A new method for securing regulating capacity for load frequency control using seawater desalination plant in small island power system

In this present paper, a risk analysis approach is applied to an Algerian reverse osmosis seawater desalination plant using the MADS MOSAR method. MADS MOSAR method is a stepwise risk analysis approach containing many phases. Our work begins with analyzing a review of past accidents triggered by the Ben in Saf Water Company (BWC) seawater desalination plant locating in the Algerian coast in Ain Temouchent region and analyzing their similar seawater desalination plants (or plants that using similar and potential equipment). Then, the MADS MOSAR method will apply essentially for the macroscopic vision (Module A). The macroscopic vision corresponds to a main risk analysis. In the current case study, we were able to identify eight subsystems where sources and scenarios of hazards are identified, accident scenarios are assessed, recognized and ranked by Severity×Probability grid. We found twenty-six scenarios whose we were able to assess them in function of their and using probability x severity grid criteria. At the end of the analysis, we were able to define and suggest the most appropriate prevention and protection barriers for the potential elements in the studied seawater desalination plant, including pipelines, transformers, compressors, high pressure pumps, pressure vessels and energy recovery devices.

Objectives The production cost of reverse osmosis (RO) seawater desalination plant is determined by the CAPEX (Capital expenditure) and OPEX (Operating expenditure). In detail, CAPEX and OPEX are composed of direct cost, overhead cost, electricity cost, and other O&M costs. However, CAPEX and OPEX may vary by country and region. Therefore, this study tries to estimate the production cost by calculating the construction and maintenance costs depending on production capacities based on the operation results such as TDS concentration and the energy consumption from a seawater desalination plant in Korea. Methods A two-stage RO based seawater desalination plant with a capacity of 10 MIGD (45,000 m3/d) was used in this study. The plant consists of a 2 MIGD (9,000 m3/d) unit having DABF (Dissolved air bio-ball filter) and UF (Ultrafiltration) as pretreatment processes, and another 8 MIGD (36,000 m3/d) unit having DABF and DMF (Dual media filtration) as pretreatment processes. To estimate the production cost, construction and maintenance costs were calculated by using GWI's Desaldata cost estimator. CAPEX (Capital expenditure) was calculated based on production capacity, recovery rate, TDS concentration and temperature of seawater, while OPEX (Operating expenditure) was calculated based on production capacity, country, energy consumption, and electricity unit price. Results and Discussion The energy consumptions from EMS (Energy Management System) were 5.48 kWh/m3 at SLC (9,000 m3/d) and 3.4 kWh/m3 at MLC (45,000 m3/d), respectively. In the CAPEX, MLC was reduced by 395,954 ￦/m3 compared to SLC, and the LLC was lower by 192,019 ￦/m3 than MLC. Overall, CAPEX decreased as the production capacity increased. The CAPEX of small plants with production capacity between 10,000 and 50,000 m3/d was significantly different; however, there was no significant difference in larger plants having a capacity above 100,000 m3/d. The OPEX for the annual production capacity showed a sizable difference with 742.3 ￦/m3, 636.5 ￦/m3 and 580.3 ￦/m3 for SLC, MLC, and LLC, respectively. The electricity cost was a substantial portion of OPEX. Also, the production costs based on the interest rates (3% and 5%) were 1,326-1,384 ￦/m3, 1,163-1,209 ￦/m3, and 1,023-1,070 ￦/m3 for SLC, MLC, and LLC, respectively. The results were consistent with 1.0 US$/m3, which is the average production costs presented from other references. Conclusions The production cost estimated using the Desaldata cost estimator based on the CAPEX and OPEX tends to decrease as the capacity increases. However, when the capacity increased over 50,000 m3/d, the production cost decreased by an average of 40 ￦/m3. Thus the decrement of production cost reduced. From these results, the production cost of tap water through seawater desalination was estimated between 1,023 ￦/m3 and 1,070 ￦/m3 above 100,000 m3/d. Therefore, it is difficult to introduce a large-scale desalination plant in Korea, because the average tap water price was 834.6 ￦ in Korea in 2017. However, It is expected that the seawater desalination will be introduced as an alternative water source whenever drinking water price rises, or when the quantity of available drinking water sources reduce due to climate change and water pollution, or whenever energy consumption is reduced as a result of the steady development of the component technologies such as the reverse osmosis membrane, high-pressure pump, and energy recovery device. Key words: Reverse osmosis seawater desalination plant, Water price, Capital expenditure, Operating expenditure, Energy consumption

