Convective Energy Losses Research Articles

Reducing convective losses in a solar cavity receiver VoCoRec by creating a controlled vortex of returned air

The efficiency of air-type solar towers influences the minimal cost of electricity/heat produced by them, which limits their use despite the widespread use of many forms of concentrated sun power plants. Nonetheless, the temperature potential of this kind of concentrated plant is the highest. To improve the efficiency of an air-type solar tower, a technique for reducing convective energy losses with return air is therefore suggested. In order to increase a cavity receiver's thermal efficiency, a little-known concept called vortex creation will be discussed in this work. The article models different ways of creating an air vortex inside the cavity receiver. Using the VoCoRec design as an example, cases are shown where the vortex increases and decreases the thermal efficiency of the receiver. The concept of Air Return Ratio (ARR) is used to determine the convective losses in a solar collector. This coefficient indicates the convective losses of the receiver due to buoyancy forces and has a direct proportional dependence on the convective efficiency coefficients of the receiver. The VoCoRec receiver, which incorporates the directional vortex inside the receiver, increased the air return coefficient by 4 % (at the same air mass flow rate). The dependence of the air return coefficient on different angles of the air outlet to the absorber plane, including in the radial direction, was also investigated. Increasing the angle of inclination of the air outlet to the main absorber increases the air return coefficient in all cases, but also increases the aerodynamic drag of the receiver (pressure drop).

A modeling study of aerosol effect on summer nocturnal convective precipitation in Beijing

Using the WRF model with chemistry (WRF-Chem), this study investigates the potential contributions of aerosol direct (ADE) and aerosol indirect (AIE) effects on the nocturnal convective precipitation occurred on 9–10 September 2019 in Beijing. It shows that ADE plays a more important role in spatiotemporal changes of heavy precipitation than AIE in urban areas. Further simulation analyses show that ADE suppresses precipitation by inducing greater surface shortwave radiative cooling and stability before 13:00 (UTC, hereafter) on 9 September, which reduces convective available potential energy (CAPE) losses and then increases the later CAPE. The ADE-induced CAPE increase makes updrafts stronger, increasing cloudiness and transporting more cloud water into the upper troposphere. This, in turn, causes greater latent heat release from freezing and then stronger convection, producing higher rain rate during 13:00–21:00. During 12:00–18:00, AIE causes a decrease in CAPE, which weakens updrafts. AIE decreases the snow mixing ratio above 700 hPa except at 15:00–16:00 on 9 September, which can decrease the release of latent heat from freezing, contributing to the decrease in precipitation after 18:00. Due to the greater stability before 10:00 and the longer time required for updrafts to overcome this stability, ADE necessitates 2–3 h to adjust the simulated rainfall time series.

Sorbent-coated carbon fibers for direct air capture using electrically driven temperature swing adsorption

•Sorbent-coated carbon fibers exhibit rapid temperature swing by Joule heating •The DAC system can fully regenerate in under 10 min •Wind-driven DAC modules recover CO2 product from the air at ∼82% purity •The cost of CO2 from this wind-driven DAC system is projected to be ∼$160/tonne Direct air capture (DAC) by electrically driven temperature swing adsorption (ETSA) is an emerging technology due to its simplicity and ease of pairing with renewable electricity energy sources. Herein, we describe the preparation of sorbent-coated carbon fibers via roll-to-roll process that exhibit 400 ppm CO2 adsorption of ∼1.2 mmol gfiber−1. The fibers exhibit Joule heating upon application of a potential, reaching CO2 regeneration temperatures within 1 min. DAC modules show fast electrothermal CO2 desorption with directly applied electric potential, releasing the adsorbed CO2 six times faster than externally driven thermal desorption. The simplicity and modularity of the sorbent-coated carbon fibers and their rapid adsorption/desorption cycling by ETSA have the potential to improve the productivity of DAC systems. A techno-economic analysis of a pilot-scale ETSA-DAC system projects an overall cost of about 160 $ tCO2−1, with convective energy losses to the ambient accounting for only 7% of the Joule heating input during desorption. Direct air capture (DAC) by electrically driven temperature swing adsorption (ETSA) is an emerging technology due to its simplicity and ease of pairing with renewable electricity energy sources. Herein, we describe the preparation of sorbent-coated carbon fibers via roll-to-roll process that exhibit 400 ppm CO2 adsorption of ∼1.2 mmol gfiber−1. The fibers exhibit Joule heating upon application of a potential, reaching CO2 regeneration temperatures within 1 min. DAC modules show fast electrothermal CO2 desorption with directly applied electric potential, releasing the adsorbed CO2 six times faster than externally driven thermal desorption. The simplicity and modularity of the sorbent-coated carbon fibers and their rapid adsorption/desorption cycling by ETSA have the potential to improve the productivity of DAC systems. A techno-economic analysis of a pilot-scale ETSA-DAC system projects an overall cost of about 160 $ tCO2−1, with convective energy losses to the ambient accounting for only 7% of the Joule heating input during desorption.

