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Alliance Green Builders built this 3,129-ft2 home in the hills above Ramona, California, to the high-performance criteria of the DOE Zero Energy Ready Home (ZERH) program. The home should perform far better than net zero thanks to a super-efficient building shell, a wind turbine, three suntracking solar photovoltaic arrays, and solar thermal water heating.
The Iowa Tribe of Kansas and Nebraska (ITKN) is a federally recognized Native American Tribe located along the Missouri River on the border of northeast Kansas and southeastern Nebraska. There are over 800 residents (Tribal citizens and non-Tribal) who live on the reservation, as well as more than 500 people who visit or work on the reservation on a daily basis. The ITKN faces many energy challenges, including rising service costs and dozens of power outages annually that impact resident well-being and business activities on Tribal lands. Power service issues are made more challenging by the remoteness of the reservation, which is 20 miles from the nearest town. Despite this, the ITKN has a long history of cultural and economic resilience: Local self-reliance, environmental stewardship, respecting the carrying capacity of the land, and strengthening the community are Tribal communities' traditional strengths. Long-term energy goals for the ITKN are centered around achieving energy sovereignty. Priority actions include: (1) Establishing a Tribal Utility Authority (TUA) to promote social welfare and community development.; (2) Deploying renewable community microgrids with ground-mount solar arrays and sustainable energy storage systems to advance energy sovereignty, resilience, and reliability. To advance these goals, the ITKN partnered with the U.S. Department of Energy's (DOE's) Communities LEAP (Local Energy Action Program) pilot. From August 2022 to March 2024, the ITKN community coalition collaborated with technical assistance providers at DOE's National Renewable Energy Laboratory (NREL) and Sandia National Laboratories to evaluate TUA planning needs and microgrid deployment scenarios. This fact sheet provides an overview of the results and outcomes from the Communities LEAP technical assistance process.
In the pursuit of sustainable and land-use-efficient solutions to mitigate climate change, the concept of agrivoltaic systems, which integrate renewable solar energy into conventional agriculture, has emerged. By deploying solar arrays above the crop field, these systems are designed to maximize the land use efficiency or, in other words, the value of generated electricity and crop yield per unit area. While power generation has been extensively studied and modeled, research gaps persist in simulating crop performance [1], [2]. Early studies utilized generalized relationships between photosynthetically active radiation (PAR) and crop production. However, significant variations in crop performance due to other factors, such as weather and soil, can compromise the reliability of the results [2]. Current studies focus on comprehensive process-based crop models, such as DSSAT [3] and STICS [4]. Nevertheless, the validation status varies greatly across different species, and the validation process requires well-designed experiments to adjust specific processes. For less common shade-tolerant crops with limited validation, such as cabbage, physiological behaviors can be difficult to predict [5]. This study investigates an adaptive dynamic agrivoltaic production tool (ADAPT) with few data requirements and minimal on-site calibration that can be easily applied in real applications.
A combined PV panel assembly jig and forklift transport pallet is used to assemble PV panels for transport to a field array from a protected manufacturing environment. The panels are assembled to have adhesively applied rails for transport by a robotic drone on a ground-support rack and are pre-wired. The PV panel assembly jig holds, protects, and aligns the PV panels in an upside down position, opposite to their operational position, for ease of wiring in order to decrease the manual labor required in the field. Once the pallet is transported to the load station at the end of a row of solar panel racks in the field array, a robotic loader lifts the upside down PV panels from the combined PV panel assembly jig and forklift transport pallet in an arcing overhead motion that lifts, tilts, and deposits the PV panels in an upright position at the loading station of a railed rack support as ground-mounted in a solar panel field array.
