Opportunities for emerging PV technologies

The decarbonization of Utah’s coal-fired power plants is essential for achieving the state and federal climate policy targets, including the Utah Roadmap objective of a 50% reduction in greenhouse gas emissions by 2030 and the U.S. Environmental Protection Agency’s (EPA) proposal to achieve a 90% reduction in CO₂ emissions from power generation by 2035. This study presents a comprehensive parametric analysis to evaluate the technical, economic, and regulatory implications of retrofitting Utah’s coal-fired power plants with carbon capture and storage (CCS). Three coal-fired power plants were examined, collectively consisting of six electric generating units (EGUs). The Bonanza unit was selected as a case study to explore the influence of different operational parameters, policy frameworks, and economic factors. Three CO₂ capture technologies including: amine-based absorption, solid adsorption, and membrane separation are assessed. Among these, amine-based absorption demonstrates superior performance, offering higher net power output, improved thermal efficiency, and lower costs across all evaluated economic metrics. Capture efficiency emerged as a critical parameter in the analysis, increasing CO₂ capture rate from 85% to 95% significantly reduced emissions and the cost per ton of CO₂ captured, but also led to higher parasitic energy loads, cooling water demand, and levelized cost of electricity (LCOE). The impact of plant operating mode showed that ultra-supercritical systems delivered higher efficiency and lower emissions, whereas subcritical plants were more economically viable due to lower capital costs. Incorporating a natural gas auxiliary system improved net plant efficiency and water use but increased the LCOE due to high gas prices and limited operational lifespan in Utah. Sensitivity to coal price was linear, with a 25% reduction in coal cost significantly improving LCOE and CO₂ mitigation economics. Capacity factor had a strong influence, with higher utilization rates substantially lowering all cost metrics. From a policy perspective, imposing taxes on CO₂ emissions raised project costs; a breakeven tax of ~$83/ton of CO2 was needed to make CCS competitive with the base/existing case (Without CCS). In contrast, the 45Q federal tax credit had a strong positive effect: a $20/ton credit enabled CCS feasibility for most EGUs, while credits above $60/ton led to negative CO₂ avoidance costs. The results confirm that CCS viability hinges not on any single factor but on the alignment of capture technology, efficiency, fuel economics, and incentive structures. A hybrid policy combining carbon emission taxation with targeted tax credits as well as capturing efficiencies technological advancements presents the most viable path to enabling deep decarbonization in Utah’s aging coal fleet.

Carrier Dynamics Engineering for High-Performance Electron-Transport-Layer-free Perovskite Photovoltaics

This paper presents a comparison between the performance of crystalline and thin-film type photovoltaic (PV) module technologies. The rooftop and ground mounted PV system installation conditions were considered in the study. The respective system performances were compared in terms of total energy generated, energy yield and Levelized Cost of Energy (LCOE). The PV system installation site's meteorological parameters were obtained from Meteonorm, a comprehensive meteorological database for solar applications and system design. The key findings suggest that the ground mounted thin-film system has the highest energy yield, which is mainly driven by its lower temperature coefficient and greater airflow. However, under the current Feed-in Tariff scheme in Malaysia, the rooftop thin-film PV system installation has the highest economic benefit for the utility scale PV power plant.

Milk production and energy efficiency of Holstein and Jersey-Holstein crossbred dairy cows offered diets containing grass silage

In this work, the levelised cost of energy (LCOE) from floating solar photovoltaics (PV) is calculated and mapped in the Mediterranean Sea. A breakdown of the factors that influence the LCOE is presented, including site-specific aspects such as distance to shore, water depth and solar resources. To address the uncertainties inherent to any novel technology, a sensitivity analysis is conducted, in which the effects on the LCOE of variations in its factors are quantified. With respect to the numerator of the LCOE (the costs), the results indicate that installation costs, which increase rapidly with distance to shore, play the main role. With respect to the denominator (the energy output), the substantial solar resources of the Mediterranean Sea translate into large annual energy productions overall – a clear advantage for the development of floating solar PV. Going into greater detail, LCOE values are found to be particularly sensitive to: (i) parameters directly linked to the production of energy, e.g., panel capacity and number of panels per structure; (ii) general project and project finance parameters, e.g., number of structures, project lifetime and discount rate; (iii) sources of costs, e.g., structure weight and installation of components. The lowest LCOEs occur in nearshore areas of Libya and Egypt. The Iberian Peninsula presents LCOE values in the range 340–380 €/MWh, and Italy, in the range 380–400 €/MWh. In the Aegean Sea there is high spatial variability, with LCOE values ranging from 320 €/MWh to 500 €/MWh. These results help to identify optimal locations for the deployment of floating PV in the Mediterranean Sea and indicate the key parameters for reducing its cost in future.

