Predicting the hydraulic and life-cycle cost performance of rainwater harvesting systems using a computer based modelling tool

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
R.M Roebuck ◽  
R.M. Ashley
Keyword(s):  
Life Cycle Cost ◽  
Rainwater Harvesting ◽  
Cost Savings ◽  
Potential Cost ◽  
Capital Costs ◽  
Harvesting Systems ◽  
Computer Based ◽  
Monetary Savings ◽  
Lifetime Expenditure ◽  
Financial Issues

Rainwater harvesting systems are a recognised technique for reducing reliance on potable mains supply and as a potential way to save money. However, the widespread uptake of these systems has been slow partly due to the level of uncertainty surrounding hydraulic and financial performance. Current methods of assessment tend to be simplistic, using generalised rather than site-specific data. Often little account is taken of financial issues other than capital costs, such as operating/maintenance and decommissioning expenses. To overcome these shortcomings, a computer based modelling tool called RainCycle© was developed that has the capability to perform more detailed analysis than is possible with existing methods. The program includes a detailed hydraulic model of a typical rainwater harvesting system and also has the ability to explicitly account for all major costs associated with these systems. Modelling a number of proposed designs revealed that many of the current methods overestimate the hydraulic efficiency and potential cost savings that are achievable. However, it was found that water and monetary savings are still possible under favourable conditions. Further, it was found that capital, maintenance and required mains top-up water account for the majority of the whole life costs, whilst energy and decommissioning costs represent a small fraction of the required lifetime expenditure.

Rainwater harvesting: model-based design evaluation

2010 ◽  
Vol 61 (1) ◽  
pp. 85-96 ◽  
Author(s):  
S. Ward ◽  
F. A. Memon ◽  
D. Butler
Keyword(s):  
Rainwater Harvesting ◽  
Simulation Models ◽  
Simulation Modelling ◽  
Design Methods ◽  
Continuous Simulation ◽  
Capital Costs ◽  
Harvesting Systems ◽  
Catchment Size ◽  
The Uk ◽  
Near Future

The rate of uptake of rainwater harvesting (RWH) in the UK has been slow to date, but is expected to gain momentum in the near future. The designs of two different new-build rainwater harvesting systems, based on simple methods, are evaluated using three different design methods, including a continuous simulation modelling approach. The RWH systems are shown to fulfill 36% and 46% of WC demand. Financial analyses reveal that RWH systems within large commercial buildings maybe more financially viable than smaller domestic systems. It is identified that design methods based on simple approaches generate tank sizes substantially larger than the continuous simulation. Comparison of the actual tank sizes and those calculated using continuous simulation established that the tanks installed are oversized for their associated demand level and catchment size. Oversizing tanks can lead to excessive system capital costs, which currently hinders the uptake of systems. Furthermore, it is demonstrated that the catchment area size is often overlooked when designing UK-based RWH systems. With respect to these findings, a recommendation for a transition from the use of simple tools to continuous simulation models is made.

scholarly journals Sustainable Water Resources Management in Small Greek Islands under Changing Climate

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1694
Author(s):  
Ioannis M. Kourtis ◽  
Konstantinos G. Kotsifakis ◽  
Elissavet G. Feloni ◽  
Evangelos A. Baltas
Keyword(s):  
Water Supply ◽  
Life Cycle Cost ◽  
Water Resource Management ◽  
Rainwater Harvesting ◽  
Optimal Solution ◽  
Aegean Sea ◽  
Management Scenarios ◽  
Sustainable Water Resources Management ◽  
Harvesting Systems ◽  
Alternative Water

