氢将如何——乃至是否——能为可持续能源经济作出贡献，是能源政策中最大的未知数之一。结果取决于技术性能的改善、成本的降低、公众的接受，而最重要的，取决于促成系统性变革。不要指望这本书——或任何其他书——给出对未来的预测。但如果您想把这一复杂问题理出头绪，舍此别无他选。这本书会告诉您关于我们所不知道的一切您需要知道的内容。——吉姆·斯基亚（Jim Skea）教授，英国能源研究中心研究主任
How - and whether - hydrogen might contribute to a sustainable energy economy is one of the great imponderables of energy policy. The outcome depends on improving technological performance, lowering costs, gaining public acceptance and above all engineering systemic change. Don't look to this book - or any other book - for a prediction of the future. But if you want this complex problem untangled look no further. This book will tell you all you need to know about what we don't know. - Professor Jim Skea, Research Director, UK Energy Research Centre