An Heuristic Approach to Renewable Energy Optimization

Author(s):  
Andy Walker

An analytical approach is often taken to predict the performance of renewable energy systems at a site, but an analytic approach requires detailed information on the system to be modeled that is better determined during schematic design than guessed-at during pre-design. This paper describes a heuristic approach to identify and prioritize renewable energy project opportunities before detailed system information is available. The method determines the combination of renewable energy technologies that minimize life-cycle cost at a facility, often with a specified goal regarding percent of energy use from renewable sources. Technologies include: photovoltaics (PV); wind; solar thermal heat and electric; solar ventilation air preheating; solar water heating; biomass heat and electric (combustion, gasification, pyrolysis, anaerobic digestion); and daylighting. The method rests upon the National Renewable Energy Laboratory’s (NREL) capabilities in: characterizing of the empirical cost and performance of technologies; geographic information systems (GIS) resource assessment; and life-cycle cost analysis. For each technology, simple heuristic algorithms relate renewable energy resources at a site to annual energy delivery with coefficients that are determined empirically. Initial cost and operation and maintenance (O&M) cost also use empirical data. Economic performance is then calculated with a site’s utility rates and incentives. The paper discusses how to account for the way candidate technologies interact with each other, and the solver routine used to determine the combination that minimizes lifecycle cost. Results include optimal sizes of each technology, initial cost, operating cost, and life-cycle cost, including incentives from utilities or governments. Results inform early planning to identify and prioritize projects at a site for subsequent engineering and economic feasibility study. Case studies include industrial sites, military bases, and civic buildings.

2019 ◽  
Vol 11 (8) ◽  
pp. 2444 ◽  
Author(s):  
Ming Hu

A comprehensive case study on life-cycle cost analysis (LCCA) was conducted on a two- story education building with a projected 40-year lifespan in College Park, Maryland. The aim of this paper was to (1) create a life cycle assessment model, using an education building to test the model, (2) compare the life cycle cost (LCC) of different renovation scenarios, taking into account added renewable energy resources to achieve the university’s overall carbon neutrality goal, and (3) verify the robustness of the LCC model by conducting sensitivity analysis and studying the influence of different variables. Nine renovation scenarios were constructed by combining six renovation techniques and three renewable energy resources. The LCCA results were then compared to understand the cost-effective relation between implementing energy reduction techniques and renewable energy sources. The results indicated that investing in energy-efficient retrofitting techniques was more cost-effective than investments in renewable energy sources in the long term. In the optimum scenario, renovation and renewable energy, when combined, produced close to a 90% reduction in the life cycle cost compared to the baseline. The payback period for the initial investment cost, including avoided electricity costs, varies from 1.4 to 4.1 years. This suggests that the initial investment in energy-efficient renovation is the primary factor in the LCC of an existing building.


2021 ◽  
Vol 13 (1) ◽  
pp. 396
Author(s):  
Norasikin Ahmad Ludin ◽  
Nurfarhana Alyssa Ahmad Affandi ◽  
Kathleen Purvis-Roberts ◽  
Azah Ahmad ◽  
Mohd Adib Ibrahim ◽  
...  

Sustainability has been greatly impacted by the reality of budgets and available resources as a targeted range of carbon emission reduction greatly increases due to climate change. This study analyses the technical and economic feasibility for three types of solar photovoltaic (PV) renewable energy (RE) systems; (i) solar stand-alone, a non-grid-connected building rooftop-mounted structure, (ii) solar rooftop, a grid-connected building rooftop-mounted structure, (iii) solar farm, a grid-connected land-mounted structure in three tropical climate regions. Technical scientific and economic tools, including life cycle assessment (LCA) and life cycle cost assessment (LCCA) with an integrated framework from a Malaysian case study were applied to similar climatic regions, Thailand, and Indonesia. The short-term, future scaled-up scenario was defined using a proxy technology and estimated data. Environmental locations for this scenario were identified, the environmental impacts were compared, and the techno-economic output were analysed. The scope of this study is cradle-to-grave. Levelised cost of energy (LCOE) was greatly affected due to PV performance degradation rate, especially the critical shading issues for large-scale installations. Despite the land use impact, increased CO2 emissions accumulate over time with regard to energy mix of the country, which requires the need for long-term procurement of both carbon and investment return. With regards to profitably, grid-connected roof-mounted systems achieve the lowest LCOE as compared to other types of installation, ranging from 0.0491 USD/kWh to 0.0605 USD/kWh under a 6% discounted rate. A simple payback (SPB) time between 7–10 years on average depends on annual power generated by the system with estimated energy payback of 0.40–0.55 years for common polycrystalline photovoltaic technology. Thus, maintaining the whole system by ensuring a low degradation rate of 0.2% over a long period of time is essential to generate benefits for both investors and the environment. Emerging technologies are progressing at an exponential rate in order to fill the gap of establishing renewable energy as an attractive business plan. Life cycle assessment is considered an excellent tool to assess the environmental impact of renewable energy.