Five different water resource management scenarios are examined on eight dry islands of the Aegean Sea in Greece, pitting the current practice of water hauling via ship against alternative water supply schemes in delivering a sustainable solution for meeting water demand. The first scenario employs current water supply practices along with the operation of domestic rainwater harvesting systems. Desalinated water, provided through the operation of wind-powered desalination plants, is considered the main source of potable water in the rest of scenarios. Wind-powered desalination may be combined with rainwater harvesting as a supplementary source of water and/or seawater pumping and an additional source of energy that is supplied to the system. All different alternatives are evaluated for a 30-year lifespan, and an optimal solution is proposed for each island, based on a life cycle cost (LCC) analysis. The performance of this solution is then assessed under six climate change (CC) scenarios in terms of the rate of on-grid versus off-grid renewable energy that is required in order to achieve a certain reliability level. Overall, the examined scenarios show a decreasing performance in terms of reliability under CC for the eight islands.

scholarly journals Sizing of Domestic Rainwater Harvesting Systems Using Economic Performance Indicators to Support Water Supply Systems

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 783 ◽  
Author(s):  
Umapathi ◽  
Pezzaniti ◽  
Beecham ◽  
Whaley ◽  
Sharma
Keyword(s):  
Economic Performance ◽  
Performance Indicators ◽  
Rainwater Harvesting ◽  
Water Supply Systems ◽  
Recovery Method ◽  
Capital Costs ◽  
Rainwater Tank ◽  
Catchment Areas ◽  
Harvesting Systems ◽  
Roof Area

This paper presents a monitoring-based investigation of rainwater collection systems using economic performance indicators in a group of households with nonconventional end-uses for rainwater that are not traditionally associated with rainwater supply. The monitored data for five household rainwater tank systems were analysed in two stages. For the first stage, the data was empirically analysed to develop a method to predict effective roof catchment areas. For the second stage, the effective roof catchment areas, together with roof area connection percentages, were analysed against different types of water demands in individual households. The individual systems were investigated for yield capacities, costs and water security using a modified Roof Runoff Harvesting Systems average annual yield model based on daily water balance procedures. The Life Cycle Costing analysis of the systems using the model was based on the Capital Recovery Method by taking into consideration the capital costs as well as ongoing costs for maintenance, replacement and operation of the systems. The analysis established the optimal sizing requirements for the studied rainwater tanks and their corresponding roof area connectivity.

scholarly journals Optimization Simulation, Using Steel Plant Off-Gas for Power Generation: A Life-Cycle Cost Analysis Approach

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2884 ◽  
Author(s):  
Yang-Kon Kim ◽  
Eul-Bum Lee
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Life Cycle Cost ◽  
Power Plants ◽  
Capital Expenditure ◽  
Thermodynamic Simulation ◽  
Cost Savings ◽  
Greenhouse Gas Mitigation ◽  
Potential Cost ◽  
Gas Power Plant

This research aims to contribute to the international desires of greenhouse gas mitigation through a study on the optimization of 100 MW off-gas power plants’ subcritical steam cycle, operating in conjunction with steel plants. The performance and fiscal efficiency of the off-gas power plants are based on data collected from Krakatau Steel plants in Indonesia, simulated and analyzed through thermodynamic simulation model (PEPSE). The three scenarios simulated for comparison are: (1) 100 MW off-gas power plant as-is operation, (2) 100 MW off-gas power plant optimized, and (3) 100 MW cogeneration off-gas power plant. The optimization of the off-gas power plant and use of steam extraction was found to have a 45 M and 26 M USD savings in comparison to the base power plant, assuming a 5.5% discount rate and 400 Million USD capital expenditure. The theoretical findings are of use to academia and industry in providing proof of potential cost-savings of integrating off-gas into existing power generation operations.

scholarly journals An Evaluation Technique for Determining the Cost Effectiveness of Condition Monitoring Systems

1978 ◽  
Author(s):  
P. T. George ◽  
A. T. Parker
Keyword(s):  
Cost Effectiveness ◽  
Monitoring System ◽  
Condition Monitoring ◽  
Life Cycle Cost ◽  
Cost Savings ◽  
Monitoring Systems ◽  
Potential Cost ◽  
Condition Monitoring Systems ◽  
Condition Monitoring System ◽  
The Cost

A technique for analyzing the cost-effectiveness of condition monitoring systems has been developed both to provide a quantitative assessment of the value of condition monitoring and to guide the selection of items to be monitored by the system. The technique uses historical data combined with catalog cost estimating to estimate both the life cycle cost of the condition monitoring system and the potential cost savings offered by the system for commercial engines. The results are obtained in a form that can be easily converted to any of the primary cost-effectiveness parameters in current use by industry. Key to the technique is the definition of a series of condition monitoring system concepts of increasing complexity for analysis, with each increase representing a logical step with respect to cost-effectiveness. This feature permits the results of the cost-effectiveness analysis to be applied directly to the design definition process without iteration or further cost analysis.

