Application of stochastic and evolutionary methods to plan for the installation of energy storage in voltage constrained LV networks

Energy storage is widely considered to be an important component of a decarbonised power system if large amounts of renewable generation are to provide reliable electricity. However, storage is a highly capital intensive asset and clear business cases are needed before storage can be widely deployed. A proposed business case is using storage to prevent overvoltage in low voltage (LV) distribution networks to enable residential photovoltaic systems. Despite storage being widely considered for use in LV networks, there is little work comparing where storage might be installed in LV networks from the perspective of the owners of distribution networks (DNOs). This work addresses this in two ways. Firstly, a tool is developed to examine whether DNOs should support a free market for energy storage in which customers with PV purchase storage (e.g. battery systems) to improve their self-consumption. This reflects a recent policy in Germany. Secondly, a new (published) method is developed which considers how DNOs should purchase and locate storage to prevent overvoltage. Both tools use a snapshot approach by modelling the highest and lowest LV voltages. On their own, these tools enable a DNO to determine the cost of energy storage for a particular LV network with a particular set of loads and with PV installed by a given set of customers. However, in order to predict and understand the future viability of energy storage it is valuable to apply the tools to a large number of LV networks under realistic future scenarios for growth of photovoltaics in the UK power system. Therefore, the work extracts over 9,000 LV network models containing over 40,000 LV feeders from a GIS map of cables provided by one of the UK’s electricity distribution networks- Electricity North West. Applying the proposed tools to these 9,000 network models, the work is able to provide projections for how much LV energy storage would be installed under different scenarios. The cost of doing so is compared to the existing method of preventing reinforcement- LV network reconductoring. This is a novel way of assessing the viability of LV energy storage against traditional approaches and allows the work to draw the following conclusions about the market for energy storage in LV distribution networks in the UK: - Overvoltage as a result of PV could begin to occur in the next few years unless UK regulations for voltage levels are relaxed. There could be a large cost (hundreds of millions of pounds) to prevent this if the traditional approach of reconductoring is used. - If overvoltage begins to occur, a free market for energy storage (randomly purchased by electricity consumers) cannot offer large benefits to DNOs in reducing the reinforcement cost unless this is properly controlled, located and/or widely installed by customers. - Optimally located storage by the DNO can reduce overall reinforcement costs to mitigate overvoltage. This would enable more energy storage to balance renewable generation and present large savings to the power system. The exact topology of storage and the storage rating in each LV network could be determined using the tool proposed in this work

New and significant avifaunal records from Batam and Bintan Islands, Riau Archipelago

Observations made during 2000-2003 and 2012, mainly in estuarine and other coastal habitats, increase the list of bird species known from Batam and Bintan islands by 15 (to 137) and two species (to 181) respectively. These records include five species new for the Riau Archipelago (Red-tailed Tropicbird Phaeton rubricauda, Cattle Egret Bubulcus ibis, Wood Sandpiper Tringa glareola, Curlew Sandpiper Calidris ferruginea and House Crow Corvus splendens). We also present additional records of species previously noted as uncommon or of restricted distribution in the region. Differences between the Riau Archipelago and nearby Singapore in the total number of known bird species (229 and 375 species, respectively) may be partly due to their relative isolation from mainland Southeast Asia, but the much greater survey effort on Singapore over many years must also be a significant factor. Additional, hitherto unpublished, observations by birdwatchers are sought to assess the relative importance of these explanations

An assessment of the economic feasibility of the floating PV technology in Aotearoa–New Zealand

Electricity generation from utility-scale solar facilities is projected to grow to between 5 and 16 TWh by 2050 in Aotearoa–New Zealand. The floating photovoltaic (FPV) technology is considered a viable option for the country, because of the good solar resource at existing hydropower schemes. This paper aims to inform the understanding of the economic feasibility of FPV systems through the analysis of specific cases – Maraetai Dam and Lake Tekapo. To do so, the solar resource and FPV outputs are obtained through the modelling of Solargis and using industry standard technical specification. As well as the normal uncertainties associated with (potential) FPV performance evaluations, the influence of water temperature is also considered. The overall FPV output is estimated to be between 1,115 and 1,497 kWh/kWp. Using available Engineering, Procurement and Construction (EPC) costs, the levelized cost of energy (LCOE) metric, for a 10 MW installation, is determined to be between NZ$176 and NZ$237 per MWh, with total electricity generation over 25 years between 263 and 353 GWh. In order to reach the required LCOE value of less than NZ$100/MWh for utility scale generation, the EPC costs will have to be reduced by a factor of 2 to around NZ$1,500/kWp

Are wearable electronic vision enhancement systems (wEVES) beneficial for people with age-related macular degeneration? A scoping review

