A community-scale hybrid energy system integrating biomass for localised solid waste and renewable energy solution: Evaluations in UK and Bulgaria

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Growing pace of urban living is expected to simultaneously aggravate both the waste and the energy crises. This study presents feasibility assessment of a community scale hybrid renewable energy system (HRES) utilising biomass to serve the local energy needs while reducing the household solid waste volume. A modelling framework is presented and evaluated for a biomass HRES, comprising of a Wind turbine-PV Array-Biogas generator-Battery system, applied to two European cities - Gateshead (UK) and Sofia (Bulgaria) - accounting for their distinct domestic biowaste profiles, renewable resources and energy practices. Biogas generator is found to make the most substantial share of electricity generation (up to 60–65% of total), hence offering a stable community-scale basal electricity generation potential, alongside reduction in disposal costs of local solid waste. Net present cost for the biomass-integrated HRESs is found within 5% of each other, despite significant differences in the availability of solar and wind resources at the two sites. Based on a survey questionnaire targeting construction companies and energy solution developers, project costs and planning regulatory red tapes were identified as the two common implementation challenges in both the countries, with lack of awareness of HRES as a further limitation in Bulgaria, impeding wider uptake of this initiative

Green buildings and design for adaptation: strategies for renovation of the built environment

The recent EU Directives 2010/31 and 2012/27 provide standards of nearly zero energy buildings for new constructions, aiming at a better quality of the built environment through the adoption of high-performance solutions. In the near future, cities are expected to be the main engine of development while bearing the impact of population growth: new challenges such as increasing energy efficiency, reducing maintenance costs of buildings and infrastructures, facing the effects of climate change and adjusting on-going and future impacts, require smart and sustainable approaches. To improve the capability of adaptation to dynamics of transformation, buildings and districts have to increase their resilience, assumed as ‘the capacity to adapt to changing conditions and to maintain or regain functionality and vitality in the face of stress or disturbance’ (Wilson A., Building Resilience in Boston, Boston Society of Architects, 2013). This paper describes the research methodology, developed by the Department of Architecture, a research unit of Technology for Architecture, to perform the assessment of resilience of existing buildings, as well as the outcomes of its application within Bologna urban context. This methodology focuses on the design for adaptation of social housing buildings, aiming at predicting their expected main impacts (energy consumption, emissions, efficiency, urban quality and environmental sustainability) and at developing models for renovation

Driving success towards zero carbon energy targets for UK's Local Authorities

This paper draws on three case studies which show feasible and economic results in meeting net zero carbon emissions targets through Smart Local Energy Systems (SLES) in different localities across England, exploring opportunities to utilise waste heat from industry. They are based on the GreenSCIES model for which the blueprint was developed in London, Study 1. It consists of a fifth generation (5G) ambient loop district heat network using waste heat from a data centre, integrated with electric vehicle charging, storage and solar PV. The network includes decentralised heat pumps and allows for (i) heat sharing between buildings and (ii) applications for heat recovery from local sources. Study 2 is based on a heat network with waste heat from a foundry and some cooling supply and heat storage in the aquifer. Study 3 explored waste heat from a glassworks and considered mine workings for providing heat storage. These SLES projects illustrate how to integrate local waste heat sources in 3G and 4G heat networks, adapting the original GreenSCIES concept, providing pathways towards net zero carbon for a diverse range of urban locations with different waste heat sources, and further demonstrate the importance of collaboration between researchers, local government and industry

Challenges and prospects of renewable hydrogen-based strategies for full decarbonization of stationary power applications

The exponentially growing contribution of renewable energy sources in the electricity mix requires large systems for energy storage to tackle resources intermittency. In this context, the technologies for hydrogen production offer a clean and versatile alternative to boost renewables penetration and energy security. Hydrogen production as a strategy for the decarbonization of the energy sources mix has been investigated since the beginning of the 1990s. The stationary sector, i.e. all parts of the economy excluding the transportation sector, accounts for almost three-quarters of greenhouse gases (GHG) emissions (mass of CO2-eq) in the world associated with power generation. While several publications focus on the hybridization of renewables with traditional energy storage systems or in different pathways of hydrogen use (mainly power-to-gas), this study provides an insightful analysis of the state of art and evolution of renewable hydrogen-based systems (RHS) to power the stationary sector. The analysis started with a thorough review of RHS deployments for power-to-power stationary applications, such as in power generation, industry, residence, commercial building, and critical infrastructure. Then, a detailed evaluation of relevant techno-economic parameters such as levelized cost of energy (LCOE), hydrogen roundtrip efficiency (HRE), loss of power supply probability (LPSP), self-sufficiency ratio (SSR), or renewable fraction (fRES) is provided. Subsequently, lab-scale plants and pilot projects together with current market trends and commercial uptake of RHS and fuel cell systems are examined. Finally, the future techno-economic barriers and challenges for short and medium-term deployment of RHS are identified and discussed.This research is being supported by the Project ENERGY PUSH SOE3/P3/E0865, which is co-financed by the European Regional Development Fund (ERPF) in the framework of the INTERREG SUDOE Programme and the Spanish Ministry of Science, Innovation, and Universities (Project: RTI2018-093310-B-I00)

