Time-of-use electricity pricing is characterised by
high 'peak' prices, generally throughout the day and evening,
and low 'off-peak' prices, generally at night. Consumers can
benefit from time-of-use pricing provided their ratio of peakto-
off-peak electricity consumption is less than a ratio of the
relative prices of the two tariffs. To alter their consumption
ratio, consumers can time-shift their demand, known as
demand response. Consumers with grid-connected PV
systems, however, already have reduced net demand during
the day-time peak, due to the PV generation. The first
question of interest to this paper is whether consumers with
PV systems would benefit financially from switching to timeof-
use pricing even if they do not engage in demand response.
There remains the concern, however, of high prices during the
evening peak, when the PV is not generating. Consumers
unwilling or unable to engage in demand response during
these periods can install battery storage systems, which are
charged during the day and discharged during the evening.
Two additional questions are therefore: what is the additional
financial benefit of battery storage to PV systems with time-ofuse
pricing and are batteries financially viable for domestic
consumers with PV? These questions are answered using data
from real dwellings with PV in the UK and simulating power
flows using a published lead-acid battery model. Economic
impacts are measured for a range of time-of-use pricing tariffs
from the UK and Ireland. Results indicate that PV has little
effect on the financial benefit of time-of-use pricing with day
period prices that are similar to the flat rate price. For tariffs
where the day period price is greater than the flat rate price,
PV improves the benefit, but not enough to make it an
economic choice for the average consumer. Battery storage
improves the financial return, but this is not enough to make
the business case positive. Even using optimistic assumptions,
such as lossless batteries and high electricity price increase,
system costs need to be lowered by at least 33.5% for lead-acid
systems, and 195% for lithium ion systems