Residential PV-BES systems: Economic and grid impact analysis

The energy industry has seen a revolutionary transformation in the growth of renewables over the past decade. With recent advances in battery storage performance, solar energy is fast becoming the focus of the global energy shift towards a more sustainable future. Photovoltaic (PV) systems integrated with Battery Energy Storage (BES) systems are expected to play an important role in the UK’s future energy industry, aided in part by manufacturing cost reductions. For energy consumers, these systems can deliver considerable savings in utility costs and potentially bring a financial return via a feed-in-tariff (FIT) scheme. Such a system could also help energy suppliers and network operators ease the burden of a huge surge of future energy demand, mitigate network congestion and improve system resilience and autonomy. There is, however, limited literature that utilises simulation to investigate the influence of PV-BES system deployment at urban scale on the grid based on economic and technical analysis. In this work, a household-level model is developed that includes load demand heterogeneities, as well as BES and PV systems. The single household model can be scaled to higher levels, such as streets and community, hence the model can be applied to study the interaction between households, the wider community and the grid, in terms of electricity im/export, BES usage and network injection impact. A comprehensive analysis of both technical and economic perspectives is presented based on several key performance indicators (KPIs), such as self-consumption rate (SCR), self-sufficiency rate (SSR) and reduction in peak charges. The addition of a BES system can significantly increase the self-consumption of a home PV system, by at least 15%, however the expensive upfront cost of the BES system leads to a much longer payback time

Techno-enviro-economic assessment of household and community energy storage in the UK

Residential electricity demand is expected to rise in the next few decades due to the electrification of heating and transport. Both European and UK national policies suggest that efforts should be made to reduce carbon emissions and increase the share of renewable energy, an important element of which is encouraging generation, typically PV, in partnership with energy storage systems in the residential sector. The scale of the energy storage system is important, i.e. in individual properties or as a community resource. Many advantages of community energy storage (CES) over household energy storage (HES) have been identified, but the design and operation of CES has received significantly less attention. Most existing research has analysed CES at community level only, but the performance and impact on individual households has yet to be fully explored. In this study an agent-based model is proposed to investigate and analyse CES based on a range of criteria. Results indicate that both HES and CES can significantly reduce the grid peak power import and export, improve the community self-consumption rate (SCR) and self-sufficiency rate (SSR), and contribute to much higher energy saving. Furthermore, optimising the CES capacity leads to more effective use of PV power and better demand localisation during high PV-generation periods. It is found that an important challenge for CES systems is to realise the value of the shared electricity equitably amongst the participants and potentially to seek other revenue streams

Surfaces roughness effects on the transmission of Gaussian beams by anisotropic parallel plates

Influence of the plate surfaces roughness in precise ellipsometry experiments is studied. The realistic case of a Gaussian laser beam crossing a uniaxial platelet is considered. Expression for the transmittance is determined using the first order perturbation theory. In this frame, it is shown that interference takes place between the specular transmitted beam and the scattered field. This effect is due to the angular distribution of the Gaussian beam and is of first order in the roughness over wavelength ratio. As an application, a numerical simulation of the effects of quartz roughness surfaces at normal incidence is provided. The interference term is found to be strongly connected to the random nature of the surface roughness.Comment: 18 pages, Journal of Physics D: Applied Physics, volume 36, issue 21, pages 2697 - 270

Signatures of three-nucleon interactions in few-nucleon systems

Recent experimental results in three-body systems have unambiguously shown that calculations based only on nucleon-nucleon forces fail to accurately describe many experimental observables and one needs to include effects which are beyond the realm of the two-body potentials. This conclusion owes its significance to the fact that experiments and calculations can both be performed with a high accuracy. In this review, both theoretical and experimental achievements of the past decade will be underlined. Selected results will be presented. The discussion on the effects of the three-nucleon forces is, however, limited to the hadronic sector. It will be shown that despite the major successes in describing these seemingly simple systems, there are still clear discrepancies between data and the state-of-the-art calculations.Comment: accepted for publication in Rep. Prog. Phy

Foot health education for people with rheumatoid arthritis : the practitioner's perspective