Worldwide LCOEs of decentralized off-grid renewable energy systems

Recent events mean that the security of energy supplies is becoming more uncertain. One way to achieve a more reliable energy supply can be decentralised renewable off-grid energy systems, for which more and more case studies are conducted in research. This review gives a global overview of the costs, in terms of levelised cost of electricity (LCOE), for these autonomous energy systems, which range from $0.03/kWh to about$1.00/kWh worldwide in 2021. The average LCOEs for 100% renewable energy systems have decreased by 9% annually between 2016 and 2021 from $0.54/kWh to$0.29/kWh, presumably due to cost reductions in renewable energy and electricity storage. Our overview can be employed to verify findings on off-grid systems, and to assess where these systems might be deployed and how costs are evolving

Financing of residential rooftop photovoltaic projects under a net metering policy framework: the case of the colombian caribbean region

The inclusion of photovoltaic energy in the Colombian energy matrix has had several difficulties due to the lack of energy policies and regulations in renewable energy projects. The lack of government support with subsidies that extend the coverage of PV energy projects in residential areas has made the collection of funds more challenging. This paper presents a techno-economic analysis for the implementation of grid-connected photovoltaic projects on the roofs of residential areas, under the net metering policy framework. For the profitability analysis, the discounted cash flow (DCF) method was used. The revenues were obtained from the forecasts of the electrical power production of the PV system, based on the characteristics of the Colombian Caribbean Region. For this purpose, the meteorological data (2013-2017) of this region were used as an input for the calculation of the economic benefits that can be achieved with the implementation of PV systems. Based on the technical sizing and economic assumptions, it was proved that the DCF method allows to accurately determine the optimal debt ratio. After evaluating the three scenarios proposed, it was demonstrated that profitability and self-sustainability, with investment from creditors, is obtained from the implementation of PV systems of at least 3 kWp

Understanding the formative stage of Technological Innovation System development. The case of natural gas as an automotive fuel

This study contributes to insights into mechanisms that influence the successes and failures of emerging energy technologies. It is assumed that for an emerging technology to fruitfully develop, it should be fostered by a Technological Innovation System (TIS), which is the network of actors, institutions and technologies in which it is embedded. For an emerging technology a TIS has yet to be built up. The research focuses on the dynamics of this build-up process by mapping the development of seven key activities: so-called system functions. The main contribution revolves around the notion of cumulative causation, or the phenomenon that the build-up of a TIS may accelerate due to system functions reinforcing each other over time. As an empirical basis, an analysis is provided of the historical development of the TIS around automotive natural gas technology in the Netherlands (1970-2007). The results show that this TIS undergoes a gradual build-up in the 1970s, followed by a breakdown in the 1980s and, again, a build-up from 2000-2007. It is shown that, underlying these trends, there are different forms of cumulative causation, here called motors of innovation. The study provides strategic insights for practitioners that aspire to support such motors of innovation.functions of technological innovation systems; cumulative causation; automotive natural gas.

Identification and analysis of impact factors on the economic feasibility of photovoltaic energy investments

The introduction of environmental impact targets around the world has highlighted the need to adopt alternative sources of energy, which can supply the demand and mitigate the damage caused to the environment. Solar energy is one of the main sources of alternative energy, and is considered an abundant source of clean energy. However, to facilitate and encourage investors interested in the installation of photovoltaic energy systems for electricity production, it is essential to evaluate the factors that impact the economic viability of the projects. Therefore, the objective of this research is to present a systematic analytical framework, in order to identify and analyze the main factors that impact the financial feasibility of projects for the installation of photovoltaic energy plants. For this purpose, a systematic literature review was carried out, analyzing the main studies related to the topic and identifying the main factors that may financially affect investments in photovoltaic energy systems. From this review, 29 influencing factors were identified and separated into five categories, namely, location, economic, political, climatic and environmental, and technical factors. The main factors highlighted are the investment cost, power generation, operation and maintenance costs, solar radiation, lifetime, energy tariff, efficiency, electricity consumption, and interest and taxes. The results may assist policy makers, investors, researchers, and other stakeholders to identify the key factors that are being examined in the literature, and to evaluate which ones should be considered in their study to ensure the sustainable development of power generation through the solar source