Researchers at VTT focus on energy storage as a means to overcome bottlenecks in renewable power systems.
Research by the team at VTT has studied gas powerstorage at three distinct scales - KW, MW and Terrawatt (TW). The first stage covers smaller house-hold devices and storage units at this scale are already commercially available. The MW scale projects are expected to start appearing within the next year paving the way to TW storage systems designed to meet the needs of national utilities.
”We aim at showing how storage technologies can balance the electricity grid, and how they mobilise the transport sector. We have a concept ready for the Terrawatt-scale unit,” said Pasi Vainikka, principal scientists at VTT. ”In modelling we would have a platform that can be used in designing an energy system with mobility and electricity grids merged and with large storage infrastructure in place.”
Looking further into the future the team are modelling systems that are entirely renewable, where gas used to store energy is created artificially from excess solar power. This would greatly reduce the environmental impact of gas power generation as there are no extraction or transportation costs.
Natural gas favoured over hydrogen in short term
The driver behind all of this research has been to understand the economics of widespread renewable penetration. As a result the benefits of hydrocarbon based energy storage are more apparent. While there is a range of promising technology focused on hydrogen power generation the costs quickly spiral when TW-scale storage systems are considered.
“We concentrate on hydrocarbons. Why? Because if we really want to do something about climate change by, say, 2030 one would need TerraWatt-hours to move very soon and while hydrogen is nice there are currently no capabilities to store 1 TWh hydrogen if it falls in your lap tomorrow,” Vainikka said, adding that in our existing hydrocarbon infrastructure “it is possible.”
VTT predicts that the technology under development today will largely be complementary to the integration of electricity grids, particularly, in the EU. This is expected to have major strategic impact to energy security, feasibility of solar and wind, as well as energy storage access.
The state of California has recently mandated operators to provide 1.3 GW of energy storage by mid-2020 to strengthen the grid. Converting excess power to gas has a number of advantages, not least the wide availability of existing gas pipelines and infrastructure.