由DCD中国授权DKV编译并发表于DeepKnowledge微信公众号。
James Green是领先的应急发电提供商Aggreko的全球客户经理
燃气发电机提供独立于电网的便捷电力供应
数据中心对于提供社会所依赖的许多日常服务至关重要，包括通信、能源系统、运输和医疗等服务。随着全球数据中心的兴起，数据中心选址对于确保最佳效率表现至关重要。
尽管临时性的燃气发电面临一些小挑战，但总体而言，它提供了一种实用且可靠的解决方案，因为燃气发电机可以提供使新的或扩展的数据中心从建造和调试到最终的日常运行所需的电力--至少直到电网的电力供应正常。
以下是使用燃气发电的利弊：
可持续的动力供应
数据中心运营商多年来一直在其现场使用柴油发电机作为应急/备用电源。他们还利用它们来克服电网供应不足的挑战，帮助他们弥合供电缺口，以使新的数据服务器按时上线。但是，长时间不间断地使用柴油发电代替主电源是不合算或不可持续的。
柴油发电机组用于后备电源，是因为它们可以在外市电断电后能够承受较大的负载阶跃，因此它们可以快速联机以从数据中心的UPS系统接管负载。但是，考虑到燃油系统的后勤供应和安全问题，柴油发电机需要强大而昂贵的燃油管理策略。
柴油发电机也具有长期的环境影响。由于NOx污染物的有害性和破坏性，许多地方政府对在建筑密集和人口稠密地区长期持续使用柴油发电产生担忧。建筑法规的变化和严格的规划控制意味着开发商必须探索替代方案，以最大程度地减少能源浪费、温室气体排放并改善空气质量。
此外，利用热电联产技术，发电机引擎冷却系统产生的废热可以为该数据中心提供额外的电力供应。与传统发电机产生的电力相比，此过程效率更高，温室气体排放更低。废热也可以转移到吸收式制冷机上使用，以提供冷冻水供数据中心的冷却系统使用。
总体而言，天然气是一种较清洁的能源，其排放量比柴油少，因此对于连续运行，天然气发电比柴油发电更有利。
电网同步
与柴油机发电机一样，燃气发电机可与电网有效同步，并与外部电力并联运行。这可以通过以下方式实现：
独立，连续供电
燃气发电机还可以孤岛模式运行（在这种模式下，它们不与电网连接），使其适合于已经有足够的中压或高压气源但没有市电的数据中心。运营商可以将燃气发电用作基础电力提供商，并建立了自己的小型电站来提供运营服务。
高弹性标准
数据中心电源策略的最关键因素是弹性，要使燃气发电有效，数据中心必须能够配置满足最高弹性标准的配置。
大多数运营商在设计其数据中心时都使用了最低水平的冗余电源，以确保由于UPS故障、备用发电机故障或总电源中断而导致的停机故障恢复能力高。数据中心的主要基础架构需要完全冗余，以实现Uptime Institute规定的Tier IV标准，并实现每年99.995％的正常运行时间。
尽管每个项目都不尽相同，通常可以使用不同的发电机配置来达到数据中心所需的冗余级别，燃气发电可以达到Tier IV级和2N + 1级的冗余。
缺点也是真实的
鉴于许多数据中心都位于人口稠密的地区，因此，临时天然气发电的最大障碍是寻找可使用的天然气来满足发电机要求。
尽管使用天然气长期成本与柴油相比节省是巨大的，但从公用事业提供商到临时发电机的管道设施、安装还有其他成本，几乎可以抵消这些节省。
另外，如果没有天然气，则必须要有替代燃料。可以使用液态天然气或压缩天然气，尽管成本高昂、也有严格的安规障碍，但是，与柴油发电解决方案相比，如果这意味着使站点更快地启动并运行12-18个月，则可能仍然具有成本优势。
总而言之，随着数据中心的发展和发电设备公司对研发的大量投入，天然气生产技术得到较大提高，临时天然气发电是柴油发电的可行的替代方案。当电力公司无法满足数据中心的需求时，这些发电机不仅可以帮助弥合差距，还可以为市电提供可持续的长期替代方案。
英文原文
James Green,Aggreko
James Green is the global account manager at Aggreko, aleading temporary power generation provider
Gas-poweredgenerators offer a convenient supply of elec
Data centers areessential to delivering many daily services that society relies on, includingcommunications, energy systems, transport and health services. As more data centersare popping up across the globe, it’s critical to identify suitable locationsto ensure optimal efficiency performance.
A critical factorin this decision is ensuring the site has an adequate electricity supply topower and cool its facilities, as data centers are large energy users and addsignificant electrical loads to existing electricity infrastructures. In somecountries, systems are already operating near to full capacity, so new datacenters place significant additional strain on the local and nationalelectricity grid.
