Facility produces at least as much energy on-site as it uses in a year

Transcription

1 Marc Claas, Research Intern Doug Reindl, Director Industrial Refrigeration Consortium University of Wisconsin-Madison What is Net-Zero? Net-Zero Site Energy Facility produces at least as much energy on-site as it uses in a year Net-Zero Source Energy produces at least as much energy as it uses in a year, when accounted for at the source Net-Zero Energy Costs $ utility pays owner for the energy the facility exports to grid is equal to or less than the amount the owner pays the utility for the energy services and energy used over the year Net-Zero Energy Emissions Building produces at least as much emissions-free renewable energy as it uses from emissions-producing energy sources 1

2 Interest in Net-Zero is High EISA 2007 is targeting net-zero energy for US commercial buildings New construction by 2030; 50% of stock by 2040; and 100% of stock by 2050 Net-zero, is it possible? residential dwellings = expensive but doable commercial buildings = expensive 2 and extremely difficult industrial = exp(expensive) and near impossible What is the challenge? Food manufacturing w/storage [Source: IRC, Unpublished] Healthcare facility [Source: EIA, Commercial Building Energy Consumption Survey, 2003] Office building [Source: EIA, Commercial Building Energy Consumption Survey, 2003] Residence, single family [Source: EIA, Residential Energy Consumption Survey, 2005] Energy Intensity, kbtu/ft 2 -yr 2

3 Sources of Electricity Production Solar Photovoltaic Concentrating Solar Power (CSP) Wind Biomass Photovoltaic Solar Resource 3

4 Concentrating Solar Resource Wind Resource (50m) 4

5 Biomass Resource Let s take a brief look at possible electric generation technologies for use in a net-zero food plant 5

6 Overview of Solar Power Technologies Photovoltaic (PV) Conversion of sunlight directly to electricity Solar Thermal Generation Heats working fluid which is used in power cycle Concentrating trough or power tower configs Stirling Dish Dish concentrates sunlight onto a Stirling engine/generator Photovoltaics (PV) The conversion of sunlight directly to DC electricity Utilize direct and indirect solar radiation (generally uses only energy in the visible spectrum) PV modules are either fixed mount or tracking Requires an inverter to convert DC to AC Output of module is sensitive to Incident radiation Ambient/module temperature 6

7 PV Fundamentals University of Central Florida Florida Solar Energy Center Department of Energy Department of Energy Concentrating Solar Power (CSP) Use of optics to magnify incident solar radiation Heated working fluid (oil, salt, or steam) used as source for traditional Rankine Cycle power block Oil HTF 390 C (734 F) Molten Salt HTF 565 C (1,049 F) Proven technology at the utility scale Capable of storing to extend operating window Innovations are being pursued e.g. supercritical CO2 for power block 7

8 Power Tower 565 C 290 C 9/10/2010 The CSP Technologies Trough (SEGS) Dish Stirling (SES) Linear Fresnel (Biotech Novasol) Power Tower ( Solar Two, U.S. DOE) Source: McMahan, Industry Trends in Renewable Energy IRC R&T Forum 2008 Source:M. Wagner, UW SEL Presentation (1/09) 8

9 Wind Turbines Converts wind into kinetic energy Rotating shaft can then turn a generator to produce electricity Numerous examples of multiple turbines installed for utility-scale electric generation Capacities up to 2 MW with 5 MW units currently being tested for off-shore use Significant new installations continue today Source: AWEA Biomass Generation of energy from plant or animal matter: wood, crop residue, animal byproducts, animal waste, etc Hybrid Poplar Burn a sustainable amount of wood for energy Harvest on a 6 year cycle Can harvest as needed Crop residue e.g. corn waste Need to collect, transport and store significant quantities Anaerobic digester Use organic waste to produce biogas Product waste Animal manure 9

10 Monthly Energy Use, kwh Monthly Peak Demand, kw 9/10/2010 The Prototype Facility Food production and storage facilities Production-driven electricity use Approximately 250,000 ft 2 of low temperature refrigerated storage and 250,000 ft 2 of production Energy use Annual electric energy use is 75,000 MW-h Average electrical consumption is typically 75% of maximum each month Electric demand ranges from MW each month Two locations considered: Madison & Phoenix Prototype Facility Energy Use Profile 9,000,000 14,000 8,000,000 Peak Demand 12,000 7,000,000 10,000 6,000,000 Energy Consumption 8,000 6,000 5,000,000 4,000 4,000,000 2,000 3,000,000-10