This study develops a new method to evaluate the economic viability of co-generation electric vehicle stations that concurrently generate electricity and hydrogen for charging battery electric vehicles and refueling hydrogen vehicles. The approach uniquely differentiates the costs associated with various energy outputs in co-generation stations and includes often-overlooked peripheral devices critical for accurate evaluation of the levelized cost of electricity (LCOE) and hydrogen (LCOH). The method was tested across three design configurations: two featuring single storage options (battery and fuel cell, respectively) and a third using hybrid storage employing both. Each configuration was modeled, simulated, and optimized using HOMER Pro 3.14.2 to determine the most optimal sizing solution. Then, based on the optimal sizing of each design, LCOE and LCOH were evaluated using the proposed method in this study. The analysis revealed that excluding often-overlooked peripheral devices could lead to a 27.7% error in LCOH evaluation, while the impact on LCOE was less than 1%. Among different configurations, the design with hybrid storage proved economically superior, achieving a total levelized cost of energy (TLCOE) for the entire system of USD 0.113/kWh, with the LCOE at USD 0.025/kWh and LCOH at USD 0.088/kWh (or USD 3.46/kg). Comparative analysis with state-of-the-art studies confirmed the accuracy of the proposed method. This study provides a more precise and holistic approach that can be leveraged for the feasibility analysis of electric vehicle stations globally, enhancing strategic decision-making in sustainable energy planning.

Retrospective and prospective studies show that lean mass or strength is positively associated with metabolic health. Mice deficient in myostatin, a growth factor that negatively regulates skeletal muscle mass, have increased muscle and body weights and are resistant to diet-induced obesity. Their leanness is often attributed to higher energy expenditure in the face of normal food intake. However, even obese animals have an increase in energy expenditure compared to normal weight animals suggesting this is an incomplete explanation. We have previously developed a computational model to estimate energy output, fat oxidation and respiratory quotient from food intake and body composition measurements to more accurately account for changes in body composition in rodents over time. Here we use this approach to understand the dynamic changes in energy output, intake, fat oxidation and respiratory quotient in muscular mice carrying a dominant negative activin receptor IIB expressed specifically in muscle. We found that muscular mice had higher food intake and higher energy output when fed either chow or a high-fat diet for 15 weeks compared to WT mice. Transgenic mice also matched their rate of fat oxidation to the rate of fat consumed better than WT mice. Surprisingly, when given a choice between high-fat diet and Ensure® drink, transgenic mice consumed relatively more calories from Ensure® than from the high-fat diet despite similar caloric intake to WT mice. When switching back and forth between diets, transgenic mice adjusted their intake more rapidly than WT to restore normal caloric intake. Our results show that mice with myostatin inhibition in muscle are better at adjusting energy intake and output on diets of different macronutrient composition than WT mice to maintain energy balance and resist weight gain.

Forage crops options are required by dry-stock farmers to fill summer feed gaps. This trial compared a brassica monoculture with simple and hyper-diverse mixtures containing up to 21 forage species sown in October on a Waikato dry-stock farm. Two of the twelve treatments were established at paddock scale. Species included rape, oats, plantain and red clover. Seedling emergence was assessed four weeks after sowing and herbage production, metabolisable energy and botanical composition in mid-January. Rape was common in all mixtures for the provision of high-quality forage. Oats suppressed rape production, even at low sowing rates (<13 kg/ha), and reduced weed ingress. Plantain, sown at <2 kg/ha, contributed negligible dry matter in mid-January but provided ground cover and additional forage by late February. Red clover failed to establish. Most diverse treatments provided a similar energy yield (MJ ME/ha) to rape. Simple mixtures and hyperdiverse mixtures were similar for most metrics. Results at plot and paddock scale were consistent for the energy yield effects. When these data were combined withproduction costs, the energy costs were similar for most treatments. The most promising was a rape dominant mixture, with high energy yield, low weed abundance and low energy costs.

