2018年1月11日 星期四

阿爾及利亞: A Desert Nation Fighting to Maintain Water Supplies

Algeria: A Desert Nation Fighting to Maintain Water Supplies


Considering that the Sahara Desert covers most of Algeria, it comes as no surprise that the country is a water-scarce nation. Beyond the severity of its climate and geography, however, overexploitation is degrading Algeria's naturally available water resources to an alarming extent. To support a growing and rapidly urbanizing population, Algiers hopes to employ technological solutions to maximize the country's limited water supplies.

Desalination plants and large water conveyance projects involving tunneling, channeling and pipelines offer a potential fix, but there will be an associated increase in production costs. Water infrastructure maintenance will also become more expensive as a result. Low oil prices, coupled with the political need to maintain social spending ahead of a transition of government, are straining the Algerian budget. As a result, public-private partnerships are vital to assuring — if not improving — access to water throughout the country.

Algeria's per capita water availability is less than 300 cubic meters per year, which puts the country well below the threshold for the U.N. definition of water poverty. By comparison, Mexico's per capita water availability is roughly 3,700 cubic meters per year, and Egypt's is approximately 700 cubic meters per year.

It doesn't help that Algeria's water is unevenly distributed. Most of the country's surface water resources, in the form of rivers and lakes, are concentrated in the country's north, along with the bulk of Algeria's population. Desalination production accounted for approximately 7 percent of water consumed in 2012, but this still favors the north, which has access to the limited shoreline. Growing desalination capacity has helped increase water availability in the coastal cities, but as much as 30 percent of general supply is lost as it is distributed through Algeria's aging, leaking water transportation infrastructure. Many citizens simply do not have daily access to running water.

There is water in the sparsely populated central and southern parts of the country, but it is primarily groundwater — and it is at risk. Not only are the aquifers beneath Algeria's desert very slow to recharge, the non-renewable water drawn from them is sometimes called fossil water because it has sat undisturbed in the aquifers for millennia. As well as suffering from declining quality — increased salinity, nitrate contamination — the slowly draining aquifers have resulted in dry wells in some regions. Algerian groundwater withdrawals are roughly double the annual recharge rate: Approximately 3 billion cubic meters are withdrawn, but only 1.5 billion cubic meters are renewed each year. And the problem is spreading: Even aquifers farther north, on the Moroccan border near the Mediterranean, are showing signs of diminishing quantity and quality.




The vast Northwestern Sahara Aquifer System that lies beneath most of Algeria's interior is already showing signs of decline. Exploitation of the aquifer has increased significantly over the past several decades, and withdrawals now are estimated to be more than 2.5 billion cubic meters per year. Recharge rates, however, are only estimated at around 1 billion cubic meters per year. Unfortunately for Algeria, withdrawals from this aquifer system will only increase, contributing to the decline of water supplies and quality overall. In 2006, the government attempted to enumerate the amount of wells and boreholes in the nation's aquifer systems to get a better idea of how much water was being extracted. Algiers hopes to regulate usage more effectively, but illegal drilling — potentially in the order of tens of thousands of illegal boreholes — has made estimating and regulating water use nearly impossible. Because of overexploitation and illegal drilling, wells have to be drilled deeper, which raises the cost of access and contributes to environmental damage.


As Algeria's population grows and urbanizes, less water will be available per person. In the 1960s, Algeria's annual per capita availability was more than 1,000 cubic meters. Now it is 292 cubic meters. In contrast to availability, the volume of pumped water increased by 525 percent over the second half of the 20th century. Algeria's annual water consumption is now approximately 67 percent of its renewable resources, or about 8.4 billion cubic meters out of 11.7 billion cubic meters. By comparison, Turkmenistan and Azerbaijan — both energy-producing countries with per capita GDPs comparable to Algeria's — consume 113 percent and 35 percent of their total renewable water resources respectively. Both countries also have much higher per capita water availability than Algeria does.

