David Campi Aragon Energy Storage

SUPERCHARGER WITH AN AUXILIAR

ENERGY STORAGE SYSTEM

STUDENT: David Campi Aragon

TEACHER: Álvaro de Gracia Cuesta
David Campi Aragon Energy Storage

INDEX:
1. Introduction
2. Description of the system
3. Baseline
4. Description of the supercharger component
5. Analysis of the data
6. Benefits and advantages
7. Conclusions
David Campi Aragon Energy Storage

1. Introduction
In a world where sustainable mobility is a priority, electric vehicles are becoming an
increasingly popular choice. However, one of the fundamental challenges faced by electric
vehicle owners is the availability of fast-charging stations that can meet the growing demand.
With the aim of addressing this need, we present the project of an electric vehicle
supercharger that uses a high-power energy storage system for charging, and the central
focus of the project is the dimensioning of this energy storage system.

The primary goal of this project is to design and dimension an efficient and powerful energy
storage system that enables fast charging of electric vehicles. This energy storage system will
serve as a reliable and high-capacity power source, delivering energy as needed to meet the
charging demands of electric vehicles.
The dimensioning of the energy storage system will be done considering several factors, such
as the required discharge power for fast charging, the necessary storage capacity to support
multiple charges, and the overall energy efficiency of the system. The charging needs of
electric vehicles and energy consumption patterns will be evaluated to find the best size and
characteristics of the storage system.

The use of a high-power energy storage system in the supercharger will reduce reliance on
the electrical grid during peak demand periods, thereby alleviating the strain on existing
infrastructure and supplying a fast and efficient charging experience for electric vehicle
owners.

The chosen location for the supercharger station is the service area in Lleida along the AP2
highway, as it strategically lies between Barcelona and Zaragoza. This placement offers a
convenient and accessible charging point for electric vehicle drivers traveling along this major
route. The service area in Lleida also provides ample space to accommodate the supercharger
station and the battery container, ensuring efficient operations and ease of installation. By
setting up the supercharger station at this location, it enables drivers to conveniently charge
their vehicles, minimizing range anxiety and supporting the adoption of electric vehicles in
the region. Furthermore, the strategic positioning of the station along a popular highway
contributes to the development of an EV charging infrastructure that connects major cities,
promoting sustainable mobility and reducing carbon emissions in the transportation sector.
Finally, an economical study will be offered to the company that owns the supercharger to
show the benefits of installing an energy storage system.
David Campi Aragon Energy Storage

2. Description of the system

At the core of the system is the energy storage system, which consists of a set of high-capacity
batteries. These batteries are specifically designed to deliver fast discharge power and
sufficient storage capacity to supply the charging needs of multiple EVs before requiring
recharging.
The connection between the supercharger and the energy storage system is achieved through
a direct current (DC) configuration. This involves a direct connection between the
supercharger and the storage batteries, enabling efficient energy transfer without the need
for other converters. The DC connection ensures faster charging and reduces energy losses
during transfer.
Furthermore, the system incorporates an energy management and control system that
monitors and regulates the energy transfer between the supercharger and the storage
system. This allows for optimal energy management, ensuring efficient charging of EVs and
avoiding overloading or underutilization.
The high-power energy storage system offers several significant advantages, including
reduced demand on the electrical grid during periods of high charging demand, the ability to
fast charge multiple vehicles simultaneously, and a more convenient charging experience for
EV owners.
David Campi Aragon Energy Storage

3. Baseline
The system requires a power output of 120 kW to accommodate the charging requirements
of electric vehicles with a capacity of 60 kWh in just 30 minutes. The high-power rating is
essential to supply a rapid charging experience for EV owners, enabling them to charge their
vehicles quickly and conveniently. With a power output of 120 kW, the supercharger system
can deliver a substantial amount of energy in a brief period, significantly reducing the charging
time for EVs.

For this project it has been created a supposed flux of cars and with this flow, we have
obtained a total consumption for a busy day.
For the optimization of the system when there are two cars charging simultaneously the
battery will interact with the charger to charge them without using the net electricity and let
the company contract less maximum power.

