Passive House as a Baseline for Plus- Energy Residential Microgrids. Kurt Hurley

Transcription

1 Passive House as a Baseline for Plus- Energy Residential Microgrids Kurt Hurley kurthurley@gmail.com

2 Post-Passive House Project questions: A Passive House really uses 80% less energy, but what about the remaining 20%? Electric Vehicles reduce GHG Emissions but it depends on whose electricity?

3 Optional Islandable Microgrid

4 Four Microgrid Components Energy Demand (Building) Energy Supply Energy Storage Electric Vehicles

5 Benefits of Islandable Microgrids 1) Opportunity to achieve Zero Carbon without waiting for Utility RPS compliance 2) Eliminating pricing uncertainty of future gridsourced energy 3) Support of Peak Load further reduces carbon 4) More proximal AC Reactive Power benefits grid 5) Avoided New Transmission Infrastructure & Power Transmission Losses (TAC now 1.5 kw/h) = $10B savings over 20 yrs with high DG scenario 6) Attain Disaster Resiliency & Optional Autonomy

6 Why this topic matters! Figure 1 Commercial & Residential Buildings Transportation

7 Site Examples for Microgrid Scenarios Figure 2 ID Project Name/ SQFT HDD (65ºF) CDD (65ºF) Annual Electric kwh (site) Jun / Daily kwh Dec / Daily kwh Space Heating DHW #1 Midori Haus/ / (4390)* (19)* Hydronic Solar Thermal Hydronic Solar Thermal #2 NZE Selma CA/ / Ducted HP HPWH #3 NIST Test/ / ?? Air Heat Xchanger HPHW? #4 NIST Test as Hydronic PH / /1307??? Hydronic Solar Thermal * Total Site Energy use with 29.3 KWh/Therm Hydronic Solar Thermal

8 Figure 3 Seasonal Electric Usage Day/Night Property Name + Annual Electric kwh Midorihaus 2870 Selma NZE NIST Test NIST TEST as PH Average Daily June / Dec kwh June Avg Day kwh June Avg Night kwh Dec Avg Day kwh Dec Avg Night kwh 7.2 / /40.0

9 PV Array-Storage Capacity vs Autonomy/Cost Figure 4 Project Name Scenario A: 8-12 hr back up only Midorihaus Santa Cruz CA NZE Selma CA NIST Test Gaithersburg MD NIST Test as PH No PV-10 kwh $16K No PV-40 kwh $53K No PV-45kWh $61K Scenario B: Structure Off Electric Grid / EVs Grid-Charged Scenario C: Structure + EVs Off Electric Grid 2.5 kw-10kwh $28K 6 kw 25 kwh $57K 10 kw-40kwh $103K 13.5 kw 55kWh $124K 11 kw-45kwh $116K 14.5 kw- 60kWh $135K

10 10yr GHG Emissions Microgrid Scenario (B): Decade #1 Figure 5

11 10 yr GHG Emissions Microgrid Scenario (B): Decade #2 Figure 6

12 10 yr GHG Emissions Microgrid Scenario (B): Decade #1 Solar Thermal makeup converted to electric HPWH Figure 7

13 10 yr GHG Emissions Microgrid Scenario (B) Decade #1 Solar Thermal makeup converted to electric HPWH Re Calculation with Site Irradiance +21% PV + 83% Inverter Figure 8

14 10 yr GHG Emissions Microgrid Scenario (B) Decade #1 Re-Calculation with US egrid AVG 2009 EF adding 15% renewables Figure 9

15 Primary Energy GHG Emissions from EV charging using utility grid Figure miles of driving a ~20 mile/gallon gasoline vehicle results in 50 gal gasoline use = (300lbs HCs) and ~1000 lbs of GHG emissions 1000 miles of EV 0.3 kwh/mile arises from the use of [0.3 MWh/0.83 AVG EV charge efficiency ] = MWh electricity charge with an AVG 441 lbs of GHG emissions per US EPA 2009 (0.581 kg/kwh)..but with PGE 2014 forecast Emissions Factor (0.187 kgco2/kwh) = 148 lbs

16 10 year EV Charging GHG Emissions in kg CO2 20,000 driving miles/yr (Decade #1) 0.2 kwh/mile EV* Microgrid Scenario C 0.3 kwh/mile EV* Microgrid Scenario C 0.2 kwh/mile EV on PGE grid kwh/mile EV on PGE grid kwh/mile EV on US egrid 2009 AVG 0.3 kwh/mile EV on US egrid 2009 AVG Figure 11 10yr (Decadal) Source Energy Emissions kg 20,000 miles/yr Embedded Carbon in kg CO2 equivalent for 50kWh Li Ion Electric Vehicle Battery Embedded Carbon in kg CO2 equivalent for additional 3.5kW PV for EV Charging in Microgrid C 20 MPG Gasoline Vehicle Microgrid Scenario C includes kg CO2 equivalent for a 15kWh stationary battery kg CO2

17 10 year EV Charging GHG Emissions in kg CO2 20,000 driving miles/yr (Decade #2) 0.2 kwh/mile EV* Microgrid Scenario C 0.3 kwh/mile EV* Microgrid Scenario C Microgrid Scenario C includes kg CO2 equivalent for a 15kWh stationary battery Figure kwh/mile EV on PGE grid kwh/mile EV on PGE grid kwh/mile EV on US egrid 2009 AVG 0.3 kwh/mile EV on US egrid 2009 AVG 20 MPG Gasoline Vehicle 10yr Source Energy Emissions in kg CO2 equivalent for 20,000 driving miles/yr Embedded Carbon in kg CO2 equivalent for 50kWh Li Ion Electric Vehicle Battery kg CO2

