Gilbert, Arizona

Neely Solar Facility

2015 Wastewater Treatment Committee Annual Seminar

“Optimizing Wastewater Treatment for the New Normal”

Solar Project Location

Western Canal

Neely WRP

Neely Recharge Facility

Project Design Details

• Public/Private Partnership

• Located at Gilbert’s Neely Recharge Facility

• System Size: 2 mega-watts (2,257.92kW DC)

• 8000 solar panels - single axis tracker system

• Arrays are constructed over 5 recharge basins

• Solar panels are mounted on beams installed

20 feet underground and having a height

clearance of 6½ feet above ground

• 5 inverters mounted on concrete pads - the

inverters convert solar energy to electricity

• Solar system will help supply power to the

Neely Wastewater Reclamation Plant

• Initial concept discussions about the solar project began with

Severn Trent Services, Gilbert staff and SPG Solar in June, 2010

• Gilbert applied for a renewable energy incentive (Credit Purchase

Agreement) through APS in August, 2010 for the proposed project

• Gilbert was notified by APS that the project had been selected to receive a

renewable energy incentive in September, 2010

• The APS CPA (incentive) provides a 60% contribution towards project

construction in exchange for renewable energy credits

• A Land License Agreement and Power Purchase Agreement (PPA) were

negotiated and approved by the Gilbert Council in November, 2010

• Project design began in December, 2010 followed by construction activity

beginning in February through October, 2011

• The system Interconnection and Operating Agreements with APS were

approved in August, 2011

• The system began producing power at the end of September, 2011

Project Evolution

Power Purchase Agreement

• Sun-Edison (Formally SPG Solar) – Was required to perform project design

and construction, also responsible for system operation and maintenance

throughout agreement term

• Sun-Edison (formally Integrys Energy) is the solar system owner (Investor)

while Gilbert is considered the system host

• PPA has a 20 year term with options at the end for either agreement

renewal, ending the agreement with system removal (at owner’s cost), or

Gilbert can purchase the system at a depreciated value

• PPA requires Gilbert to purchase all of the power generated by the solar

system at a fixed rate structure

• The solar power rate is anticipated to be at or less than the electrical

power rate Gilbert would otherwise pay APS

• Forecasted savings for Gilbert is estimated to be approximately $2 million

over the agreement term (20 years)

Year

Utility Bill

Without Solar

Energy

Annual Solar

kWhsPPA Rate

Forecasted

PPA Annual

Bill

Remaining

Annual Utility

Bill with Solar

Total Annual

PPA Bill +

Utility Bill

Annual

Projected

Savings

1 $1,031,903 4,837,552 0.0750 $362,816 $667,706 $1,030,522 $1,381

2 $1,073,179 4,813,364 0.0769 $370,027 $694,414 $1,064,442 $8,738

3 $1,116,106 4,789,297 0.0788 $377,382 $722,191 $1,099,572 $16,534

4 $1,160,751 4,765,351 0.0808 $384,882 $751,078 $1,135,961 $24,790

5 $1,207,181 4,741,524 0.0828 $392,532 $781,122 $1,173,653 $33,527

6 $1,255,468 4,717,817 0.0849 $400,333 $812,366 $1,212,700 $42,768

7 $1,305,686 4,694,227 0.0870 $408,290 $844,861 $1,253,151 $52,536

8 $1,357,914 4,670,756 0.0892 $416,405 $878,656 $1,295,060 $62,854

9 $1,412,231 4,647,403 0.0914 $424,681 $913,802 $1,338,482 $73,748

10 $1,468,720 4,624,166 0.0937 $433,121 $950,354 $1,383,475 $85,245

11 $1,527,469 4,601,045 0.0960 $441,729 $988,368 $1,430,097 $97,371

12 $1,588,567 4,578,039 0.0984 $450,509 $1,027,903 $1,478,412 $110,156

13 $1,652,110 4,555,149 0.1009 $459,463 $1,069,019 $1,528,482 $123,628

14 $1,718,194 4,532,374 0.1034 $468,595 $1,111,780 $1,580,374 $137,820

15 $1,786,922 4,509,712 0.1060 $477,908 $1,156,251 $1,634,159 $152,764

16 $1,858,399 4,487,163 0.1086 $487,406 $1,202,501 $1,689,907 $168,492

17 $1,932,735 4,464,727 0.1113 $497,093 $1,250,601 $1,747,694 $185,041

18 $2,010,044 4,442,404 0.1141 $506,973 $1,300,625 $1,807,598 $202,446

19 $2,090,446 4,420,192 0.1170 $517,049 $1,352,650 $1,869,699 $220,747

20 $2,174,064 4,398,091 0.1199 $527,326 $1,406,756 $1,934,081 $239,983

Total $30,728,089 92,290,352 0.0958 $8,804,520 $19,883,002 $28,687,522 $2,040,567

Gilbert - Neely Solar Project

Forecasted Savings & Cash Flow Summary

PPA Forecast Inputs:

• Starting Solar Rate of $0.075/kWh with 2.5% Annual Escalator

• Estimated Average Annual Utility Power Inflation Rate of 4%

Solar Integration

• Gilbert did not have to pay for any of the project’s capital

costs (~ $10.4 million)

• Gilbert is not required to operate or maintain the solar

system during the agreement term

• The System is off-setting 44% of the Neely Plant’s power needs

with clean renewable energy

• Gilbert’s forecasted savings (~$2 million over 20 years)

• Water recharge operations and wildlife habitat not impacted

• Public/private partnership – economic development

• Community marketability – promotes sustainability

• Gilbert will be contributing to the betterment of the

environment by off-setting an estimated 86 million pounds of

carbon dioxide over the life of the system

• Fits Gilbert’s Strategic Initiatives – “Clean, Safe, Vibrant”

Project Benefits - Gilbert

Featured in The Water Environment

Federation’s “WE&T” Magazine - April, 2012

QUESTIONS?

Mark Horn

Gilbert, Arizona

Wastewater Manager

(480) 503-6420

mark.horn@gilbertaz.govAerial Photos Courtesy of “SPG Solar”

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