Algeria's Expensive Water Strategy

Algiers' water management strategy focuses on making the most of existing water resources through redistribution, increased storage capacity and enhanced desalination capacity. The Algerian water distribution network stretches more than 58,000 kilometers (roughly 36,000 miles) and can move over 3 billion cubic meters of water per year. In terms of storage, there are already more than 70 large dams in Algeria, but increasing storage capacity is an important part of the capital's water strategy. When it comes to desalination production capacity, growth has skyrocketed from less than 50,000 cubic meters per day in 2002 to more than 2 million cubic meters per day in 2015. The Magtaa plant, which began operations in 2014, has a capacity of half a million cubic meters per day — enough to provide adequate drinking water for 5 million citizens. There are plans to expand desalination capacity for seawater and brackish groundwater in the near future.

For a country with some of the lowest water prices in the region, Algeria relies heavily on expensive water management solutions. Even with recent revisions to the water pricing system, the cost of water is so low that it does not encourage conservation. In fact, prices do not even cover production and maintenance costs, let alone treatment of wastewater. Moving a comparatively heavily liquid such as water from its point of origin to point of consumption entails significant costs, both for the initial construction of the infrastructure and for operations and maintenance thereafter. A large-scale transfer project to move water from Ain Salah to Tamanrasset (completed in 2011) cost roughly $2.5 billion, not including the ongoing operation and maintenance expenses. Desalination operations are even more energy intensive and costly than water conveyance. Water produced at desalination plants in the Arab region costs between 50 cents and 60 cents per cubic meter — compared to around 5 cents per cubic meter for groundwater, and 20-50 cents per cubic meter for surface water. Although energy is a factor in the higher price of water from desalination plants, more than half of the cost is attributed to factors other than energy, such as labor and chemicals.

Without investment from the government — not just in big nameplate projects but also in routine maintenance and efforts to improve efficiency and regulation — the availability and quality of Algeria's water supply will keep declining. However, the government cannot foot the bill alone. Private investment will be necessary to safeguard the country's water supply. Public-private partnerships in the water sector are partly responsible for the recent surge in desalination capacity. In addition, private organizations are responsible for water management in some of the country's largest cities, including Algiers, Annaba, Oran and Constantine.

Algeria's 2015-2019 Development Plan earmarked nearly $18 billion for water infrastructure projects. But throughout 2015 and into 2016, low oil prices have put a burden on the government's budget. Algiers' top spending priority will be security services, especially for energy assets. Furthermore, the country has a history of using social spending to quell civil unrest. President Abdel Aziz Bouteflika used public spending campaigns to fend off protests after the Arab Spring brought down other leaders in the region. Even with low oil prices straining Algiers' finances, the government is more likely to spend its reserves on subsidies than risk unrest. Whatever government takes power following the upcoming transition, it will likely continue with that strategy because Algiers and the populace remain wary of political unrest, a legacy of the country's decadelong civil war (1991-2002).

Water's Role in Algeria's Future

Because oil prices are expected to remain low for a while, Algiers is searching for new sources of revenue. Algeria's vast potential shale reserves are one such source. However, water security was a common theme during recent protests regarding shale extraction, and concerns about water scarcity could hinder the development of Algerian shale over the next five to seven years. Technological solutions that limit or eliminate water's role in hydraulic fracturing could allow Algeria to exploit its shale reserves in the long term, although given the protest culture of the country and region, demonstrations against hydraulic fracturing could still occur even if water use is addressed.

There is little doubt that water is part of a circle of causation and control: It remains a key factor in keeping Algeria's security situation manageable, which is vital to keeping the country attractive to foreign investment, which in turn is crucial to maintaining the water supply. The protest culture in Algeria means that subsidies that benefit the population cannot be rolled back easily. Therefore, water prices will remain low and foreign investment will still be needed to maintain or improve Algerians' access to water.

Climate changes — specifically, higher temperatures and less rain — are predicted for the coming decades in Algeria and the wider region. At the same time, the population is expanding and urbanizing, consuming more water than ever before. This adds to the stress on the country's already scarce water resources. Greater desalination capacity, improvements to existing infrastructure and additional water conveyance projects — created through cooperation between the public and private sectors — could alleviate some supply concerns, especially in urban areas. But, if short-term budgetary problems lead Algiers to neglect the country's water infrastructure, the longer-term implications are dire. Declining quality, infrequent availability or more dependence on expensive water from desalination plants will contribute to the potential for social unrest. As overexploitation creates more obvious environmental degradation and further reduces water supplies, dissent will become a greater threat to the government.

