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Contents Table of Contents 1 Executive Summary 2 Background and Research Challenge 2 Methodology I. Site Selection 2 II. Solar Energy Production 2 III. Emissions Reductions 3 IV. Battery Storage Potential 3 V. Policy Analysis 3 Results 4 Recommendations 5 Appendices Appendix A – Snapshot of Assumptions 6 Appendix B – Future Directions 6 Appendix C – Array Sizes for City Property 7 Appendix D – Early AAPS Estimates 10 Appendix E – PVWatts Documentation 16 Appendix F – GeoPlanner for ArcGIS 20 Appendix G – Battery Modeling with SAM 25 Appendix H – Emissions Reductions 27 Appendix I – Policies and Regulations 29

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University of Michigan Solar Microgrid Feasibility Study for City of Ann Arbor

Executive Summary

Background As part of its 2012 Climate Action Plan (CAP), the city of Ann Arbor, Michigan set goals to reduce emissions by 8 percent of year 2000 carbon dioxide equivalent (CO2e) levels by 2015, 25 percent by 2025, and 90 percent by 2050. Meeting such aggressive emissions reduction goals requires higher penetration of carbon-free energy sources into the city’s existing energy mix, with CAP solar goals calling for 24 MW of new solar installations by 2025. While the city’s electric utility provider is taking similarly aggressive steps to reduce its CO2e emissions through 2050, Ann Arbor has actively sought ways to expedite the transition from a fossil fuel-heavy portfolio to a more renewables-centered one by exploring the possibility of distributed generation resources on city-owned properties. This study, conducted by a multidisciplinary team of students from the University of Michigan, assessed the feasibility of solar microgrid installations at sites owned by the city of Ann Arbor. Research Challenge Ann Arbor’s request called for an assessment of possible sites for microgrids, focusing on resilience of assets and reduction of emissions. Initial research and discussion led to the conclusion that solar photovoltaic (PV) systems were the most easily adapted to available city sites, and thus represented the best opportunity for microgrid installations. Further discussion prompted the decision to incorporate battery storage at select sites for increased resilience potential. Wind, biomass, and hydroelectric power (via two local dams) were also initially considered as potential generation sources, but were not pursued in depth. In addition, all sites chosen for study were evaluated with respect to policy concerns in order to ensure that microgrid installations could be permitted according to state and federal laws and local ordinances. Methodology

I. Site Selection From an initial listing of 212 city-owned sites, land shapefiles were analyzed in GeoPlanner for ArcGIS in order to highlight city-owned land footprints that were relatively large and not considered parks or nature areas. The final listing of properties for further consideration numbered 60 sites and was comprised of fire stations 1-4, parking structures, the city landfill, and a collection of Ann Arbor Public School properties. Using building area footprint data from the City of Ann Arbor Data Catalog, new shapefiles were created that chose only specific sections of given land footprints that emphasized ideal orientation and exposure conditions for solar. A more detailed description of the site selection process is provided in Appendix A.

II. Solar Energy Production Determination of solar energy production potential at specific sites required calculation of annual energy-per-area solar ratios, in kWh/m2/yr; this was done using

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estimates from the National Renewable Energy Lab (NREL) PVWatts calculator for specific locations and array configurations. Solar ratios were then multiplied by specific land area footprints to create production estimates for each site, adjusted for incident solar radiation variation according to site geography and latitude. The PVWatts calculator uses historical weather data for a given area to calculate approximate incident solar radiation per square meter, both monthly and annually. NREL’s Typical Meteorological Year 3 (TMY3) dataset provided the solar radiation values used in this study. Calculations for solar system costs were completed using an estimated price of $1.75/Watt installed for a fixed standard array, ground-mounted or rooftop, which reflects current local installation costs in southeast Michigan. Industry experts maintain that costs are expected to decrease in coming years such that prices of $1.25/Watt installed could be possible by FY 2019, with estimates of approximately $1.50/Watt installed for carport solar installations. More detailed descriptions of the calculations involved are provided in Appendices E and F.

III. Emissions Reductions Life-cycle emissions reductions were estimated using NREL life cycle analysis (LCA) Harmonization emission factors of 870 gCO2/kWh for coal and 72 gCO2/kWh for solar. These factors take into account a life cycle assessment of an energy source, which allows accurate comparison of different fuel sources and realistically accounts for the amount of carbon dioxide emitted during construction and energy production. To calculate the amount of carbon dioxide emitted, the annual load for each site (in kWh) was multiplied by the gCO2/kWh/year ratio for each fuel source. The gCO2 value was then converted to tonnes of CO2 for a more digestible number. A more detailed description of the calculations is provided in Appendix H.

IV. Battery Storage Potential NREL’s System Advisor Model (SAM) was used to model and compare lithium-ion and lead-acid battery installations at select sites, using input values for desired capacity of six hours at peak load, desired maximum battery discharge rate (C-rate) of 0.17, and standard voltage of 238 V. Final assumptions developed for consistent and comparable estimates specified lithium-ion nickel manganese cobalt oxide (NMC) batteries sized for six hours at peak load, for resilience purposes. Calculations for battery system costs were completed using a conservative estimated price of $600/kWh installed, although industry experts have indicated that battery costs are also decreasing. A more detailed description of the battery model decision-making process can be found in Appendix G.

V. Policy Analysis Site installation potential was analyzed for policy constraints based on location, ownership, and size according to Michigan Compiled Laws, Chapter 460 (Public Utilities) and the Ann Arbor Code of Ordinances. Federal and Michigan state tax codes were also evaluated as potential barriers to solar PV installation due to finance and ownership. Existing policies were cross-referenced with ongoing docket reports for state- and

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federal-level legislative proceedings, which are currently ongoing as of September 2017, in order to highlight potential changes that could influence the feasibility of renewable installations. Policy conclusions were used to inform decision-making on future work and final recommendations. A more detailed collection of related policy and regulatory notes can be found in Appendix I.

Results Solar and battery installations at fire stations 2,3, and 4 would cost approximately $306,200 and would result in total LCA emissions reductions of 81.4 tonnes of CO2e/year, with a combined potential generation capacity of 162.3 MWh/year. Fire station 1 has a solar generation potential of 186 MWh/year, but has an annual load of 377 MWh/year; by installing solar panels onsite, it would result in an LCA emissions reduction of 93.4 tonnes of CO2e/year. The Maynard parking structure, highlighted as an example of a typical parking structure, was shown to have a generation potential of 497 MWh/year and an LCA emissions reduction potential of 249 tonnes of CO2e/year at a cost of $737,000, assuming 50 percent usage of rooftop area. The city landfill has a solar generation potential of 40,600 MWh/year and an LCA emissions reduction potential of 20,300 tonnes of CO2e/year, at a cost of $59,500,000 and using 112 acres of a 120-acre total land footprint. Importantly, of the total land footprint, 8 acres were set aside for operations and management, and only 50 percent (56 acres) of the remaining space is assumed available for panel coverage in order to enable operations and maintenance. The total solar generation potential of Ann Arbor Public School properties was estimated to be 35,200 MWh/year, with rooftop potential accounting for 22,800 MWh/year and parking lot potential accounting for 12,400 MWh/year. Total LCA emissions potential for the Ann Arbor Public Schools was estimated to be 17,600 tonnes of CO2e/year. The results are summarized in the Table 1 below.

