Renewable Electricity for Minnesota’s Future
Xcel Renewable Development FundAdvisory Group Presentation
December 12, 2017
Project funding provided by customers of Xcel Energy through a grant from the
Renewable Development Fund
Agenda
• REMnF Project Overview
• Project Presentations
• Questions
Impact• 20 articles published or under review in scientific journals
o 12 in 2017
• 37 presentations nationally and internationallyo 27 in 2017
• 2 patents filedo 1 in 2017
• 27 people employedo 16 student RAs, 5 post-docs, 5 PIs
• Commercialization Effortso Value Design Proposition Workshop through the Office of Technology
Commercialization
Funding
Total Budget Total
Disbursed
Expenses Encumbrances Unencumbered
Expenses
Total
Expenses
$3,000,000 $3,000,000 $846,594 $230,739 $615,855 $1,077,333
Project Funding Start Date: 5/30/2016
Advisory Board
Renewable Electricity for Minnesota’s Future
First Name Last Name Position Organization
Nina Axelson Vice-President, Public Relations Ever-green Energy
Bill BlazarSenior Vice-President of Public Affairs
and Business Development MN Chamber of Commerce
Dan King Program Director Midwest Renewable Energy Tracking System
J. Drake Hamilton Science Policy Director Fresh Energy
Paul LehmanManager of Community Energy
Partnerships Xcel Energy
Laureen Ross-McCalibManager, Resource Planning and
Regulatory Affairs Great River Energy
Rolf Nordstrom President and CEO Great Plains Institute
Kelly Schwinghammer Executive Vice-President BlueGreen Alliance
Will Seuffert Executive Director Environmental Quality Board
Doug Shoemaker Vice-Chairperson MN Renewable Energy Society
Kaya Tarhan Chief Development Officer SolarStone
David Russick Founder Gopher Angels
Projects
• Richard James & Bharat Jalan: The direct conversion of heat to
electricity using fast switching of ferroelectric oxides
• Chris Leighton: Pyrite FeS2: A Low-Cost Earth-Abundant Photovoltaic
Solution for Renewable Electricity in Minnesota
• Lian Shen: Simulation, Measurement, Modeling, and Control of Wind
Plant Power
• Ned Mohan: Research on Power Electronics and Control: Grid-
Interface for Renewables, Storage and Green Micro-Grids
University of Minnesota
Driven To Discover
Introduction
Senior Personnel
The direct conversion of heat to electricity using fast switching
of ferroelectric oxides
Prof. Richard James, Aerospace Engineering and Mechanics, UMN
Prof. Bharat Jalan, Chemical Engineering and Materials Science, UMN
Post Doctoral Fellows
Graduate Students
Dr. Ryan Haislaier, PhD from Penn State, December 2016 – December 2017 (to Intel)
Dr. Paul Plucinsky, PhD from Caltech, September 2017 – present
Dr. Ashley Bucsek, PhD from Colorado School of Mines, starts on January 2018
Ms. Hanlin Gu, 4th year
Mr. William Nunn, 3rd year
Supported by Xcel Energy - Renewable Development Fund
University of Minnesota
Driven To Discover
Sources of heat at small temperature difference
n Waste heat rejected in exhaust systems of automobiles, and power plants
n Waste heat from air conditioning systems*
n Waste heat from laptop and desktop computers and
supercomputer clusters
n Handheld electronic devices (phones, videogames),
watches, stand-alone sensors
n Major environmental sources: solar thermal plants, temperature difference between
air and sub-ice water in winter, accumulate heat in attics in summer
*Collaboration with Daikin Applied, 13600 Industrial Park Blvd., Plymouth, MN
A strategy for
minimizing
hysteresis
(λ2 to 1). Near
zero hysteresis
demonstrated
Key technological breakthrough
Thin film
devices:
chip level
integration
University of Minnesota
Driven To Discover
Objectives and progress
To develop energy conversion devices based on phase transformation in ferroelectric films
through the establishment of molecular beam epitaxy (MBE) growth and the computational
design.