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Algeria's Expensive Water Problem  

轉載自:  https://worldview.stratfor.com/article/algerias-expensive-water-problem




Algeria's per capita water availability is less than 300 cubic meters per year, which is well below the threshold for the U.N. definition of water poverty. Many citizens simply do not have daily access to running water. The country's water is also unevenly distributed, with most of its surface water resources concentrated in the north, along with the bulk of its population.

There is water in the sparsely populated central and southern parts of the country, but it is primarily groundwater — and it is at risk. Not only are the aquifers beneath Algeria's desert very slow to recharge, the non-renewable water drawn from them is sometimes called fossil water because it has sat undisturbed in the aquifers for millennia. Algerian groundwater withdrawals are roughly double the annual recharge rate, and the problem is spreading: Even aquifers farther north are showing signs of diminishing quantity and quality.

Algiers' water management strategy focuses on making the most of existing water resources through redistribution, increased storage capacity and enhanced desalination capacity. But for a country with some of the lowest water prices in the region, Algeria relies heavily on expensive water management solutions. Without government investment, the availability and quality of Algeria's water supply will continue to decline. However, the government cannot foot the bill alone — private investment will be necessary to safeguard the country's water supply.

Climate changes — specifically, higher temperatures and less rain — are predicted for the coming decades in Algeria and the wider region. At the same time, the population is expanding and urbanizing, consuming more water than ever before. Greater desalination capacity, improvements to existing infrastructure and additional water conveyance projects — created through cooperation between the public and private sectors — could alleviate some supply concerns, especially in urban areas. But, if short-term budgetary problems lead Algiers to neglect the country's water infrastructure, the longer-term implications are dire. Declining quality, infrequent availability or more dependence on expensive water from desalination plants will contribute to the potential for social unrest.

澳大利亚光伏市场及政策简析

澳大利亚光伏市场及政策简析

2018-01-04  PV兔子 

在此前的推文中,针对东南亚的一些热门国家的光伏政策进行过相关的介绍,主要是考虑其靠近中国的地理优势而言。而针对其他发展光伏的优质国家,由于其良好的当地政府信誉,及其较为丰富的太阳辐照资源,这些国家也越来越受到光伏投资企业的关注。本文将针对澳大利亚光伏市场及其政策进行简要的介绍。
能源结构及光伏市场现状
根据澳大利亚政府环境和能源部的统计数字,2016年澳大利亚的发电量中仍有62.9%来自煤电,18.5%天然气发电,2.3%为燃油发电,可再生能源比例为16.2%(其中6.9%水电、5%风电、2.7%屋顶光伏)。具体结构比例及发展情况请见下图。
截止至目前,根据澳大利亚光伏研究所(APVI)的最新年度报告显示,太阳能光伏发电目前占澳大利亚全国发电量的11%。但是,随着大规模太阳能市场的发展,这些数字将会增长。

截止至2017年第一季度,澳大利亚全国光伏总装机容量达到6GW。其中户用住宅光伏市场,增幅明显。截止至2016年底,其全国共计安装160万户,占全国家庭总数的20%。储能及工商业系统也在不断增加。
2017年大型光伏项目大幅增加

在2017年,大规模的太阳能光伏发电在澳大利亚获得巨大的推动。总装机容量近1GW的20多个项目在当年融资到位。此外总量超过3.7GW的大规模太阳能发电项目也获得推动。这主要得益于澳大利亚可再生能源机构(ARENA)成功的竞争性融资以及清洁能源金融公司持续的2亿5千万澳元的大规模太阳能融资计划。