Thermal Modelling Utilizing Multiple Experimentally Measurable Parameters

This paper presents three equivalent thermal circuit models with multiple input parameters, namely, the state of health (SOH), state of charge (SOC), current and temperature. Typical physiochemical models include parameters such as porosity and tortuosity, which are not easily experimentally available; this model allows for model parameters such as the internal impedance to be easily estimated using more practical inputs. The paper models the internal impedance resistance of a LiFePO4 battery at five different ambient temperatures (5, 15, 25, 35, 45 °C), at three different discharge rates (1C, 2C, 3C) and at three different SOHs (90%, 83%, 65%). The internal impedance surface fit experimental measurements with a Pearson coefficient of 0.945. Three thermal models were then created that implemented the internal resistance model. The first two thermal models were 0D models that did not include the influence of the thermal conductivity of the battery. The first model assumed simple heating through internal resistance and convection energy loss, while the second also included the Bernardi Reversible heat term. The final third model was a 2D model that included all previous heat source terms as well as tab heating. The 2D model was solved using a simple Euler method and finite center difference. The R2 values for the 0D thermal models were 0.9964 and 0.9962 for the simple internal resistance and reversible heating models, respectively. The R2 value for the 2D thermal model was 0.996.

Three-Dimensional Artificial Transpiration Structure Based on 1T/2H-MoS2/Activated Carbon Fiber Cloth for Solar Steam Generation.

The rise of solar steam generation is an effective strategy to mitigate clean water shortages. However, achieving further improvements in conversion efficiency and stability remains a challenge. Here, 1T/2H-MoS2 nanosheets were uniformly assembled on activated carbon fiber cloth (A-CFC) through a facial hydrothermal method, and a three-dimensional (3D)-artificial transpiration device (ATD) was prepared using the plant transpiration process. The combination of activated carbon fiber cloth and 1T/2H phase MoS2 exhibits high light absorption (∼97.5%), excellent mechanical stability, large evaporation area, and easy escape of vapor. Additionally, the 3D hollow cone of the MoS2/carbon fiber cloth can effectively reduce radiative and convective energy loss and then achieve the enhancement of energy collection from the environment. An outstanding evaporation rate of 1.61 kg·m-2·h-1 with an optimum conversion efficiency of 97% under one sun is reached. Based on the facile fabrication, excellent stability, and high solar conversion efficiency, this nature-inspired design of 3D 1T/2H-MoS2/A-CFC is expected to facilitate large-scale applications for seawater purification and desalination.

On cooling rate of metal melt in steel-pouring ladle and tundish during steel continuous casting

Correlation analysis methods were used to study the thermal state of liquid metal at the stage of steel continuous casting under the assumption that measurable objects are random variables. Thermal state of the metal melt is characterized by the values ​​of the metal temperature Tn at this stage and duration of the stages τn and it is described by an integral indicator – cooling rate Wn . Cooling rate is the ratio of temperature difference of the liquid metal at the beginning and end of the stage to the duration of this stage. The metal cooling rates were calculated at various stages of steel continuous casting. The first stage includes the period from the completion of metal processing at a unit of complex steel processing to the start of vacuum treatment. The second stage includes the period from the start of vacuum treatment to its completion. The third stage includes the period from the end of vacuum treatment to the first temperature measurement in the tundish. And further, there are periods of successive temperature measurements in the tundish. It has been established that the metal cooling rates vary considerably depending on the technological stages. Absolute values ​​of the cooling rate differ by more than an order of magnitude. The minimum metal cooling rate is fixed in the tundish. Its value is 0.09 °С/min. The maximum cooling rate of the metal was revealed when the metal was tapped from the steel-pouring ladle into the tundish, while the cooling rate was 1.43 °C/min. The main factors influencing the metal cooling rate were revealed. These factors include the presence of a layer of liquid slag on the metal melt surface in the steel-pouring ladle after out-of-furnace processing. These factors include initial temperature of the liquid metal after completion of treatment at the unit of complex steel processing, the liquid metal temperature after completion of vacuum treatment, presence of oxide solution formed by slag-forming mixtures on the liquid metal surface, presence and effectiveness of heat-insulating mixtures, as well as the heat-insulating characteristics of refractory linings. During vacuum treatment, the metal cooling rate was essentially determined by convective energy losses and energy losses for heating the inert gas. After the stage of vacuum treatment, the cooling rate is significantly reduced due to the use of heat-insulating mixtures. The highest metal cooling rate is set when it passes through the steel outlet channel and the metal protection pipe when filling the tundish. The lowest metal cooling rate is typical when it is in the tundish, due to the presence of a porous plastic refractory layer with low thermal conductivity.