This is the curve of power during the day with the highest use of the supercharger:

With this consumes it has been calculated the capacity of the battery considering the
efficiency of discharge and the efficiency of the tower charger that is 95%.

The battery will interact when a second car per hour is connected to the charging tower due
to this condition the regions from the figure coloured in green are regions where the battery
will deliver energy to charge the battery cars. The regions in yellow are where the battery will
be charged considering an efficiency of charge of 100%.
David Campi Aragon Energy Storage

Capacity needed:
C=E/(DoD*SoH)
Weekend:

E= 67.19-60+67.19-20+134.38-40+67.19-20+67.19-20+67.19= 310.32 kWh

C = 310.32/ (0.8*0.96) = 404.07 kWh
Week:
E= 67.19-60+67.19+67.19+67.19-60+67.19= 215.95 kWh

C = 215.95/ (0.8*0.96) = 295.98

After the calculation of the capacity needed for the battery, it has been decided to take a
battery of 300kWh due to the energy in the weekend is less expensive than during the week
and the cost of buy a bigger battery is extremely high.

The chosen energy storage technology for this project is lithium iron phosphate (LiFePO4)
batteries, as they are the most common and offer a reasonable balance between quality and
price. LiFePO4 batteries have gained popularity in the industry due to their excellent
performance characteristics, including high energy density, long cycle life, and enhanced
safety features. Their stable chemistry minimizes the risk of thermal runaway or fire incidents,
ensuring a reliable and secure energy storage solution. Additionally, LiFePO4 batteries show
a good power-to-weight ratio, making them suitable for high-power applications such as fast
charging in the supercharger system. Overall, the choice of LiFePO4 batteries supplies a
robust and cost-effective energy storage solution for efficient and sustainable electric vehicle
charging.
To do these calculations it has been considered an efficiency of discharge of 95%, an SoC
range of 80% due to the battery goes from 10% SoC to 90%, a 96% of SoH and finally an
efficiency of the charger of 94%.
David Campi Aragon Energy Storage

4. Description of the Supercharger components

For the energy storage system, it has decided to install a battery from the company Ecube.
This company offers lots of types of batteries, but it has been decided to obtain a lithium
battery container. The group of batteries that are formed by 96 pcs of cells of 3.2V and
50Ah, and these are the specifications of the battery:

Model GRES-300-200
Battery type Lithium iron phosphate
Total power (kWh) 307.2
Max output power (kW) 220
DoD 80% (10%-90%)
Efficiency 95%
SoH 96%

Components of the battery:

- This battery has integrated all the systems needed to make use of it with the charger.
As we want to pass the electricity directly in DC this battery has a good advantage that
we can pass electricity by the DC/DC module. Also, it has an AC/DC module if we need
to use it instead of passing the current in direct way.
- As it can be seen in the system topology the battery container has a Static Transfer
Switch which can realize fast switching from on to off-grid state.
- A BMS is integrated in the battery to protect the battery from overcharge, over
discharge and overcurrent.
- A Power Management System, this system operation data monitoring is useful to do
an operation strategy management, has a historical data record, a system status
record, etc.
The battery will have a total cost of 100699,50€.

For the charger in this project has been chosen the Ultrafloox 150, this charge tower has a DC
output power of 150kW. This charged is sell by the company Flooxpower, which also it is a
company from Spain concretely from Barcelona. This charger has an inner efficiency in the
greatest point of 94%.

It’s important to say that this battery will be charged during the hours where the charger it’s
consuming 60kWh or when it’s not being used.
David Campi Aragon Energy Storage

5. Analisis of the data

Dimension:
- Battery: 2.4m x 1.54m x 2.3m
- Charger: 0.6m x 1.9m x 0.8m
Weight:
- Battery: 3170 kg
- Charger: 425 kg

