Multi-Objective Optimization and Performance Assessments of an Integrated Energy System Based on Fuel, Wind and Solar Energies

The integrated energy system (IES) is an efficient method for improving the utilization of renewable energy. This paper proposes an IES based on fuel, wind and solar energies, following an optimization study focused on determining optimal device capacities. The study included gas turbines, wind turbines, solar photovoltaic panels, ground source heat pumps, absorption chillers/heaters, batteries, and thermal storage. Objectives were incorporated into the optimization model for the overall performance of the IES; these included the primary energy saving rate, annual cost-saving rate, and carbon dioxide emission reduction. Then, the nondominated sorting genetic algorithm II was employed to solve the optimization problem for multiple objectives. Ultimately, the verification and sensitivity analyses of the optimization method were achieved by a case study of hospital buildings in Harbin. The optimization results indicated a primary energy saving rate, annual cost saving rate, and carbon dioxide emission reduction rate of 17.3%, 39.8%, and 53.8%, respectively. The total installed capacity for renewable energy generation accounted for 64.5% of performance optimization. Moreover, the price of natural gas affected the economic indicators of the IES–but failed to impact energy consumption indicators.

Campus Study of the Impact of Ultra-Low Flush Toilets on Sewerage Networks and Water Usage

Water demand management often focuses on quantifying the benefits of water efficiency rather than the potential impact of reduced flows on the sewer network. This study assessed the impact of a high-density deployment of ultra-low flush toilets (ULFT). A pre-installation washroom survey was carried out in July 2018. Water demand and sewer network condition were assessed ahead of the installation of 119 ULFTs and a real-time monitoring system across seven buildings on the University of Exeter campus. ULFTs were flushed 257,925 times in 177 days saving an estimated 2287 m3 per annum (compared to traditional 6 litre WCs). The annual cost saving of this reduction is approximately £12,580/annum, assuming a volumetric cost of £5.50/m3 of water. Mean discharge to the sewer network reduced by 6 m3/day. In the six-month period, 95 maintenance issues were reported, equating to 1 in 2700 flushes (0.037%). However, the frequency of incidents decreased after an initial commissioning period. There is no evidence, from blockage reports or photographs of manhole flow conditions, that the risk of blockage in the sewer network increased as a result of the ULFT installation programme.

The Power Reclamation of Utilizing Micro-Hydro Turbines in the Aeration Basins of Wastewater Treatment Plants

Upgrading the aeration basin technology can improve the oxygen transfer efficiency (OTE), while keeping the energy consumption at its minimum level. Therefore, this paper introduces a new idea of installing micro-propeller turbines in the aeration basin of a wastewater treatment plant (WWTP) to extract power from the high-velocity location in the water column. This extracted power can be used to operate a mixer at the top of the membrane to induce the mixing in that region, which will drive the less oxygenated wastewater into the water column. The rest of the extracted power will rotate microturbine rotors for electric power generation. By applying the proposed microturbines to the 13 audited facilities, it was demonstrated to achieve a gross annual energy-savings of 3,836.9 MWh, a gross annual cost-saving of $260,497, and total CO2 emissions that would be reduced by 2,714 metric tons/year. Generally, the addition of the proposed microturbines can save up to 15.7% of the annual plant electricity consumption (1.3–12.8% of the plant annual electricity bills).