Forecasting of cosmic rays intensities with HelMod Model

HelMod model allows one to describe how solar modulation affects the propagation of galactic cosmic rays (GCR) through the heliosphere with an accuracy of the level of actual experimental uncertainties. The GCRs mainly constitute the high energy population of the so-called space radiation environment. The model treats the physical processes involved in solar modulation, like diffusion, particle drift, convection and adiabatic energy losses, and it embeds a description of both the inner and outer heliosphere. To obtain the modulated intensities, the model requires the knowledge of a few time-dependent heliospheric quantities, i.e., sunspot number, tilt angle of the neutral current sheet, solar wind speed and density, and interplanetary magnetic field. Using historical records, we present a template-based procedure that allows one to predict the heliospheric parameters for coming years, and, in turn, the forecasted modulated spectra. The forecasting templates reconstruct the typical time variation along with solar cycles and may be tuned to the current solar cycle. We estimate that the uncertainty of the forecasted cosmic rays intensity is below 5% (±10% at 68% C.L.) on average for short time predictions (up to 4 years), and below 15% (±(20-25)% at 68% C.L.) for long time predictions (up to 11 years).

Determining the critical insulation thickness of breathing wall: Analytical model, key parameters, and design

Breathing wall (BW) based on air-permeable porous medium offers an alternative solution for utilizing the conductive heat loss of building envelope to preheat the infiltration ventilation airflow within porous medium. However, current studies neglect the influence of pressure drop within porous medium on the energy performance of BW, which may lead to an overestimation or non-optimal design. In this study, we proposed a framework to determine the critical insulation thickness of BW for minimizing its convective heat loss and pressure drop related energy loss. An analytical model was developed and validated to calculate the heat loss of BW under third-type boundary condition. Darcy's law was applied to estimate the pressure drop of infiltration airflow and its associated energy loss. Case studies were conducted to identify the critical insulation thickness of BW. The critical thickness of BW under different scenarios was investigated. The results demonstrate the existence of critical thickness, which yields the lowest overall heat loss of BW. A larger infiltration airflow rate or lower air permeability of porous medium will result in a downward trend of this critical thickness. The outcomes of this study can provide a design guideline of BW for maximizing its energy saving potential.

X-Ray through Very High Energy Intrabinary Shock Emission from Black Widows and Redbacks

Abstract Black widow and redback systems are compact binaries in which a millisecond pulsar heats and may even ablate its low-mass companion by its intense wind of relativistic particles and radiation. In such systems, an intrabinary shock can form as a site of particle acceleration and associated nonthermal emission. We model the X-ray and gamma-ray synchrotron and inverse Compton spectral components for select spider binaries, including diffusion, convection, and radiative energy losses in an axially symmetric, steady-state approach. Our new multizone code simultaneously yields energy-dependent light curves and orbital-phase-resolved spectra. Using parameter studies and matching the observed X-ray spectra and light curves, as well as Fermi Large Area Telescope spectra where available, with a synchrotron component, we can constrain certain model parameters. For PSR J1723–2837 these are notably the magnetic field and bulk flow speed of plasma moving along the shock tangent, the shock acceleration efficiency, and the multiplicity and spectrum of pairs accelerated by the pulsar. This affords a more robust prediction of the expected high-energy and very high energy gamma-ray flux. We find that nearby pulsars with hot or flaring companions may be promising targets for the future Cerenkov Telescope Array. Moreover, many spiders are likely to be of significant interest to future MeV-band missions such as AMEGO and e-ASTROGAM.

