Modelling energy transitions for climate targets under landscape and actor inertia

The speed at which established socioeconomic and technological systems can be adapted to alternatives that are compatible with a climate stabilised, 2. C world remains unknown. Quantitative models used for assessing this challenge typically make a number of arguably optimistic assumptions regarding human behaviour and decision making. This often restricts the insights produced to futures approximating a so-called . first-best policy landscape. However, empirical studies of socio-technical change have shown that technological diffusion is often influenced by actors and institutions interacting under less ideal, . second-best conditions. This paper quantifies these factors in a formal energy model as . landscape and actor inertia and employs them for the first time in BLUE, a dynamic stochastic socio-technical simulation of technology diffusion, energy and emissions inspired by the multi-level perspective. Using the UK energy system as an example, the results illustrate how socio-technical inertia may significantly blunt future efforts to achieve climate targets

Achieving net-zero emissions through the reframing of UK national targets in the post-Paris Agreement era

The Paris Agreement provides an international framework aimed at limiting average global temperature rise to well below 2 ∘C, implemented through actions determined at the national level. As the Agreement necessitates a ‘net-zero’ emissions energy system by 2100, decarbonization analyses in support of national climate policy should consider the post-2050 period. Focusing solely on mitigation objectives for 2030 or 2050 could lead to blindsiding of the challenge, inadequate ambition in the near term, and poor investment choices in energy infrastructure. Here we show, using the UK as an example, that even an ambitious climate policy is likely to fall short of the challenge of net-zero, and that analysis of the post-2050 period is therefore critical. We find that the analysis of detailed, longer-term national pathways that achieve net-zero is important for future reassessment of ambition under nationally determined contributions (NDCs)

Reactivity of a dititanium bis(pentalene) complex toward heteroallenes and main-group element–element bonds

The reactivity of the Ti=Ti double bond in (μ,η 5 :η 5 -Pn † ) 2 Ti 2 (1; Pn † = 1,4-{Si i Pr 3 } 2 C 8 H 4 ) toward isocyanide and heteroallene substrates, and molecules featuring homonuclear bonds between main-group elements (E-E) has bee n explored. Reaction of 1 with methyl isocyanide or 1,3-N,N′-di-p-tolylcarbodiimide resulted in the formation of the 1:1 adducts (μ,η 5 :η 5 -Pn † ) 2 Ti 2 (μ,η 2 -CNMe) (2) and (μ,η 5 :η 5 -Pn † ) 2 Ti 2 (μ-C{N(4-C 6 H 4 CH 3 )} 2 ) (3), respectively, which are thermally stable up to 100 °C in contrast to the analogous adducts formed with CO and CO 2 . Reaction of 1 with phenyl isocyanate afforded a paramagnetic complex, [(η 8 -Pn † )Ti] 2 (μ,κ 2 :κ 2 -O 2 CNPh) (4), in which the "double-sandwich" architecture of 1 has been broken and an unusual phenyl-carbonimidate ligand bridges two formally Ti(III) centers. Reaction of 1 with diphenyl dichalcogenides, Ph 2 E 2 (E = S, Se, Te), led to the series of Ti-Ti single-bonded complexes (μ,η 5 :η 5 -Pn † ) 2 [Ti(EPh)] 2 (E = S (5), Se (6), Te (7)), which can be considered the result of a 2e - redox reaction or a 1,2-addition across the Ti=Ti bond. Treatment of 1 with azobenzene or phenyl azide afforded [(η 8 -Pn † )Ti] 2 (μ-NPh) 2 (8), a bridging imido complex in which the pentalene ligands bind in an η 8 fashion to each formally Ti(IV) center, as the result of a 4e - redox reaction driven by the oxidative cleavage of the Ti=Ti double bond. The new complexes 2-8 were extensively characterized by various techniques including multinuclear NMR spectroscopy and single-crystal X-ray diffraction, and the experimental work was complemented by density functional theory (DFT) studies

Spatially explicit techno-economic optimisation modelling of UK heating futures

This thesis describes the use of a spatially explicit model to investigate the economies of scale associated with district heating technologies and consequently, their future technical potential when compared against individual building heating. Existing energy system models used for informing UK technology policy do not employ high enough spatial resolutions to map district heating potential at the individual settlement level. At the same time, the major precedent studies on UK district heating potential have not explored future scenarios out to 2050 and have a number of relevant low-carbon heat supply technologies absent from their analyses. This has resulted in cognitive dissonance in UK energy policy whereby district heating is often simultaneously acknowledged as both highly desirable in the near term but ultimately lacking any long term future. The Settlement Energy Demand System Optimiser (SEDSO) builds on key techno-economic studies from the last decade to further investigate this policy challenge. SEDSO can be distinguished from other models used for investigating UK heat decarbonisation by employing a unique combination of extensive spatial detail, technical modelling which captures key cost-related nonlinearities, and a least-cost constrained optimisation approach to technology selection. The study yields a number of original contributions to knowledge that are relevant for policymakers. Results described in the thesis suggest that the marginal economics of UK district heating schemes are significantly improved when compared against individual heat pumps rather than gas boilers. This is relevant because under current policy direction individual heat pumps are likely to be the major counterfactual option to district heating post-2030. Results also illustrate how assumptions about technology availability can drive large shifts in optima, and that utility-scale electric heat pumps could be a key enabling technology for district heating to supply a large fraction of UK heat demand in a post-gas heating future

