Transcript IBM Presentations: Blue Pearl DeLuxe template
How I Built a Carbon-Neutral House
Chandu Visweswariah
March 15, 2010
Summary
We built a carbon-neutral house in Croton on-Hudson, NY We have been living in the house since May, 2009 including one tough winter No carbon products involved or burned for our house’s energy needs No oil, no propane, no natural gas, no electricity produced from coal (or nuclear plants) Carbon-neutral house == Carbon-neutral home No compromises on comfort No attempt to construct the house in a sustainable manner/sustainable materials Adds too much to the cost!
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Agenda and purpose
1.
2.
3.
4.
Geothermal heating, cooling and domestic hot water Photovoltaic solar panels Other considerations $$$ (costs, incentives, pay back periods) Outside the scope of this discussion Global warming and its effects Energy policy and “dependence on foreign oil” The travails of building a house How I built a carbon-neutral house Do not copy without permission 3 of 56
The only “political” chart today*
How I built a carbon-neutral house *New York Times, 03/14/10 Do not copy without permission 4 of 56
1. Geothermal
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Intuition
Ever been inside a cave in the summer?
The cave is cooler than the air outside During the winter, that same constant cave temperature is warmer than the air outside Same principle behind ground source heat pumps (GHPs) In the winter, they move heat from the earth into your house; in the summer, they pull heat from your home and discharge it into the ground How I built a carbon-neutral house Do not copy without permission 6 of 56
Geothermal principles
The earth is at a constant 12.6
o C (53 o F) year-round after about 2 m (6’) of depth* Depends on soil, rocky earth is better Geothermal heating and cooling takes advantage of this abundant reservoir of heat in the winter and “coolness” in the summer We will discuss three main parts Energy exchange with the earth Heat pump and refrigerant Distribution in the house *7 o C (45 o F) to 18 o C (75 o F) depending on latitude How I built a carbon-neutral house Do not copy without permission 7 of 56
Basic idea (one example)
Summer Winter How I built a carbon-neutral house Do not copy without permission Drawing courtesy of Prof. Andrew Chiasson, Oregon Instititute of Technology 8 of 56
Energy exchange with the earth
Closed loop Vertical loop Horizontal loop Pond loop Open loop With underground water aquifer Energy exchange material Direct exchange (DX): Puron under pressure in copper pipes Indirect exchange: Glycol+water mixture (also called “anti-freeze” or “brine”) in PEX tubing How I built a carbon-neutral house Do not copy without permission 9 of 56
Closed vertical loop
6 m (20’) bore spacing (7.5 m (25’) in our case), 91 m (300’) deep Each well or set of wells used for one zone How I built a carbon-neutral house Courtesy of Prof. Andrew Chiasson, Oregon Instititute of Technology Do not copy without permission 10 of 56
Closed horizontal loop
How I built a carbon-neutral house Courtesy of Prof. Andrew Chiasson, Oregon Instititute of Technology Do not copy without permission 11 of 56
Closed pond loop
How I built a carbon-neutral house Courtesy of Prof. Andrew Chiasson, Oregon Instititute of Technology Do not copy without permission 12 of 56
Pond loop photos
HDPE pipe Copper pipe How I built a carbon-neutral house Do not copy without permission 13 of 56
Open loop
How I built a carbon-neutral house Courtesy popularmechanics.com
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How a heat pump works
Compressor Low pressure Low boiling point: gas Accepts latent heat Low temperature High pressure High boiling point: liquid Gives out latent heat High temperature How I built a carbon-neutral house Courtesy etccreations.com
Expansion valve Do not copy without permission 15 of 56
How a heat pump works, part 2
How I built a carbon-neutral house Do not copy without permission http://www.dimplex.de/animationen/kreislauf.php?lang=en 16 of 56
How a heat pump works, part 3
How I built a carbon-neutral house Do not copy without permission http://www.dimplex.de/animationen/waermepumpe-passiv.php?lang=en 17 of 56
Domestic hot water
Desuperheater In summer, take heat that is extracted from the house to heat hot water Heat water for free!
