LNG: strategic solution for flexible demand in the Brazilian electricity sector
The Brazilian electricity sector matrix is mainly composed of hydroelectric plants that represent approximately 80% of the installed electricity production capacity. Whenever necessary, the National System Operator (ONS) determines the thermoelectric dispatch on a complementary basis, aiming at maintaining a safe level of water in the reservoirs of hydroelectric plants.
This characteristic of the Brazilian electrical system brought a new challenge for Petrobras: to find a flexible option for the supply of natural gas that allows the service to the thermoelectric segment according to its seasonal and uncertain demand. Thus, LNG emerged as an efficient alternative to respond to this specificity of the Brazilian matrix, since its supply can be modulated according to demand.
Petrobras LNG Project
In 2009, Petrobras entered the Liquefied Natural Gas (LNG) international market with the implementation of two LNG regasification terminals, one in Pecém-CE and the other in Guanabara Bay-RJ, with a regasification capacity of 7 million m³/day and 20 million m³/day, respectively, with a total investment of R$ 1.25 billion.
These projects were the result of an unprecedented project of fundamental importance to make the supply more flexible and diversify the sources of natural gas supply in Brazil. Their introduction in the country aimed, mainly, to meet the demand of thermoelectric plants for the generation of electric energy.
Instead of opting for an onshore terminal - as is common in most LNG consuming countries - Petrobras has developed an innovative model whereby regasification is carried out on board a methane tanker, adapted to be able to store and regasify the product. This vessel, called a regasifier, is supplied by means of fixed arms at the terminal and a system of pipes and valves, all cryogenic – capable of withstanding minus 162º C. These equipments transfer the gas in liquid form from a supply vessel to the regasifier vessel, where the LNG is transformed into a gaseous state. After regasification, it is injected into the pipeline with the specified characteristics to be delivered to the consumer market. Each terminal has six LNG transfer arms and two compressed natural gas (CNG) transfer arms, as well as a knock-out drum (KOD).
The regasification model is also unprecedented, in which ships - supplier and regasifier - are moored at a terminal equipped with equipment such as those mentioned above to transfer LNG between them. Brazil was also the first to use existing methane tankers adapted to store and regasify LNG.
By choosing to tranship LNG through cryogenic arms and natural gas through CNG arms, Petrobras sought to meet the international requirements of the LNG industry. The Guanabara Bay and Pecém terminals have the specifications so that 85% of the world's methane tankers can dock at their facilities. Another favorable point for the model developed in Brazil is the versatility that the solution offers, since the regasifier ships can be moved between terminals and taken to other countries.
Due to their innovative characteristics and potential for global replication, the Pecém and Guanabara Bay terminals are among the top 100 infrastructure projects in the world, according to a survey presented in 2010 by the consulting firm KPMG together with the Infrastructure Journal, an English service on global infrastructure and project finance.
Gustavo Mussel Barros is LNG Asset Manager and management is GE-GQL/PAGNL/AGNL.