Joe Plummer & Terry Webster

Top Ten Ways to Save EnergyPLUS

Heating and Cooling Options for Your Home

Who we are..• Office of Energy Security

▪ Minnesota Department of Commerce

–Providing energy information for over 30 years…

▪ Energy conservation, efficiency, & renewables▪ Through technology, analysis, grants, programs,

& public outreach• Data, reports, publications, presentations, website,

call center, training, public events• Energy fairs, CERTs, Eco-Experience at the Minnesota

State Fair

• Annual statewide energy use:–1.979 quadrillion Btus

CommercialBuildings – 18%

ResidentialBuildings – 22%

Industrial – 31%

Transportation – 29%

We use a lot of energy!

All Buildings: 40%

Source: Energy Information Administration 2008

Energy Use• This includes…

–Enough natural gas to fill nearly 6,000 Metrodomes

–Enough coal to fill a train stretching from Duluth to New Orleans—and back

–Enough petroleum to make a layer 15 feet thick over Interstate 94 from Hudson to Moorhead—all four lanes

Energy Use• And all this energy use

generates over 105 million tons of CO2…–Enough to fill the Mall of America

over 24,000 times–EVERY YEAR

Every year the typical MN house uses…

• Over209 millionBtus of energy–Electricity–Natural gas–Propane–Heating oil

1. Energy Audit• Building Performance Review

▪ For residential, small & large commercial, industrial, & public buildings

▪ Evaluation of how buildings work• Minimum: blower door test

• Infrared camera recommended

• Available through:▪ Most utility companies

• Utilities will identify qualifying rebates and programs

▪ Also from private contractors• Minnesota Building

Performance Association (www.mbpa.us)

2. Seal Air Leaks • Attic Air Leaks

▪ Attic door▪ Plumbing, Electrical,

Ducts, Vents, Chimney▪ Insulation is not enough!

– PRIMARY CAUSE OF ICE DAMS!

• Windows & Doors▪ Reduce air infiltration, drafts ▪ Weather strip▪ Caulk▪ Plastic film on inside

3. MechanicalSystems Check

• We (mostly) maintain our cars, software, lawns, teeth…–Mechanical systems are important, too!– Inspections/tune-ups assure safety

and performance▪ Furnace, annually▪ Air conditioning units, every two years

–Check all combustion appliances▪ Water heater, gas fireplace, gas stove

4. Heat/Cool Efficiently

• Fans can reduce A/C use– Draw cooler outside air in

▪ Myth:• Window fans should blow inside air outside

in summer, through upper windows• Can lead to dangerous back drafting

– Cool people through ‘wind chill’▪ Myth:

• Room or ceiling fans cool rooms• Like leaving a light on just because you might come back later

• ‘Saver Switch’ from utility– Save up to 15% electric bill in summer

4. Heat/Cool Efficiently

• Myths:– Space heaters save money

▪ Unvented, combustion unsafe▪ Electric add to load,

increase carbon output, will give you a higher electric bill

– Fans save energy in winter▪ Air temp ceiling to floor: 2-3 degrees▪ Constant use of furnace fan or ceiling fan uses a lot of

electricity—and can increase ‘wind chill’ effect▪ Control uneven temperatures through

registers, distribution ductwork baffles, & duct-sealing

5. Programmable Thermostat

• Save 1% of your fuel bill–For each degree/8 hours of setback–Can easily pay for itself–Works for AC, ERV, humidifier too

• Myths:–Takes more energy to

heat/cool house after setback–Setting thermostat at 800 heats

house faster

6. Control Hot Water Use– Turn down water heater to 1200

– Wash clothes in cold water, mostly– Install low-flow showerheads

▪ Standard shower:• 5.5 gal/min.

• 70%h 30%c mix for 10 min. shower uses 39 gal. hot water!

▪ Low-Flow:• Under 2 gpm, some1.6 gpm

• 11 gal. hot water!

