1.4. Emerging Microgrid Use, Applications, and Opportunities_Barr_EPRI/SNL Microgrid
Understanding the Definitions and Defining Microgrid ...
Transcript of Understanding the Definitions and Defining Microgrid ...
• Understanding the Definitions and
Defining Microgrid Language
• Deploying Microgrids
• Lessons Learned and Success Factors
• Additional Resources
Section 1 - Microgrid OBJECTIVES
What is a Microgrid?• Microgrids are defined by their function, not their size
• Independent Energy Systems
• Key components:
– Generation
– Control
– Distribution
– Storage
– Load
• All linked together in a network, they can operate as an
isolated mini-grid or interact with the utility
Image courtesy ZBBEnergy.com
Microgrid-enabling technologies
• Distributed Generation (DG)
• Islanding Inverters
• Smart Meters
• Distribution Automation (DA)
• Substation Automation
• Microgrid Control Systems
• Smart Transfer Switches
• Advanced Energy Storage
Securicon, LLC
Types of Microgrids
• Off-Grid Microgrid
• Campus Microgrids
• Community Microgrids
• Nanogrids/Picogrids
Kenya
Tanzania
Cape Verde
AC Coupled, DC Coupled and Hybrid
Solar Microgrid Configurations
University microgrid feasibility study in Ghana - 2015
AC Coupled
The storage inverter controls battery charging/discharging
Pros Cons
Improved conversion efficiencies Typically more expensive
Simplified serviceability and system
monitoringLarger physical space requirements
Easier to isolate the storage system
for troubleshooting
System control can be harder with
two inverters
AC Coupled
DC Coupled
Power flow from both the battery & utility ports
is bi-directional
Pros Cons
Can reduce material and labor costs Harder to find and source products
Generally more compact (Physical space) Lack of functionality
Simpler design & can provide performance
benefitsNo revenue grade meters available
DC Coupled
Hybrid
Integrates additional generator(s) – AC or DC coupled
Pros Cons
Reduces energy storage capacity
requirementsCost of Diesel or other fuel
Extended days of autonomy Generator Maintenance
Increase overall system reliability
and resiliency
Increased complexity = more
complex commissioning and
troubleshooting
Hybrid
Engineering/Design Considerations
• Energy Storage
• Site Evaluation
• Design Calculations
• Point of Connection
• Backup Loads
• Sequence of Operations
• Safety
EarthSpark Microgrid - 93kw PV in Haiti
System capabilities
– Stacking
– Control System
Microgrid distribution infrastructure in Les Anglais
Managing Customer Expectations
Economic performance
– Costs of operation
– Life expectancy of components (Batteries)
1st Technical Step in Deployment…
• Project screening and
Rapid Assessment
Sensitivity analysis helps point to where more data is
needed
Microgrid Engineering Optimization
• Calculates the total lifetime system cost
– Installation costs
– Operation and Maintenance costs
– Replacement costs and salvage value
Fits all the pieces together
Peter Lilienthal, Ph.D.
Additional Resources
Case Studies and Tools Mini Grid Policy Toolkit*
http://minigridpolicytoolkit.euei-pdf.org/downloads
http://minigridpolicytoolkit.euei-pdf.org/policy-toolkit
Resources
Sunny Island SMA Microgrid Video
http://microgridknowledge.com
http://www.microgridinstitute.org
• Overview of Haitian Context
• Discuss EarthSpark Model and History
• SparkMeter™ and Evolving Models
• Pre-Payment System and Tier system
• Challenges – Theft*
• Lessons Learned and Success Factors
Section 2 – EarthSpark Objectives
Haitian Context• In Haiti 75% of households lack access to electricity
• Households spend an
average of $10/month* on
kerosene and candles
and $4/month on cell
phone charging
* Approx. 6.5% of annual income on household lighting
Haiti’s National Electric Grid
• Owned by Electricitè d’Haiti (EDH)
– Poor infrastructure and maintenance
– Old and deteriorating equipment
– Power is primarily produced by diesel and HFO
generators
• Unstable network
– Outages are frequent and often unscheduled for the small
percentage of the population that has access to the
national grid
Haiti’s National Electric Grid
Between 2002-2003,Haiti suffered from a total loss
rate of 53.6%1 (Including technical and non-technical losses).
Theft of electricity is also a major problem in Haiti –
In 2002, approx. 64% of utility electricity produced
was unmetered!
Source: Ministry for Public Works, Transportation and Communications
Mission: to eradicate energy poverty
Method: R&D on business models that can
spin off and scale
EarthSpark International
Energy Access market segmentation by location
and consumption Central Grid
Grid Extension and Infill
Microgrids and captive storage
Stand-alone-systems
(small and large)
• Pre-Payment – Allows customers to purchase
electricity as they purchase kerosene – in small
quantities as needed.
