Heat Pumps: Save Money, Save Energy, Save the Environment

Transcription

1 Heat Pumps: Save Money, Save Energy, Save the Environment

2 Outline 1) Understand how a heat pump works. 2) Understand how we save energy. 3) How does this save us money? 4) End by discussing how heat pumps help save the environment.

3 How a Heat Pump Works

4 Energy Overview Energy comes from many places: - burning oil, flowing water, etc Energy exists in many forms: - heat, electricity, etc Energy can be converted from one form to another: - electricity is used to produce heat, etc

5 Units Watt = Basic unit of power (electricity) Example: 60 watt light bulb uses 60 watts Kilowatt = 1000 watts KWh = # of kilowatts used over an hour

6 Examples One 60 watt light bulb uses 0.06 KW and uses 0.06 KWh after 1 hour. Two 60 watt light bulbs left on for one hour use 0.12 KWh. One 60 watt light bulb left on for 2 hours uses 0.12 KWh.

7 Another Unit Btu = Basic energy unit (heat) 1 KWh = 3413 Btu s

8 Heat Pumps are more efficient since you get more energy out than you put in.

9 Energy Flow of an Oil Burner We only get out what we put in.

10 Energy Flow of a Heat Pump Pull extra heat from the outside air.

11 Measure of Efficiency COP = Btu's out Btu's in

12 Example COP

13 Moving heat: Heat Pump 1. Absorb heat in refrigerant. 2. Pump refrigerant inside house. 3. Eject heat from refrigerant.

14 How does a Heat Pump do it? We must understand the Ideal Gas Law. PV = nrt P = Pressure V = Volume n = # of particles of gas T = Temperature R is a constant

15 PV = nrt As pressure goes up, temperature goes up. Pressure Temperature

16 Refrigeration Cycle

17 Mini-Split Heat Pumps

18 Save Energy

19 Goal Burn oil to produce heat

20 Question What produces the most energy?

21 Two Choices Burn Oil at Home Produce Heat at Home Burn Oil at Power Plant Produce Electricity Produce Heat at Home

22 Assumptions Oil burner at home is 80% efficient Power plant is 30% efficient Use a Heat Pump to convert electricity to heat with a COP of 3.4 Note: An average oil furnace is 80% efficient, an average oil-burning power plant is 33% efficient, transmission + distribution loss is 9%, and the Fujitsu 9RLS mini-split heat pump has an average COP of 3.4 when in used in Maine.

23 How Much Heat is Produced? Option 1: Burn Oil at Home 1000 Btu Oil 80% Efficient 800 Btu Heat

24 How Much Heat is Produced? Option 2: Burn Oil at Power Plant 30% Efficient COP of Btu Oil 300 Btu Electricity 1020 Btu Heat

25 Which Choice is Better? Using 1000 Btu of oil: Burn Oil at Home 800 Btu Heat Produced Burn Oil at Power Plant 1020 Btu Heat Produced Choice 2 is 28% Better!!!

26 Ultimately New power plants will be needed: Gas Power Plants Natural Gas More Efficient Electricity can potentially come from very efficient sources

27 Save Money

28 Question Installing a Heat Pump: How much money is saved?

29 Heating Wherever they come from, you need Btu s to heat your home. When it is colder, you need more Btu s to heat your home. Heat pumps: more efficient when it s warmer out. Oil Burners: more efficient when it s colder out.

30 Fact: While the Heat Pump is Running, it is Saving you Money

31 Limitations of Heat Pumps The 9RLS Mini Split Heat Pump shuts off at 5º F. Heat Pump works best when you need the least amount of heat.

32 How do we Calculate the Savings?

33 When is the Heat Pump Running? At some point, the heat pump puts out more heat than is needed.

34 Assumptions Oil burner at home is 80% efficient Price of electricity: $0.16 per KWh Price of # 2 Heating Oil: $3.00 per gallon # of Btu s per gallon of # 2 Heating Oil = 140,000 btu s 9RLS Mini Split Heat Pump runs at full capacity at 40 F and below. Indoor temperature kept at 70 F.

