Management of night-only electricity meters

In this Master’s thesis, the influence of PhotoVoltaic (PV) panels on the distribution network
is explained and related available solutions are also mentioned. We focus on a solution which
consists of optimally using flexible loads. We consider a price signal with two settings: off-
peak tariff and on-peak tariff. Some suitable loads are connected to specific electricity meters,
called ‘night-only meters,’ which allow the consumption of power only in off-peak periods. We
describe the meters’ characteristics and the suitable loads. We also discuss the aspects related
to the practical implementation. Historically, off-peak periods were located during the night
and on-peak periods during the day. Changing the assignment of off-peak periods is an easy
method for distribution system operators to access to the flexibility of small consumers. This
solution can be implemented quickly as the infrastructure needed already exists.
We propose a mixed-integer linear model to assign optimally the off-peak hours so as to
maximize a social welfare. This welfare gathers together the cost of electricity, the financial
losses due to energy curtailments of PV installations and the loads’ wellbeing. Our model
considers automatic tripping of inverters and constraints of the electrical distribution networks.
We target night-only meters, but an extension to dual-hourly meters is also presented.
The results compare the application of the classical pattern against the optimal one for
summer and winter days, the influence of the available variable power for a summer day, and
the use of a monthly-optimal pattern against the classical one for a summer month. The new
disposition of off-peak hours can reduce by 50% the PV energy curtailed in the summer, and can
also help reducing the power flow going through the High-Voltage (HV)/Medium-Voltage (MV)
transformer. The document ends by a cost analysis comparing the homes’ money gains in two
main cases: classical pattern and monthly-optimal one, for a summer month. For each case, the
Distribution System Operator (DSO) either refunds curtailments or not. Four different types
of homes are considered: with or without night-only meters, with or without PV. This analysis
allows to know rapidly who earns money and who looses money by getting plausible values of
electricity bills.