1. DC Microgrids The economic case for adoption
Secure energy solutions
Copyright 2016 Positive Energies, LLC

2. The New Electron Economy
Future of Civilized Progress is Based on Use of Electrons
Source: ABB – Innovations in DC Technology
EMerge Alliance © 2013

3. Of All Electricity Ever Generated – ½ Used in Last 15 Yrs.
Electron Use Climbs
Of All Electricity Ever Generated – ½ Used in Last 15 Yrs.
Source: ABB – Innovations in DC Technology
EMerge Alliance © 2013

4. Power Conversions Take Their Toll
Efficiency, Complexity, Reliability, Cost
Source: ABB – Innovations
DC Technology
EMerge Alliance © 2013

5. Sources & Loads Continue Moving To DC
Power Electronics & Electronic Equip. Drive Power Architecture
Source: ABB – Innovations in DC Technology
EMerge Alliance © 2013

6. Current Grid Architecture

7. Why Microgrids?

8. What is a Microgrid?

9. From Smart Grid to Microgrids
Balancing the Renewable Power Equation
Smart Meters
Generation
Transmission Distribution
Smart Buildings
Closing the Loop with Microgrids
Smart Homes
Why Microgrid Energy?
Increase renewable energy availability
Improve, reliability & independence / security
Improve availability in underserved markets
Create open environment for energy innovation
Local Energy Storage
Local Generation
Slide Courtesy of Intel Research Labs
© 2011 EMerge Alliance

10. Zero Energy Buildings (ZEB)
A ZEB driven network will look much like the Internet
National Grid
Entire Power Network
Generation Storage Communications
Smart Grid
Regional Grid
MACROGRIDS
Sensors Computation
Public Utilities
Distribution Grid
Generation Storage
ENERNET
Community
Communications Sensors Computation
Building Microgrid
Generation Storage
Smart Building
Campus
Communications Sensors Computation
Room Microgrid
MICROGRIDS
Building Layer
Generation Storage Communications Sensors & Devices
Room/Floor Layer
Bi‐directional power exchange
Electrical Devices
EMerge Alliance © 201‐ 3
Smart Grid
Smart Building

11. Electronic Digital Data Base
Internet: Information Technology Convergence
A Standardized Common Platform Was Key
Words Languages
Images Video
Ink Paper
Photo Chemical
Electronic Digital Data Base
Mechanical Registers
Magnetic Tape
Math Accounting
Voice Sounds
EMerge Alliance © 2013

12. Power Technology Convergence
Solar
Fuel Cell
Non Synchronous DC
Non Synchronous DC
DC STORAGE
& DISTRIBUTION
Non Synchronous AC or DC
Synchronous AC or DC
Wind
Turbine
EMerge Alliance © 2013

14. Water Transport: On Board Local DC Grid
1000 VOLT DC Power
20 MW
20% Energy Saving
30% Foot Print and Weight Reduction

15. Status Quo DC DC AC AC AC AC AC AC Common Building Loads (80%DC)
Typical
Conversion
Loss
VFD AC DC
4% to 8% Loss
4% - 8%
2% to 10% loss AC DC
AC Bus
12% to 20% loss AC DC AC DC AC
Present electrical power use is centered around connection to the AC grid, then distribution of AC power throughout a building.
If you use renewable energy, which produces power in DC form, this power must then by AC. This produces a conversion loss.
If you use a battery energy storage, you would endure 2 sets of conversion losses as shown.
Then, as you connect to the load, (80% of which are DC devices), you must then convert the AC to DC producing another conversion loss. AC DC
15% to 20% loss
AC Grid
4% to 8% Loss
4% to 8% Loss AC DC
DC storage
3% to 10% loss

16. A Better Way DC DC DC DC AC DC AC DC AC DC Microgrid Technology
DC / Semiconductor Based Loads DC
VFD DC
2% to 5% loss
0% loss
2% to 5% loss AC DC
DC Bus
3% to 6% loss
AC Grid DC
3% to 5% loss AC DC
Higher Efficiency
Minimal Conversion Loss
Lower Operating Expense
Safer
Fewer Components
More Reliable
Less Real Estate
Reduced Carbon Footprint
3% to 6% loss DC
0% to 2% loss AC DC
DC storage
1% to 5% loss