Thermomechanical conversion in metals: dislocation plasticity model evaluation of the Taylor-Quinney coefficient

Using a partitioned-energy thermodynamic framework which assigns energy to that of atomic configurational stored energy of cold work and kinetic-vibrational, we derive an important constraint on the Taylor-Quinney coefficient, which quantifies the fraction of plastic work that is converted into heat during plastic deformation. Associated with the two energy contributions are two separate temperatures – the ordinary temperature for the thermal energy and the effective temperature for the configurational energy. We show that the Taylor-Quinney coefficient is a function of the thermodynamically defined effective temperature that measures the atomic configurational disorder in the material. Finite-element analysis of recently published experiments on the aluminum alloy 6016-T4 [1], using the thermodynamic dislocation theory (TDT), shows good agreement between theory and experiment for both stress-strain behavior and temporal evolution of the temperature. The simulations include both conductive and convective thermal energy loss during the experiments, and significant thermal gradients exist within the simulation results. Computed values of the differential Taylor-Quinney coefficient are also presented and suggest a value which differs between materials and increases with increasing strain.

Reversing heat conduction loss: Extracting energy from bulk water to enhance solar steam generation

Interfacial solar steam generation offers a sustainable and affordable technology for seawater desalination and water treatment. During solar steam generation the temperature of the solar evaporation surface is generally higher than the bulk water, which results in energy loss to the bulk water by heat conduction. While many strategies have been developed to minimize and/or eliminate the conductive heat loss, this study focuses on completely reversing conductive heat loss and turning it into an energy extraction from the bulk water to enhance the evaporation during solar steam generation. This was achieved by introducing a certain area of cold evaporation surface between the solar evaporation surface and the bulk water, which led to the conductive heat loss from the solar evaporation surface being completely absorbed and consumed by the cold evaporation surface before reaching the bulk water. Meanwhile, due to its lower surface temperature, the cold evaporation was also able to extract energy from the bulk water, turning the heat conduction loss from the evaporator to the bulk water into the energy harvest from the bulk water. When the surface area of the cold evaporation surface was increased to a certain point (50.3 cm2 in this work), heat flow was reversed, and energy was extracted from the bulk water by the evaporator to enhance solar evaporation. Theoretical simulations agreed well with the experimental results. In addition, as parasitic effects, the cold evaporation surface was also able to gain energy from the ambient air and lower the temperature of the solar evaporation surface, reducing both radiation and convection energy loss. As a result, the evaporation rate and the light-to-vapor energy efficiency of the evaporator were far beyond the theoretical limits, confirming that this strategy has great potential for further practical applications.

Graphene and Rice-Straw-Fiber-Based 3D Photothermal Aerogels for Highly Efficient Solar Evaporation.

Solar-steam generation is one of the most promising technologies to mitigate the issue of clean water shortage using sustainable solar energy. Photothermal aerogels, especially the three-dimensional (3D) graphene-based aerogels, have shown unique merits for solar-steam generation, such as lightweight, high flexibility, and superior evaporation rate and energy efficiency. However, 3D aerogels require much more raw materials of graphene, which limits their large-scale applications. In this study, 3D photothermal aerogels composed of reduced graphene oxide (RGO) nanosheets, rice-straw-derived cellulose fibers, and sodium alginate (SA) are prepared for solar-steam generation. The use of rice straw fibers as skeletal support significantly reduces the need for the more expensive RGO by 43.5%, turning the rice straw biomass waste into value-added materials. The integration of rice straw fibers and RGO significantly enhances the flexibility and mechanical stability of the obtained photothermal RGO-SA-cellulose aerogel. The photothermal aerogel shows a strong broad-band light absorption of 96-97%. During solar-steam generation, the 3D photothermal aerogel effectively decreases the radiation and convection energy loss while enhancing energy harvesting from the environment, leading to an extremely high evaporation rate of 2.25 kg m-2 h-1, corresponding to an energy conversion efficiency of 88.9% under 1.0 sun irradiation. The salinity of clean water collected during the evaporation of real seawater is only 0.37 ppm. The materials are environmentally friendly and cost-effective, showing great potential for real-world desalination applications.