• Aerators: high pressure spray

7. Efficient Lighting

• Save BIG Energy with CFLs–A CFL bulb can save $30

over life of the bulb– If every household in US

replaced 5 most frequently used bulbs...▪ 21 power plants would not

need to be built

• LEDs are coming!

8. Outlet Strips• “Phantom Load”

–Standby power for TVs, chargers, computers, etc. can be 40% of “on”

–Standby power in Minnesota could powerall single-family homesin St. Paul

–Outlet strips can shut everything off with one switch

9. Timers & Motion Detectors

• Only have it on when you need it on!

• Great for:– Lighting

▪ outside ▪ infrequently used▪ with impractical switch locations▪ where people forget to turn off

– Battery chargers– Vehicle engine block heaters

10. ENERGY STAR• Program of EPA & DOE

–Standards for efficiency/reliability– If it uses energy, check for the

ENERGY STAR label

So, now what?• You have decided to invest in your

home heating and cooling systems

• You want to make smart choices by minimizing:–Cash outlay–Operating expenses–Environmental impact

Seems simple, eh?

Situation #1:• 2,000 sq ft, two-story house

• Built pre- 1940

• Central MN

• Winter is approaching and your old, inefficient gas furnace requires replacement

Options:1. Electric thermal storage heater

–100% efficient–$1,500 installed cost–Move to off-peak rate of 4.5 cents/kWh

2. ENERGY STAR natural gas furnace

–94% AFUE–$3,000 installed cost

Questions:• Which system is most

economical? – Initial purchase–Operating costs

• Which system has the lower carbon load?

• How can you compare?

mncee.org

Economic Analysis• Electric resistance heating

– Annual energy costs = $2,662– Purchase cost = $1,500

• Gas furnace– Annual energy costs = $1,976– Purchase cost = 3,000

• Gas furnace will pay for itself in about 2.2 years– Simple Payback = (Additional $) / (Reduction in Energy $)– (3,000 – 1,500) / (2,662 – 1,976) = 1,500 / 686 = 2.2 years

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Electric FurnaceCosts

ElectricGasSavings

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Gas vs. Electric FurnaceCumulative Savings

ElectricGasSavings

Sim

ple

Payb

ack:

2.2

Yea

rs

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Gas vs. Electric FurnaceCosts & Savings

ElectricGasSavings

50.61 tons/year CO211.89 tons/year CO2

Why?• Why does the natural gas furnace

have lower carbon emissions and lower energy costs, even though the thermal efficiency is lower?–Answers:▪ MN’s carbon-heavy electric mix▪ Inefficiency of electricity generation and delivery▪ Relative costs of fuels per unit of energy▪ Relative carbon content of fuels

Minnesota Electric Power Generation by Energy Source, 2008Source: U. S. Energy Information Administration

Coal58.0%

Petroleum0.4%

Natural Gas5.2%

Nuclear23.7%

Hydroelectric1.3%

Other Renewables

10.7%

Other0.6%

The Electric Grid

Source: National Energy Education Development Project (Public Domain)

7-8% losses

66% losses

Cost of Fuels

$2.6

3

$1.7

0

$0.1

1

$0.9

2

$0.00

$5.00

$10.00

$15.00

$20.00

$25.00

$30.00

$35.00

Heating Oil, gal Propane, gal Electricity, kWh Natural Gas, therm

Cost per std unitCost per mmBtu

However…

0

0.02

0.04

0.06

0.08

0.1

0.12

02468

101214161820

$/kW

h

$/M

cf

MN Residential Utility Costs

GasElectricity

Source: US Energy Information Administration (2011)

Future Prices?

