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

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

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

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

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

Current Grid Architecture

Why Microgrids?

What is a Microgrid?

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

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

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

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

Water Transport: On Board Local DC Grid 1000 VOLT DC Power 20 MW 20% Energy Saving 30% Foot Print and Weight Reduction http://www05.abb.com/global/scot/scot293.nsf/veritydisplay/b4f3f099e9d21360c1257a8a003beac2/$file/ABB%20Generations_20%20Onboard%20DC%20grid.pdf

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

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

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

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

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

PV Manufacturer : 25 years Warranty http://us. sunpower Sun Power: 40 Years Useful Life (99 % of Modules will provide 70 % Power) Inverters: 10-15 years warranty http://us.sunpower.com/sites/sunpower/files/media-library/white-papers/wp-sunpower-module-40-year-useful-life.pdf

PV and Battery Cost Reduction Leading to DC Networks http://www.greentechmedia.com/articles/read/why-moores-law-doesnt-apply-to-clean-technologies?utm_source=Solar&utm_medium=Picture&utm_campaign=GTMDaily

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

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

Standards Organizations working to Advance DC EMerge Alliance © 2013

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

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?