3,176 research outputs found
Food utopias: hoping the future of agriculture
No full textWhen one walks the aisles of a typical America, Australian or German wealthy supermarket, the shelves are teeming with food-- cans, bags, packages, fruits, vegetables, freezers and refrigerators teeming with safely sealed meat packages, deli counters with gruyere and potato casserole, edamame salads, swimming lobsters-- a literal cornucopia of food. For many in the developed and wealthy classes of the world, this vision of access to any and all kinds of varieties of food is the norm. In contrast to our book Food Systems Failure (2011), which chronicled the most recent international food crises prompted by high staple crop prices, Food Utopias aims to highlight the various stories that food tells us about ourselves, both critical and hope-filled
The Recognition of Fires Originating from Photovoltaic (PV) Solar Systems
No full textThere has been an observable increase in the fitting of photovoltaic (PV) solar panels on the roofs
of buildings in the UK over the last decade. The origin of some fires in domestic and commercial
properties has been attributed to PV systems. This thesis examines the ability of fire examiners to
recognise and record details of fires believed to have originated from PV systems, as well as
investigating the effect of internal heating in direct current (DC) isolators to the point at which they
fail.
National fire data was examined along with the methods for collecting and collating these data.
This clarified that national fire data cannot identify the specifics of electrical fires. Validity of these
data was then tested by identifying the confidence and competence in the recognition of the origin
of fire, (especially when associated with PV systems), of some fire staff responsible for collecting
fire data. This suggests that some fire scenes examiners are not confident in their own ability to
recognise fires originating from PV systems. Evidence for fires occurring in PV systems in Kent
between 2009 and 2014 was then examined, including a cold case forensic review of the
evidence. This provided an indication that a potential common point of failure, which may lead to
fire originating from a PV system, was to be found within the DC section of the PV circuits and
probably within the DC isolator switch itself. Experimentation revealed that internal heating of a
terminal connection can lead to changes of the phase of the insulating material, causing failure of
structural integrity and therefore allowing an arc to be established. Observable post fire indicators
associated with this mechanism of failure have been identified as well as hydrocarbons evolved
from pyrolysis of isolator insulating material.
Finally, areas for further experimental research and training of fire staff are suggested as well as
the modification of recording mechanisms and building regulations
Flat roofs renovation: a life cycle approach for environmental impact assessment and economic effectiveness
No full textThe high energy consumption caused by the building sector and the continuous growth and ageing of the existing housing stock show the importance of housing renovation to improve the quality of the environment. This research compares the environmental performance of flat roof systems (insulation, roofing membrane and covering layer) using Life Cycle Assessment (LCA). The aim is to give indications on how to improve the environmental performance of housing. This research uses a reference building located in the Netherlands and considers environmental impacts related to materials, energy consumption for heating and maintenance activities. It indicates impact scores for each material taking into account interconnections between the layers and between the different parts of the life cycle. It compares the environmental and economic performances of PV panels and of different materials and thermal resistance values for the insulation. These comparisons show that PV panels are convenient from an environmental and economic point of view. The same is true for the insulation layer, especially for materials as PIR (polyisocyanurate) and EPS (expanded polystyrene). It shows that energy consumption for heating causes a larger share of impact scores than production of the materials and maintenance activities. The insulation also causes larger impact scores comparing to roofing membrane and covering layer. The results show which materials are preferable for flat roof renovation and what causes the largest shares of impact. This gives indication to the roofers and to other stakeholders about how to reduce the environmental impact of the existing housing stock
PV in Australian Apartment Buildings – Opportunities and Barriers
No full textThis paper outlines opportunities for, and barriers to, increasing PV deployment on apartment
buildings in Australia. With PV penetration reaching 40% of residential dwellings in some
parts of the country, access to renewable energy for the 14% of Australians who live in
apartments has lagged behind. Installation of PV on apartment buildings can help relieve
network congestion as well as reduce household energy bills, and with multi-unit dwellings
accounting for 25% of new residential building, the opportunities are significant.
Most apartment buildings in Australia operate under strata title which enables individuals or
businesses to own a section of a property, while sharing ownership of the common property
(CP) of the building. Despite some major advantages of this framework compared with other
approaches, issues around strata organisation have led to a perception that PV on apartments
is ‘too hard.’ However, new models are emerging, including those from developers and from
community energy organisations, to overcome these barriers to PV deployment.