Regulatory challenges of Palestinian strategies on distribution of desalinated water

Regulatory challenges of Palestinian strategies on distribution of desalinated water

It is proposed that the seawater desalination system as a controllable load for compensating the power fluctuation caused by renewable energy in small island power system. For controlling the power consumption of the system, the system modeling is needed. In this paper, the high pressure pump and the RO membrane are modeled, and the accuracy of that model is discussed. In addition, it is necessary to make it clear the boundary condition of the upper and lower limitation of the power consumption of the system. The boundary condition derived from the mechanical restriction of using RO membranes is discussed through modeling and experiment.

Water scarcity is a global issue that has extreme effects on conflict zones in particular. Therefore, seawater desalination provided a practical solution to reduce the problem. The Gaza Strip suffers from potable water scarcity due to groundwater contamination and the deterioration of the coastal aquifers. Thereby, the Palestinian Water Authority (PWA) had constructed three seawater desalination plants (SDP’s) in addition to purchasing potable water from the Israeli company (Mekorot). Due to the importance of the SDP’s, a flexible and comprehensive management system is required to ensure the sustainability of the performance. Thereby, this study aims to assess the potentiality of applying the Integrated Management System (IMS) in seawater desalination plants. This study used data collected from reports, questionnaires, and interviews, which is then analysed statistically, in order to identify the effects and barriers of applying the IMS in seawater desalination plants. The data also was used in SWOT analysis to formulate strategies for applying the IMS. The reports showed that the physicochemical water quality of samples from seawater desalination plants is compatible with PWA and WHO standards. The results from the questionnaire showed that there are positive impacts of applying the IMS on the performance of the desalination plants in terms of the financial, administrative, technical, environmental, and socio-economic aspects. However, the study identified 12 barriers which were analysed through SWOT analysis to formulate strategies to facilitate the implementation of the IMS. The highest priority and most applicable strategy is the formation of a partnership with the UN institutions to obtain international protection and facilitate the entry of the required materials.

This paper assesses the contribution of a controllable load (a reverse osmosis [RO] seawater desalination plant), together with an energy storage system in Porto Santo's small islanded electric power system. The controllable load and storage system are used to (i) smooth the net‐demand fluctuations and adapt it to the availability of renewable energy sources (RES), thus avoiding possible curtailments and contributing to a higher dissemination of RES, (ii) minimize the overall operational cost associated with the production of electricity and potable‐water, and (iii) reduce the environmental pollutants associated with the electric power systems on the island. The nonlinear nature of the problem makes it difficult to quickly obtain a robust solution through conventional mathematical tools. Therefore, an evolutionary algorithm is developed to find feasible solutions for dispatching the resources for a one‐week simulation period. The proposed algorithm determined the power output of the conventional thermal power plant, the RO desalination plant operating periods, and the storage charging and discharging periods and powers. In the proposed scenario, through a seven‐day simulation, 50% of the demand is supplied by renewable sources. The numerical results illustrate a reduction in the average total electricity‐peak demand of the island. The obtained diagrams are compared with the data gathered on Porto Santo's energy system. They display that the proposed solution is economically beneficial for the management of the electric power grid of the island of Porto Santo, while reducing the global warming potential (GWP) of the electric power system. Furthermore, it reveals that in a scenario with 50% penetration of renewable sources, through the proposed solution, a more efficient and predictable operation of the conventional electricity generators and the RO desalination plants can be achieved. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