Optimization of milk procurement routes of FPO owned dairy unit

Raw milk quality and quantity is the corner stone of excellent dairy products. Milk procurement guards this with an eagle eye and ensures that company’s production needs are met. Milk procurement is the starting point of FPO’s dairy supply chain. The FPO owned dairy unit has adopted a system of milk collection through village level milk pooling points (MPP’s). MPP is a common place in villages where the farmers pool their milk. The person who collects the milk from the farmers is called as “Pala Mitra” / “MPP operator”. The present study was carried out at the selected BMC centre of a FPO owned dairy unit in Chittoor district of Andhra Pradesh. The principal objective of the study was to optimize the milk procurement routes using travelling salesman model. The findings of the study show that in route-1 the optimized distance is 48.2 kilometers, time travelled to cover all the milk pooling points is 83.5 minutes and the total cost per trip is around 345 Rs. In route-2 optimized distance is 26.7 kilometers, time travelled to cover all the milk pooling points is 76 minutes and the total cost per trip is around 191 Rs. In route-3 optimized distance is 18.4 kilometers, time travelled to cover all the milk pooling points is 71 minutes and the total cost per trip is around 132 Rs.There was a significance reduction of total distance, time and cost in raw milk transportation for the identified bulk milk cooling unit with the optimization of routes was observed. The total distance for travelling to procure the milk to BMC unit has been reduced to 186.8 kilometers per day from 194.6 kilometers per day. The total time of travelling to procure milk to BMC unit was reduced from 501 minutes per day to 461 minutes per day. The total cost incurred for transportation of raw milk to BMC unit has been reduced from 1391.4 Rs. to 1335.6 Rs. With route optimization in all routes of identified bulk milk cooling unit a total reduction in cost of transportation of 55.77 Rs. per day could be achieved. As these transportation operations are routine and need to be done throughout the year an annual cost saving of 20,356 Rs. per annum for the identified BMC unit could be achieved.

Sustained proton pump inhibitor deprescribing among dyspeptic patients in general practice: a return to self-management through a programme of education and alginate rescue therapy. A prospective interventional study

BackgroundDyspepsia guidelines recommend that patients treated with proton pump inhibitors (PPIs) should step down to the lowest effective dose or return to self-care, but rebound hyperacidity can make this difficult. Many patients continue on PPIs in the long term, which may lead to safety and financial implications.AimTo determine if a nurse-led educational support programme and rescue therapy for rebound symptoms can help patients achieve a sustained reduction in PPI use.Design & settingA prospective interventional study was conducted at 26 surgeries across the UK.MethodAdult patients, treated with PPIs for ≥2 consecutive months with an active repeat prescription, were invited to a 20-minute dyspepsia clinic appointment with a trained nurse adviser. An action plan to reduce and/or stop their PPI usage was agreed and alginate supplied for the self-management of rebound symptoms. After 12 months, PPI status was reviewed and prescribing cost savings calculated.ResultsAfter 12 months, 75.1% of 6249 eligible patients stepped down or off PPIs (35.3% stepped off; 5.0% stepped down then off; 34.8% stepped down only), while 8.7% of patients had reverted to their original PPI dose. PPI prescriptions fell from 89 915 to 45 880 and alginate prescriptions increased from 2405 to 6670. An average of 1.7 bottles (500 ml each) of alginate were used per patient who stepped down or off. Estimated annual cost-saving on prescriptions was £31 716.30.ConclusionA programme of education and short-term rebound symptom management helped the majority of patients to successfully step down or off PPIs, significantly reducing the potential risks associated with chronic therapy.

Risk Analysis of Lightning and Surge Protection Devices for Power Energy Structures

This paper studies the risk data and protection measurements of lightning based on the IEC62305 standard. In addition, Visual Basic (VB) is used to build a lightning risk calculation program with a Graphical User Interface (GUI). The data structure, including environment data, line data, zone data, economic data, and protection measures is designed to simulate risk of loss of human life (R1) and risk of loss of economic value (R4). To achieve the most economical protection structure design, additional protection measurements and annual savings are considered. In the practical application, the main purpose is to discuss effective protection distances of surge protective devices (SPDs) for low-voltage power distribution. This paper takes advantage of Electromagnetic Transients Program (EMTP) to simulate the voltage of equipment with different types of loads and length of the cable. After using the protection measures, the value of risk of human life reduces form 21.299 × 10−5 to 0.439 × 10−5 and the value of risk of economic value reduces from 2696.754 × 10−5 to 98.062 × 10−5. The results mean that the protection measures let the values of the risk below the tolerance. By considering the annual cost saving. Assume the cost of protection measures, the interest rate, the depreciation rate, and the maintenance rate are 150,000 $, 4%, 5%, and 1%, respectively. The annual cost before using protective measures, the annual cost after using protective measures, the annual cost of protective measures, and the annual cost saving are $925,000, $33,635, $15,000 and $876,365, respectively. Consequently, it is feasible that the simulation result can provide users with great suggestions to choose the best installation location and achieve the most effective protection design.

