Modern energy services are crucial to human well-being and to a country’s economic development. Access to modern energy is essential for the provision of clean water, sanitation and healthcare and for the provision of reliable and efficient lighting, heating, cooking, mechanical power, transport and telecommunications services. The World Energy Outlook (WEO) has for more than a decade devoted attention to the topic of energy access, informing the international community with key quantitative analyses, including energy access databases, projections and estimates of the investment needs and implications for global energy use and carbon- dioxide (CO 2 ) emissions of universal energy access. The latest contribution to the debate is the WEO-2012 chapter “Measuring Progress towards Energy for All”. This chapter has a special focus on the critical issue of how to track universal modern energy access and presents a new Energy Development Index. The first part of this methodology note discusses the WEO energy access databases, projections and investment model. The second part zooms in on the methodology for our Energy Development Index. Supplementary energy access materials are available on our website: 

现代能源服务是至关重要的人类福祉和一国的经济发展。获得现代能源是提供清洁水，卫生设施和医疗保健及提供可靠和高效的照明，取暖，做饭，机械动力，交通运输和电信服务是必不可少的。世界能源展望（WEO）有十多年专门关注能源接入的话题，通知与关键定量分析，包括能源接入数据库，预测和投资需求，并影响全球能源使用的估计和国际社会碳的二氧化碳（CO2）的宇宙能量进入排放。在辩论中提出的最新贡献是WEO-2012篇“朝着能源计量全人类的进步”。本章有一个特别注重如何跟踪普遍的现代能源接入的关键问题，并提出了一种新的能源发展指数。这种方法笔记的第一部分讨论了世界经济展望能源接入数据库，预测和投资模式。第二部分放大为我们的能源发展指数的方法。补充能量的访问资料可在我们的网站：