In winter, utilize the same mechanism used to heat water for house heating to heat water for domestic use Reduce water-heating costs by ½ Can also heat water directly by solar power 18 of 56 How I built a carbon-neutral house Do not copy without permission
Refrigerant
Direct exchange Copper pipes with puron under pressure More efficient Allows for domestic hot water Indirect exchange Glycol + water mixture (also known as “anti-freeze” or “brine”) PEX piping Less efficient 19 of 56 How I built a carbon-neutral house Do not copy without permission
Properties of Puron
Puron is R-410A, a non-proprietary 50/50 blend of 2 non-chlorinated refrigerants Azeotropic blend* with negligible glide temperature (0.3
o F) History 1987 Montreal Protocol 1990 Clean Air Act Amendments R-11 and R-12 (CFCs) phased out 1995 HCFCs have lower ozone-depleting potential R-22 (freon) production stopped Jan 1, 2010, phase-out date for existing units 2030 AlliedSignal/Honeywell invented Genetron AZ-20 (HFC) which was given a generic name R-410A, brand name Puron How I built a carbon-neutral house Do not copy without permission 20 of 56 *Same boiling point, so cannot be separated by fractional distillation; same composition in liquid and vapor states when distilled or partially evaporated
Puron vs. freon
ASHRAE number Type of refrigerant Chemical name Chemical formula Molecular weight Specific heat of liquid (at 86 o F) Specific heat of vapor at constant pressure C P (at 86 o F, 1.0 atm) Ozone depletion potential (ODP)* R-410A HFC azeotropic mixture of HFC-32 and HFC-125 Difluoromethane (R-32) Pentafluoroethane (R-125) CH 2 F 2 (R-32) 50% by mass, CHF 2 CF 3 (R-125) 50% 72.6 0.42 Btu/lb o F 0.21 Btu/lb o F R-22 HCFC Chlorodifluo romethane CHClF 2 86.5
0.31
0.16
0.00
0.05
Montreal Protocol phase out date None 2030 Higher pressure, lower mass flow, quieter, 31% higher heat-carrying capacity For more comparison data, see Appendix How I built a carbon-neutral house Do not copy without permission 21 of 56 *ODP: a normalized indicator of the ability of a refrigerant to destroy stratospheric ozone molecules referenced to a value of 1.000 for CFC-11
Enthalpy curves for refrigerants
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Puron enthalpy curves
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System in our basement
Zone valves Air handler Heat exchange coils Heat pump Heat pump Heat pump How I built a carbon-neutral house Do not copy without permission 24 of 56
Winter
HP1 HP2 HP3 HP4 HEC1 HEC2 HEC3 HEC4 HP5 HEC5 Well Return Tank for house heating/cooling For topping off Domestic hot water tank To house Return Radiant zones Air handlers How I built a carbon-neutral house Do not copy without permission 25 of 56
HP1 HP2 HP3 HP4 HEC1 HEC2 HEC3 HEC4 HP5 HEC5
Summer
Tank for house heating/cooling For topping off Domestic hot water tank To house Return Air handlers How I built a carbon-neutral house Do not copy without permission 26 of 56
Distribution within the house
Forced air works, but radiant is best How I built a carbon-neutral house Do not copy without permission 27 of 56
Sub-floor radiant
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Well drilling in “emory” land
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Air source heat pumps
Mitsubishi Mr. Slim 26 SEER 9,000 BTU Heat Pump INVERTER Mini Split System Recent breakthroughs allow operation at low temperatures No wells, no trenches!
The face of the future?
How I built a carbon-neutral house Do not copy without permission 30 of 56
Agenda and purpose
1.
2.
3.
4.
Geothermal heating, cooling and domestic hot water Photovoltaic solar panels Other considerations $$$ (costs, incentives, pay back periods) Outside the scope of this discussion Global warming and its effects Energy policy and “dependence on foreign oil” The travails of building a house How I built a carbon-neutral house Do not copy without permission 31 of 56
Average solar irradiance W/m
2 Fastest growing source of energy Do not copy without permission 32 of 56
Basic physics: light
electricity
Photons from sunlight hit silicon Some pass through (lower energy), some reflect, some are absorbed (energy > band gap) These create electron/hole pairs Pairs that don’t recombine form a DC current An inverter is used to produce AC current No easy way to store this energy!
