is 0.1058 and the suitable land for PV power generation is about 993,000 km2 in 2015. The PV power generation potential of China is 131.942 PWh, which is approximately 23 times the electricity demand of China in 2015. The spatial distribution characteristics of PV power generation potential mainly showed a downward trend from northwest to southeast. Meanwhile, there were clear spatial dislocations between the PV power generation potential and the population distribution and electricity demand in China. In areas that accounting for about 75% of the PV potential, population and electricity demand only accounted for about 16% of the total population and total electricity demand in China. Besides, the degree of tapping PV potential in China is not high, and the installed capacity of most provinces in China accounted for no more than 1% of the capacity potential, especially in the PV potential-rich areas.

Research areas: Energy Production/Use
Multi-Criteria Assessment for City-Wide Rooftop Solar PV Deployment: A Case Study of Bandung, Indonesia (2022)

The world faces the threat of an energy crisis that is exacerbated by the dominance of fossil energy sources that negatively impact the sustainability of the earths ecosystem. Currently, efforts to increase the supply of renewable energy have become a global agenda, including using solar energy which is one of the rapidly developing clean energies. However, studies in solar photovoltaic (PV) modelling that integrates geospatial information of urban morphological building characters, solar radiation, and multiple meteorological parameters in low-cost scope have not been explored fully. Therefore, this research aims to model the urban rooftop solar PV development in the Global South using Bandung, Indonesia, as a case study. This research also has several specific purposes: developing a building height model as well as determining the energy potential of rooftop solar PV, the energy needs of each building, and the residential property index. This study is among the first to develop the national digital surface model (DSM) of buildings. In addition, the analysis of meteorological effects integrated with the hillshade parameter was used to obtain the solar PV potential value of the roof in more detail. The process of integrating building parameters in the form of rooftop solar PV development potential, energy requirements, and residential property index of a building was expected to increase the accuracy of determining priority buildings for rooftop solar PV deployment in Bandung. This study shows that the estimated results of effective solar PV in Bandung ranges from 351.833 to 493.813 W/m2, with a total of 1316 and 36,372 buildings in scenarios 1 and 2 being at a high level of priority for solar PV development. This study is expected to be a reference for the Indonesian government in planning the construction of large-scale rooftop solar PV in urban areas to encourage the rapid use of clean energy. Furthermore, this study has general potential for other jurisdictions for the governments focusing on clean energy using geospatial information in relation with buildings and their energy consumption.

Research areas: Energy Production/Use
The Water-Energy Nexus of Hydraulic Fracturing: A Global Hydrologic Analysis for Shale Oil and Gas Extraction (2018)

Shale deposits are globally abundant and widespread. Extraction of shale oil and shale gas is generally performed through water-intensive hydraulic fracturing. Despite recent work on its environmental impacts, it remains unclear where and to what extent shale resource extraction could compete with other water needs. Here we consider the global distribution of known shale deposits suitable for oil and gas extraction and develop a water balance model to quantify their impacts on local water availability for other human uses and ecosystem functions. We find that 31-44% of the world's shale deposits are located in areas where water stress would either emerge or be exacerbated as a result of shale oil or gas extraction; 20% of shale deposits are in areas affected by groundwater depletion and 30% in irrigated land. In these regions shale oil and shale gas production would likely compete for local water resources with agriculture, environmental flows, and other water needs. By adopting a hydrologic perspective that considers water availability and demand together, decision makers and local communities can better understand the water and food security implications of shale resource development.

Research areas: Energy Production/Use
Identification of potential locations for small hydropower plant based on resources time footprint: A case study in Dan River Basin, China (2023)

Small hydropower has attracted extensive interest as a clean technology. This study first identified possible sites of small hydropower plants with estimated capacity, and then utilized resources time footprint as a novel way to evaluate the impact of small hydropower plants on the aspects of materials, CO2, labor, and land. Resources time footprint is a sustainability indicator that uses a uniform time unit (years). It assesses whether the usage of resources exceeds the amount allocated to different people and generations. The smaller the value of resources time footprint, the more environmentally friendly is the process. Preferential locations for small hydropower in Dan River were specified, with a potential capacity ranging from 273 to 1175 kW. Resources time footprint of copper is 8.947.3 times as large as that of steel. Resources time footprint of CO2 emissions is much smaller than that of other aspects, revealing that small hydropower has a great potential to mitigate the greenhouse effect. The overall resources time footprint decreases with an increase in the installed capacity. The methodology proposed in this study can be used to identify the ideal locations for setting up small hydropower plants in other regions as well.

Research areas: Energy Production/Use