“Micro” Combined Heat and Power Project · 2017-08-29 · • A/E source selection criteria – Past CHP projects • Feasibility Study is critical. • Treat the CHP as a “boiler”

Tampa Convention Center • Tampa, Florida

“Micro” Combined Heat and Power Project

[Session Title]

A.J. Ballard, C.E.MMaine Army National Guard

August 16, 2017

Energy Exchange: Connect • Collaborate • Conserve

Does Micro CHP work??

123,000 SF AASF Average Annual Electric and Fuel bill ~$210,000

FY16 and FY17 the 75 KW CHP generated the following:

– $27,500 in average electrical savings

– $26,500 in average fuel savings (normalized for fuel prices and HDD)

– $54,000 in annual energy savings

– ~ 26% reduction in building energy consumption

– ~ 5% reduction of the MEARNG total energy bill

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Energy Exchange: Connect • Collaborate • Conserve3

CHP Producing Electrical Load Over 24 hours

Jan 23, 2017 ~ 25F Jan 8, 2017 ~ 20F


Greetings from Maine Roof New Milcon - February 2015

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One of the most critical roles of Army Energy

Managers is to develop the most economic and

sustainable solutions possible to ensure mission

readiness.


Maine Army National Guard “Micro” - 75 KW CHP

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The objective of the pilot MEARNG CHP project was to determine if CHP was viable for 50,000 sf or larger National Guard Facilities in states above the

5,000 Heating Degree Day line

> 5000 HDD

> 6000 HDD

> 7000 HDD


There are a significant number of

guard facilities above the 5,000

heating degree day line.

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110 Training Centers with ~2,070 Bldgs

734 Ground Maintenance Bldgs 293 Aviation Support Facilities

2,386 Readiness Centers

> 5000 HDD

> 6000 HDD

> 7000 HDD


75 KW CHP Generated over 27% in Energy Savings in FY16 and FY17

*Natural gas and fuel oil normalized/corrected for price and heating degree days.FY15 - March switched to fuel oil based on cost.FY17 – January switched back to natural gas.

Electric Cost*Natural gas and fuel oil

costTotals

FY15 $90,100 $119,430 $209,530FY16 $62,557 $91,457 $154,014FY17 $62,615 $94,393 $157,008Avg annual savings $27,514 $26,506 $54,020Avg savings % 31% 22% 26%

MEARNG 75 KW CHP Savings

CHP on line Apr 2015 – May 2015 (shake down)CHP on line Oct 2015 – May 2016CHP on line Oct 2016 – May 2017


MEARNG 75 KW CHP Time Line

• Nov 2013 FEMP CHP submission (not selected – Mar 2014)

• Mar 2014 National Guard Bureau Funds Project (QUTM – energy funds)

• May 2014 A/E Design selection • Aug 2014 Design complete• Sep 2014 Contract Award• Mar 2015 CHP on line “Shake down”• May 2015 CHP off line (end of heating season)• Oct 2015 CHP on line (beginning of heating season)• May 2016 CHP off line • Oct 2016 CHP on line (beginning of heating season)• May 2017 CHP off line• FY 2018 Optimization Modernization Project

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AASF is a ~ 123,500 sf building with a 43 KW Solar PV system, (3) 4.3 MMBtu and (1) 850,000 Btu

boilers and a 75 KW CHP

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75 KW Combined Heat and Power unit (CHP)

454 GM big block engineNatural gas input : 930,000 Btu per hour, 9.3 therms (~6.8 gals fuel oil/hr equivalent) Electric production : 75 kWh per hour Waste heat injection : 525,000 Btu per hour, 5.25 therms (~3.8 gals fuel oil/hr equivalent )

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~70 dB noise rating


Aegis 75 KW CHP Compact Design Fit Through the Mechanical Room Double Doors


AASF 123,500 SF

Green = 75 KW CHP and boilers Red = Radiant floors and snow meltYellow = 43 KW Solar PV on the roof

Blue = Hydronic make up air handler units

The remainder of the facility is heated with baseboard radiation, unit heaters and roof top units.

KWPV43

CHP Boilers

Hangar Door Snow Melt


40,000 SF of Low Temperature (< 100F) Radiant Floors = Good Match for CHP


CHP installed in primary loop: resulted in one 4.3 MMBTU boiler remaining off for the season and the other two coming on later and off earlier which contributed to the fuel savings.