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Ideal conditions
South-facing single roof Solar south* is 13 o West of South A 9/12 pitch is ideal No chimneys, poles, trees in the way In our case 7.6 KW system 8,100 kWhr per year average Eliminates 14,000 lbs of CO 2 per year How I built a carbon-neutral house Do not copy without permission *Solar south is the angle of the sun at solar noon 34 of 56
Stand-offs and mounting
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Stand-offs
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Inverter (in garage)
From panels Inverter Private meter 8,871 kWhr to date How I built a carbon-neutral house To utility Do not copy without permission meter 37 of 56
PVWATTS
Performance calculator for grid-connected PV systems http://rredc.nrel.gov/solar/codes_algs/PVWATTS Inputs to the program Location (latitude, longitude, elevation) DC rating of panels (e.g., 5 kW) DC to AC derate factor (e.g., 0.77) Array type (fixed, 1-axis tracking, 2-axis tracking) Array tilt (e.g., 37 o for a 9/12 roof) Array azimuth (e.g., 180 o roof) for a South facing How I built a carbon-neutral house Do not copy without permission 38 of 56
DC to AC derating factor
Component Derate Factors
PV module nameplate DC rating Inverter and Transformer Mismatch Diodes and connections DC wiring AC wiring Soiling System availability Shading Sun-tracking Age
Overall DC-to-AC derate factor
How I built a carbon-neutral house
PVWATTS Default
0.95
0.92
0.98
0.995
0.98
0.99
0.95
0.98
1.00
1.00
1.00
0.77
Do not copy without permission
Range
0.80 - 1.05
0.88 - 0.96
0.97 - 0.995
0.99 - 0.997
0.97 - 0.99
0.98 - 0.993
0.30 - 0.995
0.00 - 0.995
0.00 - 1.00
0.95 - 1.00
0.70 - 1.00
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Type of arrays
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Tilt angle and azimuth
Roof Pitch
4/12 5/12 6/12 7/12 8/12 9/12 10/12 11/12 12/12 How I built a carbon-neutral house
Tilt Angle ( °)
18.4
22.6
26.6
30.3
33.7
36.9
39.8
42.5
45.0
Heading
N NE E SE S SW W NW Do not copy without permission
Azimuth Angle ( °)
0 or 360 45 90 135 180 225 270 315 41 of 56
Energy production by month
900 800 700 600 500 400 300 200 100 0
Assume dc rating=5 kW, inverter derating =0.77, azimuth=180 o , pitch=36.9
o (9/12), total annual kWh=6,121/7,615/7,840
Solar radiation 100Wh/m^2/day kWh fixed kWh 1D kWh 2D Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
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Energy vs. tilt and azimuth
6000
Assume 5 kW dc, inverter derating 0.77, NYC
5500 5000 4500 4000 3500 3000 2500 4/12 pitch 5/12 pitch 6/12 pitch 7/12 pitch 8/12 pitch 9/12 pitch 10/12 pitch 11/12 pitch 12/12 pitch
43 of 56 How I built a carbon-neutral house Do not copy without permission
Agenda and purpose
1.
2.
3.
4.
Geothermal heating, cooling and domestic hot water Photovoltaic solar panels Other considerations $$$ (costs, incentives, pay back periods) Outside the scope of this discussion Global warming and its effects Energy policy and “dependence on foreign oil” The travails of building a house How I built a carbon-neutral house Do not copy without permission 44 of 56
3. Other considerations
Insulation Polar walls R-30 (2x8) Double-fascia roof R-51 Windows Double-pane, low-e argon coating 100% compact fluorescent lamps (CFLs) Think “passage lighting” during design Can now use with dimmers!
Transportation alternatives Use bicycles, carpool, hybrids, electric cars, public transportation… “Passive power” reduction/instrumentation Instrumentation is a powerful way to change habits Reduce, recycle, reuse How I built a carbon-neutral house Do not copy without permission 45 of 56
Agenda and purpose
1.
2.
3.
4.
Geothermal heating, cooling and domestic hot water Photovoltaic solar panels Other considerations $$$ (costs, incentives, pay back periods) Outside the scope of this discussion Global warming and its effects Energy policy and “dependence on foreign oil” The travails of building a house How I built a carbon-neutral house Do not copy without permission 46 of 56
Rule of thumb for geothermal
1600 sq. ft. requires one 3 ton unit, one 300’ vertical well, and costs ~$10K Add one unit/well for domestic hot water Federal Gov’t will kick back $3K (30%) per heat pump as a tax credit How I built a carbon-neutral house Do not copy without permission 47 of 56
Payback time: geothermal
Federal income tax credit of 30% of the cost with no limit till 2016 (undiminished by AMT) For everything up to the heat pump, including labor/install; need to fill form 5695 Requires COP >= 3.5, EER >= 15 for DX systems Different ways of looking at it HVAC system doubles in cost Provides heating at equivalent of $1.25/gallon of oil Additional monthly mortgage cost is less than the monthly energy savings Pays for itself from day one!