Location Cost ($) Generation Capacity

(MWh/year)

Emissions Reduction

(tonnes CO2e/year)

Array Size (kW)

Payback Period, solar only

(years)

Payback Period, solar + battery (years)

Fire Station 1

276,000 186 93.4 158 10 23

Fire Stations 2,

3, and 4

306,2000 162 81.4 138 10 13

Maynard Parking

Structure

737,000 497 249 422 10 --

Landfill 59,500,000 40,6000 20,3000 * 10 -- Ann Arbor

Public Schools

* 35,200 17,600 * 10 --

Table 1:Summary of cost, generation potential and emissions reduction potential of select sites. For Fire Stations 2, 3, and 4, each value listed represents the combined total of all three fire stations. * Values left out of table indicate complex results more accurately described in appendices. Some payback period values were left blank as they were not calculated or not reflected in recommendations.

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Recommendations As the state of Michigan currently has no laws directly enabling community solar, solar easements, or microgrids, and has no state-level tax incentives for renewable projects, the city of Ann Arbor was encouraged to work with third parties and the electric utility to explore pilot programs for community solar and landfill solar systems, especially for the city landfill and public schools. For resilience purposes, a recommendation was also made for exploration of a core downtown area microgrid of city-owned critical sites, which could potentially allow all fire stations and other critical service buildings to island in the event of a wider grid outage, despite any individual building having a low generation potential. Finally, recommendations were made detailing the need for future study, especially with respect to future policy changes at the state and federal level, potential changes in price of installation, and potential inclusion of additional renewable generation resources such as hydropower, geothermal, and natural gas and small-wind turbines.

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Appendices

Appendix A: Summary of Assumptions and Relevant Sources Used in Study Solar Arrays Tilt 34 degrees, South-facing Efficiency 15% (standard) Average generation potential 177 kWh/m2/yr (fixed rooftop)

179 kWh/m2/yr (fixed open rack) Operations and Management coverage Landfill and Parking: 50%

Rooftop: 62.5% (NREL 2016) SAM Size 6 hours at peak load Battery use Storage, resiliency Battery type Li-ion Costs PV System $1.75/Watt installed Battery $600/kWh Emissions DTE 2016 fuel mix

NREL 2013 emissions factors Appendix B: Future Directions for Study To close the gap between CAP carbon emissions goals and identify low-emissions energy potential, more study is needed in order to incorporate renewable generation sources in addition to solar PV, bolster resilience for the Wheeler Center and Water Treatment Plant, convert remaining diesel generators to natural gas, and explore a core downtown microgrid of city-owned assets. Additionally, cooperation with Ann Arbor Public Schools should continue in order to conduct detailed assessments of school properties, and could potentially culminate in a robust project template for use in future assessments.

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Appendix C: Array Size Estimates for Select City Properties

Using Geoplanner Std. Rooftop Model (Annual)

Building Name Array Size (kW) Generation - Std (kWh/yr)

Ann Arbor Senior Center 60.21 71134.2 Bryant Community Center NA NA Buhr Park Bathhouse 178.19 210519.9 Cobblestone Farm Visitor Center 29.67 35053.2 Kerrytown Farmer’s Market 230.62 272462.6 Fuller Park Bathhouse 98.84 116773.0 Mack Pool 295.52 349137.7 Northside Community Center 18.21 21513.9 Veteran’s Memorial Bathhouse and Ice Arena 253.12 299044.8 2700 S. Industrial Hwy -- Ann Arbor Transportation “TheRide” 2275.43 2688272.8 Ann Arbor Municipal Airport Admin Building 363.24 429144.5 Ann Arbor Municipal Center (Justice and Larcom) 781.72 923551.4 Fire Station 1 (5th) 197.41 233227.1 Fire Station 2 (E Stadium) 41.73 49301.3 Fire Station 3 (Jackson) 70.07 82783.2 Fire Station 4 (Huron Pkwy) 60.19 71110.6 Fire Station 5 (Plymouth) 182.43 215529.2 Fire Station 6 (Briarwood) 130.52 154200.9 Forest Ave Parking 553.04 653380.8 Fourth/Washington Parking 215.88 255048.2 Fourth/William Parking 565.09 667617.1 Liberty Parking 446.25 527215.4 Maynard Parking 842.23 995040.1 Blake Transit Center 128.75 152109.8 Wheeler Center 1341.16 1584493.5 Water Treatment Plant (WTP) 1674.48 1978289.4 Wastewater Treatment Plant (WWTP) 3531.37 4172084.3

Solar Ratio for 34º Tilted Rooftop in A2 using TMY3 Data 165.4009091 kWh/m^2/yr

165.4009091

Using Geoplanner Std. Rooftop Model (Annual) 80% ARRAY

SIZE 80% GENERATION

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Building Name Ann Arbor Senior Center 48.168 56907.4 Bryant Community Center Buhr Park Bathhouse 142.552 168415.9 Cobblestone Farm Visitor Center 23.736 28042.5 Kerrytown Farmer’s Market 184.496 217970.0 Fuller Park Bathhouse 79.072 93418.4 Mack Pool 236.416 279310.2 Northside Community Center 14.568 17211.1 Veteran’s Memorial Bathhouse and Ice Arena 202.496 239235.9 2700 S. Industrial Hwy -- Ann Arbor Transportation “TheRide” 1820.344 2150618.2 Ann Arbor Municipal Airport Admin Building 290.592 343315.6 Ann Arbor Municipal Center (Justice and Larcom) 625.376 738841.1 Fire Station 1 (5th) 157.928 186581.7 Fire Station 2 (E Stadium) 33.384 39441.0 Fire Station 3 (Jackson) 56.056 66226.5 Fire Station 4 (Huron Pkwy) 48.152 56888.5 Fire Station 5 (Plymouth) 145.944 172423.4 Fire Station 6 (Briarwood) 104.416 123360.7 Forest Ave Parking 442.432 522704.7 Fourth/Washington Parking 172.704 204038.6 Fourth/William Parking 452.072 534093.7 Liberty Parking 357 421772.3 Maynard Parking 673.784 796032.0 Blake Transit Center 103 121687.8 Wheeler Center 1072.928 1267594.8 Water Treatment Plant (WTP) 1339.584 1582631.5 Wastewater Treatment Plant (WWTP) 2825.096 3337667.5

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50% Array Size For Parking

Building Name Array Size (kW)

Generation - Std (kWh/yr)

Forest Ave Parking 553.04 653380.8 276.52 326690.4242 Fourth/Washington Parking 215.88 255048.2 107.94 127524.1009 Fourth/William Parking 565.09 667617.1 282.545 333808.5705 Liberty Parking 446.25 527215.4 223.125 263607.6989 Maynard Parking 842.23 995040.1 421.115 497520.0274 Blake Transit Center 128.75 152109.8 64.375 76054.88232 Wheeler Center 1341.16 1584493.5 670.58 792246.726 Water Treatment Plant (WTP) 1674.48 1978289.4 837.24 989144.6939 Wastewater Treatment Plant (WWTP) 3531.37 4172084.3 1765.685 2086042.173

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Appendix D: Ann Arbor Public Schools Solar Potential

Rooftops: Assuming 62.5% available rooftop space. Highlighted values shown in presentation.

