© Q3 Energieelektronik GmbH Page 1 Monitoring and Operation of PV-Battery Systems Daniel Föhr, M.Eng. Product Manger Energy Systems Q3 Energieelektronik

© Q3 Energieelektronik GmbH Page 1

Monitoring and Operationof PV-Battery Systems

Daniel Föhr, M.Eng.

Product Manger Energy Systems

Q3 Energieelektronik GmbH


Content

The QBEE Energy System

Determine load profiles

Recording methods and quality of load profiles

Requirements of intelligent PV-battery systems

Advantages of monitoring PV-battery systems

Outlook – From PV to Smart Grid


QBEE – The Energy System

Maximum usage of own PV energyby minimal purchased power

For new installations

For existing installations

State of the art lithium-ion technology

Compact and powerful


Setup and components of the QBEE Energy System

1.5 kW bidirectional inverterSuitable for photovoltaic and wind energy with integrated charge controller and energy management

BatteryWith integrated battery management systemwith 2.0 / 4.0 / 8.0 kWh

Grid SensorMonitoring the input and reference power of all thre phases


QBEE as DC/AC coupled system

Installation as a retrofit for an exisiting system or with an additional PV generator.In this case the battery can be charged via the DC input and/or over the AC connection.


Determine of load profiles

Determine of the load profile is essential for the battery system layout

The layout of the ideal PV generator and the matching storage capacity for each individual household gets more and more complex

Do not store more than necessary!

Oversized batteries can rarely be exploited

Unused capacity increase costs per kW

The base load capacity determines the storage capacity


Consumption behaviour

During the day almost never at homeConsumption mainly at night. At daytime long time to charge. High storage potential, no large-scale PV generator needed

Partially workingConsumption is distributed relatively evenly. Tuned mix of PV and Battery

Family with childrenConsumption is highest during the day. Less excess energy available for loading. Large PV generator for natural self-consumption

1

2

3

Consumption behavior can be divided into categories


Determine of load profiles

QBEE GridSensor

Inductive power measurement of all three phases.

No separation of the lines needed.

Easy DIN rail mounting in the meter cupboard.

Ideal for determining an accurate statement:

One year measurement with a time resolution of 1 second and irradiation data


Standard load profile

00:0000:45

01:3002:15

03:0003:45

04:3005:15

06:0006:45

07:3008:15

09:0009:45

10:3011:15

12:0012:45

13:3014:15

15:0015:45

16:3017:15

18:0018:45

19:3020:15

21:0021:45

22:3023:15

0

50

100

150

200

250

Standard load profile H0 for households in winter (BDEW)

Mo - Fr Saturday Sunday

Time

Lo

ad

in W

att

s

Example of a standard load profile (H0) with average values of 15 minutes

So

urc

e:

BD

EW


Individual load profile

Example of an individual load profile with pulsed loads in a temporal resolution of 1 second


Alternative method – consumption behavior by consumer groups

▪ On the basis of the yearly load consumption a standar load profil is scaled

▪ Merge into main consumer groups

▪ Determine of percentage weighing and tempral distribution

▪ Accuracy of +/- 10%


Advantages of Monitoring PV-Battery Systems

Requirements:

Fast acting battery system and cell technology

Communication interface between EMS and BMS

Interface for external variables

Interface for Demand Site Management

Bidirectional communication link for external


Battery System with Forecasting

EMS

BMS

Forecasts

Generator andload models

Load profile forbattery system

Battery model

SOC forecast

Communication interface between EMS and BMS

Weather forecast/Market price prediction

Forecast and determineof load profiles

Optimized operation of battery management

SOC prediction independence on loadprofile forecast


Dynamic control of EEG regulations

Dynamic 70 or 60%regulation according to the EEG considering:

Entire house load

AC-coupled battery system as an intelligent load

Additional access load


Demand site management

Excessive energy consumers:e.g. white goods, hot water don‘t need to be supplied by the battery system

Monitoring of PV-Forecast

Deposited load profile

Link with Home Automation

System

Shift consumption in peak

PV production time

Increase natural

self-consumption

Relief of public grid and battery


Purchase and Sale of Electricity

PV electricity can be offered profitable outside the EEG market regulations.

In combination with battery, monitoring an forecasts:

Determine excess energy/demand

Supply security for the time period

Voltage stability in case of short-term weather changes

PV systems can combine to generate a virtual power plant and use their backup capacity for short term trading at the EEX.

Source: Solarworld


Offering balancing energy

Based on the monitoring data also unused storage capacity can be identified

Receptive systems can have a positive effect on the grid by providing balancing energy: If they are able to obtain and delivery energy in times of grid overload.

In combination with a bidirectional connection a lucrative market model for the expiring EEG.

E.g. municipal utilities are eagerto regulate their power withintheir own grid.

PV-battery systems can alsoact as a virtual power plant

Source: next-kraftwerke.de

Short term trading with virtual power plants


Conventional Storage

Conventional storage has no relief effect for the public grid

Maximum feed-ininto the grid

Charge till battery is full

Consumption of PV electricity

Peak production goes directly into the grid

Source: BSW


Grid optimized charging

Charge when much electricity is generated

Reduced feed-in into the public grid

Low feed-in power increases local grid capacity

Combinded with an PV forecast the battery systems can contribute to:

Regulating the voltage on local low voltage grid

Regulating the frequency in the whole European grid

Source: BSW


Outlook – From PV to the Smart Grid

PHOTOVOLTAIC

Feed-in

70% Regulation/Load management

Power Balancing/Reactive power control

Supervision & Control

SMART GRID

Intelligent purchase and sale of electricity

Supply of positive and negative control power

Load Management (E-Mobility Devices)

SMART HOME

Energy management

- Energy saving

- Intelligent energy distribution

- Demand site management

Link with Home Automation System

Emergency supply

Hot water preparation

Quelle: www.tret.net


Q3 Energieelektronik GmbH & Co. KG

Daniel FöhrProduct Manager for Energy Systems

Marktplatz 4888400 BiberachGermany

Mail [email protected] www.q3-energieelektronik.de

Thank you for your attention

Documents

© Q3 Energieelektronik GmbH Page 1 Monitoring and Operation of PV-Battery Systems Daniel Föhr, M.Eng. Product Manger Energy Systems Q3 Energieelektronik