2015 ◽  
Vol 15 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Saravanan Dhanushkodi ◽  
Vincent H. Wilson ◽  
Kumarasamy Sudhakar

Abstract Cashew nut farming in India is mostly carried out in small and marginal holdings. Energy consumption in the small scale cashew nut processing industry is very high and is mainly due to the high energy consumption of the drying process. The drying operation provides a lot of scope for energy saving and substitutions of other renewable energy sources. Renewable energy-based drying systems with loading capacity of 40 kg were proposed for application in small scale cashew nut processing industries. The main objective of this work is to perform economic feasibility of substituting solar, biomass and hybrid dryer in place of conventional steam drying for cashew drying. Four economic indicators were used to assess the feasibility of three renewable based drying technologies. The payback time was 1.58 yr. for solar, 1.32 for biomass and 1.99 for the hybrid drying system, whereas as the cost-benefit estimates were 5.23 for solar, 4.15 for biomass and 3.32 for the hybrid system. It was found that it is of paramount importance to develop solar biomass hybrid dryer for small scale processing industries.


2020 ◽  
Vol 12 (7) ◽  
pp. 2880 ◽  
Author(s):  
Hasan Masrur ◽  
Harun Or Rashid Howlader ◽  
Mohammed Elsayed Lotfy ◽  
Kaisar R. Khan ◽  
Josep M. Guerrero ◽  
...  

Following a rise in population, load demand is increasing even in the remote areas and islands of Bangladesh. Being an island that is also far from the mainland of Bangladesh, St. Martin’s is in need of electricity. As it has ample renewable energy resources, a renewable energy-based microgrid system seems to be the ultimate solution, considering the ever-increasing price of diesel fuel. This study proposes a microgrid system and tests its technical and economic feasibility in that area. All possible configurations have been simulated to try and find the optimal system for the island, which would be eco-friendly and economical with and without considering renewable energy options. The existing power supply configuration has also been compared to the best system after analyzing and investigating all technical and economic feasibility. Sensitivity and risk analysis between different cases provide added value to this study. The results show that the current diesel-based system is not viable for the island’s people, but rather a heavy burden to them due to the high cost of per unit electricity and the net present cost. In contrast, a PV /Wind/Diesel/Battery hybrid microgrid appeared to be the most feasible system. The proposed system is found to be around 1.5 times and 28% inexpensive considering the net present cost and cost of energy, respectively, with a high (56%) share of renewable energy which reduces 23% carbon dioxide.


Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2109 ◽  
Author(s):  
Zhe Lv ◽  
Zengping Wang ◽  
Wanyu Xu

In the context of global warming and energy shortage, this paper discusses the techno-economic feasibility of a residential household based on 100% renewable energy in China. The energy storage life, equipment’s residual value, system shortage capacity and atmospheric pollution emissions were considered comprehensively. A life cycle evaluation model based on the net present value (NPV) was built. Taking a real household as an example, the levelised cost of energy (LCOE) is 0.146 $/kW and the unmet load is only 0.86%, which has a big economic advantage when compared with diesel generators. If grid-connected, the system can bring $8079 in 25 years when the LCOE is −0.062 $/kW. The effects of the allowed shortage capacity, renewable energy resources, battery price and the allowed depth of discharge on the economy and energy structure were examined. For example, due to the features of the residential load, the influence of wind resource richness is more obvious than the irradiance. The maximum depth of discharge has less impact on the economy. This paper verifies the techno-economic rationality and feasibility of 100% renewable energy for a household.


Author(s):  
Laxman Y. Waghmode ◽  
Ravindra S. Birajdar ◽  
Shridhar G. Joshi

It is well known that the pumps are the largest consumers of industrial motor energy and account for more than 25% of electricity consumption. The life cycle cost of a pump is the total lifetime cost associated with procurement, installation, operation, maintenance and its disposal. For majority of heavy usage pumps, the lifetime energy and/or maintenance cost will dominate the life cycle costs. Hence a greater understanding of all the cost components making up the total life cycle costs should provide an opportunity to achieve a substantial savings in energy and maintenance costs. This will further enable optimizing pumping system efficiency and improving pump and system reliability. Therefore in this context, the life cycle cost analysis of heavy usage pumps is quite important. This paper focuses on an application of a methodology of determining the life cycle cost of a typical heavy usage multistage centrifugal pump. In this case, all the cost components associated with the pump-set have been determined and classified under different categories. The data with regard to initial investment costs, operation costs, maintenance and repair costs and disposal costs for the pump considered for this case study was collected from the concerned pump manufacturer along with the unit cost of each component, quantity used and their weights. By applying the principles of reliability and maintainability engineering and using the data obtained from the design, manufacturing and maintenance departments, the component-wise values of MTBF (Mean Time Between Failures) and MTTR (Mean Time To Repair) were estimated. The results of the life cycle cost analysis of the specimen pump were compared with the life cycle costs of similar pumps reported in the literature. From this comparison of results, it can be concluded that, the initial cost of the pump is the only a fraction of the total life cycle cost. The operating cost of the pump dominates the life cycle costs especially in case of heavy usage pumps. The maintenance cost varies approximately from 0.6 to 2.5 times the initial cost of the pump. The life cycle cost of the pump varies approximately from 12 to 33 times the initial cost of the pump. The operation and maintenance cost is almost 92 to 97 per cent of the life cycle cost. The detailed analysis carried out in this paper is expected to provide guidelines to the pump manufactures/practicing engineers in selecting a heavy usage multistage centrifugal pump based on the total lifetime cost rather than only on initial price.


