Friedrich Schulte from the RWE AG talks about energy storage options from a utility perspective at the BASF Science Symposium: smart energy for a sustainable future on March 9th 2015 in Ludwigshafen, Germany. For more information see https://creator-space.basf.com/content/basf/creatorspace/en/events/symposium-ludwigshafen.past.html.

1. RWE 4/21/2015 PAGE 1
Energy Storage – from a Utility Perspective
Mannheim, 09.03.2015
Friedrich Schulte, RWE AG
150 years
Science symposium
Smart energy for a sustainable future

2. RWE Research and Development PAGE 2
Agenda
Current situation and upcoming challenges in Germany
Energy storage options
Conclusion
1
2
3

3. RWE Research and Development PAGE 3
The German Federal Government assumes a decrease of
power generation of 45 % until 2050
Source: EWI/Prognos/GWS Studie
Energy concept of the German Federal Government
2010 2020 20502030 2040
Nuclear energy Conventional generation
RES
(~ 80% of generation)
Imports
Decrease of power consumption
- 45%
17%
25%
58%
45%
10%
20%
25%

4. RWE Research and Development PAGE 4
15,000
10,000
5,000
0
20,000
12.04. 13.04. 14.04. 15.04. 16.04. 17.04. 18.04. 19.04. 20.04. 21.04. 22.04.
Supply of very
high load
Providing large
amounts of power for
longer time frame
Very high load
gradients
German wind energy production at selected days in April 2011
Wind generation in MW
Integration of fluctuating power generation requires flexibility

5. RWE Research and Development PAGE 5
Energy storage is just one of four ways to increase the
flexibility of the system
Applications for energy
storageTechnical measures to increase flexibility
> For 10…20 a the required
flexibility can be provided by
other, more cost-effective
technologies such as
- flexible power generation,
- demand side management
- and grid expansion.
New storage capacity only
required with a very high
share of renewables
> Nevertheless, is there a
sweet spot for energy
storage in the meantime?
Flexible power generation
1
Grid expansion
Energy storage
4
Demand side management
3
2

6. RWE Research and Development PAGE 6
Agenda
Current situation and upcoming challenges in Germany
Energy storage options
Conclusion
1
2
3
Decentral energy storage
Regional energy storage
Central energy storage

7. RWE Research and Development PAGE 7
Energy storage can be implemented in different ways –
decentral applications are key driver for market growth
Intraday-
arbitrage
Day ahead-
arbitrage
Ancillary
services
Peak
production
management
T&D deferral
Increase RES
consumption
on consumer
level
Potential application
Flexibility
for
electricity
sector
Grid-
release
Others
Decentral Regional Central
Short/mid Limited short/mid
in specific
local situations
No short to
midterm
Potential additional application
for already financed storage
Conclusion
> In short and midterm ramp-
up of storage capacities will
be driven by decentral
energy storage systems
(stationary batteries, heat
storage, immersion heaters)
> Decentral energy storage
devices are driven by local
use of RES. If aggregated -
additional flexibility and grid
release services at very low
marginal costs possible.
> Decentral storage potentially
reduces the demand for
regional and central storage
1
2
3
Profitability:

8. RWE Research and Development PAGE 8
> PV-power generation
achieved grid parity
> Increase of local
consumption by home
batteries is feasible and
will be economically
attractive for inverstors in
the near future
> Business Case depends
on market distortion due
to own consumption
privilege and is subject to
regulation
DescriptionEconomy of PV
Declining PV-costs and increasing end customer energy
prices make battery storage interesting
Decentral energy storage
ConsumeFIT Wholesale market
time
Energycost/-prices
End
customer
price
Wholesale
price
Cost of PV-power generation
Today

9. RWE Research and Development PAGE 9
Batteries allow for an increase of the local consumption
Local PV power generation and consumption
can be decoupled time-wise
For a typical1 B2C customer a battery will
increase the self consumption by about 20 %
1 Family household, 4.500kWh annual consumption, 5 kWh Battery, 5 kWp PV
2423222120191817161514131211109876543210
Houshold
power consumption
PV power
generation
Battery
charging
Battery
discharging
hour of the day
kW
0%
20%
40%
60%
80%
100%
1 2 3 4 5 6 7 8 9 10
PVselfconsumption
PV System size [kWp]
15,00 kWh
5,00 kWh
0,00 kWh
+20%
> The economics of batteries rely on the avoided power purchases
> Business case depends on regulation and avoided grid fees, taxes, …
> With decreasing battery prices home-storage will be profitable for the investor
Decentral energy storage

