Solar 101By Micah Jasuta, Texas Solar Energy Society
Bluebonnet Solar TourSept. 9, 2017
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Agenda
• Solar ABC’s
• What Are You Buying?
• Solar and Electric Utilities
• Incentives
• How to Shop & Choose an Installer
Solar ABC’s
• Solar Photovoltaics (PV)
– The photovoltaic effect was first discovered by Alexandre Edmond Becquerel in 1839
– The first practical silicon solar cell was invented by Bell Labs in 1954
– In a single hour, the amount of power from the sun that strikes the Earth is more than the entire world consumes in a year.
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Solar ABC’s
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Solar ABC’sMonocrystalline Silicon
Polycrystalline Siliconhttps://static.solarmarket.com.au/wp-content/uploads/2013/08/mono-crystaline-cell.jpg
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Solar ABC’s
• Power vs. Energy
– Power is instantaneous (kW)
– Energy takes time (kWh)
• Your electric company bills you in kWh
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Rate of flow = Power
Water in the bucket = Energy
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Solar ABC’s• Power vs. Energy
– Power is instantaneous (kW)
• Your solar system has a power rating in kW
– Energy takes time (kWh)
• Your electric company bills you in kWh
• Your solar system generates kWh over time
• A hair dryer using 1 kW for 2 hours will consume 2 kWh
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Solar ABC’s• Solar Modules (Solar Panels)
– 2 general physical sizes
• 60-cell (65” x 39”) & 72-cell (78” x 39”)
– The power rating (in Watts) is determined at Standard Testing Conditions (STC) in a laboratory
– Efficiencies vary. 60-cell may be 240 W –365 W in the same footprint
– (10) x 300 W Modules = 3,000 W system = 3 kW system
– Actual Power varies throughout the day and year https://i.pinimg.com/564x/94/69/c8/9469c81345af25f581fd9f32315401d7.jpg
Solar ABC’s• Orientation
– Azimuth and Tilt
– Solar’s output changes as the sun moves
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Solar ABC’s
• Orientation (azimuth and tilt)
– Azimuth’s closest to South (180 degrees) are optimal.
– Tilt equal to the location’s Latitude is optimal.
– www.pvwatts.nrel.gov
Solar ABC’s
• Orientation (azimuth and tilt)
– Non-optimal orientations still function.
– Flat array produces 91% of optimal orientation
Solar ABC’s
• Orientation (azimuth and tilt)
– Non-optimal orientations still function.
– 0 degree azimuth (due North) at 30 degree tilt produces 65% of optimal orientation
What Are You Buying?
• Grid tied vs. off grid
• What happens
– At night
– During an outage
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What Are You Buying?
• Roof Attachments
• Racking
• Solar Modules (Panels)
• Inverter(s)
• Conduit
• Switchgear
• Roof Attachments + Racking
What Are You Buying?
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What Are You Buying?
• Inverter(s)
– String inverters
– Microinverters
– DC Optimizers
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• Conduit
– Protects wiring
– All wires not underneath the solar panels will need to be in conduit
What Are You Buying?
What Are You Buying?
• Switchgear and Metering PV Meter
Main Electrical Panel
“Net” Meter
Conduit
from PV
arrayInverter
(String
inverter)
DC
Disconnect
AC
Disconnect
Conduit
to/from
the Grid
Solar and Electric Utilities
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Red = Home’s ConsumptionGreen = Solar Production
Solar is self-consumed
Solar is exported to the grid
• Bluebonnet Electric Cooperative
– Bills on delivered energy
• You’re only charged for the energy they send to you
– Credits you for received energy
• Until August 2018, you get 0.0632732/kWh for what you send back to the grid
Solar and Electric Utilities
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Incentives
• Federal
– Solar Investment Tax Credit (ITC)
• 30% of your solar installation costs
• Dollar for dollar
• Reduces the amount you would otherwise pay in income taxes
• 2020: 26%
• 2021: 22%
• 2022+: 0%
$21,000 * 30% = $6,300$21,000 - $6,300 = $14,700
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Incentives
• Federal
– Solar Investment Tax Credit (ITC)
• You will need to have tax liability in order to take advantage of this tax credit
• Equipment and labor are eligible
• Consult a tax professional
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How to Shop & Choose a Solar Installer
Understand how solar worksKnow your utility’s solar policies Know what incentives are available to youo Ask friends/family, ask your utility company, and
use review sites to find reputable solar installerso Get at least 3 solar proposals/bidso Compare your proposals apples-to-appleso Read your contract before signing it!o Make sure your solar installer is a licensed
Electrical Contractor with the Texas Department of Licensing and Regulations (TDLR)
How to Shop & Choose a Solar Installer
o Ask friends/family, ask your utility company, and use review sites to find reputable solar installers
• Better Business Bureau
• Yelp
• Solarreviews.com
• Angie’s List
How to Shop & Choose a Solar Installer
o Get at least 3 solar proposals/bids
• Don’t succumb to high-pressure sales
• Ask questions
• Negotiate
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• Compare your proposals apples-to-apples
– System Price
• Price per Watt ($/W)
How to Shop & Choose a Solar Installer
System 1:
9 kW for $27,000
$3.00/W
System 2:
6.5 kW for $20,150
$3.10/W
System 3:
4.25 kW for $16,150
$3.80/W
• Compare your proposals apples-to-apples
– Production Estimates
• Kilowatt-hour per kilowatt (kWh per kW)
• Use PVWatts – www.pvwatts.nrel.gov
How to Shop & Choose a Solar Installer
System 1:9 kW & 10,350 kWh/year
1,150 kWh/kW
System 2:6.5 kW & 9,100 kWh/year
1,400 kWh/kW
System 3:4.25 kW & 7,438 kWh/year
1,750 kWh/kW
• Compare your proposals apples-to-apples
– Utility Rate Escalator (Utility Inflation Rate)
• Assumption that utility rates will increase by a certain percentage each year
• Higher utility rates mean that solar energy will offset greater and greater values, so the financial models look more favorable
• Bluebonnet Electric Cooperative’s rates may increase 3% over 5 years, or 0.6% per year
How to Shop & Choose a Solar Installer
• Read your contract before signing it!
– 3 day right to cancel
– Timeline
– Subcontractors
– Verbal promises should be included
– Arbitration
How to Shop & Choose a Solar Installer
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• Make sure your solar installer is a licensed Electrical Contractor with the Texas Department of Licensing and Regulations (TDLR)
– https://www.tdlr.texas.gov/LicenseSearch/
– Must be licensed to perform or offer to perform electrical work
– Be very careful with 3rd party sales companies
– All ads, websites, proposals, contracts, business cards should include the contractor’s TECL #
How to Shop & Choose a Solar Installer
Thank You!
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