Experimental transmittance of polyethylene films in the solar and infrared wavelengths

The growing use of plastic film coverings in agriculture is due to the possibility of increasing the air temperature around the plants, reducing radiative and convective energy losses, protecting fruit trees from adverse weather conditions, reducing fungal diseases, assuring less reliance on herbicides and pesticides, better protection of food products and more efficient water conservation. Low-density polyethylene (LD-PE) is one of the most widely used plastic films for greenhouse coverings, low and medium tunnels and soil mulching. In this paper, we present radiometric properties of a new and old (used for more than five years) LD-PE film, experimentally investigated using different methodological approaches for different wavelength bands, especially at medium IR. Experimental measurements in the IR wavelength spectrum, included the Near (0.78–3 μm), i.e. N-IR-A (0.78–1.4 μm) and N-IR-B (1.4–3 μm) and Medium (3–50 μm) in accordance with ISO 20473 (E) 2007 were carried out. Experimental results obtained are in agreement with those in the literature and show that the aging effects are minimal in the plastic film used for five years. This finding is crucial for greenhouse design. Referring to practical applications, energy balance of an ordinary agricultural greenhouse was also evaluated. The authors believe that this research results on all the optical properties in a wide spectral range of LD-PE will be useful not only in agriculture, but also for any other solar engineering application.

Stability of a gravity-driven thin electrolyte film flowing over a heated substrate.

The stability of a thin electrolyte liquid film driven by gravity over a vertical substrate is presented. A film thickness evolution equation is derived and solved numerically. The substrate is non-uniformly heated from below which is modeled by imposing a temperature profile at the liquid-solid interface. The electrohydrodynamics is included in the model with Maxwell's stress tensor. The governing flow and energy equations are simplified using the lubrication approximation. The Poisson-Boltzmann equation with Debye-Hückel approximation is used for the potential which is generated inside the film due to a charged layer at the liquid-solid interface. The positive temperature gradient at the substrate leads to the formation of a thermocapillary ridge due to an opposing Marangoni stress. This thermocapillary ridge becomes unstable beyond critical parameters related to Marangoni stress and convective energy loss at the free surface. The electroosmotic flow has no effect on the base profile of the film, but enhances its instability. A parameter space is presented delineating the stable and unstable regimes for the film dynamics.

Optimization of Solar Energy for Salt Extraction from Lake Katwe, Uganda

<p>The solar evaporative crystallization process at Lake Katwe was studied using brine evaporation rates, thermal, convection, and radiation energy losses as well as reported meteorological data around the salt lake basin. A simulation model of a salt pan was developed on a lumped basis to study its behaviour with the effects of the different factors affecting the evaporation process investigated. Moreover, an analysis to assess the possibility of increased productivity of the salt pans through implementation of parabolic solar collector technology to enhance brine evaporation was done. Results showed that the brine evaporation rates and temperature of the salt pan are strongly influenced by in-situ weather conditions. Furthermore, a thermal-fluid analysis of the proposed system showed that the pond solution layer temperature increases thereby increasing the evaporation flux hence leading to increased salt production rate. </p>

Latitudinal Dependence of Cosmic Rays Modulation at 1 AU and Interplanetary Magnetic Field Polar Correction

The cosmic rays differential intensity inside the heliosphere, for energy below 30 GeV/nuc, depends on solar activity and interplanetary magnetic field polarity. This variation, termed solar modulation, is described using a 2D (radius and colatitude) Monte Carlo approach for solving the Parker transport equation that includes diffusion, convection, magnetic drift, and adiabatic energy loss. Since the whole transport is strongly related to the interplanetary magnetic field (IMF) structure, a better understanding of his description is needed in order to reproduce the cosmic rays intensity at the Earth, as well as outside the ecliptic plane. In this work an interplanetary magnetic field model including the standard description on ecliptic region and a polar correction is presented. This treatment of the IMF, implemented in the HelMod Monte Carlo code (version 2.0), was used to determine the effects on the differential intensity of Proton at 1 AU and allowed one to investigate how latitudinal gradients of proton intensities, observed in the inner heliosphere with the Ulysses spacecraft during 1995, can be affected by the modification of the IMF in the polar regions.

Energy Analysis in TIG Welding Process

Abstract An analysis of energy utilization during TIG welding process has been reported in this paper. Fifteen samples of three different diameters of pipe pieces of ASTM A 106 Gr. B, seamless type and API 5LS Gr. B, spirally welded type, are selected for experimentation. The temperatures on the external surface at different locations on each of these seamless pipes (of different diameters) during welding have been measured with the help of electronic pyrometers. The amount of total electrical energy input during welding has been recorded in the wattmeter. The convection and radiation energy losses, that take place from the surface of the pipe piece, have also been determined by using suitable mathematical expressions developed for the purpose. An overall energy balance is carried out taking into account the convection heat loss, the radiation heat loss and the unaccounted loss, for each sample. Then the variation of the ratio of the percentage of unaccounted energy loss to total weld energy input against total weld energy input has been plotted. From the graphs it is seen that with increase in diameter of the pipe and with rise in total weld energy input, the percentage unaccounted energy loss gradually decreases.

