This article omits important context : these 7 countries have massive hydro power (+geothermal for Iceland) for very little demand.

The only countries with <100 g CO2/kWh and >10TWh/y are using nuclear. Large scale batteries are exciting for the future but need more development. The 2 biggest battery investments in the world are being made in Australia and California, yet still produce 4x the g CO2/kWh of France.

https://app.electricitymaps.com/map/5y/yearly