School Name Area (acres) Area (m^2) Solar Area (62.5%) A2 Virtual + Academy Abbot Elementary School 1.37 5544.1982 3465.123875 Allen Elementary School 1.45 5867.947 3667.466875 Angell Elementary School 0.484 1958.68024 1224.17515 Ann Arbor Open @ Mack School 0.616 2492.86576 1558.0411 Ann Arbor STEAM @ Northside School 1.23 4977.6378 3111.023625 Bach Elementary School 0.783 3168.69138 1980.432113 Bryant Elementary School 1.28 5179.9808 3237.488 Burns Park Elementary School 0.462 1869.64932 1168.530825 Carpenter Elementary School 1.19 4815.7634 3009.852125 Clague Middle School 2.22 8984.0292 5615.01825 Community High School 0.512 2071.99232 1294.9952 Dicken Elementary School 1.08 4370.6088 2731.6305 Eberwhite Elementary School 1.13 4572.9518 2858.094875 Forsythe Middle School 3.25 13152.295 8220.184375 Haisley Elementary School 1.36 5503.7296 3439.831 Huron High School 4.402 17814.27772 11133.92358 King Elementary School 1.4 5665.604 3541.0025 Lakewood Elementary School 1.06 4289.6716 2681.04475 Lawton Elementary School 0.357 1444.72902 902.9556375 Logan Elementary School 1.29 5220.4494 3262.780875 Mitchell Elementary School 1.31 5301.3866 3313.366625 Pathways To Success Academic Campus 1.01 4087.3286 2554.580375 Pattengill Elementary School 1.24 5018.1064 3136.3165 Pioneer High School 6.55 26506.933 16566.83313 Pittsfield Elementary School 0.975 3945.6885 2466.055313 PreSchool and Family Center 1.02 4127.7972 2579.87325 Scarlett Middle School 2.69 10886.0534 6803.783375 Skyline High School 3.87 15661.3482 9788.342625 Slauson Middle School 1.45 5867.947 3667.466875 Tappan Middle School 1.44 5827.4784 3642.174 Thurston Elementary School 1.32 5341.8552 3338.6595 Wines Elementary School 1.14 4613.4204 2883.38775 Totals 50.941 206151.0953 128844.4345

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School Name Standard Array Size

(kW) Standard (kWh/yr)

Standard (MWh/yr)

A2 Virtual + Academy Abbot Elementary School 519.7685813 614072.852 614.072852 Allen Elementary School 550.1200313 649931.1207 649.9311207 Angell Elementary School 183.6262725 216942.5258 216.9425258 Ann Arbor Open @ MS 233.706165 276108.6692 276.1086692 Ann Arbor STEAM @ Northside School 466.6535438 551320.8817 551.3208817 Bach Elementary School 297.0648169 350962.8052 350.9628052 Bryant Elementary School 485.6232 573732.2997 573.7322997 Burns Park Elementary 175.2796238 207081.5019 207.0815019 Carpenter Elementary 451.4778188 533391.7474 533.3917474 Clague Middle School 842.2527375 995066.9573 995.0669573 Community High School 194.24928 229492.9199 229.4929199 Dicken Elementary School 409.744575 484086.6279 484.0866279 Eberwhite Elementary 428.7142313 506498.0458 506.4980458 Forsythe Middle School 1233.027656 1456742.167 1456.742167 Haisley Elementary School 515.97465 609590.5684 609.5905684 Huron High School 1670.088536 1973101.237 1973.101237 King Elementary School 531.150375 627519.7028 627.5197028 Lakewood Elementary 402.1567125 475122.0607 475.1220607 Lawton Elementary School 135.4433456 160017.5242 160.0175242 Logan Elementary School 489.4171313 578214.5833 578.2145833 Mitchell Elementary School 497.0049938 587179.1505 587.1791505 Pathways To Success camp. 383.1870563 452710.6427 452.7106427 Pattengill Elementary 470.447475 555803.1653 555.8031653 Pioneer High School 2485.024969 2935895.752 2935.895752 Pittsfield Elementary School 369.9082969 437022.6501 437.0226501 PreSchool and Family Ctr 386.9809875 457192.9263 457.1929263 Scarlett Middle School 1020.567506 1205734.286 1205.734286 Skyline High School 1468.251394 1734643.75 1734.64375 Slauson Middle School 550.1200313 649931.1207 649.9311207 Tappan Middle School 546.3261 645448.8371 645.4488371 Thurston Elementary School 500.798925 591661.434 591.661434 Wines Elementary School 432.5081625 510980.3294 510.9803294 Totals 19326.66518 22833200.84 22833.20084

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School Name Premium Array Size (kW)

Premium (kWh/yr)

Premium (MWh/yr)

A2 Virtual + Academy Abbot Elementary School 658.3735363 784644.4942 784.6444942 Allen Elementary School 696.8187063 830463.1508 830.4631508 Angell Elementary School 232.5932785 277202.8724 277.2028724 Ann Arbor Open @ Mack School 296.027809 352803.6558 352.8036558 Ann Arbor STEAM @ Northside School 591.0944888 704461.8452 704.4618452 Bach Elementary School 376.2821014 448450.1014 448.4501014 Bryant Elementary School 615.12272 733098.5055 733.0985055 Burns Park Elementary School 222.0208568 264602.7418 264.6027418 Carpenter Elementary School 571.8719038 681552.5169 681.5525169 Clague Middle School 1066.853468 1271467.721 1271.467721 Community High School 246.049088 293239.4022 293.2394022 Dicken Elementary School 519.009795 618551.8641 618.5518641 Eberwhite Elementary School 543.0380263 647188.5244 647.1885244 Forsythe Middle School 1561.835031 1861382.924 1861.382924 Haisley Elementary School 653.56789 778917.1621 778.9171621 Huron High School 2115.445479 2521171.579 2521.171579 King Elementary School 672.790475 801826.4904 801.8264904 Lakewood Elementary School 509.3985025 607097.1999 607.0971999 Lawton Elementary School 171.5615711 204465.7551 204.4657551 Logan Elementary School 619.9283663 738825.8376 738.8258376 Mitchell Elementary School 629.5396588 750280.5018 750.2805018 Pathways To Success Academic Campus 485.3702713 578460.5395 578.4605395 Pattengill Elementary School 595.900135 710189.1773 710.1891773 Pioneer High School 3147.698294 3751402.509 3751.402509 Pittsfield Elementary School 468.5505094 558414.8773 558.4148773 PreSchool and Family Center 490.1759175 584187.8716 584.1878716 Scarlett Middle School 1292.718841 1540652.328 1540.652328 Skyline High School 1859.785099 2216477.513 2216.477513 Slauson Middle School 696.8187063 830463.1508 830.4631508 Tappan Middle School 692.01306 824735.8187 824.7358187 Thurston Elementary School 634.345305 756007.8338 756.0078338 Wines Elementary School 547.8436725 652915.8565 652.9158565 Totals 24480.44256 29175602.32 29175.60232

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Parking lots: Assuming 50% available parking lot space. All fixed arrays; ground mounted.

