The Standing Group on Long-Term Co-operation (SLT) encourages co-operation among IEA member countries to ensure their collective energy security, improve the economic efficiency of their energy sector and promote the environmental protection in provision of energy services. To achieve these "three E’s", IEA governments in 1976 agreed to a programme for long-term co-operation in formulating and implementing national energy goals. The SLT makes efforts to increase the awareness of the member countries and to ensure that they will share the same understanding and main policy directions through the following contributions: forward-looking economic analysis of the energy sector through medium- to long-term world energy outlook (WEO); topical studies on energy pricing, diversification of energy supply through increased shares of gas, coal, renewables, hydro and nuclear and better management of the gas, coal and electricity markets; protection of the environment including greenhouse gas emissions reductions and improved energy efficiency.

At their summit in Gleneagles in 2005, G8 leaders asked the IEA to analyse best policy practices, energy performance and options and strategies for a cleaner energy system. The IEA reputed on its initial anlysis, presented proposals on energy efficiency to the G8 Summit in St. Peterburg in 2006 and made concrete recommendations at the Heiligendamm Summit in 2007. IEA experts will report further results to the G8 Summit in Toyako, Japan in 2008.

Another major driver of co-operation is the process of in-depth reviews of the energy policies of member countries. The policies of six individual countries a year are reviewed by their peers. A team gathering peer countries’ experts and IEA Secretariat visits the country and prepares a report including recommendations to move towards the IEA Shared Goals approved by IEA Ministers in 1993.

The SLT meets four times a year to provide guidance to the Secretariat, to undertake broad policy analysis, to share the results of the in-depth reviews and to provide a lively forum for the development of policies related to economic analysis of the energy sector, energy diversification and regulatory reforms, climate-friendly energy use and energy efficiency.

The SLT established a separate expert body for energy efficiency: the Working Party on Energy Efficiency.