Energy Life Cycle Cost Research Articles

The Environmental Performance and Cost of Innovative Technologies for Ductile Iron Foundry Production

The authors and collaborators have devised innovative technologies that decrease foundry costs, pollution, materials use, and energy. These include: (a) applying advanced oxidation to green sand and baghouse dust to diminish clay, coal, sand, volatile organic compounds (VOCs), and costs; (b) replacing phenolic urethane core binders with collagen-alkali silicate binders to diminish VOCs; (c) replacing coke with anthracite fines held together with biomaterial to reduce energy and costs. It is proposed by the authors that if a foundry were to concurrently employ all these innovative technologies (with 50% anthracite bricks), it could potentially diminish overall costs by 6.6%, life cycle energy costs by 15%, VOC pollution by 57%, sand by 85%, clay and coal by 50%, and iron scrap by 9%. These computations are per full-scale operations for advanced oxidation; and R&D results for replacing binders and coke. This paper also notes that when electricity comes primarily from coal fired power plants, electric induction furnaces consumes more life cycle energy than do cupolas for melting iron.

An Enhanced Model for combined heat and air infiltration energy simulation

The need for efficient, sustainable, and planned utilization of resources is ever more critical. Several building energy analysis tools have been developed to assess energy demands and lifecycle energy costs in buildings. Such analyses are essential for an efficient heating, ventilation, and air conditioning design that overcomes the pitfalls of an under/over-designed system. Studies have estimated air infiltration accounts for up to 50% of a building’s energy demand. This stresses the need that energy simulation engines accurately account for air infiltration. An Enhanced Model for air infiltration has been developed.

Design optimization of energy efficient residential buildings in Tunisia

A sequential search technique is applied to optimize the design of residential buildings in Tunisia in order to minimize their life cycle energy costs while increasing their energy efficiency. In the analysis, design features of air-conditioned single-family homes (i.e., villas) are considered including orientation, window location and size, glazing type, wall and roof insulation levels, lighting fixtures, appliances, and efficiencies of heating and cooling systems. First, the results of the sequential search technique are compared against those obtained by a more time consuming brute-force optimization approach. Then, the optimal design features for villas are determined for selected locations in Tunisia. The optimization results indicate that adding roof insulation, reducing air infiltration, installation energy efficient appliances, lighting fixtures, and heating and cooling equipment are required energy efficiency measures to design high energy performance homes throughout climatic zones in Tunisia. In particular, it is found that implementing these measures can cost-effectively reduce the annual energy use by 50% compared to the current design practices of homes in Tunisia.

An approach and a tool for setting sustainable energy retrofitting strategies referring to the 2010 EP

The 2010 EPBD asks for an economic and social analysis in order to preserve social equity and to promote innovation and building productivity. This is possible with a life cycle energy cost (LCEC) analysis, such as with the SEC (Sustainable Energy Cost) model whose bottom up approach begins with a building typology including inhabitants. Then the analysis of some representative buildings includes the identification of a technico-economical optimum and energy retrofitting scenarios for each retrofitting programme and the extrapolation for the whole building stock. An extrapolation for the whole building stock allows to set up the strategy and to identify the needed means for reaching the objectives. SEC is a decision aid tool for optimising sustainable energy retrofitting strategies for buildings at territorial and patrimonial scales inside a sustainable development approach towards the factor 4. Various versions of the SEC model are now available for housing and for tertiary buildings.

Optimization of heat pump system in indoor swimming pool using particle swarm algorithm

When it comes to indoor swimming pool facilities, a large amount of energy is required to heat up low-temperature outdoor air before it is being introduced indoors to maintain indoor humidity. Since water is evaporated from the pool surface, the exhausted air contains more water and specific enthalpy. In response to this indoor air, heat pump is generally used in heat recovery for indoor swimming pools. To reduce the cost in energy consumption, this paper utilizes particle swarm algorithm to optimize the design of heat pump system. The optimized parameters include continuous parameters and discrete parameters. The former consists of outdoor air mass flow and heat conductance of heat exchangers; the latter comprises compressor type and boiler type. In a case study, life cycle energy cost is considered as an objective function. In this regard, the optimized outdoor air flow and the optimized design for heating system can be deduced by using particle swarm algorithm.

Life cycle energy cost savings through careful system design and pump selection

Much of a pump's initial cost is not through the initial purchase, but in the energy it uses throughout its life. However, proven steps can be taken to reduce these costs considerably when designing a pump system. Here Jukka Tolvanen, product manager from ABB's low-voltage AC drives factory in Helsinki, explains why it is important that all aspects of ownership cost are explored, not just initial purchase and installation.