The huge variety amongst existing building stock precludes standardised retrofitting solutions
for PV, while financial viability of such systems is highly dependent on specific load profiles
and network tariffs. PV can potentially be installed to supply electricity to CP, to serve
individual apartments, or as a resource shared between multiple apartments through
embedded networks or virtual net metering. Each approach has particular technical, legal,
regulatory and financial issues. The paper explores these issues, and suggests some possible
paths forward to facilitate the deployment of PV in multi-unit strata-titled buildings
Solar PV rural electrification and energy-poverty: A review and conceptual framework with reference to Ghana
No full textIn spite of the intention of governments to increase the use of renewable energy in electricity supply, particularly the use of solar photovoltaic (PV) for energy poverty reduction in rural and peri-urban areas of Africa, there is relatively little information on how solar PV electrification impacts on energy poverty reduction. Therefore, there is a gap in the literature and hence the need for continuous research. Using Ghana as a reference country, the historical trend, donor cooperation and other aspects of solar PV rural electrification are discussed . The paper illustrates the intersectoral linkages of solar PV electrification and indicators on education, health, information acquisition, agriculture and micro-enterprises. It also reviews sustainability related issues including costs and market barriers, subsidies, stakeholders involvement, political and policy implications, which are critical factors for sustainable market development of solar PV and other renewables. Finally, a common framework is developed to provide a basic understanding of how solar PV electrification impacts on energy-poverty. This framework provides a structure of the interrelated concepts and principles relevant to the issues under review.Rural electrification; solar PV electrification; energy-poverty; renewable energy; economic development; Ghana; Africa
Solar PV hosting capacity: Grid-based vs. market-based scenarios
No full textAssessing the capability of a distribution grid to accommodate new solar PV installations, namely its hosting capacity (HC), has been a prevalent research topic. Although providing a technical limit to how much additional solar PV can be integrated into a distribution grid without trespassing operational limits, commonly used HC analysis (HCA) does not consider consumer preferences or the economic feasibility of installations. Using a market-based optimal power flow (MBOPF) and HCA, we compare the economic and technical limits of solar PV capacity integration in low voltage distribution systems (LVDS). Findings illustrate that (1) the PV HC computed using grid limits only does not give a complete picture of solar PV capacity integration potential, (2) linear, deterministic power flow is not a foolproof method for assessing the network-secure amount of PV, and (3) the number of technically feasible installation sites supersedes the economically feasible ones.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Energy and Industr
Analysing the Waste Potential of Solar PV In India
No full textWith growing demand for energy and the shift towards renewable energy, countries like India are targeting energy mixture with alternate sources like solar, wind and water. With the current growth of solar energy use in India, it is predicted that high amounts of Solar Photovoltaic (PV) waste would be generated in the near future which left improperly managed would lead high amount of useful and expensive material ending up in landfills. This research focuses on the potential material generated from the growth of solar PV stock in India.This research studied the growth of solar PV industry and the spread of Solar PV growth in India. The stock growth of solar PV till 2030 based on India’s renewable energy goal of 280 GW solar energy is taken. Further study on End of Life (EOL) management of Solar PV was studied and the best practice scenarios from around the globe for handling Solar PV waste was studied. The circular economy approach for the Solar PV industry was also reviewed. 3 scenarios were created to determine how the waste from these Solar PV would be managed based on the current state in India, using best-case scenario from around the world and circular economy practices. These scenarios were simulated using dynamic material flow analysis to determine the waste inflow and outflow of material based on the defined scenario.It was determined that more than 21 million tonnes of waste would end up in landfill by 2060 if India does not increase its recycling capabilities. Also, by adapting Germany’s WEEE regulation for solar PV waste management, 2 other scenarios are created, which uses extended producer responsibility and would provide India with the capability to handle future Solar PV waste. A comparison of these 2 scenarios showed higher recovery of material in one (423 thousand tonnes) while generating 21 times more waste to landfill than the other (16 thousand tonnes).It is found that the outflow of tonnes of material is same in all 3 of the scenarios and the highest amount of waste produced by the 280GW target of 2030 would be in 2055 at over 1.6 million tonnes. It is predicted that landfill can end by 2033 or 2044 in the defined scenarios but shows variation in the amount of recovered material would differ between them. Achieving the scenarios put forward would involve coordination between Government agencies, producers of solar PV and the actual users of PVs. A shift to a formal waste management sector would be required and a successful implementation of policies and targets would lead to improvement in multiple Sustainable Development Goals (SDG) for India.Industrial Ecolog
PV-boats: Design issues in the realization of PV powered boats
No full textPV integration in boats is rarely seen, but offers clean and silent transportation while on the water. In order to research the PV realization into boat design challenges, the University of Twente and the NHL hogeschool, both in the Netherlands, started a joined research into PV integration in boats. By studying 3 cases, PV boat specifications and the key design challenges are researched. The first case, the Frisian Solar Challenge 2010, offered the possibility to gather information about 44 innovative PV powered racing boats. The Frisian Solar Challenge is a 5 day 220km race for PV powered boats. Boats need to be fast, efficient and reliable to finish the race at high positions. The second case shows the NHL hogeschool\u92s PV powered racing boat design and building process which attended the Frisian Solar Challenge 2010. The third case is a study in PV powered boats found worldwide. From 105 boats, specifications are collected to learn recent developments in PV powered boats. From these 3 cases follows that light weight is one of the key parameters to build a successful PV powered boat. Especially PV modules with lower weight can bring successful PV powered boat designs. Furthermore, boats equipped with monohull designs offer high efficiency with low drag. However, catamaran designs prove to be successful as well, bringing higher stability in boat designs. Mature technology is needed to sail with reliable hardware
Comprehensive modelling and sizing of PV systems from location to load
No full textPhotovoltaic (PV) systems are progressively used for decentralized electricity generation. To obtain the maximum yield from such systems, optimisation of all components is essential. In this contribution, we provide a comprehensive modelling and sizing of PV systems for any location. Three applications are here presented providing real time monitoring of PV potential, accurate prediction of yield taking into account thermodynamic temperature effects, optimization of modules orientation addressing the effects of shading and efficient sizing of inverter for a higher yield output. When combined, these models can accurately predict the real time performance of any PV system.Accepted Author ManuscriptPhotovoltaic Materials and DevicesDC systems, Energy conversion & Storag
PV Module Integrated Converter for Distributed MPPT PV Systems
No full textDriven by constant advances and cost reductions in photovoltaic (PV) technology,together with incentive government policies toward cleaner environment, the PV energy became one of the fastest growing market in the world. In many countries the amount of installed PV power is increasing at an exponential rate, in all sectors from large utility scale power plants to small residential PV systems.DC systems, Energy conversion & Storag
- …
