Energy Provisioning and Operating Costs in Hybrid Solar-Powered Infrastructure

<strong class="journal-contentHeaderColor">Abstract.</strong> With the growth of the floating wind industry, new operation and maintenance (O<span class="inline-formula"><i>&amp;</i></span>M) research has emerged evaluating tow-to-port strategies <span class="cit" id="xref_paren.1">(<a href="#bib1.bibx42">Offshore Wind Innovation Hub</a>, <a href="#bib1.bibx42">2020</a>)</span>, but limited work has been done on analysing other logistical strategies for offshore floating wind farms. In particular, what logistical solutions are the best for farms located far offshore that cannot be reached by crew transfer vessels (CTVs)? Previous studies have looked at the use of surface effect ships (SES) and CTVs during the operation and maintenance (O<span class="inline-formula"><i>&amp;</i></span>M) of bottom-fixed wind farms, but only some of them included service operation vessels (SOVs). This study analyses two strategies that could be used for floating wind farms located far from shore using ORE Catapult's in-house O<span class="inline-formula"><i>&amp;</i></span>M simulation tool. One strategy comprises of having a SOV performing most of the maintenance on the wind farm, and the other strategy uses an offshore maintenance base (OMB) instead, which would be located next to the offshore substation and would accommodate three CTVs. This paper provides an overview of the tool and the inputs used to run it, including failure rates of floating wind turbine subsea components and their replacement costs. In total six types of simulations were run with two strategies, two different weather limits for CTVs and two weather datasets ERA5 and ERA-20C. The results of this study show that the operational expenditure (OPEX) costs for the strategy with an OMB are 5 %–8 % (depending on the inputs) lower than with SOV, but if capital expenditure (CAPEX) costs are included in the analysis and the net present value (NPV) is taken into account then the fixed costs associated with building the offshore maintenance base have a significant impact on selecting a preferred strategy. It was found that for the case study presented in this paper the OMB would have to share the foundation with a substation in order to be cost competitive with the SOV strategy.

There is growing interest in investigating how the 5G capabilities can be extended to the critical communications vertical, in an expedited time scale. This paper provides a comprehensive cost analysis of a drone-based 5G deployment solution for emergency services. The proposed deployment uses existing 4G and 5G ground small cells and the fronthaul, backhaul network. The cost analysis develops an analytical approach to minimize the Total Cost of Ownership (TCO), where the key parameters of drone unit cost, number of drones per link, and link capacity are jointly optimized. The Capital Expenditure(CAPEX) costs are derived from available market data and the Operational Expenditure (eg: fronthaul and backhaul lease costs) are derived from established models. Our numerical analyses look at the TCO sensitivity to the above parameters to find sweet spots for deployment in different parameter combinations. The 3GPP centralization options are also investigated in terms of the TCO, and it is observed that centralization split points at higher layers benefit from lower TCO in this deployment model.

Cloud Computing has revolutionized the way Information Technology (IT) operates. Resource sharing in the cloud enables multiple users or providers to share resources, which improves the utilization of their resources. In the cloud, aggregated resources create a resource pool. The resource pools handle the dynamic demand of IT. Resource sharing enables cloud providers and customers to reduce their capital expenditure, operational expenditure, and total cost of ownership. Multiple cloud service providers connect to form a federation to share their resources among themselves to meet the dynamic demand of their customers. This chapter discusses the resource sharing in Intercloud, Social cloud, Mobile cloud, Manufacturing cloud, Vehicular cloud, and Green cloud. In each cloud, the various resource sharing approaches, strengths, and challenges are discussed.

Pseudo-wire emulation edge-to-edge over multiprotocol label switching (MPLS) is a promising technology for layer 2 transparent service support in metro networks. It supports Ethernet private line applications such as virtual private wire services (VPWS), multipoint local area network (LAN) applications such as virtual private LAN services (VPLS), frame relay, asynchronous transfer mode (ATM), and even the emulation of time division multiplexing (TDM) services. In the case of Ethernet, this technology circumvents the disadvantages of native Ethernet-based services, such as the need for spanning trees. In combination with traffic engineered label-switched paths (LSPs), it promises support for quality of service (QoS) differentiation and traffic engineering for high-value business services. MPLS is currently viewed as the technology that could satisfy this need, but because it serves so many other purposes as well, it entails complex control plane protocols and relatively high cost. This is in opposition to operator demand for low capital expenditure (CAPEX) and operational expenditure (OPEX) cost when introducing new services. This paper presents an analysis of how TDM-based transport networks can evolve, maximizing the benefit of established transport technologies, while supporting existing layer 2 transport services as well as new services such as Internet Protocol television (IPTV) and video on demand. The paper identifies which of the mechanisms that are underlying MPLS-based pseudo-wire services are truly essential, and which could be implemented by other means and thus offer new possibilities for migration and convergence. Besides conceptual considerations, the network efficiency of alternative implementation options is analyzed and compared. © 2007 Alcatel-Lucent.