Life cycle energy cost analysis of heat pump application for hotel swimming pools

This paper presents the work on evaluating the thermal performance and life cycle energy cost of using heat pumps for hotel swimming pools in subtropical climates. A roof top pool in a city hotel was investigated. The energy requirement for maintaining the pool water temperature was analysed in terms of the energy loss through four major processes, namely evaporation, radiation, convection and water refill. The governing equations for these four heat loss processes were developed based on a review of the literature. It was found that substantial energy savings could be achieved. Compared with conventional electric boilers and condensing/non-condensing gas fired boilers, the total energy savings during a 6 1 2 month (mid-October to April) heating season ranged from 39.9 to 46.3 MW h. A life cycle of 10 years was used to calculate the net present value of the energy cost. Over a 10 year life cycle, the energy cost could be reduced by HK$ 275,700 if a heat pump (with a mean seasonal coefficient of performance of 3.5) were used instead of a conventional electric boiler or condensing boiler.

00/01979 A comparative life cycle energy cost analysis of photovoltaic and fuel generator for load shedding application

00/01979 A comparative life cycle energy cost analysis of photovoltaic and fuel generator for load shedding application

A comparative life cycle energy cost analysis of photovoltaic and fuel generator for load shedding application

Comparative life cycle energy cost analysis for different electricity generators (photovoltaic generator, kerosene generator and diesel generator) used during load shedding is presented. The parameters considered for calculation of the unit cost of energy are: the discount rate, inflation rate, IREDA loan facility to promote PV, operation and maintenance cost of PV and fuel generator (FG) set and the associated fuel cost. It is found that the unit cost of PV electricity is comparable to or less than that of FG generated electricity at present market prices.

Evaluating the reliability and availability of photovoltaic systems

SOLREL, a new reliability/availability simulation model, incor porates design, reliability, cost, and maintenance information to predict annual maintenance cost and energy production for photovoltaic [PV] power systems. SOLREL considers failures, lost production, and both scheduled and unscheduled mainte nance. Combined with initial cost and operating cost informa tion, the model predicts levelized cost per kWh. It gives photovoltaic system designers a way to evaluate design trade- offs and minimize life-cycle energy cost. Large terrestrial photovoltaic power systems (over 50 kWp) are a recent development. Thus, failure rate, repair time, and cost data are lacking for many subsystems and components. In spite of this, reliability/availability models can still aid in design decisions by allowing designers to estimate changes in life-cycle energy costs for alternative subsystems and con figurations. As more test and field data become available, the models can be made more detailed and more accurate. At present, their principal value is to emphasize reliability and maintainability early in system design, with resulting im provements in component selection and subsystem design.

A Methodology for Photovoltaic System Reliability & Economic Analysis

This paper describes the approach and progress on a 1981 study of photovoltaic (PV) system reliability being conducted by Battelle-Columbus for Sandia Laboratories as part of DOE's PV Systems Definition Project. Initially, the study is concerned with the functional modeling of reliability and maintenance of a PV system. We begin with relatively general, but simple, system level reliability models that can be expanded to more detailed, lower-level forms as input data justify. Corrective maintenance is Included to permit estimates of system availability. The output of these models will be coupled with life-cycle energy cost models and applied to PV system designs.

The Interrelation between Recurrent and Capital Costs in a Solar Thermal Process Heat System

The effect of operation and maintenance (O&M) costs on energy produced by solar collector systems is crucial to the market penetration of solar process heat as an alternative energy source. In the present paper, a particular O&M operation, regular collector cleaning, is considered in order to determine its effect upon annualized life cycle energy cost. A first-order model of mirror reflectance degradation as a function of time is constructed from experimental data taken at Albuquerque, N.M. This is used as input to a systems optimization model of a line-focus solar collector process heat installation. The energy cost variation is considered as a function of cleaning cost per unit of collector aperture and cleaning interval. Results are presented for a process heat temperature of 177°C.

Optimization of a Point-Focusing, Distributed Receiver Solar Thermal Electric System

This paper presents an approach to optimization of a solar concept which employs solar-to-electric power conversion at the focus of parabolic dish concentrators. Modularity is obtained through the use of multiple concentrators to achieve the desired power level (up to 10MW); the system is connected to an electric utility grid but is capable of operation in a stand-alone mode. The power conversion subsystem is packaged into a single assembly which includes (1) a cavity receiver, (2) thermal transport hardware, (3) a heat engine and (4) a synchronous a-c generator. In the example presented, the baseline heat engine is a Stirling cycle power plant and the receiver is a high temperature (∼800°C) sodium pool boiler; thermal transport is provided by a short pipe with the dual function of delivering sodium vapor to the engine heater head and returning liquid condensate to the boiler. The optimization procedure is presented through a series of trade studies, which include the results of optical/thermal analyses and individual subsystem trades. The optical/thermal analyses include the effect of concentrator rim angle, surface slope error, pointing error, geometric concentration ratio and pertinent cavity parameters including shape, temperature and inner surface radiation properties. For the concentrator, the effects pf slope error, rim angle and diameter on unit cost (dollars/m2 of aperture) are presented as part of an overall cost analysis which generates total system life-cycle energy cost as the optimization parameter. Alternate closed-cycle and open-cycle Brayton engines and organic Rankine engines are considered to show the influence of the optimization process, and various storage techniques are evaluated, including batteries, flywheels and hybrid-engine operations.