Dave Elliott: Prof. Mark Jacobson and his team at Stanford University got some flack for their 100% global renewable energy study last year. It said 139 countries around the world could obtain 100% of their energy from wind, water and solar (WWS) sources by 2050. It had been based on their 2015 study that examined the ability of 48 US states to meet all their energy needs stably from these renewables. Some said their approach was flawed, and, for example, relied too heavily on energy storage solutions and on adding turbines to existing hydroelectric dams to get extra power. In response, Jacobson and colleagues at Stanford, the University of California at Berkeley and Aalborg University in Denmark have now produced a new study, focusing on 20 global regions encompassing the 139 countries, with supply and demand matching modelled for a range of storage/backup options over the period 2050-54. The team is adamant that there would be no major problems with balancing. They note that many previous studies had examined matching time-dependent demand with supply for up to 100% renewable electricity and some has looked at all-energy matching. All had found that ‘time-dependent supply can match demand at high penetrations of renewable energy without nuclear power, natural gas, or fossil fuels with carbon capture’. So had they. But they claim to have added more certainty: in their new scenarios they say ‘100% of all end-use energy, rather than 100% of just electricity (which is ~20% of total end use energy), is decarbonized’ with balancing solutions found ‘by considering many storage options, namely heat storage in rocks and water; cold storage in water and ice; electricity storage in CSP-storage, pumped hydropower, existing hydropower reservoirs, and batteries; and hydrogen storage; and by considering demand response and, in one scenario, heat pumps’.
Environmental Research Web 21st April 2018 read more »