School Name Area (acres) Area (m2) Solar Area (50%) A2 Virtual + Academy Abbot Elementary School 0.184 744.62224 372.31112 Allen Elementary School 0.478 1934.39908 967.19954 Angell Elementary School 0.141 570.60726 285.30363 Ann Arbor Open @ Mack School 0.736 2978.48896 1489.24448 Ann Arbor STEAM @ Northside School 0.442 1788.71212 894.35606 Bach Elementary School 0.199 805.32514 402.66257 Bryant Elementary School 0.997 4034.71942 2017.35971 Burns Park Elementary School 0.582 2355.27252 1177.63626 Carpenter Elementary School 0.759 3071.56674 1535.78337 Clague Middle School 0.696 2816.61456 1408.30728 Community High School 1.25 5058.575 2529.2875 Dicken Elementary School 0.228 922.68408 461.34204 Eberwhite Elementary School 1.144 4629.60784 2314.80392 Forsythe Middle School 1.861 7531.20646 3765.60323 Haisley Elementary School 0.738 2986.58268 1493.29134 Huron High School 5.926 23981.69236 11990.84618 King Elementary School 0.436 1764.43096 882.21548 Lakewood Elementary School 0.227 918.63722 459.31861 Lawton Elementary School 0.48 1942.4928 971.2464 Logan Elementary School 0.433 1752.29038 876.14519 Mitchell Elementary School 0.32 1294.9952 647.4976 Pathways To Success Academic Campus 0.223 902.44978 451.22489 Pattengill Elementary School 0.177 716.29422 358.14711 Pioneer High School 5.478 22168.69908 11084.34954 Pittsfield Elementary School 0.297 1201.91742 600.95871 PreSchool and Family Center 0.713 2885.41118 1442.70559 Scarlett Middle School 0.941 3808.09526 1904.04763 Skyline High School 6.098 24677.75228 12338.87614 Slauson Middle School 0.56 2266.2416 1133.1208 Tappan Middle School 0.409 1655.16574 827.58287 Thurston Elementary School 0.481 1946.53966 973.26983 Wines Elementary School 0.468 1893.93048 946.96524 Totals 34.102 138006.0197 69003.00986

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School Name Standard (kWh/yr)

Standard (MWh/yr)

Premium (kWh/yr)

A2 Virtual + Academy Abbot Elementary School 66654.63567 66.65463567 84944.02582 Allen Elementary School 173157.1514 173.1571514 220669.8062 Angell Elementary School 51077.73712 51.07773712 65092.9763 Ann Arbor Open @ Mack School 266618.5427 266.6185427 339776.1033 Ann Arbor STEAM @ Northside School 160116.027 160.116027 204050.3229 Bach Elementary School 72088.43749 72.08843749 91868.81053 Bryant Elementary School 361166.6944 361.1666944 460267.3573 Burns Park Elementary School 210831.5106 210.8315106 268681.6469 Carpenter Elementary School 274950.3721 274.9503721 350394.1065 Clague Middle School 252128.4045 252.1284045 321310.0107 Community High School 452816.8184 452.8168184 577065.3928 Dicken Elementary School 82593.78768 82.59378768 105256.7276 Eberwhite Elementary School 414417.9522 414.4179522 528130.2475 Forsythe Middle School 674153.6792 674.1536792 859134.9568 Haisley Elementary School 267343.0496 267.3430496 340699.4079 Huron High School 2146713.973 2146.713973 2735751.614 King Elementary School 157942.5063 157.9425063 201280.409 Lakewood Elementary School 82231.53422 82.23153422 104795.0753 Lawton Elementary School 173881.6583 173.8816583 221593.1108 Logan Elementary School 156855.7459 156.8557459 199895.4521 Mitchell Elementary School 115921.1055 115.9211055 147728.7405 Pathways To Success Academic Campus 80782.5204 80.7825204 102948.4661 Pattengill Elementary School 64118.86149 64.11886149 81712.45962 Pioneer High School 1984424.425 1984.424425 2528931.377 Pittsfield Elementary School 107589.2761 107.5892761 137110.7373 PreSchool and Family Center 258286.7132 258.2867132 329158.1 Scarlett Middle School 340880.5009 340.8805009 434414.8277 Skyline High School 2209021.567 2209.021567 2815155.812 Slauson Middle School 202861.9346 202.8619346 258525.296 Tappan Middle School 148161.663 148.161663 188815.7965 Thurston Elementary School 174243.9117 174.2439117 222054.7631 Wines Elementary School 169534.6168 169.5346168 216053.2831 Totals 12353567.31 12353.56731 15743267.22

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Carpenter Elementary School Array Size (kW)

Production (kWh/yr) Cost ($)

% Rooftop

Clague Middle School 1053.49883 1247195.362 1495968.338 79.95% Community High School 573.642405 682309.7383 814572.2151 33.86% Dicken Elementary School 478.945881 566680.4155 680103.151 85.55% Eberwhite Elementary School 775.9348193 920915.998 1101827.443 55.25% Forsythe Middle School 1797.868141 2130895.846 2552972.76 68.58% Haisley Elementary School 739.968351 876933.618 1050755.058 69.73% Huron High School 3468.715463 4119815.21 4925575.958 48.15% King Elementary School 663.482697 785462.209 942145.4297 80.05% Lakewood Elementary School 471.054504 557353.5949 668897.3957 85.37% Lawton Elementary School 281.1303056 333899.1825 399205.034 48.18% Logan Elementary School 620.8389098 735070.3292 881591.2518 78.83% Mitchell Elementary School 594.1296338 703100.256 843664.0799 83.65% Pathways To Success Academic Campus 450.8707898 533493.1631 640236.5214 84.99% Pattengill Elementary School 524.1695415 619922.0268 744320.7489 89.75% Pioneer High School 4147.6774 4920320.177 5889701.908 59.91% Pittsfield Elementary School 460.0521034 544611.9262 653273.9868 80.41% PreSchool and Family Center 603.386826 715479.6395 856809.2929 64.13% Scarlett Middle School 1306.174651 1546614.787 1854768.004 78.13% Skyline High School 3319.082815 3943665.317 4713097.597 44.24%

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Appendix E: PVWatts Tool Documentation Objective To estimate solar energy potential using GeoPlanner for ArcGIS, we need to input a solar production ratio (kW / m2 / timeUnit) to estimate how much potential we have for the space available. Ideally, annual values will allow us to estimate how much energy we can produce throughout the year via solar PV cells; however, it would also be beneficial to look into how daily production changes throughout the year as the inclination of direct solar rays changes throughout the year, relative to our location. Additionally, it would be beneficial to account for different types of solar modules (fixed array, rotating array, rooftop array…) and different film (standard, premium, thin) within the model, as these variables affect how much solar energy can be converted to AC output. Available Tools Using the PVWatts calculator from NREL (National Renewable Energy Laboratory), it’s fairly easy to get a good estimate for solar potential at a given location. The calculator allows users to input data specific to a project (including local weather data, array size, losses, etc.) and produce annual, monthly, and even hourly estimates for potential generation. NREL provides access to its application programming interface (API) for PVWatts. Using a developer key (free to obtain from NREL), users can make requests to the PVWatts calculator and quickly retrieve data in JSON or XML format. Using this API and the programming language Python (for ease of use and automation), it should be relatively straightforward to calculate all the ratios one would need to build an effective model. Methodology

• Take input from user to collect project-specific parameters (including location, module type, film coating, losses, tilt…)

• Build a GET request with Python to access the PVWatts API and retrieve data for a specific system/project (using standard request library)

• Summarize hourly data into daily data • Select max, min, and median generation estimates from daily data • Calculate ratios using max, min, median, and annual generation estimates and system

area (m2) Once the code is written for the above steps, the same process can be iterated over different module types and coatings to quickly generate the ratios we need to build out GeoPlanner model. Tool Availability The PVWattsTool python package is still in development, but the 1.1.0 version is available online via PyPI and GitHub.

