Changing the game: fast mover advantage in household solar and battery programs

Household solar and battery programs often include more lucrative financial
subsidies in early stages to support earlier adoption of technologies. There are
numerous international examples of subsidy re-designs that left a ’window of
opportunity’ for fast moving households to lock-in higher financial support, which
raises questions about unintended equity and distributional impacts. Since there is
limited knowledge of recent household battery programs, we utilise postcode-level
monthly data from the Australian public register of small-scale technology
certificates to understand the impacts of the Cheaper Home Batteries program on
the installation of household batteries, roof-top solar, solar water heaters, and heat
pumps. Differential interaction regressions estimate the impacts of the program on
battery installs across postcodes and event study regressions are used to
understand the spillover effects onto other technologies. Over the first 9 months of
the program, there were 912 more battery installs in each major city postcode with
high socio-economic status and a history of high solar installations. This corresponds
with 3.6% more households having installed a battery and an additional 36MWh of
capacity installed in each of these more prosperous postcodes. We find that an
announced re-design of the program has coincided with a higher rate of battery
installations and larger batteries being installed. Since the program started, there
has been a doubling of solar PV capacity installed in more prosperous postcodes.
Rather than entrench energy inequity, household programs could be designed
differently with the aim of more equitable support during the early stages of
household technological adoption programs.