Renewable energy future from energy coupling perspective is analysed by using global energy system model. Energy system with high renewable share is examined by four scenarios differentiated by biomass potential and electric vehicle market share. For comparison, business-as-usual scenario with emission fees but without non-renewable energy exclusion is used. In renewable scenarios non-renewable energy sources are phased out by high tax for year 2050 and letting model find cost-optimal path from 2010 to 2050. Results indicate that high renewable share poses major changes in each energy system sector, especially in power generation, industry and transportation. Substantial biomass utilisation is required, and increased electrification of energy system, especially in industrial sector, is necessary with high penetration of solar and wind power. Solar photovoltaics (PV) reaches globally 39-44% share in primary energy and 75% share in electricity generation since positive development of PV technology directs especially power generation in Asia to solar power. This requires high capacity of power-to-x technologies, which use electricity to produce synthetic fuels used in industrial and transport sectors, and electricity storages. Transition to renewable energy system mitigates CO2 emissions by 90% from 2010 to 2050, even though the issue of non-CO2 greenhouse gas emissions remain. (C) 2018 Elsevier Ltd. All rights reserved.