11 Analysis Tool NREL s Solar Advisor Model (SAM) Includes performance models for most solar technologies CSP - parabolic trough, dish-stirling, and power towers Flat plate and concentrating photovoltaic technologies Incorporates information on capital costs of equipment and technologies Assumes 30 year life cycle Net Zero: Photovoltaic Cells Madison, WI 56.6 MW nameplate 90 Acres of Panel Capital cost: $177 million Maintenance cost: $7 to 14 million (annual) Phoenix, AZ 44 MW nameplate 70 Acres of Panel Capital cost: $145 million Maintenance cost: $6 to 12 million (annual) With 1% System degradation Output starts at 79 million kwh Ends at 59 million kwh After 6 years output drops below 75 million kwh 11

12 Net Zero: Concentrating Troughs Madison, WI 37.8 MW nameplate 142 Acres of solar field Capital cost: $446 million Maintenance cost: $6 to 12 million (annual) Phoenix, AZ 18 MW nameplate 65 Acres of solar field Capital cost: $214 million Maintenance cost: $3 to 6 million (annual) Low annual performance degradation 6 hours of thermal storage Net Zero: Concentrating Power Tower Madison, WI 25.2 MW nameplate 375 Acres of land Capital cost: $240 million Maintenance cost: $4 to 7 million (annual) 12 hours of thermal storage Phoenix, AZ 18.9 MW nameplate 215 Acres of land Capital cost: $130 million Maintenance cost: $2 to 5 million (annual) 6 hours of thermal storage No annual performance degradation 12

13 Net Zero: Stirling Dish System Madison, WI 85 MW nameplate 190 Acres of solar field Capital cost: $257 million Maintenance cost: $6 to 12 million (annual) Phoenix, AZ 39 MW nameplate 87 Acres of solar field Capital cost: $118 million Maintenance cost: $3 to 6 million (annual) Assumed a 1% annual performance degradation Hybrid Poplar Net Zero: Bio Fuels Burn a sustainable amount of wood for energy Require 108 sq mi of land rotating on a 6 year harvest cycle Corn waste plant Purchase corn waste to burn Requires 17 square miles of farmland corn waste annually 46,400 tons of waste Anaerobic digester Use organic waste to produce biogas Cow manure Product waste 13

14 Wind Madison, WI Some wind resource No high wind areas Would need 29 GE 1.5 MW turbines Each tower requires a fall radius of 121 meters 11.3 acres of open space per turbine, 327 total acres 256 feet tall at hub 264 foot rotor diameter Wind Phoenix, AZ Some wind resource Hot spots with high winds Same situation as the Wisconsin plant unless in a class 3 or above region 14

15 Combining Techs in Madison Cover the roof with PV Assuming 500,000 ft 2 of roof PV can achieve 5148 MWh 6890 each year (6.8% - 9.1% of annual kwh) $6.9 million initial investment with $637k $1335k per year $34 million over 30 years Place wind turbines GE 1.5 MW turbines producing 2700 MWh each year 5 turbines produce 17% of annual use At about $2.5 million each, $12.5 million total $42.5 million over 30 years Install an anaerobic digester 1,615,000 lbs of waste per week Can produce 28% of annual electricity using a digester Totaling 52% of annual electricity production using 30 acres Summary Location Technology Capacity [MW] Madison Phoenix Capital Cost [$] Maint. Cost [$] Footprint [acres] PV million 7-14 million 90 Trough CSP million 6-12 million 142 Power Tower CSP million 4-7 million 375 Dish Stirling CSP million 6-12 million 190 PV million 6-12 million 70 Trough CSP million 3-6 million 65 Power Tower CSP million 2-5 million 215 Dish Stirling CSP million 3-6 million 87 15

16 Summary Technology Capacity [MW] Capital Cost [$] Maint. Cost [$] Footprint [acres] Wind million 2-4 million 327 Anaerobic Digester 10 Unknown 5-8 million 142 Conclusions Energy intensity of food manufacturing facilities is high The use of renewable energy sources to achieve a net-zero plant presents significant challenges High capital costs High operating cost Large area requirements Net-zero is not viable in this application today 16

17 Additional information 17

18 Annual Capacity Factor Fraction of year that equipment is operating at full power output CF P rating E out [Wh] [W] 8760 hr 35 Average Capacity Factors in the US Energy Source Capacity Factor Nuclear 87.0% Coal 68.5% Geothermal 51.7% Hydroelectric Conventional 36.4% Wind 23.7% Natural Gas 22.8% Solar Thermal and Photovoltaic 13.9% Petroleum 12.0% Energy Information Administration,

19 Wind Resource NREL Wind Resource NREL 19