10. RWE Research and Development PAGE 10
RWE participates in the decentral energy storage market
with a broad product portfolio
> Since May 2013
RWE offers home
storage solutions for
private and small/
medium enterprise
customers
> Lead-Acid and Li-
Ion-Technologies are
available
> Connected to the
230V AC grid
> Integrated into RWE
SmartHome suite
DescriptionPortfolio RWE HomePowerStorage
Product
Type
Capacity
(kWh)
Lifetime
(cycles)
Retail
Price
(EUR)
Storage
Basic
Lead-Acid
4,9 – 14,8
2500
@50% DoD
7.599
to
10.499
Storage
Eco
Li-Ion
4,5 – 13,5
5000
@80% DoD
7.499
to
16.999
Storage
Compact
Li-Ion
4,6 – 60,0
5000
@70% DoD
12.999
to
76.699
Storage
Vario
Li-Ion
4,6 – 10,1
8000
@90% DoD
14.399
to
25.499
Decentral energy storage

11. RWE Research and Development PAGE 11
Local grid storage not the best choice to cope with a high
share of RES – grid extension is generally cheaper
Grid Description
Medium
voltage
grid
> Medium voltage grid extension cost per kW is even
cheaper than in low voltage
> Although distances are longer, the storage business
cases in the regarded scenarios do not close
> However, in specific situations energy storage is
competitive
Low
voltage
grid
> Example: PV generation requires grid extension
competing with installation of a 100kW/4h battery storage
> Grid extension costs around € 60k @ 600m branch length
> Battery storage using a 100 kW/4h Lithium-Ion Battery will
still cost about € 90k even @ a price of 225 EUR/kWh
> With 40 years grids have at least twice the operational life
time compared to storage
Regional energy storage

12. RWE Research and Development PAGE 12
RWE is about to integrate a local energy storage in
Wettringen for grid investment deferral reasons
Motivation
Parameters
Timeframe
Description
> Capacity 1000 kWh
> Power 300 kW
> Technology Li-Ion
> Clippling peak grid load caused
by PV in a rural area
> Distribution grid investment
deferral
> Specification: November 2014
> Procurement: March 2015
> Installation and test operation: Summer 2015
> Start of commercial operation (planned): 2nd half of 2015
Regional energy storage

13. RWE Research and Development PAGE 13
Only with a share of RES exceeding 50 % significant
storage increase on system level will be required
ActivitiesIncreasing share of renewable generation
Today
20 to 25%
2020
35 to 40%
2030
50 to 60%
2050
75% to 100%
Relevance of new storage
New Pumped Hydro
Compressed Air
Power-2-Gas
> Keep future
options open
> Pursue R&D
projects
> Pursue R&D
projects
Central energy storage

14. RWE Research and Development PAGE 14
RWE engages in research activities for central energy storage
P2G
Demo plant
Ibbenbüren
ADELE-ING
Adiabatic
compressed
air storage
> ADELE has reached advanced development stage
– Cost target of 1300 EUR/kW reached – on par with PHS
– Charge 200 MW, discharge 260 MW,
capacity 1-2 GWh (4-8 h), round trip efficiency 70%
> Plans for demo plant suspended due to lack of business case
> Currently working on further improvement of system to facilitate
market entry. Explored options
– Downscaling to 10-30 MW aiming at more applications
– Hybrid-configuration (semi-adiabatic using natural gas)
> Use of Power-to-Gas-technology in
intermittent operation mode in the context
of renewable power generation
> Nominal electrolyze power 100 kW
Description
Central energy storage
Project

15. RWE Research and Development PAGE 15
Agenda
Current situation and upcoming challenges in Germany
Energy storage options
Conclusion
1
2
3

16. RWE Research and Development PAGE 16
Conclusion on energy storage
> Storage is just one solution to keep the energy system balanced
competing with other measures
> The regulatory frame is the main driver for short and midterm
profitability of energy storage systems
> In short and midterm the market for decentral energy storage
will grow dynamically due to the own consumption privilege
> Aggregation decentral energy storage can generate additional
services for the energy system potentially reducing the need for
central storage
> Further effort and success of R&D is necessary to reduce cost,
increase life-time and optimize characteristics.