  We analyze how tariff design incentivizes households to invest in residential
photovoltaic and battery systems, and explore selected power sector effects. To
this end, we apply an open-source power system model featuring prosumage agents
to German 2030 scenarios. Results show that lower feed-in tariffs substantially
reduce investments in photovoltaics, yet optimal battery sizing and
self-generation are relatively robust. With increasing fixed parts of retail
tariffs, optimal battery capacities and self-generation are smaller, and
households contribute more to non-energy power sector costs. When choosing
tariff designs, policy makers should not aim to (dis-)incentivize prosumage as
such, but balance effects on renewable capacity expansion and system cost
contribution.