Empirical Study on Annual Energy-Saving Performance of Energy Performance Contracting in China

A lack of trust in Energy Service Company (ESCo) is the most critical factor affecting the development of Energy Performance Contracting (EPC) in China compared with other constraints. One cannot easily estimate the energy-saving performance of an EPC project. Under that condition, lack of trust may cause the Energy-Consuming Unit (ECU) to suspect the energy-saving performance promised by the ESCo, thus leaving potentially profitable projects without necessary funding. Currently, specific studies taking an across-projects viewpoint on annual energy-saving performance of EPC projects in multiple subsectors objectively and quantitatively are lacking. This paper studies the regression relationships of annual energy-saving quantity in terms of revamping cost and the regression relationships of annual cost saving in terms of revamping cost. The regression results show that there are statistically significant correlations in the above relationships in the nine subsectors investigated. This is significant for ESCos and ECUs because knowledge on energy-saving performance could contribute to EPC investment decisions and trust relationships between ESCos and ECUs. Then a multiple linear regression model of revamping cost is set up to analyze its influencing factors. The model indicates that the subsector the sample belongs to, financing, registered capital of the ESCo, and contract period have significant effects on revamping cost. Thus, policy implications regarding innovation of EE promotion technology, clarifying ESCos’ exit mechanism, innovation of financing mechanism, and improving the market credit environment for promoting investment in EPC projects are provided.

Empirical Study on Annual Energy-Saving Performance of Energy Performance Contracting in China

Currently, the estimation of annual energy-saving performance of Energy Performance Contracting (EPC) projects is still at the operating level of each individual project, lacking a systematic summary. This paper studies the regression relationships of revamping cost in terms of annual energy-saving quantity and annual cost saving of EPC projects. The regression results show that there are statistically significant correlations in the above relationships in the nine subsectors investigated. These results contribute to EPC investment decisions and trust relationships between Energy Service Companies (ESCos) and energy-consuming units (ECUs). Then a multiple linear regression model of revamping cost is set up to analyze its influencing factors. The model indicates that the subsector the sample belongs to, financing, registered capital of the ESCo, and contract period have significant effects on revamping cost. Finally, advice for promoting investment in EPC projects is given.

Using business models in designing market-based solutions: the case of fluoride treatment systems

This paper addresses how business models inform viability of different fluoride treatment technologies for developing countries as well as the pursuit of financial and operational sustainability. Excess fluoride concentrations in drinking water supplies negatively impact the health of communities living in fluoride affected regions of the world by causing dental and skeletal fluorosis and other severe socio-economic problems. Given that fluoride mitigation solutions have proven elusive, we apply business model logic to compare fluoride removal technologies to examine the financial sustainability of water service provisions. We analyze the investment cost of producing fluoride safe water, the annual revenues generated, and the net benefits obtained from different technologies. Furthermore, the reduced medical costs and productivity losses averted due to access to fluoride safe water can lead to an average annual cost saving of $67 per person. Our results validate the use of business models to help evaluate different technologies as a means of pursuing sustainable applications for safe drinking water.

The construction and implementation of a clinical decision-making algorithm reduces the cost of adult fracture clinic visits by up to £104,800 per year: a quality improvement study

INTRODUCTION Inappropriate referrals to the new patient fracture clinic unnecessarily consume hospital resources and many hospitals lack clear guidelines as to what should be referred. Many of these injuries can be definitively managed by the emergency department. Our aim was to construct and disseminate a clinical decision-making algorithm to reduce the frequency of inappropriate referrals to fracture clinics at our institution, to improve the management of patients with minor injuries and save the hospital and the patient the cost of unnecessary visits. MATERIALS AND METHODS Data were prospectively collected for all new fracture clinic referrals over two separate 1-week cycles with cohorts of 94 and 74 patients, respectively. After the first cycle, the referral algorithm was disseminated both electronically (intranet) and orally (presentations to emergency department staff). The results of this intervention were examined in the second cycle, which took place 6 months after the first cycle. RESULTS The introduction of this algorithm significantly reduced inappropriate referrals by almost 20% (P = 0.0445). DISCUSSION This simple intervention highlighted a potential annual cost saving of up to £104,000. We advocate the use of this concise algorithm in improving the efficiency of the referral system to fracture clinics.