Incentive effects of bonus depreciation

The hydrogen economy has experienced rapid interest in recent years, emerging as a promising pathway to decarbonization. Despite its potential, hydrogen affordability is still a massive challenge particularly due to its requirement for renewable energy. For long distance hydrogen transport, ammonia is explored as a viable medium due to its matured and scaled existing infrastructure. This study delves into the role of ammonia as the hydrogen carrier, with a focus on evaluating the techno-economic viability and emission of ammonia cracking process. A comprehensive techno-economic analysis was conducted across two distinct ammonia cracking scales, between 4,000 tons/year and 400,000 tons/year of ammonia. The ammonia cracking process simulation model was built using the Symmetry-iCON software and includes main process units such as ammonia dehydrogenation, flue gas production and hydrogen purification. Assumptions were made on the efficiency of 99% of hydrogen production. We further employed a factorial method to estimate the capital expenditure (CAPEX) of the plant, a critical component in our analysis. Operation expenditure (OPEX) estimation was included by considering factors such as cost of raw material, electricity and manpower. The techno-economic analysis shows significant differences between two scales of operation. At the smaller scale of 4,000 tons/year, the minimum hydrogen selling price to achieve 20% IRR is 14.3 USD/kg H2, while at the larger scale of 400,000 tons/year, the price reduces to 3.7 USD/kg H2. Additionally, the analysis reveals OPEX, especially the cost of ammonia (grey, blue and green) is the primary cost driver in ammonia cracking process. A sensitivity study on ammonia costs reveals that fluctuations in OPEX have the most significant impact on hydrogen costs, compared to variability in CAPEX. Other operational costs considered within this work include installation of equipment, transportation and maintenance of the equipment. The fuel type and mix were studied to understand their impact on the overall system emission. The cases considered include the use of methane, a mix of methane and hydrogen and direct use of ammonia as fuel for the cracking system. This study provides valuable insights into the techno-economic aspects of using ammonia for hydrogen storage and transportation. While ammonia cracking is technically viable for hydrogen production, its economic feasibility depends significantly on the scale of operation and ammonia cost. From a technological perspective, alternative pathways that could lead to lower energy consumption could further lower the cost of ammonia cracking.

We present our work on the dimensioning of a packet-switching wavelength division multiplexing ring in order to reduce its infrastructure (capital expenditure) cost. We study a new all-optical architecture: the packed optical add-drop multiplexer (POADM). We aim to minimize the overall cost of the network by reducing the number of indispensable devices in the nodes and the number of required wavelengths. We formalize the packing problems underlying the ring dimensioning. The elements to be packed are made up of transmissions that share the same destination. We assume that elements can be cut before being packed into boxes. We furnish a complete theoretical analysis of the complexity and approximability of these problems. We define also several measures of quality for a cut and provide an optimal cutting strategy, according to these measures. Our subsequent contribution is a heuristic solution that solves the bi-criteria packing problem (the number of boxes and the number of cuts are minimized simultaneously). The exhaustive numerical results of this heuristic algorithm come next. We rely on our optimal cutting strategy to appraise the efficiency of other strategies. We also adapt the only existing POADM dimensioning algorithm, more restrictive than ours, and we confront it with our solution. The analysis of results allows us to provide network design guidelines to perform the dimensioning in the most efficient way.

Due to overwhelming advancement in sensor networks and communication technology, Internet of Things is taking shape to help make our lives smarter. Devices working on Internet of Things are responsible for generating multifarious and mammoth data. In addition to this, academia, business firms, etc., add vast amount of data to the pool of storage systems. This data are big data. Cloud computing provides paramount solution to store and process this big data through database outsourcing, thus reducing capital expenditure and operational costs. As big data are hosted by third party service providers in the cloud, security of such data becomes one of the significant concerns of data owners. The untrustworthy nature of service providers does not guarantee the security of data and computation results. This necessitates the owners to audit the integrity of data. Therefore, integrity auditing becomes the part and parcel of outsourced big data. Maintaining confidentiality, privacy, and trust for such big data are sine qua non for seamless and secure execution of big data-related applications. This paper gives a thorough analysis of integrity auditing protocols applied for big data residing in cloud environment.

This work presents a novel approach in intradata center network design and performance evaluation, based on a tailored, long-range dependence data traffic generation model for different application classes. We examine how an intra-data center network can be efficiently evaluated and optimized by applying accurate models for machine-generated data and using assumptions on current and future commercially available data center hardware. Moreover, we show that by migrating such a Fat-Tree network to its hybrid, electro-optical counterpart by employing optical circuit switching for selected, intense traffic connections, significant capital and operational expenditure cost savings can be obtained.

