Meeting 2030 primary energy and economic growth goals: Mission impossible?

Heun, Matthew Kuperus; Brockway, Paul E.

doi:10.1016/j.apenergy.2019.01.255

Cited by 49 publications

(27 citation statements)

References 39 publications

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“…Energy consumption is increasing rapidly to meet the requirements of the growing world population and rising demand from industrialized countries [1,2]. This fact, together with the intensive use of energy sources from fossil fuels, has triggered several environmental issues [3,4].…”

Section: Introductionmentioning

confidence: 99%

Thermal and Physical Characterization of PEG Phase Change Materials Enhanced by Carbon-Based Nanoparticles

et al. 2020

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This paper presents the preparation and thermal/physical characterization of phase change materials (PCMs) based on poly(ethylene glycol) 400 g·mol−1 and nano-enhanced by either carbon black (CB), a raw graphite/diamond nanomixture (G/D-r), a purified graphite/diamond nanomixture (G/D-p) or nano-Diamond nanopowders with purity grades of 87% or 97% (nD87 and nD97, respectively). Differential scanning calorimetry and oscillatory rheology experiments were used to provide an insight into the thermal and mechanical changes taking place during solid-liquid phase transitions of the carbon-based suspensions. PEG400-based samples loaded with 1.0 wt.% of raw graphite/diamond nanomixture (G/D-r) exhibited the lowest sub-cooling effect (with a reduction of ~2 K regarding neat PEG400). The influences that the type of carbon-based nanoadditive and nanoparticle loading (0.50 and 1.0 wt.%) have on dynamic viscosity, thermal conductivity, density and surface tension were also investigated in the temperature range from 288 to 318 K. Non-linear rheological experiments showed that all dispersions exhibited a non-Newtonian pseudo-plastic behavior, which was more noticeable in the case of carbon black nanofluids at low shear rates. The highest enhancements in thermal conductivity were observed for graphite/diamond nanomixtures (3.3–3.6%), while nano-diamond suspensions showed the largest modifications in density (0.64–0.66%). Reductions in surface tension were measured for the two nano-diamond nanopowders (nD87 and nD97), while slight increases (within experimental uncertainties) were observed for dispersions prepared using the other three carbon-based nanopowders. Finally, a good agreement was observed between the experimental surface tension measurements performed using a Du Noüy ring tensiometer and a drop-shape analyzer.

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Section: Introductionmentioning

confidence: 99%

Thermal and Physical Characterization of PEG Phase Change Materials Enhanced by Carbon-Based Nanoparticles

et al. 2020

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“…Further work is needed to estimate the actual exergy return ratios in that period to determine the validity of this hypothesis. Confirming whether actual ExRR decreased over this period would reinforce the high level of correlation between annual gains in the UK and Ghana's aggregate exergy conversion efficiency and economic growth identified by Heun and Brockway (2019).…”

Section: Err Dynamics and Economic Growthmentioning

confidence: 56%

An Estimation of Different Minimum Exergy Return Ratios Required for Society

Court

2019

Biophys Econ Resour Qual

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This article shows that as technical change enhances the conversion efficiency of primary-to-final and final-to-useful exergy processes, the minimum exergy return ratios (ExRR) required for society decreases, irrespective of the boundary under consideration. Therefore, the gains in exergy conversion efficiency that mostly occurred between the 1940s and the 1970s have compensated for the concurrent decrease of exergy surpluses of the fossil energy system. However, while the minimum ExRR required for modern societies have been quite stable since the 1970s, actual ExRR prevailing for energy systems have continued to decrease. Therefore, the increased difficulty in improving exergy conversion efficiency since the mid-1970s has resulted in a tightening exergy constraint on economic growth; this could partially explain the global economic slowdown of the last forty years. Further work is needed to estimate actual exergy return ratios that prevailed in the past decades and compare their distance relatively to the minimum levels estimated in the present article, and hence have a more precise idea of the exergy constraint's magnitude acting on economic growth.

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“…However, no additional information was found to estimate the share of fans in previous years. Besides that, Heun et al [63] have recently made a study in which they calculate the exergy efficiency of fans for the period 1971-2013, for Ghana. Even though Ghana has a different climate, this was the first study estimating exergy efficiencies for fans.…”

Section: Of 22mentioning

confidence: 99%

Insights from Past Trends in Exergy Efficiency and Carbon Intensity of Electricity: Portugal, 1900–2014

et al. 2019

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We use the societal exergy analysis to identify periods and factors controlling efficiency dilution and carbon deepening of electricity in Portugal from 1900 to 2014. Besides estimating the carbon intensity of electricity production, we propose a new indicator, the carbon intensity of electricity use, which quantifies CO 2 /kWh of electricity derived useful exergy. Results show final to useful efficiency dilution until World War I (50% to 30%) due to a decrease in share of the high-efficiency transport sector and from mid-1940s to 1960 and mid-1990s onwards (58% to 47% and 47% to 40%) due to an increase in share of the low efficiency commercial and residential sector. Decarbonization from 1900 to mid-1960s, with carbon intensities of electricity production and use dropping respectively from 12.8 to 0.2 and from 33.6 to 0.4 kg CO 2 /kWh due to an increase in thermoelectricity efficiencies and an increase in share of hydro. Then, a period of carbon deepening until 1990 with carbon intensities tripling due to a shift in shares from hydro to thermoelectricity and more recently a period of decarbonization with carbon intensities decreasing to 0.35 and 0.9 kg CO 2 /kWh, due to the increase in renewable electricity despite a dilution in final to useful efficiency.Energies 2019, 12, 534 2 of 22 effects on the lives of women and society in general that resulted from time savings associated with electricity powered domestic devices such as the refrigerator and the washing machines.Due to its social and economic importance and ease of use, electricity has become a significant proportion of the present final energy consumption of OECD (Organisation for Economic Co-operation and Development) countries (22%) [4], second only to oil. Over the next few decades, it is expected that the importance of electricity will increase even more because it is a crucial energy carrier to fuel a sustainable 4th industrial revolution based on electrical and autonomous vehicles, communication, robotization, data gathering and artificial intelligence [5,6]. Additionally, it is essential that many of the end-uses that are currently being provided by fossil fuels, such as mobility, will in the future be provided by renewable electricity [5,7]. Otherwise, the decarbonization of society imposed by the need to decrease the human impact on the climate system will be difficult to achieve.The efficiencies and carbon intensities of electricity production and use are of crucial importance in determining the environmental, social and economic benefits of the imminent energy transition. In order to estimate and locate the opportunities to increase exergy efficiency and decrease carbon intensity, a thorough societal exergy analysis of the whole energy conversion chain, from the primary to final and then to the useful stage, is necessary. To properly estimate primary to final exergy efficiency, one needs to consider the efficiency of electricity generation and distribution, which depends on the energy mix and technical efficiency of the different power statio...

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Meeting 2030 primary energy and economic growth goals: Mission impossible?

Cited by 49 publications

References 39 publications

Thermal and Physical Characterization of PEG Phase Change Materials Enhanced by Carbon-Based Nanoparticles

Thermal and Physical Characterization of PEG Phase Change Materials Enhanced by Carbon-Based Nanoparticles

An Estimation of Different Minimum Exergy Return Ratios Required for Society

Insights from Past Trends in Exergy Efficiency and Carbon Intensity of Electricity: Portugal, 1900–2014

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