Source: US Energy Information Administration (2011)

Carbon content of fuels

161.2118.0 136.5

539.3

heating oil natural gas propane electricity (Midwest)

Lbs of CO2/mmBtu

Situation #2• 3,000 sq ft, two-story house

• Built in 1990s

• Twin Cities metro area

• Original furnace (80% AFUE) and central AC (SEER 10)

• You want to upgrade your heating & cooling to save $$ and reduce carbon load

Options:1. ENERGY STAR natural gas

furnace and central A/C▪ 94% AFUE furnace and 14.5 SEER A/C▪ $6,000 installed cost

2. ENERGY STAR ground source heat pump▪ 3.5 COP, 15.0 EER GSHP▪ $25,000 installed cost▪ Move to electric space heating rate of 5 cents/kWh

in non-peak months

Economic Analysis• Gas Furnace/Central AC

– Annual energy costs = $1,499– Installed cost = $6,000

• Ground Source Heat Pump– Annual energy costs = $725– Installed cost = $25,000

• GSHP will pay for itself in 24.5 years– Simple Payback = (Additional $) / (Reduction in Energy $)– (25,000 – 6,000) / (1,499 - 725) = 24.5 years

-$25,000

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GSHP Heating & Cooling Costs

GasGSHPSavings

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Natural Gas + Electric Air Conditioning

GasGSHPSavings

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GSHP Savings vs. Gas

GasGSHPSavings

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GSHP Savings vs. Gas

GasGSHPSavings

Other Considerations• Soil quality (GSHP)

• Damage to yard (GSHP)

• Real versus lab performance (both)

• Desuperheater add-on (GSHP)

• Safety (removal of combustion sources from home)

GSHP Installation

Can you dig it?

Still Other Considerations

• Green Power Programs–Pay more to offset

carbon emissions

• More wind power coming on line – (RES: 25% by 2025)

Situation #3• 2,000 sq ft, two-story house

• Built in 1970s

• SE Minnesota

• Goals:–Reduce carbon load and electric bills

Options1. Install solar PV

2. Carpool to work – (50 mile round trip)

Analysis• Solar PV

– Cost = $16,000 for 2 kW system▪ Federal tax credit of 30% = $4,800▪ State rebate of $4,000▪ Net cost = $7,200

– Annual production = 2,200 kWh– 2,200 kWh x (1.823 lbs/kWh) = 4,011 lbs of CO2– Cost per lb of CO2 = $1.80– Payback

▪ Cost of electricity = $0.11/kWh▪ 2,200 kWh/yr x $0.11/kWh = $242/yr▪ $7,200 / $242/yr = 29.7 years

Analysis• Carpooling

– 50 mi per day x 5 days/wk x 49 wk/yr = 12,250 mi/yr– Assume that miles are reduced by ½– Car mileage = 30 mi/gal– 6,125 mi / (30 mi/gal) = 204 gal of gasoline saved / yr– Carbon emissions factor of gasoline = 19.56 lbs/gal– 204 gal x (19.56 lbs/gal) = 3,990 lbs of CO2– Cost per lb of CO2 = $0 + cost or benefit of your carpool

partner

Conclusions• There are no easy answers if cost

(purchase and operating) andgreenness are concerns

Conclusions• Fuel availability constrains

choices:–Heat pumps may be a good option

when no natural gas is available▪ Otherwise, paybacks may be long and carbon load

may actually increase

–Biomass (wood/corn) may be a good choice in rural areas▪ Storage and transportation a real issue in cities

General Guidelines/Tips• Treat energy savings claims with

skepticism–Do the math or use an online calculator–Consult reputable sources–High efficiency does not necessarily

mean low cost or low carbon!

General Guidelines/Tips• Use a licensed contractor

– Installation quality matters a great deal–Some utilities have Quality Installation

programs for central AC and ASHP–Ensure that a sizing calculation is done

• Solar electric is more of a values decision (though rebates help)

General Guidelines/Tips• Efficiency first!

–Make sure your house is well insulated and air sealed before upgrading HVAC

–Follow the 10 Ways to Save Energy▪ FIRST!

• Think outside the box–Carpooling, bike commuting, air drying

your clothes all reduce carbon—and save $$

Finally…• Remember:

–The assumptions and choices we made were meant to be illustrative▪ They are based on reasonable situations and fair

assumptions

–However, your choices, assumptions, costs, etc. may make your numbers different▪ And that should make your decisions easier!

–mncee.org▪ Their calculator is MN-specific

Terry Webster and Joe Plummer

www.energy.mn.gov