GREEN GOAT

RailPower Technologies Corp.'s Green Goat—a diesel¹-electric "switcher" (small, short-distance locomotive) used for assembling, disassembling and moving train cars in rail yards—became the railroad industry's first simple hybrid² when it was completed in 2001. Green Goats are old locomotives recalled and updated with small "gensets" (the diesel engine-driven electric generators³ that power locomotives), which start and run only to keep large lead–acid batteries at the optimum charge level. When the locomotive is traveling at a constant speed or idling, the battery rather than the diesel engine can power the motor. Onboard computers handle energy management. Although this model locomotive cut emissions⁴ and diesel fuel use by 80 percent and 16 percent, respectively, compared with conventional switchers, a problem with its batteries catching⁵ fire was its undoing⁶.

GENERAL ELECTRIC EVOLUTION

General Electric worked for the past seven years to design the first diesel–electric hybrid that captures energy that would have been lost to conventional friction⁷ braking and stores it in batteries for later use. GE developed and is preparing to start manufacturing a new sodium⁸ battery to replace those currently available; the latter do not capture or store enough energy for long-distance locomotives operating on maximum power for extended periods, says Glen Merfeld, manager of GE Global Research's Chemical Energy Systems Lab. The hybrid locomotive, expected to be ready in 2010, will reduce fuel consumption by 10 percent compared with GE's Evolution series diesel locomotive.

ALTERNATIVE FUELS

Later this summer, fuel-cell technology company Vehicle Projects, Inc., in Golden, Colo., plans to complete a prototype fuel cell–battery hybrid switcher locomotive that creates no emissions. A pilot, demonstrated in June, is undergoing final mechanical and control integration⁹ and will later be rigorously tested for such parameters¹⁰ as tractive effort (the pulling force a locomotive exerts in order to move), shock and vibration¹¹ resistance, and noise, says Karen Griggs, a company spokeswoman.

ETHANOL ENGINE

Alternative Hybrid Locomotive Technologies, Inc., in Milford, Ohio, hopes to raise nearly $4.5 million in government and private funding to build an ethanol-based hybrid for short-distance switching. The locomotive is designed to run on grass-based cellulosic ethanol and would also use regenerative breaking and power management control technology, says company vice¹² president James Peeples. The Energy Independence and Security Act of 2007 set a goal for refiners to use 380 million liters of cellulosic ethanol starting 2010, yet companies trying to market the biofuel have had some trouble securing investment in the recession.

RECYCLED EXHAUST

U.K.- and Canada-based Clean Power Technologies is exploring rail applications for a hybrid power steam technology that uses heat captured from exhaust, says president and chief executive, Abdul Mitha. The company has a deal to install such systems on refrigerated truck trailers, and plans to later adapt the technology for locomotives.

“绿色山羊”

RailPower 技术公司的“绿色山羊”——使用了柴油和电力两种能源的转换器（小型，短距离火车头），以此来在铁轨上组装，拆卸并且移动火车车厢。这种转换器自2001年研制成功以来，就成为了铁路产业的第一个简易的混合能源装置。“绿色山羊”是一些被小型发电机组（一种柴油发动机——由电力发电机为火车头提供能量）撤换更新了的老火车头，这些小发电机组在启动和运行的时候使铅酸蓄电池保持在最佳的工作状态。当火车头在相对恒定速度下前进或者空转时，这时电池就为马达提供能量，柴油发动机不工作。车载电脑控制这种能源转换。虽然这种火车头模型和传统的转换器相比，减少了废气排放的80%和柴油燃料的用量的16%，但是电池容易引起火灾这一问题却一直没有解决。

通用电气的革新

通用电气公司在过去的7年里一直致力于设计第一个柴油电力混合装置，这种装置能够把传统装置通过摩擦损失掉的能量收集起来以备日后使用。通用电气公司全球研究的化学能源系统实验室的负责人格兰 马菲尔得Glen Merfeld说，通用已经研制出来具备上述特性的新型钠电池，正在准备开始生产这种电池来替换那些现在流行使用的电池；后者则不能收集储存足够的能量来供长途火车头在最大动力情况下延时运行。混合动力火车头预期在2010年研制成功，到时与传统的通用改进系列柴油发动机相比，将会减少10%的能量消耗。

多种能源的选择

今年夏末，在科罗拉多州的戈登， 燃料电池技术公司Vehicle Projects公司计划完成了带有混合燃料电池转换器火车头的模型，这种火车头不产生废气。该公司的发言人凯伦 格里兹Karen Griggs说，今年6月份，一个驾驶员正在经受最后的机械控制一体化的考验，这种一体化系统之后将会接受严格的参数检测，诸如牵引力（火车头前进时产生的拉力），震动强度，震动阻力和噪音之类。

乙醇发动机

在俄亥俄州的米尔佛得Milford，多种混合火车头技术公司Alternative Hybrid Locomotive Technologies, Inc希望从政府和私人贷款那里获得将近450万美元来建造乙醇混合能源火车头，用以提供短途能源转换。该公司副总詹姆斯 皮伯斯James Peeples说，这种火车头既能使用普通的纤维素乙醇运行工作，也具备再生的刹车装置和动力管理控制技术。2007年能源独立与安全法定下了从2010年开始要求炼油公司必须用完3.8亿升纤维素乙醇，从而那些尝试着推广生物能源的公司 在经济不景气期间遇到了一些投资安全上 的问题。

尾气的再利用

英国和位于加拿大的清洁动力技术公司Canada-based Clean Power Technologies 的总裁兼首席执行官阿布达 米撒Abdul Mitha说，该公司正在为混合动力蒸汽技术探索在铁路方面的应用，这种技术使用的能源来自尾气。这家公司打算把这种系统安装在带拖车的冷冻卡车上，之后还要把技术应用在火车头上。