$1 per year energy savings = $20.73 of house value* Our payback analysis indicates a 9 year payback period We have no backup system for heat, A/C, hot water!
How I built a carbon-neutral house Do not copy without permission *R. Nevin and G. Watson,
Appraisal Journal
, October 1998, pp. 401 —409 48 of 56
Insulation, doors, windows
Federal income tax credit of 30% of qualified insulation, furnace, doors, windows, storm door and storm window material costs only Capped at $1,500 Must fill form 5695 Must be the first user This is a post-AMT tax credit How I built a carbon-neutral house Do not copy without permission 49 of 56
Payback time: solar panels
Solar panel prices are falling!
Federal income tax credit of 30% of “system cost” with no limit till 2016 Survives AMT Includes labor, installation Must fill form 5695 NY state See NYSERDA web site at http://www.nyserda.com/ NY prior to 10/13/09: $4/W for the first 5 kW, $3/W for the next 5 kW NY prior to 01/11/10: $2.50/W for the first 4 kW, $1.50/W for the next 4 kW NY now: $1.75/W for the first 5 kW Incentives are higher for EnergyStar labeled homes and Built-in Photovoltaics (BIPVs) Additional $5K tax credit; additional 8.75% property tax credit (now 5%) VT state VT: $1.75/W for the first 5 kW CA state See CA web site at http://www.cpuc.ca.gov/PUC/energy/solar California Solar Initiative: see next page, rebates diminish with popularity Utility must buy back excess power at supply cost On each anniversary of installation, excess generation is paid at “wholesale rate” “Time-of-day” billing is very advantageous for solar customers Payback period in our case is ~9 years How I built a carbon-neutral house Do not copy without permission 50 of 56
California information
Expected Performance-Based Buy-Down Performance-Based Incentive How I built a carbon-neutral house Do not copy without permission 51 of 56
Berkeley has special financing
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LA funds solar by electric premiums
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Imagine? Floating wind turbines
The first units in production will be 4 kW residential units that will cost $10,000 How I built a carbon-neutral house Information courtesy of Paul Villarrubia Do not copy without permission 54 of 56
Energy from photosynthesis?
How I built a carbon-neutral house Do not copy without permission http://www.popsci.com/technology/article/2010-03/video-artificial-photosynthesis-produces-enough-energy-power-house-one-bottle-water 55 of 56
Thank you!
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Appendix
Properties of puron vs. freon Basic physics: electricity light How I built a carbon-neutral house Do not copy without permission 57 of 56
Puron vs. freon
ASHRAE number Type of refrigerant Chemical name Chemical formula Composition (by mass) Molecular weight Boiling point (at 1.0 atm), o F Freezing point (at 1.0 atm), o F Critical temperature, o F Critical pressure, psia Saturated liquid density (at 86 o F), lb/ft 3 R-410A HFC azeotropic mixture of HFC-32 and HFC-125 Difluoromethane (R-32) Pentafluoroethane (R-125) CH 2 F 2 (R-32), CHF 2 CF 3 (R-125) R-32: 50%, R-125: 50% 72.6
-62.9
-247 163 720 64.64
How I built a carbon-neutral house Do not copy without permission R-22 HCFC Chlorodifluo romethane CHClF 2 N/A 86.5
-41.4
-256 205 722 73.09
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Puron vs. freon
ASHRAE number Specific heat of liquid (at 86 o F), Btu/lb o F Specific heat of vapor at constant pressure C P 86 o F, 1.0 atm), Btu/lb o F (at Flammable range (% volume in air) ANSI/ASHRAE Standard 34-1992 Safety Group Classification Ozone depletion potential (ODP)* Global warming potential (GWP)**, 100 yr.
Montreal Protocol phase out date R-410A 0.42
0.21
None A1 0.00
1,997 None R-22 0.31
0.16
None A1 0.05
1,780 2030 Lower TEWI*** (Total Equivalent Warming Impact) Higher pressure, lower mass flow, quieter, higher efficiency, synthetic lubricants Over 1,000,000 units 1995-2004 *ODP: a normalized indicator of the ability of a refrigerant to destroy stratospheric ozone molecules referenced to a value of 1.000 for CFC-11. How I built a carbon-neutral house Do not copy without permission 59 of 56 ***TEWI: takes into account direct (refrigerant leaks into the atmosphere: 7.5%) + indirect effects (effects from electricity production used to run system: 92.5%).
Basic physics: electricity
light
How I built a carbon-neutral house Courtesy Wikipedia and HowStuffWorks.com
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