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Installation Instructions PVWattsTool makes use of existing libraries (including pandas, requests, and PyQt5), so it’s important to make sure all of these are already installed or included with the installation. We recommend using the Anaconda 3.6 python build from Continuum. Anaconda includes the pandas library and pip for easy installation. Once Anaconda is installed (or python 3 with pip), you can enter the following command into command prompt/Terminal to install the PVWatts_Tool:

pip install PVWatts_Tool Caution: the package title is case sensitive!

Use Instructions Once installed, the tool can be opened using three commands:

1. Open python interpreter (enter ‘python’ into command prompt/Terminal)

2. Import the PVWatts_Tool package (enter ‘import PVWatts_Tool’ into python interpreter)

3. Use the run() method to activate the tool (enter ‘PVWatts_Tool.run()’ into the python interpreter)

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If the install was successful, the above commands should open the tool’s graphical user interface (GUI):

On the left side of the window, you can enter parameters to be used by the PVWatts calculator. On the right side, output will be generated after you click ‘Submit’. Information on the request parameters is available from the NREL website: https://developer.nrel.gov/docs/solar/pvwatts-v5/#request-parameters An API Key is required to use the tool; you can obtain a key for free from NREL: https://developer.nrel.gov/signup/ You can (optionally) save the hourly data from PVWatts to a .csv file using the file selector (‘Save as…’) at the bottom of the window. If left blank, the hourly data will not be saved.

Results Using the python tool, the following output was produced. Day ratios represent kWh/m2/day. Annual ratios represent kWh/m2/yr Ratios for Standard-Fixed Arrays:

Peak Day (max) Ratio: 0.978585 Low Day (min) Ratio: 0.088981 Average Day (median) Ratio: 0.534081 Annual Ratio: 190.63893127441406

Ratios for Standard-Rooftop Arrays:

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Peak Day (max) Ratio: 0.967221 Low Day (min) Ratio: 0.088941 Average Day (median) Ratio: 0.5299870000000001 Annual Ratio: 188.85488891601562

Ratios for Standard-Rotating Arrays:

Peak Day (max) Ratio: 1.509701 Low Day (min) Ratio: 0.07151899999999999 Average Day (median) Ratio: 0.668444 Annual Ratio: 244.98611450195312

Ratios for Premium-Fixed Arrays:

Peak Day (max) Ratio: 1.231726 Low Day (min) Ratio: 0.110598 Average Day (median) Ratio: 0.670947 Annual Ratio: 242.24444580078125

Ratios for Premium-Rooftop Arrays:

Peak Day (max) Ratio: 1.2184460000000001 Low Day (min) Ratio: 0.110559 Average Day (median) Ratio: 0.6681860000000001 Annual Ratio: 240.55996704101562

Ratios for Premium-Rotating Arrays:

Peak Day (max) Ratio: 1.92896 Low Day (min) Ratio: 0.088839 Average Day (median) Ratio: 0.8479720000000001 Annual Ratio: 311.5796813964844

Note The initial python script used to find the above results is currently available on GitHub (see above for link). Future revisions include:

• Test module to make sure the package does what it’s supposed to do • Periodic debugging/maintenance

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Appendix F: Using GeoPlanner for ArcGIS to investigate solar energy generation Introduction GeoPlanner for ArcGIS is a Geographic Information System (GIS) application from Esri that allows users to change current land usage in a certain area, and investigate the impacts of that land conversion. For the purpose of the Ann Arbor Solar Microgrid study, land within the City of Ann Arbor will be converted from its original usage, such as parking and utilities, to solar energy generation, choosing between premium or standard solar panels. The land specified for conversion in GeoPlanner has been chosen based on the following criteria:

• Land owned by the City of Ann Arbor • Public land in Ann Arbor • Flat or southward facing roofs/land • Specified as areas of interest by the City of Ann Arbor

After manually converting the pieces of land to solar energy generating lands, the actual kWh/yr production is calculated in GeoPlanner, allowing for a numerical assessment of energy generation for each of the different areas chosen for solar implementation. This section describes how this study utilized GeoPlanner to create a potential solar production grid in the City of Ann Arbor. Accessing GeoPlanner

• Request Access or accept invitation for “Ann Arbor Solar Project” group o Go to myorganization.maps.arcgis.com and sign in o Open “Groups” o Click on invitations, accept “Ann Arbor Solar Project”

• Open GeoPlanner for ArcGIS • Choose “Existing” and select the “Ann Arbor Solar Project”

• Once open, the map will display the chosen land available for conversion to solar energy

generation.

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• Click the top left button on the blue bar to open the Table of Contents. From here, you can see which layers are present in the map layout and turn them on/off as needed.

• There are three modes at the top of the map: Explore, Design, and Evaluate.

o Explore allows you to explore the map and add/model data. o Design allows you to draw or change the features in the map; we’ll be using this

function to model solar potential of selected land/buildings. o Evaluate mode allows you to make charts and reports based on the modeling

done in GeoPlanner. Creating a new scenario

• At the top of the GeoPlanner page, there is a list of selected Scenarios, with the default being ‘Scenario A”

• Click Scenario A, and in the drop down menu select “Create”. • For the title of the new scenario, use something with your name so it is easily

recognizable and distinguishable (i.e. yourname-scenarioA) • The summary, description, and tags fields can be left blank, or can be used to describe

the scenario (i.e. converting all parking in Ann Arbor to solar) • More scenarios can be created using the same steps as outlined above

Switching between scenarios: In order to switch between two scenarios, use the drop down scenario menu to activate the desired scenario; the activated scenario will display on the map.

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Initializing the scenario: When a new scenario is created, it is initially empty. Data will need to be added to the scenario in order to edit and convert land to show solar energy production.

• Activate the desired scenario • Use the scenario drop down menu and select “Import”

o For Step #1, Layers and Scenarios, choose the following For Source, choose “Default LandUse- Ann Arbor” For Target, choose “Solar Land Use” Leave the rest as defaults and click “next”

o For Step #2, Feature Type Mapping, choose the following Confirm the “select a field with feature type values for features” button is

selected For Source, choose “LANDUSE” Click “next”

o For Step #3, Field Mapping Leave all defaults the same and click “next”

o For Step #4, Execution Status Leave all defaults the same and click “next”

• All created scenarios can be initialized by following the steps as described above Editing a Scenario: To start converting land to solar generation, select the design tab on the blue bar.