Sizing of district heating systems based on smart meter data: Quantifying the aggregated domestic energy demand and demand diversity in the UK

The sizing of district energy systems involves a trade-off between reliability and continuity of service, and avoidance of capital and running costs associated with oversizing. Finding the most appropriate sizing requires a thorough understanding of energy demand. However, empirical data necessary to support such an understanding is scarce, and district energy systems are typically oversized. This study uses smart meter data from the largest field trial to analyse residential energy consumption in the UK. It presents graphically the seasonal and daily variations in energy consumption patterns, the weather dependence of energy loads, and peak hourly demand during particularly cold weather conditions. It also explores the diversity effect in residential energy consumption and computes the after diversity maximum demand at different levels of aggregations. Results show that, peak hourly gas consumption was nearly seven times higher than electricity consumption during the cold spells, while diversity reduced gas and electricity maximum demand per dwelling up to 33% and 47%, respectively. This empirical quantitative analysis of energy demand and diversity can support improved design and operation of district energy, and in particular, enable reduced capital and running costs, and an improved understanding of economies of scale for district heating networks

Large Hydropower, Decarbonisation and Climate Change Uncertainty: Modelling Power Sector Pathways for Ecuador

Hydropower plays a critical role in global, South American and Ecuadorian energy policy and for achieving Nationally Determined Contributions (NDCs) aiming to reduce greenhouse gas emissions. However, long-term climatic changes may affect the role of hydropower in meeting energy and climate policy objectives. The effects of climate change on runoff availability for hydropower generation are largely uncertain. This paper uses climate change scenarios derived from a large ensemble of Global Circulation Models as input for an energy system optimisation model (TIMES-EC) to examine least-cost options for the hydropower-dominated Ecuadorian power system in the period to 2050. This is done in the context of three policy cases in order to assess trade-offs between power system configuration, emissions and costs. The results show that in the long-term hydropower will remain as one of the most cost-effective and low emission technologies in the Ecuadorian power sector. However, constraints on deployment and uncertainty around climate change impacts could hinder its ability to contribute to the fulfilment of NDC targets, as well as create uncertainty around long-term power system costs. Strategies to hedge against these risks will likely require that hydropower expansion be complemented by alternative sources, namely incremental shares of thermoelectric generation with natural gas, biomass and geothermal energy

Growth Enhancement Support Scheme (GESS) and Farmers’ Fertilizer Use in Rural Nigeria

Fertilizer use in Nigeria is estimated at 13 kg/ha, which is far below the 200 kg/ha recommended by the Food and Agricultural Organization (FAO). The objective of this investigation was to identify the determinant factors of farmers’ participation in the Nigeria’s growth enhancement support scheme (GESS). In addition, we determined the impact of the GESS on fertilizer use in rural areas. One thousand, two hundred rural farmers were sampled across the six geopolitical zones of Nigeria. Results from the use of recursive bivariate probit model indicated that GESS significantly impacted on the access and usage of fertilizer among the rural farmers; and that contact with extension agents, ownership of mobile phones, power for charging phone batteries, value output, mobile network coverage, ability to read and write were positive determinants of rural farmers participation in the GESS; whereas increased distance to registration and collection centers, and cultural constraints to married women reduced farmers’ tendency to participate in the GESS. The findings suggest that farmers’ participation in the GESS is a critical factor for raising fertilizer use in Nigeria. This implies that food security in sub-Saharan Africa can be achieved by increasing the participation of rural farmers in the growth enhancement support scheme

Solid-wall U-values: heat flux measurements compared with standard assumptions

The assumed U-values of solid walls represent a significant source of uncertainty when estimating the energy performance of dwellings. The typical U-value for UK solid walls used for stock-level energy demand estimates and energy certification is 2.1 Wm−2 K−1. A re-analysis (based on 40 brick solid walls and 18 stone walls) using a lumped thermal mass and inverse parameter estimation technique gives a mean value of 1.3 ± 0.4 Wm−2 K−1 for both solid wall types. Among the many implications for policy, this suggests that standard UK solid-wall U-values may be inappropriate for energy certification or for evaluating the investment economics of solid-wall insulation. For stock-level energy modelling, changing the assumed U-value for solid walls reduces the estimated mean annual space heating demand by 16%, and causes a proportion of the stock to change Energy Performance Certification (EPC) band. The analysis shows that the diversity of energy use in domestic buildings may be as much influenced by heterogeneity in the physical characteristics of individual building components as it is by variation in occupant behaviour. Policy assessment and guidance material needs to acknowledge and account for this variation in physical building characteristics through regular grounding in empirical field data