A systematic methodology for characterizing a novel and newly fabricated high-flux solar simulator is presented. The high-flux solar simulator consists of seven xenon short-arc lamps mounted in truncated ellipsoidal reflectors. Characterization of spatial radiative heat flux distribution was performed using calorimetric measurements of heat flow coupled with CCD camera imaging of a Lambertian target mounted in the focal plane. The calorimetric measurements and images of the Lambertian target were obtained in two separate runs under identical conditions. Detailed modeling in the high-flux solar simulator was accomplished using Monte Carlo ray tracing to capture radiative heat transport. A least-squares regression model was used on the Monte Carlo radiative heat transfer analysis with the experimental data to account for manufacturing defects. The Monte Carlo ray tracing was calibrated by regressing modeled radiative heat flux as a function of specular error and electric power to radiation conversion onto measured radiative heat flux from experimental results. Specular error and electric power to radiation conversion efficiency were 5.92 ± 0.05 mrad and 0.537 ± 0.004, respectively. An average radiative heat flux with 95% errors bounds of 4880 ± 223 kW ⋅ m{sup −2} was measured over a 40 mm diameter with a cavity-type calorimeter with an apparent absorptivity of 0.994. The Monte Carlo ray-tracing resulted in an average radiative heat flux of 893.3 kW ⋅ m{sup −2} for a single lamp, comparable to the measured radiative heat fluxes with 95% error bounds of 892.5 ± 105.3 kW ⋅ m{sup −2} from calorimetry.
One embodiment relates to a bifacial photovoltaic module having an edge reflector. The module includes a plurality of solar cells in an array, each solar cell having a front side and a back side. A reflector is configured on an edge of the array of solar cells, the first reflector being configured to reflect light onto the front side of a row of solar cells adjacent to the edge. Another embodiment relates to a method of reducing non-uniformity of power generation from a bifacial photovoltaic module. Electrical current produced from solar cells along at least one edge of the array is increased by using a reflective strip facing towards the front side of the solar cells along the edge. Another embodiment relates to a bifacial photovoltaic module having an edge refractor. Other embodiments and features are also disclosed.
Highlights: • Er-doped TiO{sub 2} nanorod absorbs IR and converts into visible light. • The introduction of Er could make a positive shift in flat-band potential. • Er-doped TiO{sub 2} solar cells show a 20% increment in the current density. - Abstract: Upconversion erbium-doped rutile TiO{sub 2} nanorod arrays were synthesized by a facile process and applied in perovskite solar cells (PSCs). The structure was characterized by X-ray powder diffraction (XRD). Energy dispersive spectrometer (EDS) and Tauc plot indicated that Er was successfully introduced and changed TiO{sub 2} band gap from 3.00 eV to 3.07 eV. The incorporation of Er shifts the flat band potential positively and enhances the electron density. The Er-doped TiO{sub 2} nanorods have a broad absorption in the infrared light and up-convert it into visible light, which provides a possibility for PSCs to use NIR light for higher performance. A higher photocurrent density (J{sub sc}) of 22.97 mA/cm{sup 2} and a power conversion efficiency (PCE) of 10.6% were obtained, showing 20% and 16.5% increment in J{sub sc} and PCE, respectively, when compared with the un-doped device. The performance improvement was ascribed to the upconversion performance, enhanced electron-injection efficiency and reduced charge recombination.
Molten mixtures of MgCl2-KCl-NaCl are promising heat transfer fluid (HTF) candidates for the next generation of concentrating solar power systems (Gen3 CSP), because of their low cost, high decomposition temperature, and favorable heat transfer characteristics. However, if the chemistry of the salts is not properly controlled, molten chlorides can cause corrosion of high-temperature metal alloys, such as Inconel (R), in CSP systems. Here we demonstrate a corrosion monitoring system that can be used to monitor the health of the structural alloys over long durations. The monitoring system includes a multielectrode array voltammetry sensor that measures the redox potential of molten MgCl2-KCl-NaCl mixture as well as the presence of corrosion products and impurities. The sensors have been successfully operated in static molten salt environments for long durations, and are capable of detecting corrosion products, such as Cr2+ and Fe2+, quantitatively at low concentrations (i.e., approximately 100 ppm) with less than 4% error.