Key Idea:
Deliverables• Development of an Oxide Film with a λ2 = 1 Interface
• Development of a Switch
• Modeling of Thermo-Electro-Dynamics of Ferroelectric Energy Conversion
• Construction and Testing of a Prototype
• Scale-up
No separate
electrical generator:
the material itself
generates electricity
Achievements 2017:
MBE growth of high quality ferroelectric films achieved
Phase pure epitaxial BaTiO3 film on SrTiO3 (001) substrate
Smooth surface morphology from the atomic force microscopy
Development of a predictive model of ferroelectric energy conversion
Demonstration of ferroelectric energy conversion
Demonstration: voltage (blue) temperature (red)
University of Minnesota
Driven To Discover
Outreach and plans
X-ray data from high quality ferroelectric
BaTiO3 film made using hybrid MBEPlans for the coming year
n Develop demonstration using grown BaTiO3 films
n Do extensive predictions using the recently developed computational model to guide device design
n Develop next generation demonstration using recently grown high quality films
n Continue intellectual property development with OTC
n Investigate the design and development of a thermal switch
Intellectual property and commercialization
n Early Commercial Assessment and literature search
done by OTC (ROI20160206, Avishek Mishra, Xu Zou)
n Provisional patent filed (20170206): The direct conversion
of heat to electricity using phase transformations in
ferroelectric oxides
n Marketing webpage developed by outside firm
n Graduate student Hanlin Gu took the Minnesota Innovation Corps
Course on Value Design Workshop, and contacted local companies
n Widely distributed publicity on our method (James gave Golden
Medallion Lecture in CSE, Timoshenko Lecture at Stanford; Jalan
gave technical lecture on heat recovery at ARPA-E)
Pyrite FeS2: A Low-Cost Earth-Abundant Photovoltaic (PV)Solution for Renewable Electricity in Minnesota
Xcel Energy RDF ProjectUniversity of Minnesota, Institute on the Environment
Prof. Chris Leighton, Prof. Eray AydilDepartment of Chemical Engineering and Materials Science
Prof. Laura GagliardiDepartment of Chemistry
Partners: (tenK Solar Inc.), Physical Electronics Inc.
Project Team
Chris Leighton(Chem. Eng. & Mat. Sci.)
electronic materials
Laura Gagliardi(Chemistry)
theoretical chemistry
Eray Aydil(Chem. Eng. & Mat. Sci.)
solar cells
(TenK Solar: Bloomington-based commercial solar installation company)
PHI (Physical Electronics): Eden-Prairie-based materials analysis company
Background / Motivation
Current PV market: Si, CdTe, CuInGaSe2 (CIGS)
Si builds on established technology, but requires costly, thick, crystalline wafers
CdTe and CIGS are thin film technologies, but require low abundance, toxic, costly elements
Grand challenge: High performance PV materials from earth-abundant, cheap, non-toxic constituents; wide-scale deployment of solar-to-electric power
The semiconductor FeS2 (pyrite, fool’s gold (!)) is a high-potential candidate:
> Outstanding abundance and cost> Extraordinary light absorption> Theoretical efficiency > 30 %> Current record: 2.8 %!!
GOAL: Remove barriers to FeS2 usage in solar cells
Progress Two known problems with FeS2:
> Doping uncontrolled, poorly understood
> Surfaces uncontrolled, poorly understood
Doping progress:
> First to resolve the “doping puzzle” in FeS2
(why are large crystals “n” and thin films “p”?)
> First to prove missing S atoms dope “n”
Surface progress:
> First comprehensive understanding of surfaceconduction
Significance:
> We can controllably “n”-dope. This is a world “first”
> We now have a route to the first “p-n homojunction” solar cell (see figure)
> Simplest route to an FeS2 solar cell (like Si); never previously possible
Upcoming publications
> Proof that missing S atoms “n”-dope FeS2
> Accompanying theoretical analysis
Develop a “p”-dopant:
> Mn, As, etc. being studied
> Alternative idea: P (see figure)
Proof-of-principle p-n homojunction solar cell:
> Single crystal; ion implantation
Thin film p-n homojunction solar cell
> Intellectual property
> Sputtered n,p films
> Sputtered solar cells
Future Plans
Research ProductsPublications:
Presentations: Bryan Voigt, Materials Research Society Fall Meeting, Nov 2017
Eray Aydil, 3M Technical Forum, June 2017Bryan Voigt, U of M IPRIME Annual Meeting, May 2017 Chris Leighton, Materials Research Society Spring Meeting, April 2017All participants, External Advisory Board Meeting, Jan 2017
Industrial Interactions: Extensive interactions with PHI (Physical Electronics, Eden Prairie)
> Scientific collaboration> Free access to unique instrumentation
Voigt, Moore, Manno, Walter, Aydil and Leighton, in preparation (2017)Ray, Voigt, Walter, Aydil, Leighton and Gagliardi, in preparation (2017)
ST. ANTHONY FALLS LABORATORYST. ANTHONY FALLS LABORATORY
SIMULATION, MEASUREMENT, MODELING, AND CONTROL
OF WIND PLANT POWER
Lian Shen – Director of St. Anthony Falls Laboratory (SAFL)Professor of Mechanical Engineering
Michele Guala – Associate Professor of Civil, Environmental, and Geo- Engineering and SAFL
Jiarong Hong – Assistant Professor of Mechanical Engineering and SAFL
Jeff Marr – Associate Director for Engineering and Facility of SAFL
Joseph Nichols – Assistant Professor of Aerospace Engineering and Mechanics
Peter Seiler – Associate Professor of Aerospace Engineering and Mechanics and SAFL
ST. ANTHONY FALLS LABORATORY
Project Overview
MotivationMajor roadblock to wind energy realizing its transformative potential: • Inherently variable nature of the wind; and • The associated challenges in integrating wind
resources within the power grid.