해수담수화 플랜트 시장 진출 유망 국가 분석을 위한 지수를 개발하였고 이를 위해서 관련된 자료를 수집하고 분석하였다. 자료의 특성상 국가별로 편차가 커 스케일 재조정 방법을 통해 각 지표별로 표준화를 실시하였고, 해수담수화 플랜트에 대한 전문가들을 대상으로 Delphi 기법을 통한 설문 조사를 통해 가중치를 결정하였다. 총 23개의 지표를 3가지 요소로 나누어 각각의 항목별로 가중치를 결정하였으며, 사우디아라비아, UAE, 쿠웨이트, 이란, 카타르, 중국, 싱가포르, 인도, 알제리, 터키, 미국 등 11개 국가, 즉 해수담수화 플랜트 해외 시장 유망 국가들에 대해서 지수를 산정하였다. 산정된 지수를 비교하였을 때 미국이 0.537, 중국이 0.490, 사우디아라비아가 0.329로 나타났다. 현지 사정을 고려하였을 때는 미국과 중국은 해외 시장 진출을 하는데 많은 어려움이 있을 수 있지만 그 외에 국가에 대해서는 본 연구의 결과를 바탕으로 전략적으로 시장 진출을 도모하는데 도움이 될 것으로 판단된다. An index was developed for analyzing the promising countries for seawater desalination plant and related data sets were collected and analyzed. Each indicators was standardized by scale readjustment method and Delphi method was used to calculate the weights for indicators from questionnaire survey by experts in seawater desalination plant field. Twenty three indicators were selected and they were classified into three groups, economic, social, and environmental indicator groups. Eleven countries (Saudi Arabia, UAE, Kuwait, Iran, Qatar, China, Singapore, India, Algeria, Turkey, United States) were selected considering present data availability and index for each country was calculated. The results show United States and China took the first (0.537) and second (0.490) place for the most promising country for seawater desalination plant. However it will not be easy to play a significant role in the markets because of present seawater desalination technology level and national policy, etc. Saudi Arabia took the third (0.329) place and other countries which has more than 0.2 index value can be considered as a promising countries for seawater desalination plant. We can establish a strategy to export our seawater desalination technology and plant using the result of this study. The developed index can be applied to other countries, which were not included in this study, when their data is available.

小規模離島系統における海水淡水化装置を用いた需給調整容量拡大手法

5,000,000 imp.gal/day sea water desalination plant for the Ministry of Electricity and Water, Government of Kuwait

Development of the most adequate pre-treatment for high capacity seawater desalination plants with open intake

Seawater desalination plants influents and effluents analysis in Libya

Solar energy exploitation for reverse osmosis desalination plants

Parts of the USA are facing impending shortages of freshwater. One proposed solution is the construction of desalination plants to turn seawater into freshwater. Although seawater desalination plants are widely used in the Middle East, especially Saudi Arabia, there are few desalination plants in the USA. In 2003, Tampa Bay Water built the largest desalination plant in North America. Persistent operating problems and escalating costs have caused the utility to re-evaluate its reliance on the seawater desalination plant as part of a long-term regional water supply strategy. In addition, environmental effects of the plant are uncertain. Advances in reverse osmosis technology have significantly reduced desalination costs. However, desalination of seawater is still more expensive than other freshwater supply sources and demand management measures. With time and research, seawater desalination may prove to be a sustainable, cost-effective source of new freshwater supplies, especially if plants are coupled with renewable energy sources. Until then, the development of small-scale groundwater desalination plants, the re-use of water, water conservation, and a more efficient allocation of water through higher prices and rising block rates will be important strategies in meeting growing water demand. Moreover, it is important to improve the coordination between water supply planning and land use planning as populations continue to increase.

This work assesses the contribution of a reverse osmosis seawater desalination plant, as a controllable load, to smoothen the power fluctuations in a small islanded power system with the contribution of renewable generation (solar and wind production). The mismatch that may exist between energy availability and the energy consumption is one of the main barriers to higher dissemination of renewable generation for cases like Porto Santo island. Being able to deal with the variation of renewable sources may be challenging especially if demand varies in the opposite direction. Demand-side management techniques are one of the tools that may be used for dealing with such mismatch, thus facilitating the accommodation of higher renewable electricity, and at the same time allowing a more efficient operation of the power system. This is even more critical in scenarios in which there are no endogenous resources and the existing power system is based on small size thermal power plants. The proposed approach for managing the desalination plant shows a reduction in the maximum electricity demand on the island and a smoother diagram allowing a more predictable operation of conventional generators. It proves that the option of employing the desalination plant as a flexible demand/load is beneficial for managing the electric power grid of Porto Santo island.