There’s finally been some good news for a change: According to a recent analysis performed by market research company IHS, the market for photovoltaic storage systems is about to boom. In Germany alone, the total capacity is set to increase from eight to 4,900 megawatts (MW) between now and 2017. The success of storage systems is dependent on one condition, however: They must be able to pay for themselves within the estimated 20-year lifetime of a solar plant, as well as operate reliably in basements throughout the year.