当地市场新规
2017年10月,澳大利亚总理特恩布尔政府正式宣布,将接受能源安全委员会(ESB)提出的新能源建议,进行“能源系统转型”,以确保家庭和企业获得负担得起的电力。
新的能源系统下,政府不再对某些电力来源给予特殊照顾,而是提供充分的竞争。煤炭、天然气、水电和生物质能将因其可调节性适度获得鼓励,而风、太阳能和水电这些被认定为是低排放的能源,将会停止补贴。
从表面上看,针对光伏及风电停止补贴并非是一个利好政策,但与此同时,也提到了(改革计划)将在不增加补贴、不改变税收或交易方式的情况下降低电价,使系统更可靠,鼓励正确的投资,减少排放。它是真正的技术中立的,为市场需要的任何技术——太阳能、风能、煤炭、天然气、电池或抽水蓄能——的投资展现了前景。
而随着光伏发电成本的持续降低,也将意味着太阳能已经成为比煤炭发电更便宜的能源,基于以上提及的政策调整,光伏将越发的体现其竞争力。
2017年11月28日,澳大利亚对当地电力市场规则进行了修改,将实际电力调度和财务结算的时间间隔调整为5分钟。此举将促进针对快速响应技术的投资,并为价格发现创造更加高效的市场。此外,这一重要举措还将有助于平衡可变电力供需关系,并推动电网集成更多可再生能源。
当地光伏项目投标需求解析
以下内容将针对当地大型地面电站投标的要求进行着重介绍,与此同时也将针对其提及的具体需求进行解析。
对于投标方的具体需求如下:
澳大利亚本土公司才有资格进行光伏项目的投标。即海外公司需要在澳设立分公司或与当地公司成立合资公司的形式,满足投标的基本需求。而考虑到当地的项目经验及履历问题,部分企业会采用第二种方式。
大型项目,其只提供土地红线,需投标人对此标的出具投资及设计方案。此部分可以解读为,当地政府对于投标人的设计能力提出了较高的要求,与此同时,同一标的并没有强制要求进行唯一一种新能源形式,即针对同一标的,在设计中可以加入光伏、风电及储能等综合性系统,从整体设计及投资回报对项目进行评定。
对于并网接入部分,需满足当地电力机构的要求。此部分对于众多海外投资人来讲是最为重要的部分,对投标方针对当地电网的了解程度提出较高要求。针对此项,建议投标人,寻求当地有丰富经验的设计公司或中高压电力接入产品提供方,继而可以更顺利的获得项目的接入设计审核。
具体项目建设,针对政府型项目,其会明确要求项目的并网时间;而对于商业型项目,投标人须提供建议的并网时间。此二者的区别主要在于,政府型的项目,如未如期并网,政府将给予较高额度的惩罚,而商业型项目相比之下并无强制要求。以上内容主要考虑到当地人力资源的短缺问题。

太阳能光热发电几种创新型储热技术

太阳能光热发电几种创新型储热技术
2017-04-23     轉載:  http://www.beaconergy.com/news/235.html

光热电站相比光伏电站的核心优势即在于光热电站可配置储热系统,与传统的火力发电厂一样,生产出电网友好型的可调度电力,满足连续的用电需求。目前,商业化光热发电项目的储能市场仍然以二元熔盐为工质的熔盐储能技术为主流,但其凝固点过高,易冻堵管道的缺陷也饱受诟病。

  2016年下半年接连发生的美国新月沙丘电站熔盐罐熔盐泄露事故以及西班牙Gemasolar光热电站熔盐热罐损毁事故,均造成了熔盐罐维修费用及售电收入方面的巨大损失,熔盐储热系统的安全性、可靠性再次受到行业关注。

  那么,有没有一种更先进的储热技术,可替代传统的熔盐储热技术进而成为主流?近年来,创新型储能技术层出不穷,尽管其大多停留在实验室或小型示范阶段,在理论层面已证明了其发展潜力,但其商业化价值仍尚待发掘。

1. 挪威Energy Nest公司新型固态混凝土储能技术
挪威科技公司Energy Nest与德国Heidelberg水泥公司(德国跨国建材公司,全球四大水泥生产商之一)展开合作,耗时五年半研发出一种全新的特殊混凝土HEATCRETE储能技术。HEATCRETE混凝土经国际权威独立第三方实验室测试,具有高比热容和高热导率的特性。与之前最为先进的混凝土储能系统相比,HEATCRETE系统的导热系数提高了70%,比热容值提高了15%,这对电站的热力性能和传热介质来说意义重大。该公司表示,其HEATCRETE混凝土储能系统能使整个光热电站的成本下降10%,针对熔盐储能系统则能节约60%的成本。HEATCRETE混凝土储能技术还能应用于风电和生产高温设备的工厂,但光热电站是该公司的主要目标市场。