• In the design bar, select the paint can icon. When this icon is selected, the land current land uses will come up on the right hand side in a “Symbol Palette” menu. At this point, the user can select what type of solar panel they would like to use. The different types of solar include:

o Premium Solar, rooftop o Premium Solar, 2- axis tracking o Premium Solar, non-tracking o Standard Solar, rooftop o Standard Solar, 2- axis tracking o Standard Solar, non-tracking

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• The standard and premium solar options vary in efficiency, with standard panels having ~15% efficiency, and premium panels having ~19% efficiency.

• When the type of desired solar has been decided, select this version of solar from the “Symbol Palette” menu

• To convert, select one of the polygons (the color-coded shapes representing a plot of land on the custom map), ensuring that the desired type of solar is selected in the “Symbol Palette”. The polygon will change from its original color to yellow, indicating this land is now being used to produce solar energy.

• Polygons can also be selected by using the “lasso” feature, located on the left hand side in the paint blue bar

Evaluating a Scenario

• In order to see how much energy these polygons are producing, select the “Evaluate” tab

• Under the evaluate tab, select dashboard o The dashboard will display 2 charts: one expressing the different land uses on

the map and one displaying the potential power from solar in kW/yr • The “Potential Power from Solar (kWh/yr)” chart will express how much solar energy is

being produced from the scenario created by converting polygons to solar in kW/yr

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This screenshot shows how much energy would be produced by converting all potential land to solar.

• The numbers from the “Potential Power from Solar” chart can then be compared to the load data for individual buildings within the City of Ann Arbor.

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Appendix G: Battery Storage Modeling using System Advisor Model (SAM) Three tools were considered for use in modeling battery storage capabilities at select sites:

1. Hybrid Optimization of Multiple Energy Resources (HOMER) Energy LLC’s Simulation Model

2. National Renewable Energy Lab’s (NREL) System Advisor Model (SAM) 3. PV-Syst

Of the three options, HOMER and PV-Syst are both costly, while SAM is a free model with openly available documentation. Although using SAM can be cost-effective, it can be challenging for new users and requires deep understanding of the user interface to correctly modify parameter values and thus provide accurate modeling. Additionally, SAM’s battery modeling features are but one of three overall components and are not the key focus of the tool. Guiding Parameters

• City goals: o Resilience o Reduction of emissions

• Backup power target: 6 hours at peak load • Secondary benefits:

o Peak shaving o Demand response

Solar component • Required beginning inputs:

o Location variables Snow Shade Temperature

o Solar panel type o Inverter type o Desired array sizes o Optimal panel tilt (34 degrees) o Target AC-DC ratio: 1.10

• SAM autofills parameters: o Number of modules o Number of inverters o Number of modules per string o Total number of strings in array

Battery component • Beginning inputs:

o Battery type (Lead Acid VRLA gel and Lithium Ion Nickel Manganese Cobalt Oxide were both considered initially; final modeling was done using Lithium Ion batteries)

o Desired capacity (kWh) o Standard voltage (set to 238 V) o C-rate (current divided by rated capacity at that current; i.e. 1/number of target

operational hours): 0.17 or ⅙ • Additional decisions:

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o Should the connected PV system meet load before charging battery? In this study, yes

o Is the battery AC connected? In this study, yes

SAM Outputs

o Nominal capacity o Nominal voltage o Maximum power o Current o Required number of cells o Required number of strings

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Appendix H: Estimating Carbon Dioxide Emissions for DTE Fuel Mix vs Solar Energy for 22 Sites The following calculations were utilized to calculate the carbon dioxide emission reductions for the final report for the Solar Microgrid Study for the City of Ann Arbor. NREL Ratios gCO2/kWh ratios were provided by NREL for different fuel sources. These ratios were used in The University of Michigan’s “Earth 380” course to calculate the carbon dioxide emissions for DTE’s fuel mix and for renewables discussed in the class. These ratios take into account a life cycle assessment of an energy source, assessing the amount of carbon dioxide emitted during the lifetime of the energy source, from “cradle to grave”. This allows for an “apples to apples” comparison of different fuel sources, where renewables are not carbon neutral but still emit significantly less carbon dioxide during their lifetime than traditional fossil fuel sources. The ratios used are as follows: 870 gCO2/kWh for coal 487 gCO2/kWh for natural gas 16 gCO2/kWh for nuclear 72gCO2/kWh for solar DTE’s fuel mix In recent years DTE, the local electric utility, has altered its fuel mix to rely slightly less on coal and more on nuclear power. The following is the most current DTE fuel mix composition: 60.80% coal 22.87% nuclear 7.89% natural gas 0.21% oil 0.14% hydroelectric 8.10% renewables (solar, wind, biomass etc) (https://www.newlook.dteenergy.com/wps/wcm/connect/dte-web/home/community-and-news/common/environment/fuel-mix ) Calculations For the calculations for DTE’s carbon emissions, the three most-utilized energy sources were used (coal, nuclear, and natural gas). To calculate the amount of carbon dioxide emitted, the annual load for each site (in kWh) was multiplied by the gCO2/kWh/year ratio for each fuel source. The gCO2 value was then converted to tonnes CO2 for a more digestible number. Values are shown per year as the load data is the annual load for that site. Calculations for carbon dioxide emissions were only made for sites with available load data, with a total of 22 sites.

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DTE’s Carbon Emissions: [(870*load kWh*0.69)+(16*load kWh*0.18)+(487*load kWh*0.04)] / (1^6) = tonnes CO2/year Solar Carbon Emissions: (72*load kWh) / (1^6) = tonnes CO2/year Calculating total emissions reduction The tonnes CO2 per site were then summed for both DTE’s fuel mix and for solar. Total DTE CO2 emissions = 6406.7 tonnes CO2/year Total Solar CO2 emissions = 740.8 tonnes CO2/year % carbon dioxide emissions reduction from DTE to Solar: [(6406.7-740.8) / 6406.7]*100 = 88% reduction in CO2 Amount of total load provided by solar energy The total load was compared to the total potential solar energy production for the 22 analyzed sites. Total load = 10.29 GWh Total potential solar energy production = 8.13 GWh % energy provided by solar = (8.13/10.29)*100 = 79%

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Appendix I: Summary of Electric Regulation in Michigan

Using this document: This is not a comprehensive document. There are various aspects of the regulatory environment that are not included here and this document should only serve to familiarize participants or readers of the microgrid feasibility study with the regulations they are likely to encounter in implementation of distributed solar for microgrids. Please keep in mind that, as of Fall 2017, these regulations are still being debated and updated at the state level. Interested parties may wish to subscribe to email updates of proceedings at the Michigan department of licensing and regulatory affairs by visiting LARA’s website or the MPSC’s.

Federal Level

Federal Energy Regulatory Commission (FERC) ● Overview: Regulates the transmission and wholesale sale of electricity and natural gas

in interstate commerce, and regulates the transportation of oil by pipeline in interstate commerce.

