Page 31 - European Energy Innovation - Winter 2016 publication

Winter 2016 European Energy Innovation 31

PHOTOVOLTAICS

The profitability of an unsubsidised
solar PV system depends primarily on
the owner’s self-consumption, as less
energy has to be purchased from the
utility. In the case of a PV system size
that generates as much electricity as
the customer uses over a year, the
actual consumption during the time of
generation is in general only around
30% if no demand shifting or local
storage is applied. Therefore, 70 % of
the generated electricity has to be sold
to the grid. The question is what kind
of pricing should be used – contract,
wholesale or day-ahead prices.

The first option for improving Fig. 2: Comparison of European residential electricity prices with electricity
profitability is to increase generated by a PV solar system.
selfconsumption by demand shifting
and using electrical appliances like However, LCOE of residential battery as follows: “This gives customers a
the washing machine, dishwasher, storage systems do not only depend complete and compatible package
electric hot water haters or heat pumps on the CAPEX (battery pack, power and consisting of a PV system, storage
during the day when the sun shines. control electronics and installation) and device, app, and green electricity tariff.”
Another option is to use the difference total storage cycles, but are strongly
between the PV electricity generation influenced by the sizing of the PV Battery producers and storage system
costs and the household retail price and battery systems and the actual developers have started to offer their
to invest in local storage options, be use of the battery system, i.e. depth customers the organisation of their
they residential or community-owned. of discharge, overall battery system decentralised electricity generation and
The current investment costs for a efficiency, usable annual storage cycles storage facilities as virtual power plants
residential battery storage system are and actual kWh stored and used8. and acting as electricity providers and
roughly equally divided between the Therefore, there is a wide range of traders. Examples are Sonnen Gmbh or
batteries and the electronic control prices of electricity from storage at E3/DC.
components. In the future, it is very EUR 0.18 to 0.36/kWh, which has to be
likely that the solar inverter will include added to the PV LCOE. In Germany KfW is offering loans
large parts of the necessary electronics, with a non-repayable component for
thereby lowering the costs significantly. Some electricity providers in Europe PV systems including storage with a
are already offering PV systems and maximum system power of 30 kWp
As an indication of storage costs, local storage to their customers, often [KfW 2016]. The loan is only available
according to BNEF prices for battery including maintenance services. The if the maximum injected power is 50%
packs for electric vehicles have packages also include apps to monitor or less of the nominal power rating of
declined from about USD 1000/kWh in the performance of the system, use the PV system. The maximum eligible
2010 to USD 350/kWh in H2 2015 and of electricity and often functionality to amount is 25% of EUR 2.000 per kWp if
could reach USD 200/kWh by 20207. control the match between demand the PV system and the battery storage
Lithium-ion batteries have an average and supply. The motivation for this are installed at the same time and EUR
of 5000 cycles, and with the above cost model is described by those companies 2.200 per kWp of the PV system if the
estimates, this would corresponds to
net kWh costs component for the full
used battery pack of USD 0.07/ kWh
(EUR 0.063/kWh) and should fall to
USD 0.04/kWh (EUR 0.036/kWh) by
2020. However, these costs do not yet
include the investment for the power
and control electronics needed to
combine it with a PV system.

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