Hot Water and Electric Distribution


COGEN DashboardFeb 2, 2017, 32 FBldg load 151 KWStreet @ 66 KWCHP @ 75KWSolar @ 10 KW

From CHP- 205FTo CHP – 163 F

From Loop – 160 FTo Loop – 175 FDelta – 14.5 F

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Screen Shot Building Automation System, 2/2/2017


75 KW CHP FY 2018 Electrical Generation Projected

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FY18 CHP optimization - net meter/thermally

follow load -75KW/hr 24/7

53% 1440 hrs

65% Prod

4848 hrs

95% Prod4896 hrs

Indicates the % of available kWh produced by the CHP for run time period

63% Prod

4992 hrs


75 KW CHP Generated over 40% of the Building’s Electrical in FY16 and FY17

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Electric kWh purchased

MMBtuBilled

Electric CostCHP kWh produced

CHP Production % of bldg kWh

FY15 546,596 1,865 $90,100 57,072 9%FY16 321,414 1,097 $62,557 234,492 42%Fy17 341,765 1,166 $62,615 235,119 42%Avg Savings 215,006 768 $27,514% 39% 39% 31%

MEARNG 75 KW CHP Electric Savings

FY18 - CHP will thermally load follow and generate 75 KW 24/7 = ~$15,000 in additional savings


75 KW CHP MMBtu vs. Total Degree Days

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Note: MMBtu should typically be below TDD line; this indicates HVAC system is in control

Above the TDD line indicates inefficient equipment/controls

At or below the line = in control

CHP on line Oct -May


Aegis 75 KW CHP Specifications


CHP saves energy and reduces pollution

100 units of fuel in

~30 units of elec delivered

100 units of fuel in

~55 units of heat delivered

~15 units heat rejected to boiler room

Note: CHP heat rejected is used by the heat recovery unit in the mechanical room and delivered to hangar bay, resulting in efficiency of ~ 90-95%

Delivered: ~35 units elec / 100 = ~35% efficient

Delivered: elec (~30) + heat (~55) / 100 = ~85% efficient

Thermal and air pollution


Heat Recovery Unit transfers waste heat from the mechanical room to the hangar bay using a condensing unit and air handler

(7 ton AC unit condenser in hangar and evaporator in boiler room – waste heat transferred via refrigerant lines)

~ 90,000 Btu per hour delivered @ ~95F (Equivalent ~1 therm of natural gas or

~0.7 gal fuel oil per hour)

~ 3000 CFM @ ~ 65F to boiler room


As part of the project, added “removable” insulation covers on all pumps, valves, strainers, etc. to significantly reduce heat loss of the primary heat loop

piping by ~50%.


Key Design Aspect Determine Heat Loss Btu/hr

Avg hourly heat loss– Sep ~75,000 Btu/hr– Oct ~200,000 Btu/hr– Nov ~260,000 Btu/hr– Dec ~360,000 Btu/hr– Jan ~430,000 Btu/hr– Feb ~395,000 Btu/hr– Mar ~310,000 Btu/hr– Apr ~210,000 Btu/hr– May ~115,000 Btu/hr

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New project under design 70,000 sf Readiness Center


Project Design Approach

• A/E source selection criteria – Past CHP projects • Feasibility Study is critical. • Treat the CHP as a “boiler” that is replacing or being added to a

heating or process system.• Key to the design – the viable use of the “CHP jacket water waste

heat” is critical for the project success. • Determine the hourly Btu requirement for the period (heat loss) • Secondary consideration - the CHP generates electricity • Electricity is provided to the main electrical distribution panel.• The CHP is typically sized based on the buildings average hourly Btu

load and/or the electrical 15 minute demand load.• Must find an efficient use for waste heat!

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75 KW Combined Heat and Power (CHP)

• 7.4 liter (454 ci) V8 internal combustion engine (since 1970) • Input 9.3 therms/ hr natural gas (~6.8 gals fuel oil/ hr eq.)• Output 5.2 therms/ hr, 525,000 Btu/ hr (~3.8 gals fuel oil/ hr eq.) • Generates 75 kWh per hour

~5 F

~10 F

~30 F

~10 F

210F

~210F

~160 F~160 F

~210 F


75 KW CHP Waste Heat Recovery

Exhaust Gas Heat Exchanger

Heat Recovery Exhaust

Manifold

Oil Cooler Heat

Exchanger

Engine Jacket Heat Recovery

~5 F

~10 F

~10 F

~30 F

~210F

~160 F


Engineering

• $15,000 Type A (Feasibility Study Micro turbine vs. ICE)

• $27,000 Type B (Design)

• $25,000 Type C (Construction)

• $67,000 A/E cost• $893 per KW

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MEARNG CHP Economics

• $67,000 A/E cost • $350,000 project cost (total project cost $489,000)

• $ 9,285 maintenance cost ($1.85 x 4,882 hours)

• $426,285

• $55,000 savings (average annual utility cost ~$210,000)

• 7.7 years simple pay back

• Does not include demand savings estimated at ~$9,000 a year

• $4,950 per KW

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Bldg 260 Daily Report for February 14, 2017, 30F


Btu Injection and Heat Exchanger Daily Report


January 23, 2017 Compressed Day, ~ 25F


February 19 – 25, 2017


April 18, 2017, Tuesday, OAT ~ 50F


Avg ~ 4,900 hrs/yr, replace in year 7

We have separate internet line in mechanical room for CHP contractor



The Maine Army National Guard (MEARNG) was awarded the

Environmental Protection Agency’s 2016 Energy Star CHP Award in New York at

the NYSERDA Conference on December 7, 2016

for the natural gas-fired75 KW combined heat and power (CHP)

system based on efficiency and air emission reductions.