17. 380V DC as Microgrid Backbone
380V DC power bus as the common aggregation for multiple energy
sources
Grid AC power converted to 380V DC
Input from larger solar arrays at 380V DC
Potentially energy storage at 380V DC
Distribute 380V DC across distances, reducing cabling required
Convert from 380V DC to 24V DC near point-of-use
Some major building loads, such as lighting, can be powered by 380V DC directly
Energy Sources
Solar PV
Wind
Battery
Storage
Gen
Set
Fuel Cell Other
Utility Meter
MPPT
Wind Cont.
380VDC
Converter
Facility Power Server and Common Distribution / Collector (380VDC) Bus
Lighting
Loads 24V /
380VDC
Plug Loads 24VDC EV
Charger 380VDC
HVAC
Loads 380VDC
Electronic Loads 380/24VDC
Telecom
-48V / 380VDC
Data Center 380VDC
Electrical Loads

18. Electric Generation Electric Storage Plug Strips Connectors
The Eco-System for DC is rapidly Building A
Systems Portfolio
Power Power Servers MPPTs
Solar Arrays Wind Turbines
Electric Generation Electric Storage
Infrastructure
Cabling Ceiling Grids Bus Bars
Powered Ceiling Grid
Plug Strips Connectors
Peripherals
Light Fixtures A/V Equipment Security Cameras Window Shades VAV Actuators Wireless Repeaters
Controls
Motion Sensors Occ. Sensors Photo Sensors Dimmers Lighting Controls Room Controls Thermostats
Basic System Components

19. DC for Building Services
AC Motor applications are moving to AC/DC Variable Speed Drives
DC DRIVES MAY BE BETTER BECAUSE.
DC drives are less complex with a single power conversion from AC to DC.
DC drives are normally less expensive for most horsepower ratings.
DC motors have a long tradition of use as adjustable speed machines and a wide range of options have evolved for this purpose:
Can provide a wide speed range at constant torque.
Accessory mounting flanges & kits for feedback tachometers and encoders.
DC regenerative drives are available for continuous regeneration for overhauling loads. Similar AC drives are more complex and expensive.
Properly applied brush and commutator maintenance is minimal.
DC can provide starting & accelerating torques in excess of 400% of rating.
AC drives may produce undesirable audible noise in some applications.
Photos courtesy of
BLDC motor use is up: higher efficiency & torque, better articulation, increasing availability.
EMerge Alliance © 2013

20. PV Manufacturer : 25 years Warranty http://us. sunpower
Sun Power: 40 Years Useful Life (99 % of Modules will provide 70 % Power)
Inverters: years warranty

21. PV and Battery Cost Reduction Leading to DC Networks

22. Customer value of DC Micro/Nanogrid
Creates a Mesh Network Power System
Low Voltage DC is inherently safer
Power delivery is highly distribute
Renewable Generation feeds storage and loads allowing for optimization of size
Stabilizes long term cost of power
Immediate reduction in energy usage use of 20% or more

23. Additional Cost Considerations of Local DC Power
More than 50% of the cost of an LED light is in the inverter
Elimination of Power Factor
Inverters add cost and system losses while reducing system reliability
Based on DC, PV system cost is reduced by about 20%
In addition to cost savings, PV systems based on DC are more reliable
Batteries, and capacitors, store dc power. AC power increase the cost of batteries (as much as 50% in some cases)
DC use increases the competitiveness of manufacturing industry and saves jobs Energy cost is as great as 33% of the operating cost of a manufacturing plant

24. Standards Organizations working to Advance DC
EMerge Alliance © 2013

25. Applications of DC Microgrids
Devil’s Thumb Ranch Ecovillage
Ernesto Cortissoz International Airport (BAQ)
DC Microgrid with solar, batteries, and DC transition of loads
Operational guest ranch in Winter Park, Colorado
Islanded operation
2.5MM customers per year international airport in Barranquilla, Colombia
No grid connection because of economics
4MW, 3MWh battery storage
MEGs on critical loads

26. C-PACE as an Enabler of DC Microgrids
Federally supported financing program
Assesses the potential for a cash positive energy upgrade at a commercial facility
No cap ex to the business owner
Stays with the building
Verified by an independent third party (technically, financially)
What can you do?