○ Key duties (relevant to feasibility study): ■ Regulating the transmission and wholesale sales of electricity in interstate

commerce. ■ Licensing and inspecting private, municipal, and state hydroelectric

projects. ■ Ensuring the reliability of high voltage interstate transmission system ■ Monitoring and investigating energy markets. ■ Using civil penalties and other means against energy organizations and

individuals who violate FERC rules in the energy markets. ■ Overseeing environmental matters related to natural gas and

hydroelectricity projects and major electricity policy initiatives. ■ Administering accounting and financial reporting regulations and

regulating businesses of regulated companies. ○ Jurisdiction and authority:

■ Independent regulatory agency within Department of Energy (DoE) ■ NOT subject to review by Sec. of Energy.

● DoE CAN participate in FERC proceedings as 3rd party. ■ Composed of up to 5 members, appointed by President, confirmed by

Senate. Must be bipartisan (no more than 3 members of same party). ■ Sets procedures for registration as RTO (requirements, etc.); promotes

creation of ISOs and RTOs to eliminate “undue” discrimination in access to electric grid, regional and interregional transmission planning and cost allocation (landmark order no. 1000).

North American Electric Reliability Corporation (NERC) ● Appointed by FERC as part of Energy Policy Act (EPAct) of 2005 as national electric

reliability organization (ERO).

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● Creates and enforces guidelines for bulk transmission system in North America. Made up of 8 regional entities.

● ReliabilityFirst Corporation (RFC) ○ The regional entity responsible for Michigan’s lower peninsula and parts of the

upper peninsula (the other parts are Midwest Reliability Organization). ● Ultimate purpose → develop standards for bulk transmission and guidelines for power

system operations and accreditation.

Midcontinent Independent System Operator (MISO) ● Acts as primary Independent System Operator (ISO) and Regional Transmission

Organization (RTO) for the Midwest region (balancing authority). ○ I.e. they provide open-access transmission service, monitor high-voltage

transmission systems for the Midwest, and ensure supply and demand of electricity are balanced at all times.

○ ISO vs RTO ■ ISOs and RTOs both provide non-discriminatory access to the

transmission network, but RTOs must meet FERC regulations dealing with planning and expansion.

● MISO has four primary objectives: ○ Provide an efficient and reliable transmission system. ○ Access a diverse number of energy resources, including renewable energies ○ Expand energy trading opportunities. ○ Meet state and federal energy policy objectives.

● MISO also acts to provide financially binding day-ahead and real-time pricing of energy. ○ I.e. real-time energy market operation and analysis.

State Level

Michigan renewable portfolio standard (RPS): electric providers required to produce 15% of total energy production via renewables by 2021 to be in compliance with renewable energy standards (12.5% in 2019 and 2020). Michigan Public Service Commission (MPSC)

● Public Utility Regulatory Policy Act (PURPA) ○ Enacted November 9, 1978 as part of National Energy Act. ○ Enforced and interpreted by FERC and MPSC. ○ Created in response to oil embargo (1973) to encourage competition from

alternative energy sources, promote energy conservation (reduce demand) and promote greater use of domestic energy and renewable energy (increase supply).

○ Is PURPA still relevant? ■ Still important in the evolution of utilities...solar/wind developers still rely

on PURPA (economically speaking). ■ Still interpreted and applied by FERC in courts, continues to evolve.

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● E.g. Section 210 → a utility must buy capacity and energy from qualifying facilities, priced at the utility’s avoided cost. (reviving PURPA, p. 5) info on avoided costs below.

○ Qualifying facilities (QFs) → either a cogeneration facility or a small power production facility that meets the requirements of PURPA section 201. QFs are considered two distinct installations if they are over one mile apart.

■ cogeneration facility→ equipment used to produce electric energy and forms of useful thermal energy (such as heat or steam) that are used for industrial, commercial, heating or cooling purposes, through the sequential use of energy.

● There are additional operating and efficiency standards to be a qualifying cogeneration facility.

■ small power production facility → a biomass, waste, renewable resources, geothermal resources, or any combination, whose capacity owned by the same entity (or entities) or its affiliate(s) on the same site, may not exceed 80 MW.

● limited exception to the size criteria for certain qualified small power production facilities.

■ There are special criteria and provisions for small hydroelectric facilities.

● See PURPA title II manual (pdf) p. 9 ○ PURPA regulations require electric utilities to establish standard rates for

purchases from QFs with capacity of 100 kW or less, and give state commissions the authority to develop standard rates for larger QFs [18 C.F.R. § 292.304(c)(1), (2)].

■ In MI, there is a growing push to increase this standard offer contract to 2 MW installations, and contract lengths growing from 5 to 20-year contracts (enables alternative energy suppliers to better attract and obtain investment capital).

○ Avoided costs ■ PURPA leaves determination methodology to states’ discretion.

● In MI, state hasn’t mandated anything so it’s up to the MPSC. ● MPSC is moving in direction of setting avoided cost according to

the cost it would have taken for the utility to build a natural gas plant to produce the same amount of electricity (proxy unit).

● State by state priorities vary...can reflect a need for administrative simplicity, stakeholder consensus, or be based on widely accepted expert practices.

■ PURPA only says that rates: ● Cannot discriminate against qualifying small power producers or

qualifying co-generators. ● Must be just and reasonable to utility customers. ● Must be in public interest.

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■ Commission routinely considers and adopts line-loss factors in rate cases and applies those factors in power supply cost recovery cases (as a benefit of avoiding long distance high voltage transmission; it’s better to locally generate whenever feasible).

● 2016 Public Act 341 (amends 2008 PA 286 and 1939 PA 3) ○ Act 3 of 1939, Sec. 10q (4)

■ Only investor-owned, cooperative, or municipal electric utilities shall own, construct, or operate electric distribution facilities or electric meter equipment used in the distribution of electricity in this state. This subsection does not prohibit a self-service power provider from owning, constructing, or operating electric distribution facilities or electric metering equipment for the sole purpose of providing or utilizing self-service power. This act does not affect the current rights, if any, of a nonutility to construct or operate a private distribution system on private property or private easements. This does not preclude crossing of public rights-of-way.

○ Integrated Resource Plans ■ 2016 PA 341 Sec. 6t (460.6t) requires the Commission, within 120 days

of the effective date of the act (August 19, 2017) and every five years thereafter, to commence a proceeding that among other things, establishes modeling scenarios and assumptions each electric utility should include in addition to its own scenarios and assumptions in developing its integrated resource plan.

■ MPSC required to collaborate with Michigan Agency for Energy (MAE) and Department of Environmental Quality (DEQ) to gather input from the public and set modeling parameters and assumptions for utilities to use in filing integrated resource plans.

■ 460.6s (11) → details on content of IRP ○ Performance Based Regulation (PBR)

■ 2016 PA 341 Sec. 6u requires the Commission to commence a study addressing performance based regulation (PBR), under which a utility’s authorized rate of return would depend on the utility achieving targeted policy outcomes.

■ Report due by April 20, 2018.

● 2016 Public Act 342 (amends 2008 PA 295) ○ Distributed Generation Program.

■ Net metering program will continue as distributed generation program following establishment of an appropriate (reflecting equitable cost of service for utility revenue requirements) distributed generation tariff.

■ Cost-of-service based distributed generation tariff study must be completed by April 2018.

