To date, Primary Control Reserve (PCR) has dominated the energy storage debate in Germany with more than 100MW of battery storage installed in 2016 alone specifically for participating in the PCR market. At the same time, with close to 25,000 systems sold in 2016, residential storage has been stealing the limelight in the behind-the-meter segment. Julian Jansen of Delta-ee looks at how his team expects the commercial and industrial (C&I) segment to start catching up.