Background: Patient education is considered to be a key role for podiatrists in the management of patients with rheumatoid arthritis (RA). Patient education has undoubtedly led to improved clinical outcomes, however no attempts have been made to optimise its content or delivery to maximise benefits within the context of the foot affected by rheumatoid arthritis. The aim of this study was to identify the nature and content of podiatrists' foot health education for people with RA. Any potential barriers to its provision were also explored. Methods: A focus group was conducted. The audio dialogue was recorded digitally, transcribed verbatim and analysed using a structured, thematic approach. The full transcription was verified by the focus group as an accurate account of what was said. The thematic analysis framework was verified by members of the research team to ensure validity of the data. Results: Twelve members (all female) of the north west Podiatry Clinical Effectiveness Group for Rheumatology participated. Six overarching themes emerged: (i) the essence of patient education; (ii) the content; (iii) patient-centred approach to content and timing; (iv) barriers to provision; (v) the therapeutic relationship; and (vi) tools of the trade. Conclusion: The study identified aspects of patient education that this group of podiatrists consider most important in relation to its: content, timing, delivery and barriers to its provision. General disease and foot health information in relation to RA together with a potential prognosis for foot health, the role of the podiatrist in management of foot health, and appropriate self-management strategies were considered to be key aspects of content, delivered according to the needs of the individual. Barriers to foot health education provision, including financial constraints and difficulties in establishing effective therapeutic relationships, were viewed as factors that strongly influenced foot health education provision. These data will contribute to the development of a patient-centred, negotiated approach to the provision of foot health education for people with RA

Fundamental constructs in food parenting practices: a content map to guide future research

Although research shows that “food parenting practices” can impact children’s diet and eating habits, current understanding of the impact of specific practices has been limited by inconsistencies in terminology and definitions. This article represents a critical appraisal of food parenting practices, including clear terminology and definitions, by a working group of content experts. The result of this effort was the development of a content map for future research that presents 3 overarching, higher-order food parenting constructs – coercive control, structure, and autonomy support – as well as specific practice subconstructs. Coercive control includes restriction, pressure to eat, threats and bribes, and using food to control negative emotions. Structure includes rules and limits, limited/guided choices, monitoring, meal- and snacktime routines, modeling, food availability and accessibility, food preparation, and unstructured practices. Autonomy support includes nutrition education, child involvement, encouragement, praise, reasoning, and negotiation. Literature on each construct is reviewed, and directions for future research are offered. Clear terminology and definitions should facilitate cross-study comparisons and minimize conflicting findings resulting from previous discrepancies in construct operationalization

Plasmonic nanoparticle monomers and dimers: From nano-antennas to chiral metamaterials

We review the basic physics behind light interaction with plasmonic nanoparticles. The theoretical foundations of light scattering on one metallic particle (a plasmonic monomer) and two interacting particles (a plasmonic dimer) are systematically investigated. Expressions for effective particle susceptibility (polarizability) are derived, and applications of these results to plasmonic nanoantennas are outlined. In the long-wavelength limit, the effective macroscopic parameters of an array of plasmonic dimers are calculated. These parameters are attributable to an effective medium corresponding to a dilute arrangement of nanoparticles, i.e., a metamaterial where plasmonic monomers or dimers have the function of "meta-atoms". It is shown that planar dimers consisting of rod-like particles generally possess elliptical dichroism and function as atoms for planar chiral metamaterials. The fabricational simplicity of the proposed rod-dimer geometry can be used in the design of more cost-effective chiral metamaterials in the optical domain.Comment: submitted to Appl. Phys.

Europe's Twenties: A Study Using the WIATEC Model

In this paper, we use a computable general equilibrium model (WIATEC) to study the potential impact of implementing Europe's 20-20-20 climate policy. The results show that the economic costs of implementing the policy are only moderate and within the range of recent empirical evidence. Furthermore, they also indicate that there is a possibility that the existing allocations to the Europena sectors participating in the EU Emissions Trading Scheme (EU ETS) are on the low side, and therefore, there are still rooms for movement in the future