A validated predictive model of coronary fractional flow reserve

Myocardial fractional flow reserve (FFR), an important index of coronary stenosis, is measured by a pressure sensor guidewire. The determination of FFR, only based on the dimensions (lumen diameters and length) of stenosis and hyperaemic coronary flow with no other ad hoc parameters, is currently not possible. We propose an analytical model derived from conservation of energy, which considers various energy losses along the length of a stenosis, i.e. convective and diffusive energy losses as well as energy loss due to sudden constriction and expansion in lumen area. In vitro (constrictions were created in isolated arteries using symmetric and asymmetric tubes as well as an inflatable occluder cuff) and in vivo (constrictions were induced in coronary arteries of eight swine by an occluder cuff) experiments were used to validate the proposed analytical model. The proposed model agreed well with the experimental measurements. A least-squares fit showed a linear relation as (Δp or FFR)(experiment) = a(Δp or FFR)(theory) + b, where a and b were 1.08 and -1.15 mmHg (r(2) = 0.99) for in vitro Δp, 0.96 and 1.79 mmHg (r(2) = 0.75) for in vivo Δp, and 0.85 and 0.1 (r(2) = 0.7) for FFR. Flow pulsatility and stenosis shape (e.g. eccentricity, exit angle divergence, etc.) had a negligible effect on myocardial FFR, while the entrance effect in a coronary stenosis was found to contribute significantly to the pressure drop. We present a physics-based experimentally validated analytical model of coronary stenosis, which allows prediction of FFR based on stenosis dimensions and hyperaemic coronary flow with no empirical parameters.

Cosmic Rays in the Inner Heliosphere: Insights from Observations, Theory and Models

The global modulation of galactic cosmic rays in the inner heliosphere is determined by four major mechanisms: convection, diffusion, particle drifts (gradient, curvature and current sheet drifts), and adiabatic energy losses. When these processes combine to produce modulation, the complexity increases significantly especially when one wants to describe how they evolve spatially in all three dimensions throughout the heliosphere, and with time, as a function of solar activity over at least 22 years. In this context also the global structure and features of the solar wind, the heliospheric magnetic field, the wavy current sheet, and of the heliosphere and its interface with the interstellar medium, play important roles. Space missions have contributed significantly to our knowledge during the past decade. In the inner heliosphere, Ulysses and several other missions have contributed to establish the relative importance of these major mechanisms, leading to renewed interest in developing more sophisticated theories and numerical models to explain these observations, and to understand the underlying physics that determines galactic cosmic ray modulation at Earth. An overview is given of some of the observational and modeling highlights over the past decade.

Pedestal and scrape-off layer dynamics in ELMy H-mode plasmas in JET

Pedestal and scrape-off layer (SOL) dynamics due to edge localized modes (ELMs) have been studied on JET with improved diagnostic capability. The new high resolution Thomson scattering system enables detailed measurement of the space and time evolution of the Te and ne pedestal profiles. The pedestal and SOL dynamics for type I ELMy H-mode plasmas have been studied for a wide range of plasma conditions. During a short period of <200 µs after the ELM event radial profiles of filaments in the SOL electron density and temperature have been observed. After that period the SOL density is increased and remains high for several milliseconds. During the same period the electron temperature shows no increase compared with the pre-ELM values. This SOL dynamics has been observed for a wide range of plasma parameters and is independent of plasma pedestal collisionality. For the first time on JET the convective and conductive ELM energy losses have been quantified using the new kinetic profile measurements. The findings provide detailed confirmation of earlier observations based on different measurements and analysis. The pedestal region perturbed by the ELM is the same for both density and temperature and the ELM effect extends up to about 20% of minor radius. The convective energy losses do not vary significantly and are ∼5% of the pedestal stored energy (Wped) over a large range of pedestal collisionality from below to above whereas the conductive losses strongly decrease from ∼20% of Wped to 5% of Wped with increasing . The experimental observations are compared with a simple model based on losses being driven by parallel transport.