Costs:
For the economic analysis, we will focus solely on the price of the battery as it was the primary
aspect under study in this project. The cost of the battery is a critical factor in deciding the
overall feasibility and financial viability of implementing the energy storage system. By
assessing the price of the battery, we can evaluate the initial investment needed for the
system and calculate the payback period or return on investment. Considering the price of
the battery allows us to make informed decisions about the cost-effectiveness of the project
and assess its potential profitability. Other factors such as installation, maintenance, and
operational costs will be excluded from this analysis, as the main goal is to figure out the
impact of the battery price on the financial aspects of the project.
As we have mentioned before the battery has a cost of 100699,50€ that could sound like too
much money but if the supercharger has a cost of use it this investment isn’t too high. Also,
we must consider the shipment costs that considering where does it comes from (China) these
costs can be considered approximately od 2500€.
The annual benefits derived from implementing this energy storage system are primarily
attributed to the reduction in contracted power. By effectively managing our power usage,
we have achieved significant cost savings. Specifically, we have realized an annual benefit of
9669.83€. This considerable amount can be attributed to the fact that our system operates
with a power factor of 0.99, which eliminates any costs associated with reactive power.
Additionally, we have avoided penalties for exceeding contracted power levels. This
combination of factors has allowed us to optimize our power consumption, enhance our
operational efficiency, and achieve substantial financial advantages.
Economic Payback = (investment) / (yearly savings)
= (103199,5€) / (9669,83€)
= 10,67 years
This payback can be afforded earlier if the company whose own the supercharger grow a little
bit the price of the kWh of charge for the customer in the previous years where the battery is
installed. For example, by the rise in the price of 0.01€/kWh the charger will earn 4564.2€
more per year lowing this payback to 7,25 years.
David Campi Aragon Energy Storage

6. Benefits and advantages

The system offers many benefits and advantages for electric vehicle charging. Firstly, it
provides a high-power charging solution, with a power output of 120 kW, enabling rapid
charging of EVs. This significantly reduces the charging time, providing convenience and
flexibility for EV owners on the go.
Secondly, the system incorporates a high-capacity energy storage system, exceeding 200
kWh, ensuring a reliable and consistent power supply for charging multiple vehicles. This
allows for a continuous and efficient charging experience, even during peak demand periods.
Moreover, the use of lithium iron phosphate (LiFePO4) batteries as the chosen energy storage
technology brings several advantages. LiFePO4 batteries offer high energy density, allowing
for compact storage solutions without compromising performance. Additionally, they have a
long cycle life and enhanced safety features, minimizing the need for frequent maintenance
and ensuring a secure charging environment.
Another key advantage is the strategic location of the supercharger station at the service area
along the AP2 highway. Positioned between Barcelona and Zaragoza, it serves as a convenient
charging point for travellers on this major route. The ample space available at the service area
allows for easy installation and scalability of the charging infrastructure.

Furthermore, the system supports the growth of electric vehicle adoption and contributes to
sustainability efforts. By providing fast and accessible charging, it reduces range anxiety and
encourages more people to transition to electric vehicles, thereby reducing greenhouse gas
emissions and promoting cleaner transportation.
In summary, the system's benefits include fast charging, reliable power supply, advanced
battery technology, strategic location, and support for sustainable mobility. Together, these
advantages make the system an ideal solution for efficient and convenient electric vehicle
charging, paving the way for a greener and more sustainable transportation future.
David Campi Aragon Energy Storage

7. Conclusions
In conclusion, the implementation of a battery in combination with the supercharger can be
a good option but nowadays and with the efficiency of this types of batteries it does not have
a plenty sense. But on the other hand, it can be very useful to stabilize the load curve and
contract less power energy returning some economic benefits.
Through careful analysis and dimensioning of the energy storage system, we have determined
that a power capacity of 120 kW and a storage capacity of over 300 kWh are necessary to
meet the demands of our charging station. This system allows us to provide efficient and
convenient charging services, reducing charging time and improving the overall user
experience.
Finally, we think that the payback time is somehow a little bit high which can suppose a bad
point for the owner of the project. But it’s important to measure up the good advantages that
it gives us such as the reduction in the contracted power, the type of batteries owned that
have a longer lifespan, lower self-discharge rates, and do not contain hazardous materials like
lead or cadmium and obviously by the using of the energy storage system in the project we
are doing an efficient energy storage.
David Campi Aragon Energy Storage

Annex

Acquire the battery: buy

Specifications of the battery: here

Charger specifications: here

Energy prices and schedules

The consumes considered and the different calculations can be found here