2. 麻省理工学院新型液态金属储能技术
20149月,麻省理工学院的研究人员公开一种新型全液态金属电池储能系统。该液态金属储能系统内部没有使用任何固体材料制作,全部的储能元件也都采用融化的液体来制作。该系统造价低廉,且使用寿命较长。研究团队称该储能系统可使风能和太阳能这些可再生能源具备与传统能源相竞争的能力。

3. 瑞典查尔姆斯大学新型含碳化学液体高效储能
20173月,瑞典查尔姆斯理工大学研究者成功验证了以一种含碳化学液体作为介质,来高效存储太阳能的新型储能技术的可行性。通过这种化学液体,能够实现能量的自由传输以及随时释放。值得一提的是,该化学液体释放能量时,几乎可以实现能量的零损耗。研究小组将这个过程叫做分子式太阳能储热系统。目前,此项新技术已成功登上《能源与环境科学》(英国皇家化学院发行的学术期刊)的封面。
           
   

     

图:分子式太阳能储热系统模型

4.瑞典SaltX科技公司新型盐结晶储能技术
瑞典SaltX科技公司推出一种新型储能技术,主要利用盐晶体及其溶液在不同温度作用下,发生化学反应来进行储存与释放能量。可应用于光热发电、太阳能制冷和空调领域,该公司宣称可使能耗及储能成本降低约33%。该公司成立于2001年,一直致力于可再生能源的发展。凭借在欧洲绿色能源领域的快速发展,SaltX科技公司于201611月荣获BullhoundConnect大奖。目前,该公司已与美国通用电气、瑞美制造和阿法拉伐等公司建立合作关系,并提供新型储能解决方案。

5.美国新型热化学储能系统
20165月,美国俄勒冈州立大学和佛罗里达大学的科研人员合作推出一种新型热化学储能系统,可用于存储和释放太阳能。相比传统储热设备,美科研人员改进后的储能方案新增一种类似电池的热化学储能系统,其内部的转化过程是基于热能而非电流。在充电期间,碳酸锶在太阳热能作用下,分解成氧化锶和二氧化碳。当放电时,氧化锶和二氧化碳会发生合成,同时释放出储存的热量。该储能系统的材料易获得、不易燃且绿色环保,使用这些材料合成的化合物运行温度高达1200摄氏度,储热效率比现有储热系统高两倍。
              
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图:新型热化学储能系统原理图

6.澳大利亚Solastor高纯石墨储能技术
Solastor是澳大利亚一家研究太阳能储热发电技术的专业公司,其采用高纯石墨作为吸热和储热材料的塔式热发电技术一直领先于世界,其内置式石墨储能技术在十余个国家获得了知识产权的专利保护。该储能技术具有低塔、多塔、环保、安全、高容量储能和24小时热能损失低于5%,以及模块化组合等优点。
2014年,江苏润阳储能技术有限公司引进该公司内置式石墨工质塔式光热发电技术,建设我国首个石墨工质塔式光热发电示范项目。这种以石墨为介质,集吸热、储能、热交换为一体的三合一内置式先进技术,填补了我国光热发电领域的又一空白,对在我国开发太阳能塔式光热发电技术具有现实意义。
                
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图:位于江阴的我国首个石墨工质塔式光热发电示范项目

7.阿联酋Masdar理工学院沙子储热技术
201512月,阿联酋Masdar理工学院宣布,其研究人员已成功证明沙子可以储存太阳热能用于光热发电,存储温度可达1000℃。该研究项目名为“Sandstock”,目标是寻求开发一种可持续的低成本的依靠重力给料的太阳能接收器和存储系统,即使用沙子作为传热和储热介质。沙漠里的沙子是一种潜在的储热材料,其热稳定性和比热容在高温下的特性已经被研究证明。用廉价的沙子可以降低成本,同时,储热材料工作温度的增加意味着效率提升。
20167月,全球首个以沙子作为工质的塔式光热电站在意大利西西里岛正式启动。该项目的核心技术是一种基于沙子流化床的太阳能蒸汽发生技术,是首个在MW级规模对沙子储热工质进行示范的电站,能够吸收和储存太阳能并将热量转化为电力和其他热能使用。
                  
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图:位于意大利的全球首个沙子工质塔式光热电站