The Match-E-Be-Nash-She-Wish Band of Pottawatomi Indians, d.b.a. Gun Lake Tribe (Gun Lake Tribe/Tribe), installed a grid connected 68.87 kW solar photovoltaic array at the Tribe’s Jijak Property located in Hopkins, MI. The array generated 95,070 kWh its first year of operation, 7,014 kWh more than projected. The Jijak Gises solar array saved $\$$12,214 during the first year of production including $\$$6,022 in generation credit and $\$$6,192 in offset electrical cost. The array will save the Tribe more than $\$$312,000 with increasing electric rates during the normal life of the system reducing Gun Lake Tribe’s reliance on other energy resources. Competitive pricing allowed the Tribe to install a second smaller array to power the Jijak Garden. The 4.85kW Jijak Garden Array produced 6,643.96 kWh during its first year of production, 475.95 kwh more than projected saving $\$$1,126 during year one of production including invoice credits and offset energy consumption. Over the first 20 years of the array, it is expected to produce 132,879 kWh of electrical energy, saving over $26,000 over the life of the system.
SGHAT predicts the occurrence and intensity of glare caused by a user-specified solar panel array when viewed from one or more observation points. An interactive mapping interface is used to determine the latitude, longitude and elevation of the array and observation points. The presence and intensity of glare is then calculated along a given time interval throughout the year, based on the position of the sun. The potential ocular hazard is also reported. The maximum energy production of the solar array is also estimated so that alternative designs can be compared to determine the design that yields the most energy production while mitigating glare.
In this work, tandem-junction microwire array photoelectrodes have been fabricated by coating np + -Si radial homojunction microwire arrays sequentially with fluorine-doped tin oxide (FTO) and titanium dioxide (TiO 2 ). These photoelectrodes effected unassisted water splitting under simulated 1 Sun conditions with an open-circuit potential ($E_{\text{oc}}$) of –1.5 V vs the formal potential for oxygen evolution, $E^0$'(OH – /O 2 ), a current density at $E = E^0$'(OH – /O 2 ) of 0.78 mA cm –2 , a fill factor ($\textit{ff}$) = 0.51, and a photovoltaic-biased photoelectrochemical ideal regenerative cell efficiency of 0.6%.
Photovoltaic (PV) technology is becoming one the best options for supplying electricity to rural communities far from electrical networks and which have a small and disperse demand for electricity. As the cost of the technology goes down and its development advances, opportunities for applying it continue to grow. As a result, in the near future we will probably see an increase in massive application programs of this technology in rural Mexico. This document presents some of the most relevant problems needing immediate solution to increase the possibility of success in establishing photovoltaic programs for rural electrification in Mexico. These problems are influenced by economic, technological, engineering, infrastructural, social and political issues. The paper presents the requirements for an industrial center based on PV technology, the accessibility of replacement parts and maintenance service, development of financial solutions, training of the users and introducing norms and technical regulations. The document summarizes the issue of rural electrification in Mexico, emphasizing the low population density in these areas. A brief description is given of photovoltaics showing different configurations that can be utilized for supplying electricity to the rural areas. The issues involved and recommendations for introducing PV systems to the rural area are described.
The paper presents the results of an experimental study of the efficiency of the integrated controllers of PWM and MPPT PV/batteries, which are part of an autonomous photovoltaic power plant. The dependences of the efficiency on the hourly sums of solar radiation are represented, which can be used to calculate the productivity of autonomous photovoltaic systems with an hourly integration step. The operational features of the controllers during low-level periods of solar radiation are considered.