This paper examines the economic feasibility of implementing a Floating Solar Photovoltaic (FSPV) system in a Philippine Lake using the PVsyst simulation tool. The study involved a detailed simulation of the FSPV system's performance, considering various environmental and technical parameters. Key aspects such as system configuration, energy yield, and financial metrics including payback period and net present value were analyzed. Results indicate that the FSPV system could significantly contribute to local energy needs while proving to be a financially viable investment due to substantial reductions in CO2 emissions and lower energy costs compared to traditional power sources. According to assessments and simulations performed using PVSyst software, the FSPV system would possess a capacity of 10 kWp, with an expected available energy output of 13,599 kWh per year and an expected energy consumption of 12,940 kWh per year. The economic modeling of the FSPV system revealed a relatively short payback period of 4.8 years, with a net present value of Php 741,732.00 and a substantial return on investment of 227.5%. The Levelized Cost of Energy (LCOE) was estimated at Php 6.18 per kWh. The study underscores the potential of FSPV systems to meet the renewable energy needs of isolated communities by leveraging local water bodies for solar installations.

Ground mounted solar parks lead to changes in the micro-climate under and between the PV tables. In particular, the vegetation on the soil is, in various degrees, shaded from direct sunlight and indirect, diffuse light. Also, the changes in precipitation distribution, air temperature and wind speed will affect the conditions. This leads to varying conditions for the vegetation affecting photosynthesis, which on the longer term influences the soil quality. To ensure sufficient light for photosynthesis, initial thresholds for irradiance have been drafted by TNO and Wageningen University and Research for the climate conditions in the Netherlands. Based on these rules, we present for the first time a method to evaluate the trade-off between soil irradiance and energy yield, related to table configuration and module choice, for utility-scale solar parks. Irradiance on the ground has either passed around the PV tables, passed through the gaps between panels or is transmitted between the solar cells in the panels. This leads to an optimisation of the module transparency and the size and relative position of the PV tables, when minimising the costs and at the same time complying with these irradiance criteria. To illustrate this optimisation, we have simulated the annual energy yield and ground irradiance and calculated the effect on the levelised cost of electricity. We present two solar park designs, that have the same ground irradiance distribution. One design is installed with partially transparent, bifacial modules, the other with gaps between the opaque, bifacial modules. Although the transparent bifacial modules have a somewhat lower module power, this system produces more kWh per hectare and has a lower levelised cost of electricity. The present paper shows that the partial transparency of bifacial modules is a key feature to maintain the soil ecology, and profitability, thus contributing to societal acceptance.

The aim of this research is to perform an in-depth performance comparison of ground-mounted and rooftop photovoltaic (PV) systems. The PV modules are tilted to receive maximum solar irradiance. The efficiency of the PV system decreases due to the mutual shading impact of parallel tilted PV modules. The mutual shading decreases with the increasing interrow distance of parallel PV modules, but a distance that is too large causes an increase in land cost in the case of ground-mounted configuration and a decrease in roof surface shading in the case of rooftop configuration, because larger sections of roof are exposed to sun radiation. Therefore, an optimized interrow distance for the two PV configurations is determined with the aim being to minimize the levelized cost of energy (LCoE) and maximize the energy yield. The model of the building is simulated in EnergyPlus software to determine the cooling load requirement and roof surface temperatures under different shading scenarios. The layout of the rooftop PV system is designed in Helioscope software. A detailed comparison of the two systems is carried out based on energy output, performance ratio, capacity utilization factor (CUF), energy yield, and LCoE. Compared to ground-mounted configuration, the rooftop PV configuration results in a 2.9% increase in CUF, and up to a 23.7% decrease in LCoE. The results of this research show that installing a PV system on a roof has many distinct advantages over ground-mounted PV systems such as the shading of the roof, which leads to the curtailment of the cooling energy requirements of the buildings in hot regions and land cost savings, especially for urban environments.