• Deep Efficiency – Begins with locally available
appliance options
• Accompaniment – Value chain and clean energy
products
“Integrated Rural Electrification”*
“Building Clean Energy Access”
EarthSpark Model
Clean Energy Retail
Haitian Social Enterprise
• Small-scale Solar
• Portable Solar Lighting
• Efficient Cookstoves
With a national network of over 100 retailers
EARTHSPARK INTERNATIONAL
Haiti’s first prepay microgrid
‘The country’s only 24/7 source of
community electricity’
EARTHSPARK INTERNATIONAL
• 93 kW of PV
• 450 kWhs of Battery Capacity
• 30 kVA Diesel Backup
Microgrid Timeline – Stage 1
201214
CustomersPowered by Spare
Diesel Generator
Microgrid Timeline – Stage 2
201354
CustomersPowered by Spare
Diesel Generator
Microgrid Timeline – Stage 3
2015440
Customers
Powered by Solar PV,
Battery Bank and
backup Diesel
Generator
LOW Cost, HIGH Functionality
Smart Meter
SparkMeter™
• Pre-payment – Enables cost
recovery and payment
assurance
SparkMeter™ System
Consists of four major
components(under development)
• INDIA
– 150 households spread over several kilometers
• NEPAL
– 83 households, 25 micro-enterprises and 2 cell towers
(3 separate microgrids dozens of kilometers apart)
• TANZANIA
– Pilot microgrid by E.ON Off Grid Solutions with 20
current customers
• HAITI
– 440 customers on a single microgrid
http://energyaccess.org/news/recent-news/sparkmeter-brings-smart-grid-functionality-to-underserved-utility-customers/
Current SparkMeter™ Installations
SparkMeter™ Features
• Time-of-use pricing
• Load limiting
• Flat rate or block rate
• Monthly plan option
Tiered Load Limiting System
Anchor: > 600 W
Gwo Bagay: 600 W
Freezer: 360 W
TV: 120 W
Limye: 30 W
5 Levels
• 65% are using Limye
(light in Haitian Creole)
• ABC Model – Anchor, Business, Community
Time-of-use pricing
• The tariffs are based on time of day
• Large customers pay less per kWh
Approx. 34¢ - 60¢ per kWh (USA)
• Higher cost at night to incentivize customers
Additional Features…• Monthly Plan – defines
the minimum that a
customer must spend
• If customers don’t spend
the minimum they go
down a level…
• Load Limiting – The
operator can define a
limit between 2W and 4.8KW
• Non-Payment Shutoff
• Auto-shutoff when using
excess power(Allows for surge loads)
Anchor: > 600 W
Gwo Bagay: 600 W
Freezer: 360 W
TV: 120 W
Limye: 30 W
Solving Core Problems for Grid Utilities
Written by Allison Archambault
Overall Challenges • Dealing with theft
• Smart metering required
• Scarcity of specialized equipment
• Harsh environment for electronics
• Ensuring timely payments
• Lack of efficient appliances
• Lack of regulatory framework
• Lack of skilled technicians
Electricity Theft• Changing views on theft from…
• Community pressure
• Imposing fines
• Justice system
A way to ‘beat the system’
Stealing from the community
Electricity Theft• Lesson Learned Place multiple meters on tall poles
• Currently addressed by:
– Checking connection
at each house
• Future Strategy
– Use of Totalizer Meters
Lessons Learned
Supply is less than 1/2 of the equation!
– Need comprehensive load-driven analysis
– Demand doesn’t always match the supply
Storage and smart meters can smooth out peaks
in electrical demand
Thinking only about supply isn't enough, it’s about timing.
The Mill’s Electrical Electrical Requirements
The mill experiences extreme peaks in mornings
and especially on market days.
Prioritize energy services, not kWhs
Ice Making• Used to cool drinks
(coolers vs. refrigeration)
Breadfruit Processing• Harvested at same time and has
short shelf life
– Rots quickly if not processed
– Processing with electricity flour lasts
for months
Microgrid Success Factors
It is important to develop a comprehensive approach
to clean energy access
• Densely populated rural areas
– Smaller geographic area reduces time needed to
visit customers • Reduces electrical distribution costs
• Information can be easy communicated to the community
Microgrid Success Factors
• Multi-disciplinary planning and community
partnerships are KEY
– Begin by establishing an energy baseline
• Find out what people are currently using and how
much they are paying
• Desirability of pay-as-you-go
• Reliable revenue from larger customers with
PPAs and monthly billing plans
Accompanying opportunities
• Value Chain Synergies
• Fuel switching (cookstoves)
• Agriculture + Conservation
• Feminist Electrification
• Energy Efficiency Services• Sourcing energy efficient appliances
• Offering technical expertise
Virtuous Cycle
Productive businesses
strengthen the grid
The grid unlocks productive use
value
Electricity for community-based development!
Thank you
ALLISON ARCHAMBAULT
PRESIDENT
JAMIE TRAHAN
MICROGRID SPECIALIST