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■ Distributed generation program is for customers who install certain on-site grid-connected, renewable generation no larger than 150 kW (methane digester projects as large as 550 kW can also participate).

● MI true net metering is for 20 kW projects and smaller; modified net metering is for 20 kW to 150 kW projects.

● 19 other states allow renewable projects 500 kW and larger to participate in net metering programs.

■ Renewable project may generate up to 100% of a customer’s annual electricity consumption.

■ Under current state law, MI has a consumer protection that caps participation in net metering programs at 1% of a utility’s peak load (see 2008 PA 295, section 5).

● MI just exceeded 2,000 customers in 2015 (about 0.02 % of Michigan’s retail sales) see 2015 MPSC report; greatest density of customers existed in Washtenaw, Wayne and Oakland counties.

● As of December 2016, this number had grown to over 2,500 customers.

● Customers with net excess generation currently credited at retail rate in MI; credits do not expire (as of 2016).

■ Aggregate cap on net metering in MI ● 0.5% of utility’s peak load for true net metering (up to 20 kW

installations). ● 0.25% of utility’s peak load for modified net metering (up to 150

kW installations). ● 0.25% of utility’s peak load for modified net metering projects over

150 kW. ■ Interconnection standards apply; summary available at (DSIRE).

○ Green Pricing Program ■ Electric utilities must offer customers the option to participate in a

voluntary green pricing (VGP) program where customers can specify the amount of electricity provided to the customer that will be generated from renewable energy.

■ Utilities were required to submit their programs for review by October 18, 2017 and MPSC staff expects the programs to be approved by April 20, 2018.

■ This may be the most relevant piece of legislation with regard to community solar projects in MI, which currently are not supported by state energy laws.

■ EIBC, Edison Energy, Apex, ELPC, and MCP recommended that all VGP programs should provide an option that allows for large commercial and industrial customers to negotiate directly with renewable energy providers to obtain a renewable energy power purchase agreement (PPA).

● According to EIBC, this type of program “allows large customers to purchase renewable energy from an offsite facility, with the

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power purchase agreement (PPA) contract sleeved through that customer’s local utility. Customers and renewable energy developers should be allowed to negotiate directly to set the terms of such a contract, subject to utility approval and agreement. Allowing third-party developers to compete to meet customer needs will ensure that renewable energy sourced under voluntary purchasing programs will be competitively priced. This option is key to meet the needs of large corporate customers, and should be included regardless of which additional options are implemented. An alternate variation that utilities may also consider, to enable large, offsite purchases, is a ‘market-based’ rate that customers can use in conjunction with a virtual PPA.”

● See docket u-18349, page 10, for current comments/status as of July 12, 2017.

■ Finally, MCP recommends that large customers with multiple locations should have the ability to aggregate load to meet eligibility requirements, if such requirements exist. DTE Electric indicated that it was amenable to considering this option, provided that the administration of such a program was not unduly burdensome. The Commission agrees that, when feasible, combining load from different sites should be an option for participants.

● Docket u-18349, page 12 ■ DTE’s pilot MIGreenPower Program was approved on October 11, 2016

in case no. U-18076. DTE maintains that this program is in compliance with section 61 (order for voluntary green pricing programs).

● However, many of the commenters representing business customers contend that no current utility green tariff meets the needs of corporate customers.

● Commission finds that providers may need to make changes to their existing programs and should refile these proposals in October 2017 in accordance with the filing schedule set forth in Attachment A of docket U-18349. → October 18, 2017 by program case no. U-18352.

Local Level (Ann Arbor)

Ann Arbor municipal ordinances Title II: Utilities and Services

• See Chapter 37 for Energy Utility Franchises o Details on what grantees are allowed to do in franchise agreements with city. o Short version: the city can grant non-exclusive franchises to electric companies

to produce energy, but it’s written in EVERY agreement that these grantees can’t build, operate or maintain distribution infrastructure and that they HAVE TO use DTE’s distribution infrastructure.

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Title V: Zoning and Planning

• Article V -- Planned Projects o 5:68 Statement of Intent o The intent of this section is to provide an added degree of flexibility in the

placement and interrelationship of the buildings within the planned project and to provide for permanent open space preservation within planned projects. Modifications of the area, height, placement requirements, and lot sizes, where used for permanent open space preservation, of this chapter may be permitted if the planned project would result in the preservation of natural features, additional open space, greater building or parking setback, energy conserving design, preservation of historic or architectural features, expansion of the supply of affordable housing for lower income households or a beneficial arrangement of buildings. A planned project shall maintain the permitted uses and requirements for maximum density, maximum floor area and minimum usable open space specified in this chapter for the zoning district(s) in which the proposed planned project is located.

(Ord. No. 23-88, § 2, 6-20-88; Ord. No. 22-92, § 1, 5-18-92; Ord. No. 42-02, § 1, 12-2-02)

• Article X -- Special Exceptions Title VIII: Building Regulations

• Chapter 100 -- Construction Code • Chapter 105 -- Housing Code

o See 8:518 (Permits) for information on modifications to residential buildings. Financial Incentives

• Michigan currently has no state-level financial incentives (i.e. tax credits) for renewable installations.

o In 2008, the Michigan Tax Tribunal ruled that solar systems are to be considered real property (non-movable) and should be assessed as an improvement to the property on which they are installed.

The only exception would be solar systems installed on property which is not owned by the owner of the solar installation.

o According to Laura Sherman, 5LakesEnergy LLC: For commercial properties:

• “Land and any substantial improvements made by a solar developer to buildings, driveways, fencing, etc. are taxed as real property. Any electrical equipment (transformers, substations, transmission lines, etc.) is taxed as utility personal property. The solar panels themselves and the racking systems are taxed as industrial personal property, which is subject to the Michigan State Tax Commission’s depreciation schedule.”

For residential properties: • “In 2012, Governor Snyder signed into law eleven bills affecting

the taxation of personal property. These laws exempt industrial or commercial personal property that has a true cash value of less

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than $80,000 from taxation. However, there is confusion as to whether residential solar PV systems should be classified as ‘real property’ or ‘personal property.’ As a result, tax assessors in some communities (e.g., Ann Arbor) are assessing residential solar PV systems as real property, which increases the taxable value of a home with rooftop solar panels. This additional cost effectively negates the economic value of residential solar PV systems by increasing the pay back period such that it is coincident with the expected lifetime of the panels. In other communities, tax assessors have determined that solar PV systems should be exempt from taxation as industrial personal property (e.g., Long Lake township).”

• At the Federal level, the Business Energy Investment Tax Credit is still active and grants a 30% tax credit for solar, wind and fuel cells, and grants a 10% tax credit for geothermal, microturbines and combined heat and power (CHP).

o Tax credit is only applicable to commercial, industrial, investor-owned utility, cooperative utility, and agricultural properties.

o Does not apply to municipal properties, as they are tax-collecting entities. • Local incentives can still help select properties with upfront costs and electricity rate

savings. o E.g. PACE financing is available in a number of municipalities and can offer long-

term, low-interest options for energy improvements that reduce emissions. o Alternatively, local discrepancies in property tax assessment can have a negative

effect on renewable installations (see state-level incentives, above).