Solar energy plays a crucial role in helping cities to decentralize energy production and thus decarbonize the energy mix. Reliable resource assessments are needed to support the deployment of solar power systems, especially in cities of developing countries where large solar potential remains untapped. The aim of this work is to assess the potential of rooftop solar photovoltaic (PV) in three populated cities in Ecuador’s mainland (Quito, Guayaquil and Cuenca) and in the Galapagos Islands. The assessment involves (i) the estimation of the available rooftop area based on geographic information system data, (ii) the calculation of energy yield based on hourly satellite-derived irradiance and meteorological data, and (iii) the economic feasibility assessment in terms of levelized cost of electricity (LCOE) compared to representative electricity tariffs. In addition, a sensitivity analysis is carried out to assess the variability of the estimated technical and economic potential with respect to changes in the input parameters. The results reveal a total available rooftop area of about 144 km2, mainly concentrated in urban parishes. The estimated energy yield is 16.94 ± 3.38 TWh/a, which could cover almost twice the annual energy consumption in 2019 of the study areas. The economic assessment shows that the LCOE ranges between 7.65 and 21.12 USD cents/kWh. However, the comparison of LCOE against representative residential tariff suggests that rooftop PV technology is not cost-competitive under most of the financial scenarios. The findings from this study will be of interest for local authorities and other decision makers to design policies and financing strategies to increase the penetration of rooftop PV and thus exploiting the large potential assessed in the study areas. The described methodology can be used for assessing the potential in other regions of Ecuador and thereby support the diversification and decarbonization of the energy mix in the country.

Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. While biotic and abiotic cycling of organic sulfur compounds has been well documented in low-temperature anaerobic environments, cycling of organic sulfur in hydrothermal environments has received less attention. Recently published thermodynamic data have been used to estimate aqueous alkyl thiol and sulfide activities in deep-sea hydrothermal systems. Here we use geochemical mixing models to predict fluid compositions that result from mixing end-member hydrothermal fluid from the East Pacific Rise with bottom seawater. These fluid compositions are combined with estimates of methanethiol and dimethylsulfide activities to evaluate energy yields for potential organic sulfur-based metabolisms under hydrothermal conditions. Aerobic respiration has the highest energy yields (over -240 kJ/mol e⁻) at lower temperature; however, oxygen is unlikely to persist at high temperatures, restricting aerobic respiration to mesophilic communities. Nitrite reduction to N₂ has the highest energy yields at higher temperatures (greater than ∼40 °C). Nitrate and nitrite reduction to ammonium also yield significant energy (up to -70 kJ/mol e⁻). Much lower, but still feasible energy yields are calculated for sulfate reduction, disproportionation, and reduction with H₂. Organic compound family and the activity of methanethiol and dimethylsulfide were less important than metabolic strategy in determining overall energy yields. All metabolic strategies considered were exergonic within some portion of the mixing regime suggesting that organic sulfur-based metabolisms may be prevalent within deep-sea hydrothermal vent microbial communities.

Due the movement of the sun throughout the day, the insolation level incident on the fixed panel surface varies largely. The maximum level of insolation occurs only around noon. This leads to the panel to be under-utilised. To maximise the utilisation of the panel during the day, mechanical solar tracking is used. This method not only increases the utilisation of the, but increases the power being extracted from the panel. Solar tracking using one axis tracking increases the energy yield from the solar panel by 40 percent.Extended AbstractDuring the span of a day the sun's movement has been shown in figure 1. As the day passes by, the level of incident solar radiation (insolation) changes. This change takes place due to position of the sun. The angle at which the sun's rays fall on the photovoltaic panel affects the insolation level available for the panel to convert into electrical energy. For the fixed panel, the sun's rays are not normal to plane of the panel most of the time. This causes the panel to be under-utilised. To extract more energy from the same panel, solar tracking is required. This follows the sun's movement thereby increasing the insolation level throughout the day. This increase in the insolation level is due to the fact that the angle between the normal to the solar panel and incident light is to be kept minimum. Figure 1: Sun's movement throughout the day The principle of a single axis solar tracking has been shown in figure 2. The solar tracking can be accomplished by four methods: active tracking, passive tracking, chronological tracking and manual tracking [1]. Active trackers measure the light intensity from the sun using light sensors which give signal to the controller and driving mechanism. Passive trackers commonly make use of a low boiling point compressed gas. This gas is filled in two canisters each placed in east and west directions. The heating of the fluids cause the panel to tilt over to the side with more sunshine. These will have viscous dampers to prevent excessive motion in response to wind gusts [2]. A chronological tracker uses a rotation mechanism to counteract the effect of Earth's rotation. A simple rotation mechanism, turning at a constant speed of one revolution per day or 15 degrees per hour, is adequate for many purposes, such as keeping a photovoltaic panel pointing within a few degrees of the Sun. This can easily be achieved by the use of a stepper motor control. Figure 2: Principle of single axis solar tracking The data for the insolation level and temperature for the whole year have been obtained from the NASA website for Aligarh and Doha [3]. The simulations have been run assuming that there is no condition of partial shading. For the purpose of simulation of energy output during the day, five solar panels of 250 Wp were taken in parallel to give a total of 1.25 kWp of power under STC. The energy outputs for the months throughout the year were obtained for two conditions: first for the fixed panel condition, and second for the panel with continuous one-axis solar tracking. The results have been compared and shown for Aligarh and Doha in Figs. 3 and 4 respectively. In Fig. 5, the percentage increase in the energy output for each month has been shown for both the cities. Figure 3: Daily energy yield from a 1.25 kWp solar array on a monthly basis in Aligarh Figure 4: Daily energy yield from a 1.25 kWp solar array on a monthly basis in Doha Figure 5: Increase in daily energy yield on a monthly basisReferences[1] B H Khan ‘Non-Conventional Energy Resources’ Tata McGraw Hill, 2009.[2] Kamala J. and Alex J., 2014, ‘Solar Tracking for Maximum and Economic Energy Harvesting’, Int. J. of Engg. and Tech, Vol. 5(6), pp 5030–5037.[3] NASA Surface meteorology and Solar Energy website: https://eosweb.larc.nasa.gov