2016 ◽  
Vol 43 (2) ◽  
pp. 151-163 ◽  
Author(s):  
Moatassem Abdallah ◽  
Khaled El-Rayes ◽  
Liang Liu

Buildings have significant impacts on the environment and economy as they were reported by the World Business Council for Sustainable Development in 2009 to account for 40% of the global energy consumption. Building owners are increasingly seeking to integrate sustainability and green measures in their buildings to minimize energy and water consumption as well as life-cycle cost. Due to the large number of feasiblecombinations of sustainability measures, decision makers are often faced with a challenging task that requires them to identify an optimal set of upgrade measures to minimize the building life-cycle cost. This paper presents a model for optimizing the selection of building upgrade measures to minimize the life-cycle cost of existing buildings while complying with owner-specified requirements for building operational performance and budget constraints. The optimization model accounts for initial upgrade cost, operational cost and saving, escalation in utility costs, maintenance cost, replacement cost, and salvage value of building fixtures and equipment, and renewable energy systems. A case study of a rest area building in the state of Illinois in the United States was analyzed to illustrate the unique capabilities of the developed optimization model. The main findings of this analysis illustrate the capabilities of the model in identifying optimal building upgrade measures to achieve the highest savings of building life-cycle cost within a user-specified upgrade budget; and generating practical and detailed recommendations on replacing building fixtures and equipment and installing renewable energy systems.


1989 ◽  
Vol 111 (4) ◽  
pp. 637-641
Author(s):  
R. B. Spector

When aeroderivative gas turbines were first introduced into industrial service, the prime criterion for assessing the “relative value” of equipment was derived by dividing the initial (or capital) cost of the equipment by the number of kilowatts produced. The use of “dollars per kilowatt” as an assessment parameter emanated from the utility sector and is still valid providing that the turbomachinery units under consideration possess similar performance features with regard to thermal efficiency. Second-generation gas turbines being produced today possess thermal efficiencies approximately 45 percent greater than those previously available. Thus, a new criterion is required to provide the purchaser with a better “value” perspective to differentiate the various types of turbomachinery under consideration. This paper presents a technique for combining the initial cost of equipment with the costs of fuel consumed, applied labor, and parts to arrive at an assessment parameter capable of comparing the relative merits of varying types of turbomachinery. For simplicity, this paper limits the life cycle cost derivation and discussion to turbogenerator units; however, the principles of this type of life cycle analysis can also be applied to gas turbines in mechanical drive applications and/or combined cycles.


Author(s):  
Ching-Shin Norman Shiau ◽  
Scott B. Peterson ◽  
Jeremy J. Michalek

Plug-in hybrid electric vehicle (PHEV) technology has the potential to help address economic, environmental, and national security concerns in the United States by reducing operating cost, greenhouse gas (GHG) emissions and petroleum consumption from the transportation sector. However, the net effects of PHEVs depend critically on vehicle design, battery technology, and charging frequency. To examine these implications, we develop an integrated optimization model utilizing vehicle physics simulation, battery degradation data, and U.S. driving data to determine optimal vehicle design and allocation of vehicles to drivers for minimum life cycle cost, GHG emissions, and petroleum consumption. We find that, while PHEVs with large battery capacity minimize petroleum consumption, a mix of PHEVs sized for 25–40 miles of electric travel produces the greatest reduction in lifecycle GHG emissions. At today’s average US energy prices, battery pack cost must fall below $460/kWh (below $300/kWh for a 10% discount rate) for PHEVs to be cost competitive with ordinary hybrid electric vehicles (HEVs). Carbon allowance prices have marginal impact on optimal design or allocation of PHEVs even at $100/tonne. We find that the maximum battery swing should be utilized to achieve minimum life cycle cost, GHGs, and petroleum consumption. Increased swing enables greater all-electric range (AER) to be achieved with smaller battery packs, improving cost competitiveness of PHEVs. Hence, existing policies that subsidize battery cost for PHEVs would likely be better tied to AER, rather than total battery capacity.


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