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ASFF 75 KW CHP vs. 43 KW Solar PV Comparison

43 KW PV ~$200,00075 KW CHP ~$425,000


75 KW CHP vs. 43 KW Solar PV Comparison

Unit 75 KW CHP 43 KW PV %

Annual Capacity Factor % % 75 13.3 82%Annual Electricity Production* kWh 235,000 50,000 79%Annual Useful Heat Therms 12,500 0 100%Footprint Required sf Square feet 150 4,500 -2900%Annual CO2 Savings Tons 60 9 85%Cost per KW $ $4,800 $4,419 8%Capital Cost ** $ $360,000 $190,000 47%Annual Maintenance cost $ average $9,285 $0 100%Annual Energy savings $ $54,000 $6,013 89%Simple pay back Years 6.8 31.6 -362%

Bldg 260 75 KW CHP vs. 43 KW Solar PV

** Does not include design cost* CHP produced 65% of the potential kWh. At 95% = 348,000 kWh = ~ $15,000 additional savings


The MEARNG continues the steady progress of energy conservation and efficiency for all of our facilities.

A key element to our energy reduction strategy in FY16 has been the research, design and subsequent installation of a Combined Heat and Power (CHP)

plant in our largest facility, the 123,500 square foot AASF located in Bangor, Maine.

MEARNG is currently optimizing the CHP controls to maximize output and pursuing three other HVAC projects that include combined heat and power.

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Next Steps

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Maine Army National Guard CHP Projects Under Design

• Northern Maine Readiness Center (New Construction - MILCON)– 45,000 SF, ~$16M– Low temperature radiant floors and ice melt walkways– Multiple CHP’s – 2 or 3 - 10KW CHP’s

• AASF, Bangor, Maine, 123,500 SF Boiler Modernization project (SRM)– Existing 75 KW CHP and three 4.3 MMBtu boilers– Replace boilers with single or Multiple CHP’s and gas condensing boiler(s)

• AFRC, Bangor, Maine, 70,000 SF HVAC upgrade project (SRM)– Perimeter baseboard radiation, brick façade on CMU walls built ~– Multiple CHP’s – three 10 KW’s– Note: no envelope of window upgrades – keep baseboard radiation which makes CHP advantageous

• Waterville Armory, 48,000 SF, HVAC Upgrade Project (SRM)– Multiple CHP’s – three 10 KW’s– Perimeter baseboard radiation, brick façade on CMU walls built ~1960 – Note: no envelope of window upgrades – keep baseboard radiation which makes CHP advantageous

• Augusta Armory, 79,500 HVAC Upgrade Project (SRM)– Multiple CHP’s – two or three 10 KW’s– Perimeter baseboard radiation, brick façade on CMU walls built ~1955.

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MEARNG FY 2018 CHP Optimization

• Establish net metering agreement with utility

• Switch from “electrical” to “thermal” load following

• CHP will no longer “throttle down” due to reduced electrical demand during the unoccupied periods (nights and weekends)

• CHP to run at design RPM 24/7 = 75 KW / 525,000 Btu/hour

• ~ $15,000 in additional electrical and thermal savings

• ~ $9,000 annually estimated demand savings ($20/KW * 75 KW = $1,500 * 6 months = $9,000)

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NMRC layout - Primary heating will be low temperature (~110F) radiant slab through out the building.- Red areas will be dump zones if required to continue producing electricity

Cold Storage

walkw

ay

Maintenance Bay


AFRC Bldg Envelop - Brick façade/CMUConstructed ~1990.

(2) 1.8 MMBtu Fuel oil boilers Currently using 39,000 Btu per SF

Should be ~25,000 – 30,000 Btu per SF


35 KW CHP delivers ~ 200,000 Btu/hr

Avg hourly heat loss– Sep ~75,000 Btu/hr– Oct ~200,000 Btu/hr– Nov ~260,000 Btu/hr– Dec ~360,000 Btu/hr– Jan ~430,000 Btu/hr– Feb ~395,000 Btu/hr– Mar ~310,000 Btu/hr– Apr ~210,000 Btu/hr– May ~115,000 Btu/hr

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Micro CHP’s: 5 - 400 KW, 35,000 – 2 MMBtu / hr

Internal Combustion Engines&

Micro turbines

75 KW

300 KW

65 KW

35 KW

~300 KW

400 KW5 KW 10 KW 35 KW

Any questions please contact:

A.J. Ballard, C.E.M

Energy ManagerMaine Army National

Guard

[email protected]

mailto:[email protected]

Documents

“Micro” Combined Heat and Power Project · 2017-08-29 · • A/E source selection criteria – Past CHP projects • Feasibility Study is critical. • Treat the CHP as a “boiler”