18 Key Study Findings.. 1) Transit Oriented Design (TOD) is imperative 2) (CSP) (CHP) Concentrating Solar Power with small steamelectric engine linked to salt thermal storage must scale commercially 3) Passive House must be combined with Microgrid scenarios (B) and (C) with today s available technology in carbon intensive sectors of the US egrid 4) Embedded GHG (Carbon Equivalent) for PV and Lithium Ion Batteries must diminish in harmony with reduced mfg costs and vastly improved performance 5) Substantive improvements in EV electric mileage efficiency must be enabled by policy: tax on vehicle class by mass

19 (1) Transit Oriented Design (TOD) An American Example: Charlotte NC Integrated Land Use and Transit Program (2007): 64 LRT stations serving 50 square miles Avoids several hundred million Single Occupancy Vehicle (SOV) miles driven per year

20 (1) Transit Oriented Design (TOD)

21 (1) TOD Property Value Impacts

22 (2) CSP-CHP: A Game Changer Micro CSP with Advanced Steam Engine Sollector Systems DAT CSP CHP Fulfills BOTH Heat + Electric Building Loads

23 (2) CSP-CHP: A Scalable Technology 5hp/3kW Schoell Engine 3.5-4X Energy per unit area of PV Provides Electric Power baseload American Innovators: Terajoule Focal Point Energy Sollector Systems Halotechnics Global Renewable Energy Engines

24 (2) CSP-CHP Commercialization Challenges I. DNI is essential for generation, PVT possible backup II. T MAX and Standby Losses limit access to stored heat energy III. Combined Plumbing & Electrical System Reliability IV. Challenge to achieve 25% efficiency at 10kW engine power V. Standardized plumbing components VI. Manufacturing volume must scale for affordability VII. New engine design reliability unproven for high volume mfg VIII. Potential for storage-bundled CSP-CHP at 1/3 cost of PV without storage!

25 (3) Utility Emissions Factors example: RPS under California SB X1-2 (2011) Under Section , each provider must ensure that by the end of 2013, no less than 50% of its renewables consist of California Content, with such percentage increasing to 65% by the end of 2016, and 75% thereafter. Also, each provider must ensure that by the end of 2013, no more than 25% of its renewables portfolio comprises REC Content, with such percentage declining to 15% by the end of 2016, and 10% thereafter. In essence, then, starting in 2017, all providers must procure no less than 75% of their renewables from California Content and no more than 10% from unbundled RECs, with the remainder from firmed and shaped products.

26 (3) NG Emission Factors are purely combustion-based and do not account for CH 4 GWP from gas-grid leakage

27 (4) Electric Loads served by PV: Ratio of AVG June to Dec Irradiance forces oversizing of PV Array by ~1.9X of peak output:

28 (4) Photovoltaic Technology Drivers I. Power Electronics: Power Optimizer; Micro-Inverter; Micro-String Inverter II. Smart-Design PV racking to speed install and cut Balance of System (BOS) costs III. Non-normal incidence AR coatings IV. Breaking 25% Efficiency barrier w/o Optical Concentration Sono tek V. Advanced Inverters improve system efficiency & enable grid Ancillary Services, e.g. provisioning Reactive Power Hi-Q Fronius

29 (4) Microgrid Cost Impact: Figure 13 Solar Thermal DHW and Space Heating transferred to Electric Backup Project Name Scenario A: 8-12 hr back up only Midorihaus NZE Selma CA NIST Test NIST Test as PH No PV-10 kwh $16K No PV-45kWh $61K No PV-40 kwh $53K No PV-25 kwh $34K Scenario B: Structure Off Electric Grid / EVs Grid-Charged 2.5kW-10kWh $28K (5kW-19kWh $52K)* Scenario C: Structure + EVs Off Electric Grid 6 kw 25 kwh $57K (8.5kW-34kWh $78K)* 10kW-45kWh $111K 13.5 kw- 60kWh $130K 10kW-40kWh $103K 13.5 kw 55kWh $124K * Make-up heating for Solar Thermal electric HPHW

30 (4) Passive House Negawatts Cost Parity to installed PV & higher NPV PH + Solar Thermal Solar Electric PV Δ of kwh would require ~ 10.8 kw PV Cost for 10.8 $4/w installed = $43K Solar PV lasts 30yrs, inverter last 10yrs NPV ~ $11K Passive House Negawatts last 60-70yrs & Comfort & IAQ NPV ~ $61K ($0.12/kWh, 3% annual inflation for electricity, 2% discount rate)

31 (4) Serving Cooling Loads with Heat Absorption Chillers use available Solar Irradiance 4.5 kw Solar Thermal Air Conditioner from Rotartica

32 (4) Lithium Ion Battery vs Lead Acid Lithium Ion: Specific energy: W h/kg Energy density: W h/l Specific power: W/kg 2.5 W h/us$ Lead Acid Specific energy: W h/kg Energy density: W h/l Specific power: 180 W/kg 7-18 W h/us$

33 (4) Lithium Ion Batteries Require complex charging sequence to avoid fire: Constant Current Phase Balance Phase Constant Voltage Phase Fire risk reduction reduces kwh capacity (w/select positive lithium metal phosphate anode materials) Generally non-toxic but LiAsF 6 may occur in electrolyte

34 (5) EV Electric Mileage Efficiency Less than 0.5% of the energy in the fuel of a typical modern auto actually moves the driver -Reinventing Fire, Amory Lovins 2011

35 An Exciting Future! Kurt Hurley