Technologies and Design Elements Associated with Microgrids
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Technologies and Design Elements Associated with Microgrids Joe Riddle, PE, CEM, LEED AP, Vice President Angel Flores, PE, LEED AP, CxA, Mechanical Engineer October 19, 2016
Transcript of Technologies and Design Elements Associated with Microgrids
Technologies and Design Elements Associated with Microgrids
Joe Riddle, PE, CEM, LEED AP, Vice President
Angel Flores, PE, LEED AP, CxA, Mechanical Engineer
October 19, 2016
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What is a Microgrid?
− DOE: Localized grid that can connect or disconnect from a traditional grid to operate autonomously and help mitigate grid disturbances to strengthen grid resilience.
− Clearly defined electrical boundary of loads and distributed energy
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Why Have a Microgrid?
− Reliability – Power has been provided in a secure, functional & consistent manner.
• Traditional utilities have done well at providing reliable power
− Resiliency- Ability to reduce the magnitude and/or duration of a disruptive event.
• Traditional utilities have not done as well at providing resilient power
• Zero to minimal interruption time with a microgrid• Average 90% improvement in downtime with a microgrid
− Points of Failure – Traditional utility has single point of failure, microgrids eliminate this problem
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Why Have a Microgrid?
− Power Outage – Natural Disasters
• Electric utility companies with above ground service had an average of 2,500 hrs of power disruptions in 2014.
− Power Outage – Human Factors
CAUSE LOCATION AFFECTED DURATIONSoftware Bug & Poor Load Shed
Northeast/ Canada (2003) 45 Million People 2-7 Days
Hot Weather + Technician Error During Maint.
California/ Arizona(2011) 2.7 Million People 12 Hours
CAUSE LOCATION AFFECTED DURATIONHurricane Sandy (2012) 17 States 8.5 Million People 2-7 Days
Hurricane Frances (2004) Florida Kennedy – OPF Few hours- Days
Wildfires (2016) California 10 Thousand People Few hours- Days
Line Flashing & Tree Grounding West Coast 7.5 Million People 6 Hours
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Why Have a Microgrid?
− Emergency generators are typically sized for critical/ life safety loads only(Typically 2-3 days)
− Fuel tanks, pumps, and generators flooded during Hurricane Sandy
− Expensive to size generator to cover all loads
− Emergency generators require fuel storage. Roads may not be accessible for refuel.
MICROTURBINE
GAS TURBINE
FEMA P-942 Report (Nov. 2013)
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Why Have a Microgrid?
− Allows vital buildings and building systems to stay 100% online:
• Information Technology (IT) Systems• Building Controls (HVAC, Life Safety, Security) • Mission Critical Facilities
o Fire Stationso Sewage Treatmento Jailso Hospitalso Police Stations
• Public Accommodationso Pharmacieso Grocery Storeso Supply Storeso Hotels
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− Distributed Energy Resource (DER): Grid-connected devices which either generate or store energy on-site.
• Combined Heat & Power (CHP) Systems• Fuel Cells• Photovoltaic Systems• Battery
Storage• Diesel
Generators• Wind Turbines
Components of a Microgrid
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Components of a Microgrid-Natural Gas Reciprocating Engines
− 24/7 Operation− Electrical efficiencies up to
45%− High sound power levels− Does not take on load as fast
as diesel generator− High availability (98%)− NG lines underground− Approx. Cost $2,800/kW as
part of a CHP
MICROTURBINE
Atlanta VAMC: Three- 2.5 MW Gen-sets
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Components of a Microgrid-Diesel Fuel Reciprocating Engine
− High sound power levels− Quick uptime (less than
60 seconds)− Requires fuel storage
(typically 2-3 days max. at partial load)
− Stored fuel requires maintenance
− Some units have a restricted annual run-time.
− Approx. Cost $1,500/kW
MICROTURBINE
Courtesy of MTU Onsite Energy. www.mtuonsiteenergy.com
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Components of a Microgrid-Natural Gas Turbines
− 24/7 Operation
− Power output reduction as inlet air temperature increases
− 24-42% electrical efficiency depending on size
− Lower O&M costs relative to recip. engines.
− Approx. Cost $3,000/kW as part of CHP system
Typical Gas Turbine Setup
7.9 MW SGT-300 – Courtesy of Siemens
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Components of a Microgrid-Natural Gas MicroTurbines
− Does not require a building enclosure
− Low sound power levels and emissions
− Low O&M costs
− Low electrical efficiency (22-33%)
− Significant power output loss at ambient temp. above 73F
− Approx. Cost $3,500/kW as part of CHP
MICROTURBINE
GAS TURBINESOLAR TURBINES
(5) - 200 kW Microturbines – Courtesy of Capstone
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Components of a Microgrid-Steam Turbines
− 40+% Efficient
− Requires a steam source and steam demand
− Low sound power
− Low O&M cost
− May be combined with gas turbine system
− Low installed cost, approx. $1,100/kW
MICROTURBINE
GAS TURBINESOLAR TURBINES
Courtesy of Dresser
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Components of a Microgrid-Fuel Cell
− Low emissions and noise
− 47% electrical efficiency
− Sensitive to fuel impurities, requires processing
− High O&M costs relative to other generation types
− High installed cost ~$5,000/kW w/ a CHP system
MICROTURBINE
GAS TURBINECourtesy of Fuelcell Energy
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Components of a Microgrid-Photovoltaic (PV) System
− Requires a voltage source
− Low O&M costs
− Silent operation
− Zero emissions
− Los Angeles very high average annual insolation (0.5 kWh/ft2/day). Good candidate for PV system.