PurposeThis study aims to critically evaluate the COVID-19 and future post-COVID-19 impacts on office design, location and functioning with respect to government and community occupational health and safety expectations. It aims to assess how office efficiency and cost control agendas intersect with corporate social accountability.Design/methodology/approachTheoretically informed by governmentality and social accountability through action, it thematically examines research literature and Web-based professional and business reports. It undertakes a timely analysis of historical office trends and emerging practice discourse during the COVID-19 global pandemic's early phase.FindingsCOVID-19 has induced a transition to teleworking, impending office design and configuration reversals and office working protocol re-engineering. Management strategies reflect prioritisation choices between occupational health and safety versus financial returns. Beyond formal accountability reports, office management strategy and rationales will become physically observable and accountable to office staff and other parties.Research limitations/implicationsFuture research must determine the balance of office change strategies employed and their evident focus on occupational health and safety or cost control and financial returns. Further investigation can reveal the relationship between formal reporting and observed activities.Practical implicationsOrganisations face strategic decisions concerning both their balancing of employee and public health and safety against capital expenditure and operation cost commitments to COVID-19 transmission prevention. They also face strategic accountability decisions as to the visibility and correspondence between their observable actions and their formal social responsibility reporting.Social implicationsOrganisations have continued scientific management office cost reduction strategies under the guise of innovative office designs. This historic trend will be tested by a pandemic, which calls for control of its spread, including radical changes to the office at potentially significant cost.Originality/valueThis paper presents one of few office studies in the accounting research literature, recognising it as central to contemporary organisational functioning and revealing the office cost control tradition as a challenge for employee and community health and safety.

The most profound requirements of fifth-generation (5G) technology implementations are the architecture design and the radio base station technology to capably run applications such as device-to-device, machine-to machine and internet of things at a reduced latency. Owing to these requirements, the implementation of 5G technology is very expensive to mobile network operators (MNO). In this study we modified the existing 4G network to form a distributed wireless network architecture (DWNA); the picocell and distributed antenna system were modified to support the enabling technology of 5G technology were a multi-edge computer (MEC), software-defined networking (SDN), massive multiple input multiple output (MIMO), ultra-dense network (UDN), Network Functions Virtualization (NFV) and device-to-device (D2D) communication at a reduced cost of ownership, improved coverage and capacity. We present a mathematical model for operational expenditure, capital expenditure and total cost of ownership (TCO) for the DWNA. A mathematical model for DWNA capacity and throughput was presented. Result shows that it is very economical for MNO to rent the space of the tower infrastructure from tower companies. The sensitivity analysis also shows a significant reduction in TCO for both the modified picocell and modified distributed antenna systems.

Impact of solid waste treatment from spray dryer absorber on the levelized cost of energy of a coal-fired power plant

Industrial best practices of conceptual process design

One of the challenges for Mobile Network Operators (MNO) in 5G deployment is to ensure reliability in the various sections of the network as the new services and applications, for instance, video on demand, telemedicine, online learning, smart transportation and augmented reality require not only high bandwidth but also demand uninterrupted service. However, this reliability requires substantial investment. Therefore, MNO only deploys protection or backup resources in the network unless it is cost-effective. The study aims to present a reliable and low-cost protection scheme based on an Ultra-Dense Wavelength Division Multiplexing Passive Optical Network (UDWDM PON) for the transport layer of the 5G network, i.e., for the fronthaul/backhaul section. We have evaluated the Capital Expenditure (CAPEX) cost of UDWDM PON with and without protection in a dense urban area. We also measure the figure of merit between the cost and reliability of the system and, subsequently, confirm that the proposed protection scheme can achieve system reliability up to four nines with very low additional CAPEX investment. Finally, the efficacy of the proposed protection scheme is also demonstrated through simulation experiments.

Under the new round of power market reform policy, strengthening the life cycle economic evaluation of power grid projects is the key to speeding up the transformation and upgrading of power grids and improving investment efficiency. Considering that the operation and maintenance costs of power grid is unified accounting, how to calculate the operation costs of single grid project scientifically and rationally is the key to conduct economic evaluation. Firstly, the multi-factor relationship between grid operation costs and the substation capacity, line length, transmission and distribution volume and fixed asset value is analyzed to determine the key factors. Then, the operation and maintenance costs allocation model of grid project based on Performance Value is constructed in this paper. Finally, the operation data of a provincial power grid company is selected as a sample to calculate the operation and maintenance costs of different power grid projects, which verifies the effectiveness of the model.