Goal• Predict and control wind plant power output
High fidelity simulations of wind plants
Dynamic reduced-order modeling of
flows in wind plants
Active power control to minimize variability in power
output of wind plants
Measurement in
SAFL wind tunnel
Measurements in EOLOS
and other stations
ST. ANTHONY FALLS LABORATORY
Velocity Field and Coherent Structures in the Near Wake of a Utility-scale Wind Turbine
Mechanical Engineering & Saint Anthony Falls Laboratory, University of Minnesota
130 m
ST. ANTHONY FALLS LABORATORY
ST. ANTHONY FALLS LABORATORY
ST. ANTHONY FALLS LABORATORY
ST. ANTHONY FALLS LABORATORY
ST. ANTHONY FALLS LABORATORY
Plan for the Next Year
1) High-fidelity wind plant simulations on extreme-scale supercomputers to predict wind plant performance and reliability at unprecedented levels of spatial and temporal resolution;
2) Validation of simulation through measurements in wind tunnel experiments with miniature turbines (wake interactions), and utility-scale wind turbine experiments (wake evolution at realistic Reynolds numbers) in the field;
3) Physics-based, dynamic reduced-order modeling informed by big data generated from numerical simulation and experiment measurement to enable accurate and efficient real-time forecasting; and
4) Development of an active power control strategy to minimize the variability of the power output of wind plants.
RDF Progress Summary
2017
Prof. Ned Mohan and Prof. Murti Salapaka
ECE, University of Minnesota
Overall Research focus
Enable integration of renewables into the grid using
Power Electronics. Key Focus Areas:
1. High-Power Multilevel Topologies for Utility scale
applications
2. Low-Power Topologies for domestic applications
3. Control schemes for advanced grid support features
~700V34.5 kV
10-20
kHz5-60 Hz60 Hz
• High-power interface for utility-
scale wind turbines
– Megawatt scale
– Output to MV level (34.5kV)
• Uses Modular Multilevel
Converters (MMCs)
– Modular design
– Fault tolerant operation
– High performance (low harmonic
distortion in output
– Higher efficiency
• Eliminates line-frequency
transformers
– Uses high frequency magnetics
– Compact, lightweight system
– Lower total cost
1. High Power Application
(Virtual)Lg
Progress Summary• Completed:
– New modulation scheme using double fourier
analysis for back-to-back operation (Presented at
NAPS, Sept 2017)
• In Progress:
– Real-time model development on OpalRT
– Inertial mode control and grid support functions
• Future Work:
– Model Validation
– Fault-ride-through and reactive power support.
1. High Power Application
• Low voltage domestic rooftop
solar interface
– Kilowatt scale
– Output to mains voltage (120VAC)
• Uses Integrated Magnetics and
coupled inductors
– Small size, compact design
– Low ripple in currents to improve
efficiency
– Wide bandgap devices for high
switching frequency and low loss
• Integrated Super-Capacitors for
short term energy storage
2. Low Power Applications
Integrated Magnetics based converter for Low Voltage (Domestic) applications
Progress Summary• Completed:
– Analytical modelling for Cuk-derived topologies
• In Progress:– Development of ultra-low ripple scheme
– Modelling and design of coupled magnetics based
converter
• Future Work:– Lab-scale hardware prototype
1. High Power Application
A Net load aggregation algorithm is
being developed to enable:
• Real time Implementation
• Low cost, distributed computational
devices
• Utilization of available and functional
part of the grid in case of a grid
destabilization event to support
critical loads / infrastructure
• Dispatching renewable generation in
a flexible manner
• Prioritization of available renewable
energy sources in the network.
3. Modelling and Control
Net Load Aggregation of Multiple Units
Sudden Grid
Destabilization
Event
• Interfacing of renewable generation
with non linear loads pose
challenges of large current total
harmonic distortion (THD) and
circulating currents.
• Virtual impedance shaping
methods are implemented to improve
THD and reduce circulating currents.
• Experimental validation to be
performed with 600 W inverters and
non-linear electronic loads.
3. Modelling and Control
Interfacing of low inertia DERs
Fig. Interface of two Inverter system
LIS : Local Inverter System
3. Modelling and Control
Interfacing of low inertia DERs: Results
Fig. Simulation studies for alleviating circulating current and improving THD
in presence of non-linear loads
Fig. (a) THD of 24.95% for grid current with non-linear
(b) THD reduction to 9.95% of grid current with virtual
impedance shaping
(a)
(b)
QUESTIONS?Lewis Gilbert – Managing Director / COO
Christov Churchward – Program Manager
environment.umn.edu