Integrated Tubulars Supply Model Provides Cost Savings to Drilling Projects

2020 ◽  
Author(s):  
M. Hamzah
Keyword(s):  
Supply Chain ◽  
Cost Savings ◽  
Asia Pacific ◽  
Potential Cost ◽  
Alternative Scheme ◽  
Safety Stocks ◽  
Storage Location ◽  
Supply Planning ◽  
Drilling Site ◽  
Drilling Project

Classical Oil Country Tubular Goods (OCTG) procurement approach has been practiced in the indus-try with the typical process of setting a quantity level of tubulars ahead of the drilling project, includ-ing contingencies, and delivery to a storage location close to the drilling site. The total cost of owner-ship for a drilling campaign can be reduced in the range of 10-30% related to tubulars across the en-tire supply chain. In recent decades, the strategy of OCTG supply has seen an improvement resulting in significant cost savings by employing the integrated tubular supply chain management. Such method integrates the demand and supply planning of OCTG of several wells in a drilling project and synergize the infor-mation between the pipes manufacturer and drilling operators to optimize the deliveries, minimizing inventory levels and safety stocks. While the capital cost of carrying the inventory of OCTG can be reduced by avoiding the procurement of substantial volume upfront for the entire project, several hidden costs by carrying this inventory can also be minimized. These include storage costs, maintenance costs, and costs associated to stock obsolescence. Digital technologies also simplify the tasks related to the traceability of the tubulars since the release of the pipes from the manufacturing facility to the rig floor. Health, Safety, and Environmental (HSE) risks associated to pipe movements on the rig can be minimized. Pipe-by-pipe traceability provides pipes’ history and their properties on demand. Digitalization of the process has proven to simplify back end administrative tasks. The paper reviews the OCTG supply methods and lays out tangible improvement factors by employ-ing an alternative scheme as discussed in the paper. It also provides an insight on potential cost savings based on the observed and calculated experiences from several operations in the Asia Pacific region.

Improved Oxygen Dissolution Control for Oxygen Activated Sludge

1988 ◽  
Vol 20 (4-5) ◽  
pp. 101-108 ◽  
Author(s):  
R. C. Clifft ◽  
M. T. Garrett
Keyword(s):  
Activated Sludge ◽  
Control Method ◽  
Control Strategies ◽  
Cost Savings ◽  
Utilization Efficiency ◽  
Oxygen Production ◽  
Oxygen Utilization ◽  
Potential Cost ◽  
Oxygen Dissolution ◽  
The City

Now that oxygen production facilities can be controlled to match the requirements of the dissolution system, improved oxygen dissolution control can result in significant cost savings for oxygen activated sludge plants. This paper examines the potential cost savings of the vacuum exhaust control (VEC) strategy for the City of Houston, Texas 69th Street Treatment Complex. The VEC strategy involves operating a closed-tank reactor slightly below atmospheric pressure and using an exhaust apparatus to remove gas from the last stage of the reactor. Computer simulations for one carbonaceous reactor at the 69th Street Complex are presented for the VEC and conventional control strategies. At 80% of design loading the VEC strategy was found to provide an oxygen utilization efficiency of 94.9% as compared to 77.0% for the conventional control method. At design capacity the oxygen utilization efficiency for VEC and conventional control was found to be 92.3% and 79.5%, respectively. Based on the expected turn-down capability of Houston's oxygen production faciilities, the simulations indicate that the VEC strategy will more than double the possible cost savings of the conventional control method.

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