35 Heat Pump Savings Given: Outdoor Temp = 5-10 F Average # Hours = 185 hours Temp of lowest efficiency Heat Pump Capacity = 8470 Btu per hour Heat Pump COP = 2.82

36 Heat Pump Electricity Use 8470 Btu Conversion: 8470 Btu 1 KWh KWh Amount of heat 1 hour 3413 Btu 1 hour Produced per hour KWh per 2.82 hour KWh per hour Electricity use per hour KWh 1 hour 185 hours KWh Electricity Use per year

37 Heat Pump Cost Cost for heating over an average year (at a Temp of 5-10 F): KWh $0.16 KWh $26.05

38 Oil Use 8470 Btu Conversion: Btu 1 gal oil 80% efficiency Btu per gal oil 8470 Btu 1 hour 1 gal oil Btu $ gal oil $ hour Cost per hour

39 Oil Cost Cost for heating over an average year (at a Temp of 5-10 F): $ hour 185 hours $41.97

40 Savings $ $26.05 $15.92 Oil cost per year Heat pump cost per year Savings per year

41 Continue this Do this for all temperature bins from 5 to 40 degrees F

42

43 Total Savings Over an average year in Maine, we estimate that a 9000 Btu unit will save: $ per year

44 Suppose this If the furnace is 70% efficient: $ savings per year

45 Suppose this If the furnace is 70% efficient and oil costs $4.00 per gallon: $ savings per year

46 Initial Cost Equipment for a 9000 Btu unit is about $1700 (varies depending on home) Labor cost is about $900 Total $2600 initial cost

47 Tax Breaks + Rebates 30% Tax Break ($780 savings) $250 Rebate from EfficiencyMaine $75 Rebate from Bangor Hydro Electric Total Savings = $1105

48 Net Cost $2600 Initial cost - $1105 Savings $1495 Net Cost

49 Payback Given a 70% efficient furnace at $3.00 per gallon oil, the payback is: $ $1495 per year 2.6 years

50 Savings (per year) Saving Versus Price of Oil (per gal) (70% Efficient Oil Furnace) $1, $1, $1, $1, $1, $ $ $ $ $ $ $ $ $ $0.00 $2.00 $2.50 $3.00 $3.50 $4.00 $4.50 $5.00 Price of Oil (per gal)

51 Payback (years) Payback (years) Versus Price of Oil (per gal) (70% Efficient Oil Furnace) $2.00 $2.50 $3.00 $3.50 $4.00 $4.50 $5.00 Price of Oil (per gal)

52 Afterwards After unit pays itself off, you are saving money every year.

53 Take a Loan Taking a loan of $1500 at 8% interest paid over 5 years: $30.41 per month Compare to Heat Pump Savings: $47.89 per month

54 Conclusion: Heat Pump Pays for Itself + more

55 Save the Environment

56 Heating Fuel in Maine

57 Fact Heat Pumps Produce Less CO 2 then Burning Oil

58 CO 2 Emissions #2 heating oil emits kg CO 2 per million BTU s The CO 2 footprint of 1000 KWh in Maine is 1152 lbs. Average footprint of US is 20 ton per person per year

59 CO 2 Emissions for Oil Total 1 Btu kg 1,000,000 Btu 2.2 lbs 1 kg CO 2 production

60

61 CO 2 Emissions for Heat Pump Total KWh lbs 1000 KWh CO 2 production

62

63 CO 2 Savings 38.4% less CO 2 produced for same amount of heat Or ~ 1 Ton less of CO 2 per year

64 Conclusion

65 Other Alternatives Residential Windmills: ~500 KWh per year in electricity = ~$6.67 per month Residential Windmills: ~$16,500 initial Cost

66 Heat Pumps Heat Pumps: ~$47.89 per month Heat Pumps: ~$2,600 initial Cost

67 Conclusion Improve your existing heating system in order to: 1) Save money 2) Save energy 3) Save the environment