Two veterans of Tesla, the electric car pioneer owned by Elon Musk, has announced that they plan to build a $4 billion factory to manufacture the batteries, most likely in Sweden.

Peter Carlsson and Paolo Cerruti, both ex-executives for Tesla, said a massive new factory could be producing lithium-ion batteries, the energy source for electric cars, in Europe by 2020, if plans for a Nordic “gigafactory” come to fruition. 

“The problem today is that batteries are very expensive. By scaling up the battery production and taking control of the entire [value] chain, from raw material extraction to the finished product, we think we achieve a competitive business model,” said Paolo Cerruti, COO at Northvolt, formerly Carlsson’s colleague at Tesla, to Swedish business daily Dagens Industri.