INTRODUCTION: Age-related macular degeneration (AMD) is the most common cause of irreversible visual impairment in the United Kingdom. It has a wide-ranging detrimental impact on daily living, including impairment of functional ability and quality of life. Assistive technology designed to overcome this impairment includes wearable electronic vision enhancement systems (wEVES). This scoping review assesses the usefulness of these systems for people with AMD. METHODS: Four databases (Cumulative Index to Nursing and Allied Health Literature, PubMed, Web of Science and Cochrane CENTRAL) were searched to identify papers that investigated image enhancement with a head-mounted electronic device on a sample population that included people with AMD. RESULTS: Thirty-two papers were included: 18 studied the clinical and functional benefits of wEVES, 11 investigated use and usability and 3 discussed sickness and adverse effects. CONCLUSIONS: Wearable electronic vision enhancement systems provide hands-free magnification and image enhancement producing significant improvements in acuity, contrast sensitivity and aspects of laboratory-simulated daily activity. Adverse effects were infrequent, minor and spontaneously resolved with the removal of the device. However, when symptoms arose, they sometimes persisted with continued device usage. There are multi-factorial influences and a diversity of user opinions on promotors to successful device use. These factors are not exclusively driven by visual improvement and incorporate other issues including device weight, ease of use and inconspicuous design. There is insufficient evidence of any cost-benefit analysis for wEVES. However, it has been shown that a user's decision to make a purchase evolves over time, with their estimates of cost falling below the retail price of the devices. Additional research is needed to understand the specific and distinct benefits of wEVES for people with AMD. Further patient-centred research should assess the benefits of wEVES in user-led activities when directly compared with alternative coping strategies, allowing professionals and users to make better prescribing and purchasing decisions

Regulatory and Financial Hurdles for the Installation of Energy Storage in UK Distribution Networks

This paper examines the feasibility of energy storage in in a low voltage distribution network to facilitate increased Distributed Generation (DG), and electricity demand. Modelling is used to quantify technical and financial benefits of storage over a 10 year period. Technical benefits are achieved through loss reduction, prevention of voltage rise and peak shaving. However, for energy storage to be financially feasible, all multi-stakeholder benefits need to be included in any investment strategy and regulation needs to be updated to foster energy storage adoption

Green Growth Diagnostics for Africa: Literature Review and Scoping Study

This paper reviews the literature for a project which seeks to develop a new Green Growth Diagnostics methodology and apply it to countries in Africa. The original growth diagnostics methodology was developed by Haussmann, Rodrik and Velasco to identify the key constraints holding back economic growth from its full potential. Their approach was driven by the needs of policymakers facing the dilemma that most problems have multiple causes, but governments cannot tackle all of them at once, given limitations in their financial and executive capacity. This gave rise to the idea of concentrating these limited resources on the binding constraint, which would be identified going through a tool conceptualised as a decision tree. The proponents of the original growth diagnostics also realised that this binding constraint varies between countries and - we would argue - between sectors. The central point of the original growth diagnostics method was that it offered researchers and policy makers a way of identifying priorities in analysis and policy; and finding solutions which take into account local conditions. The same rationale applies to our Green Growth Diagnostic project. We build on the original approach but adapt it in four ways: 1. Applying it to the energy sector; 2. Taking into account potential knock-on effects on the economy; 3. The political economy when going from diagnostics to therapeutics; and 4. Working out the distributional consequences. Since each step takes the project into un(der)explored territory, it is built around five research questions and corresponding methodologically distinct work packages. Our five research questions are: 1. What are the binding constraints for investment in economically viable renewable energy?; 2.Which policies can more effectively target different binding constraints?; 3. Who obstructs/drives the adoption of specific sustainable energy policies?; 4. What would be the macroeconomic impacts of an increase in renewable energy investment/capacity, and the reforms needed to bring this increase about? and 5. Under what circumstances increased on-grid renewable energy capacity translates into increased access to and increased reliability of electricity supply in developing countries? This paper pulls together what we can learn from the international literature on these questions

Guidelines for the treatment of diabetic ulcers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72913/1/j.1524-475X.2006.00176.x.pd

Machine-enhanced CP-asymmetries in the electroweak sector

The violation of charge conjugation ( C ) and parity ( P ) symmetries are a requirement for the observed dominance of matter over antimatter in the Universe. As an established effect of beyond the Standard Model physics, this could point towards additional C P violation in the Higgs-gauge sector. The phenomenological footprint of the associated anomalous couplings can be small, and designing measurement strategies with the highest sensitivity is therefore of the utmost importance in order to maximize the discovery potential of the Large Hadron Collider. There are, however, very few measurements of C P -sensitive observables in processes that probe the weak-boson self-interactions. In this article, we study the sensitivity to new sources of C P violation for a range of experimentally accessible electroweak processes, including W γ production, W W production via photon fusion, electroweak Z j j production, electroweak Z Z j j production, and electroweak W ± W ± j j production. We study simple angular observables as well C P -sensitive observables constructed using the outputs of machine-learning algorithms. We find that the machine-learning-constructed C P -sensitive observables improve the sensitivity to C P -violating effects by up to a factor of five, depending on the process. We also find that inclusive W γ and electroweak Z j j production have the potential to set the best possible constraints on certain C P -odd operators in the Higgs-gauge sector of dimension-six effective field theories