Gwichyaa Zhee Gwich’in Tribal Government (GZGTG) applied for funding in 2014 under the U.S. Department of Energy Office of Indian Energy Deployment of Clean Energy on Tribal Lands funding opportunity. They were awarded 50% of the project costs for the construction of an 18kW, grid-tied solar PV array on the fort Yukon Tribal Hall, the construction of a 3kW solar PV array on the tribally owned greenhouse, the replacement of inefficient florescent lighting fixtures in the tribal hall to higher efficiency LED lights and the addition of blow in cellulose insulation to the attic of the tribal hall to assist with heat retention. Total DOE Funding for the project was $124,735. Total GZGTG funding for the project was $133,321 for a total project cost of $258,056. The Project was completed with 100% local labor on the tribal hall solar PV installation, the LED lighting retrofit and the insulation on the tribal hall. Based on the results at the tribal hall/office, the tribe also used their own tribal funding to retrofit the lighting in the community hall from florescent to LED lights. The resulting project was completed by the end of Sept 2016 and results have shown a decrease in fuel used at the tribal hall/office of 35% and a decrease in electric costs at the tribal hall of 68%. The total energy costs before the project were approximately $28,000 a year and the energy equivalent of 385 MMBTU/yr. After the project the total energy costs decreased to $11,200/yr. and an energy equivalent of only 242 MMBTU. This represents an overall decrease in energy use of 38%. All in all the tribe and the community regard this project as a huge success!
Particle-laden flows in solar photovoltaic (PV) systems are inevitable, where wind-swept debris in open environments are carried by high winds and turbulence, coating panel surfaces or damaging structures. Particle deposition, or soiling, is a well-known issue for large-scale plants which rely on uninhibited solar rays for optimal production. But understanding the mechanisms leading to soiling requires a physical and fluid dynamics-centered focus, since turbulence dominates PV panel wakes and is also known to alter particle concentration and trajectories. This study presents an experimental campaign toward consequences of particle-laden flow between two model PV panels using time-resolved particle image velocimetry. The model array was subjected to varied particle volume fractions, including a tracer particle case and a water droplet case. Characterization of mean velocity, turbulence statistics, and mean kinetic energy within the single phase and, separately, particle phase flows showed modified features due to particle inertia. Images captured at a frequency of 1 kHz in the near wake of the upstream panel allow for a first experimental look at vorticity and convective velocity of vortex structures for single-phase and particle-phase flows which are crucial to debris transport and soiling in PV environments.
A pneumatically actuated solar panel array system that includes a plurality of separate actuator assemblies that each have a top plate and bottom plate and a first and second bellows that each extend between and are coupled to the top and bottom plates at a respective top head and bottom head, the first and second bellows being configured to be separately pneumatically inflated, where the pneumatic inflation expands the bellows along a length. The pneumatically actuated solar panel array system can also include a plurality of solar panels coupled to the actuator assemblies with the solar panels being configured to be actuated based on inflation of one or more bellows associated with the plurality of actuator assembles.
A pneumatically actuated solar panel array system that includes a plurality of separate actuator assemblies that each have a top plate and bottom plate and a first and second bellows that each extend between and are coupled to the top and bottom plates at a respective top head and bottom head, the first and second bellows being configured to be separately pneumatically inflated, where the pneumatic inflation expands the bellows along a length. The pneumatically actuated solar panel array system can also include a plurality of solar panels coupled to the actuator assemblies with the solar panels being configured to be actuated based on inflation of one or more bellows associated with the plurality of actuator assembles.
This study attempts to apprise stakeholders about the accurate use of a typical meteorological year (TMY) data set for decision-making that could potentially speed up the acceptance and deployment of projects and reduce risks to financiers and developers. A TMY data set represents hourly concatenation of 12 typical meteorological months constructed using multiyear data sets. Typically, TMY data sets are constructed under horizonal irradiance conditions that are then used in photovoltaic (PV) performance models for available energy calculations in a location after transposing the data to represent a desired plane-of-array (POA) orientation. In this study, we attempt to show that a POA TMY generated with corresponding POA irradiance time-series information produces significantly different results than a POA TMY generated by transposing a TMY data set. In some months, the differences can be more than 3% for irradiance and energy yield. These results point to the need for generating TMY data sets using POA irradiance time series representing the orientation at which PV panels will be deployed.