The roof top solar systems are becoming popular these days with the need for reliable power and reducing costs. Further, with recent trends to shift towards smart grids; a new system layout has been proposed which is based on the concept of DC micro grids

1. Integration of Solar Home Systems in
Smart Grids
Master Thesis Project
2011-2012
Brhamesh Alipuria
MSc Sustainable Energy Technology
TU Delft & TU Eindhoven (3TU). Netherlands

2. Overview
• Introduction
• Research Questions
• Designing the system
• System operation and verification
• Application and simulation
• Economic aspects
• Conclusions

3. Introduction
Power system
• Increasing Demand
• Aging Infrastructure
• Renewable Energy
• User Empowerment
• Transmission distances
Focus - Developing countries

4. Solar Home system
 Backup system
 Quick and Easy setup
 Developing technology
 Low maintenance
 Off grid applications
 Increasing market penetration

5. Overview
o Introduction
o Research Questions
• Designing the system
• System operation and verification
• Application and simulation
• Economic aspects
• Conclusions

6. Research Questions
• How can we interconnect Solar Home Systems to be
an integral part of the power system?
• How can such a system be
operated?
• Is the whole system
economically feasible?

7. Overview
• Introduction
• Research Questions
o Designing the system
• System operation and verification
• Application and simulation
• Economic aspects
• Conclusions

8. Smart Grids
Communication
Smart
Buildings
Future
Loads
Storage
(Fluke corporation)
Islanding
(Micro grids)

9. Home Energy Management System
Functions
• Charge controller and MPPT
• Power conversion
• Load management
• Smart Metering
• Safety
• ICT

10. Integration of SHS
Smart Grids
+
+
SHS
HEMS
System Design
Technology
Flexibility
Efficiency
Complexity

11. Case 1
Incorporation with utility grid without power exchange.
 Technology available
PV
Modules
 Easy to apply
Load
Private Battery
-
HEMS
Utility Grid
Battery
Usage is not optimum
High investment cost
-
Maintenance

12. Case 2
Incorporation without storage
and enabling power exchange with the grid.
 Low investment cost
PV
Modules
 Simple operation
HEMS
Utility Grid
-
System balancing
-
Load
Integration of RES
-
No flexibility

13. Case 3
Incorporation with communal storage
and power exchange with grid
 Balancing of system
PV
Modules
 Integration of RES
 Community battery
Load
HEMS
Battery Bank
Utility Grid
-
Conversion losses
-
User flexibility

14. Case 4
Incorporation using DC network and communal storage
 High flexibility and reliability
 DC Network
+
+
-
DC Grid
Conversion efficiency
Power line communication
Electrical standards
Operational research
PV
Modules
Load
Load
HEMS
Utility Grid
Battery Bank

15. Evaluation of cases
Technology Flexibility
Case 1
Case 2
Efficiency
Complexity

x
x



Case 3
Case 4
Most
preferred
Least
preferred

16. System Design - Network
Micro-Grid Layout

17. System Design - Home

18. Overview
• Research Questions
• Introduction
• Designing the system
• System operation and verification
• Application and simulation
• Economic aspects
• Conclusions

19. Power Flow and Controls
HEMS
HEMS
Battery Bank
HEMS
Information
Bus
Solar PV
HEMS
HEMS
DC
Network
~
Generator
AC
Network
DC Load devices
HEMS
AC Load devices

20. Power Flow and Controls
Ddc
SOC
Pdc
η
ddc
~
Pg
η
Ldc
HEMS
Pac
Dac
Network Control
dac
User Control
Lac

21. Simulation
Matlab-Simulink model to simulate the grid design and control operation

22. Overview
• Research Questions
• Introduction
• Designing the system
• System operation and verification
• Application and simulation
• Economic aspects
• Conclusions

23. Application Scenario - 1
Reliable Grid – 2-3 hrs load shedding

24. Application Scenario - 2
Remote areas
Islanded mode

25. Application Scenario - 3
Unreliable network (12-18 hrs power cut)
Semi – Electrified villages

26. Application - Simulation
Matlab-Simulink model to simulate the effects of application of the system

27. Case Study Scenario
• Location: New Delhi
• No. of Houses: 30
• Timings: Average winter day
• Solar capacity: Total of 15kWp
• Storage Capacity: Total of 100 kWh (75A @ 48A)
• Pmax for the grid: 8kW
• Pmin for the grid: 5kW (case 1) and 4kW (case 2)

28. Case Study - 1
Fig. 1: Input to the simulation with solar
insolation, DC load and AC load for an average
day (24hrs).
Fig. 2: Output showing grid response, Alert signals
and SOC of batter during the 24 hrs simulation.

29. Case Study - 2
Fig. 1: Input to the simulation with solar
insolation, DC load and AC load for an average
day (24hrs). Here the net load was divided
between AC and DC loads.
Fig. 2: Output showing grid response, Alert signals
and SOC of batter during the 24 hrs simulation.

30. Advanced system option
• Integrating RES at grid level (AC and/or DC)
• Power exchange between SHEMS
• Local energy storage
• Resource allocation within the system
• Forecasting controls
HEMS
• Controls based on economics
HEMS

31. Overview
• Research Questions
• Introduction
• Designing the system
• System operation and verification
• Application and simulation
o Economic aspects
• Conclusions

32. Business Case

IDEA
“Sustainable and Reliable power network, empowering the user”
Research
Key Components :
o
o
o
o
Network Provider
User
Products
Services
Marketing
introduction
Expansion
and Extension
• Market survey
• Product Development
• Procurement of products
• Network setup
• Sales and Marketing
• Expand network
• Increase system size

33. Stakeholder Map
Communications
companies
Battery banks
Activist
Power plants and Grid
Financial
Community
Network
Operator
Governments
‘Prosumer’
Electric
Vehicles
SHS and HEMS
Companies
Loads

34. Overview
• Research Questions
• Introduction
• Designing the system
• System operation and application
• Economic aspects
o Conclusions

35. Conclusions
 Technical Design





Smarter, Reliable Grid
Caters to the future need
Easy integration of Renewable resources
Modular system and can be extended
Applicable in various scenarios
 Economic Feasibility
 Decreasing payback period
 Feasible business case

36. Future Research

DC Technology (standardization and operation)

Simulation of network

System expansion with other RES

Bulk storage technology

User influence on network operations

Social aspects of such a system

Business cases investigation in detail

37. Just the beginning ……..
Thank You
DC Micro-Grids
Brhamesh1@gmail.com