− Approx. Cost $1,500/kW
MICROTURBINE
Dulles AFB - Courtesy of DOE
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Components of a Microgrid-Battery Storage
− Peak load shedding(load leveling)
− Low O&M costs
− Scalable
− Voltage source for renewables
− Renewable energy generation dispatch (i.e. stores additional wind and solar energy during low peak periods)
− Approx. Cost $3,000/kW
MICROTURBINE
Courtesy of S&C. www.sandc.com
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Components of a Microgrid-Wind Turbine
− 24/7 Operation
− Clean and sustainable
− Not all sites can support wind power generation
− Noise and visual concerns
− Approx. Cost $1,500/kW
MICROTURBINE
www.renewableenergymagazine.com
www.gizmodo.com
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MICROGRID CONTROLS
− Black-Start/ Island Mode Option Required• Operates independently from utility power
• Serve as a source of permanent power during prolonged utility outages
• Minimize emergency diesel generator runtime & associated O&Mcosts
• Can help reduce the required capacities of the emergency generators
• Does not replace the need for emergency generators at mission critical sites
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MICROGRID CONTROLS
− Microgrid Controller – The central system (brain) which does all the monitoring, controls, and load forecasting.
o Optimize distributed energy resources (DERs)- Smart Switching
o Continuous communication with utility
o Electricity price monitoring and demand response
o Connect to building BAS Courtesy of Siemens
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− Connect microgrid at multiple locations on grid for redundancy (removes multiple single point of failure)
− Fiber optics & radio frequency (RF) enable fast switching and load balancing
− Existing facilities can be modified to become a microgrid by replacing existing manual switches to motor operated
MICROGRID INTERCONNECTION
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Utility Interconnect
− Grid-Parallel at utility voltage is required
− Existing power distribution downstream from tie-in is unaffected
− Existing emergency generators operation is unaffected
− Intertie circuit breakers needed between Utility and microgrid
− Can integrate with existing switchgear
− Involves extensive coordination with the Utility Company
− Generators are built to meet utility power standards
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Economics
− Produce energy regardless if microgridis in island mode or grid connected
− Electricity available for resale in somemarkets
− DOE projects natural gas price escalations for the next 25 years will be less than electric
− Peak load shaving
− Data shows facilities with renewables have a higher selling and lease price
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Economics- Combined Heat and Power Plant (CHP)
− System components were installed in containers at factory
− CHP Plant installed in close proximity to boiler plant (close to piping connections) and electrical interconnect point
− Able to achieve maximum heat recovery
− Minimal emissions control req.
− 8 Year Payback (utility incentive)HRSGEnclosure
EngineEnclosure
EngineEnclosure
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Who Has a Microgrid?
PROJECT LOCATION TYPE
University of California San Diego, CA University
Twentynine Palms Palms, CA Military
Fort Bliss Fort Bliss, TX Military
Sacramento Municipal Utility Sacramento, CA Utility
Marin County San Rafael, CA County/ Community
Howard University Washington, DC University
Los Alamos Los Alamos County, NM County/ Community
Fort Bragg Fort Bragg, NC Military
Atlanta VAMC Atlanta, GA Hospital
• Universities, Military, Communities, Utilities• Sizes ranges from 2 MW to 40 MW
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Case History – Utility Company
− Pilot Micogrid
− Two integrated Microgrid systems • Three 2 MW NG fired engines coordinated with
o 500 KW Ground Mounted PV systemo 200 KW Battery Energy Storage Systemo Several customer site located EV chargers
• Two 2 MW NG fired engine generators
− To serve more than twenty government and private sector facilities including healthcare and emergency services
− No plan for CHP component
− Justification - resiliency & conservation of revenue in the event of a power failure
(confidential client)
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Case History – Atlanta VAMC
− 7.8 MW CHP Plant designed to accommodate 100% of the hospital’s electrical demand
− Three 2.6 MW NG fired engines
− Independent PV System
− CHP to generate 6,000 lb./hr. of steam
− Justification – Reduce carbon footprint and more than $1million/year in utility savings
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Summary
− Existing facilities with on-site generation can be converted to a microgrid
− Look for incentives (Cost deferred from other areas)
− All microgrid designs should be carefully coordinated with the electric utility company.
− A well designed microgrid should operate year round to maximize payback.
− Microgrid market growing by over 10% annually ($35 billion market by 2022)