Although there are minor challenges to temporary gas generation,overall it offers a practical and reliable solution because gas generators canprovide the power needed to enable new or expanding data centers to becomeoperational - from construction and commissioning to their eventual day-to-dayrunning - at least until electricity from the grid starts to flow.
Here are the pros and cons of gas-powered rental generation.
Sustainable power
Data center operators have been using diesel generators asemergency backup/standby power at their sites for many years. Consequently,they’ve also used them to overcome grid supply challenges and help them bridgethe power supply gap to get their new data servers online on time. However,continuously using diesel generation as a substitute for mains power over longperiods of time is not cost-effective or sustainable.
Diesel generators are used for standby duty applications becausethey can accept significant load steps after a power outage, so they can be quicklybrought online to take over from a site’s UPS system. However, dieselgenerators need a robust and often costly fuel management strategy, taking intoaccount the logistical and safety issues surrounding regular refueling.
Diesel generators have long-term environmental implications aswell. Many local governments or authorities will raise concerns about thelong-term continuous use of diesel generation within built-up and denselypopulated areas, due to the harmful and damaging effects of NOx pollutants.Changes in building regulations and a tightening of planning controls mean thatdevelopers are expected to explore alternative options to minimize energywaste, greenhouse gas emissions and improve air quality.
Additionally, using combined heat and power technology, wasteheat from the cooling system of the generators’ engines could produce anadditional electricity supply for the site. This process is more efficient andhas lower greenhouse gas emissions than electricity coming from conventionalpower station generation. The waste heat could also be diverted for use with anabsorption chiller unit to provide chilled water for use in the data center’scooling systems.
Overall, gas is a cleaner energy source producing feweremissions than diesel, so gas generation is more favorable than diesel forcontinuous operation.
Grid synchronization
Like diesel variants, gas generators effectively synchronizewith the electricity grid, operating in parallel with the incoming electricitysupply. This is achieved in the following ways:
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Gas generation produces a constant power output, providing baseload power at a potentially lower price than electricity from the grid. Thedata center uses the grid supply to meet varying loads above the base load.
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Gas generation is used in addition to the existing grid supply,therefore providing additional capacity. Typically, the gas generators wouldstill take the constant base load of the site and the grid would support anyvarying load.
Advanced planning is necessary because the connection and designof parallel mode generation require the local network operator’s approval.
Standalone, continuous power
Gas generators can also run in island mode – where they are notconnected or synchronized with the electricity grid – making it suitable forsites with sufficient medium or high-pressure gas supply already available butwith no available mains power. The operator effectively uses the gas generatorsas the site’s utility provider, building its own mini power station to supplyoperations.
High resilience standard
The most critical factor to a data center’s power strategy isresilience, and for a gas generation to be effective, sites must be able to configurea set-up that meets the highest resilience standards.
Most operators design their data centers with a minimum level ofredundant power to ensure a high level of resilience to downtime as a result ofUPS malfunctions, standby generator failures or total mains power outages. Asite’s primary infrastructure needs to be fully redundant to achieve Tier IV ofthe Uptime Institute’s tier system and deliver 99.995 percent uptime per year.
While every project is different and often different generatorconfigurations can be used to achieve a site’s required redundancy level,gas-powered generation can reach Tier IV and redundancy of 2N+1.
Drawbacks are real
Given that many data centers are in highly-populated areas, thebiggest impediment to temporary natural gas-powered generation is findingaccessible and available natural gas to accommodate the generators.
There are additional costs associated with installing pipelineinfrastructure from the utility provider to the temporary generator althoughthe long-term cost savings of using natural gas over diesel is tremendous andeven offset the costs related to the pipeline installation.
Also, there are fuel alternatives if natural gas is unavailable.Companies could use liquid natural gas or compressed natural gas althoughcostly and comes with rigorous regulation hurdles. However if this meansgetting the site up and running 12-18 months quicker, it may still be costeffective, especially in comparison to a diesel solution.
In conclusion, as data centers evolve and power generationcompanies in recent years investing heavily in research and developmentprograms to advance gas generation technology, temporary gas generation is aviable alternative to diesel. Not only can these generators help bridge the gapwhen electricity networks cannot deliver on a data center’s demands, they canalso provide a more sustainable long-term substitute for mains power.
翻译：洪军
云计算认证专家ACP，阿里巴巴IDC创新研发技术专家，副研究员。主要从事一体化配电设备开发，超大型IDC自动化管控方案设计
校对：李建利
广东优世联合控股集团股份有限公司数据中心运维经理
DKV(DeepKnowledge Volunteer)计划精英成员
Uptime Institute认证AOS专家
编辑：蔡海霞
湖北威那尔机电技术有限公司
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