The relatively low generation costs associated with wind, solar photovoltaic (PV), and natural-gas power plants make it challenging for geothermal power plants to produce and sell the power that has the reliability and sustainability characteristics that are greatly needed in U.S. power markets. This is especially true for geothermal resources with low-to-medium temperatures, which results in relatively low-thermal efficiency and generation costs that are higher than those for wind, solar PV, and natural gas. This analysis evaluates solar thermal- and natural-gas combustion waste heat recovery-based topping cycle hybridization of geothermal binary power plants. This approach provides several benefits that may allow geothermal power plants to generate power at more competitive costs. First, the addition of solar thermal energy or natural-gas combustion waste heat input to a geothermal power plant provides additional heat input that can be converted to electrical power. Second, the temperature level of the heat obtained from concentrating solar collectors or natural-gas combustion exhaust is higher than that of geothermal heat, which provides opportunities for improving the efficiency of the conversion of thermal energy to electrical power. Third, the ease with which solar thermal systems integrate with energy storage and the flexibility of natural gas means power generation can occur during peak demand periods. The hybrid cycles are compared to equivalently sized, co-located, independent geothermal, concentrating solar, and/or natural-gas power plants. The hybrid cycle tends to produce slightly more power than the standalone plants combined. However, the hybrid plant Levelized Cost of Energy (LCOE) is slightly higher than the LCOE of the combined standalone power plants for each of the case study locations investigated. Using the steam-topping cycle, organic Rankine cycle (ORC)-bottoming cycle hybrid plant design to combine a solar thermal resource and low- temperature geothermal resource (<120 degrees C) leads to a hybrid plant with a lower LCOE than a standalone geothermal-only system. Thus, hybrid plants may enable the economic development of geothermal resources in locations with low geothermal resource temperatures. However, in areas with higher geothermal resource temperatures (>120 degrees C), the geothermal-only plant has a lower LCOE than the hybrid cycle and thus could be developed without the need for solar heat addition. iv A geothermal-natural-gas reciprocating engine hybrid plant was evaluated for an Elk Hills, California case study location. The Elk Hills case study analysis indicates that when the natural-gas engine operates for more than 12 hours per day the hybrid plant can produce power at an LCOE lower than a standalone geothermal plant, and comparable to that of the standalone natural-gas reciprocating engine, while also reducing the carbon intensity of the power generated relative to the standalone natural-gas engine. This may represent a scenario in which the hybrid plant provides an opportunity for the deployment of a low-temperature geothermal resource that otherwise may have an LCOE too high to develop and operate as a standalone resource, while also reducing the carbon intensity of natural-gas generation sources. A "triple-hybrid" plant that combines natural gas, solar thermal, thermal energy storage, and geothermal was also investigated. A natural-gas combustion turbine (NGCT) is added to the geothermal-solar hybrid such that the hot exhaust gas from the gas turbine provides an alternative source of heat to the steam turbine of the hybrid cycle. Analysis results suggest that the triple-hybrid plant has a significantly higher energy generation and revenue than a standalone NGCT or the original geothermal-solar hybrid. The triple-hybrid design benefits most from using a smaller solar field so that the solar energy can be dispatched at the most valuable times available. The triple-hybrid plant also has a lower LCOE than the standalone NGCT. The triple-hybrid plant was evaluated making simple assumptions about the dispatch profile of the gas cycle, and more nuanced and realistic dispatching schedules should be analyzed in future work.