grid-tied battery backup workshop...• december 2014: arizona’s srp rolls out mandatory demand...

Grid-Tied Battery Backup Workshop

Paul DaileySr. Manager, Product & Technical Sales

August 12, 2016Morrisville, North Carolina

Agenda

• 8am Coffee• 9am Why offer batteries?

‒ - The business case for expanding your service offering• 10am Backing up the grid

‒ - Grid-interactive PV/battery configurations, critical loads panel‒ - Battery selection, siting, and maintenance‒ - System Sizing

• 12pm Networking Lunch • 1pm Making AC from batteries

‒ - Sponsor presentation‒ - Inverters and power systems ‒ - Preconfigured systems

• 3pm Winning deals with ready-to-go solutions‒ - Financing options‒ - Selling to new customers with preconfigured systems‒ - Selling to past customers with retrofit AC-coupled systems

• 4pm Managing customer expectations‒ - Communicating limitations, maintenance agreements

• 5pm Networking “Happy Hour”

Introduction

• Disclaimer‒ AEE Solar is a distributor of goods and services used in the

deployment of PV and wind distributed power systems. We are not accountants, attorneys or code experts. The information presented here represents the equipment and best practices that we are aware of. However, local and project-specific requirements can vary widely.

• About Paul Dailey‒ BSME & MBA from Washington State University‒ Over 15 years experience in distributed energy including micro-

cogen, solar thermal and PV

• What do you hope to learn from this workshop?

WHY OFFER BATTERIES?The Business Case

For AEE Internal Use Only.

Why Add Batteries?• Growing market

− PV with Battery Backup− PV Self-consumption− TOU arbitrage− Demand Charge Management

• Backup technology has gotten cheaper and easier to use

• If you offer battery backup options, you don’t have to refer those customers away for a quote

• Less competition and price pressures

• Larger total sale

• Opportunity to sell maintenance contracts

• The US electrical grid is getting less reliable with age

• Storms and natural disasters are getting more frequent and severe

– Over 14 Million businesses and households were without power after major storms in 2012 and 2013

– About another million have been without power after storms so far this year

– 966 roads, 141 power lines and 39 gas pipes cross the San Andreas fault line

According to the CEC, the Aliso Canyon shortage could affect power plants providing nearly 10,000 megawatts for the Los Angeles basin, …Southern California could see up to 14 days of blackouts this summer if nothing is done.

Who Needs Battery Backup?• Disaster-prone areas

− Unstable grid− Hurricanes − Severe storms− Wildfires− Earthquakes

• Residences− Lights − Refrigerator and freezer− Communications− Entertainment− Heating system controls− Water pumps

• Businesses− Cash Registers − Refrigeration− Servers− Pumps

Who Buys Battery Backup

• Homeowners are looking for comfort and peace of mind− High-end homes on the outskirts of

the grid− Critical medical devices

• Businesses are looking for opportunities− Convenience stores− Data centers, web hosts, etc.

• Local governments are looking for safety and order− Schools and storm shelters− Police, fire and medical services

Energy Storage Unlocks PV’s True Potential

• Benefits of today’s grid-direct PV systems− Renewable energy that offsets fossil fuel power− Cost effective energy production when the sun is shining− Reliable energy production when the sun is shining

• Benefits of grid-tied PV with Energy Storage− Renewable energy that displaces fossil fuel power− Reliable and dispatchable energy production− All of the solar energy produced can be consumed on site

• Net metering becomes optional• User has control of energy production and use

− Ancillary grid services like frequency/voltage correction− Operational during a grid outage

PV + Energy Storage Can Match Loads

PV output not consumed by loads used to recharge battery rather than exported

PV output curtailed to match loads once battery is full

Loads served by battery at night

Key Drivers of Adoption

• Need to self-consume solar energy− Export of power to grid dis-

incentivized or not allowed (Hawaii)

• New Rate Structures− Residential Demand charges− Residential TOU rate structures− High kWh rates with no NEM

• Demand for Ancillary Services− Frequency or voltage correction− Demand response− Geography-specific needs

• Cost− NEM offers better value to

consumer− Installation costs more

• Utility Resistance− Same utility business threats as

solar− Utilities uncertain how to manage

distributed storage

• Lack of clear policy direction− Price signals don’t match technical

requirements of the grid − Most energy storage mandates

focused on commercial/utility scale projects

Key Drivers Slowing Adoption

Distributed Energy Storage Market is Still Nascent• Residential grid-tie storage market ~4MW/yr in 2015• Virtually all recent and ongoing projects are pilots• Most growth and volume has been in utility applications

− ~100 MW front of meter vs

The Residential Energy Storage Market Potential

Source: http://www.rmi.org/electricity load defection

• Residential energy storage markets will materialize when and where:− Demand charges and/or TOU rate structures drive positive NPV for batteries− Self-consumption of PV is forced or incentivized (Hawaii)− Ancillary grid services are compensated geographically

• Expansion of Solar + Storage will follow similar pattern to solar adoption− RMI estimates that 9.6 million households in the Northeast will have solar

plus storage systems by 2030

Who Buys Energy Storage & Management Solutions

• Homeowners want control of their energy− Homes where net metering is restricted

(HI)− Large homes with TOU or demand-

based rate structures

• Businesses want predictable costs− Businesses facing demand charges

and/or complicated TOU rate structures

• Local governments and utilities need services that overcome intermittency− Demand response with energy storage− Opportunistic supply or even load− Voltage and frequency correction

Market Signposts• December 2014: Arizona’s SRP rolls out mandatory demand

charge for residential solar PV customers− Additional utilities in state plan to follow in their rate cases

• October 2015: Hawaii PUC shuts down net metering− Non-export system applications avoid interconnection study− Installers running out of circuits they can export to

• December 2015: Nevada PUC retroactively shuts down Net metering− Imposes fixed fees on customer who already have solar− Most PV installers shut down or left the state

• January 2016: California – NEM 2.0, multi-Distributed Resource Planning (DRP)

• State-level residential NEM reviews and caps impending or recently hit:− New Hampshire, Maine, Oregon, Iowa

BACKING UP THE GRIDSystem configurations


Types of grid-tie battery backup systems

• Backup system separate from the solar grid-tied system• Grid-tied solar systems with battery backup and protected

loads panel− Basic DC coupled grid-tie w/ Battery Backup (GTBB)− GTBB using 120vAC only inverters with 120vAC loads− GTBB using 120vAC only inverters and 120/240vAC loads− GTBB using 120/240vAC inverters

• Grid-tied solar systems with battery backup for whole house backup− GTBB for whole house using a 4 pole manual transfer switch− GTBB for whole house using line side tap and manual transfer

switch− GTBB for whole house using an automatic transfer switch

• Grid-tied solar systems using AC coupling− GTBB using AC coupling and protected loads panel

Direct grid-tied system without backup

• This is a simple grid-tie system without any backup power• When the grid power goes out, the PV system is useless

Backup system separate from the solar grid-tied system

• The backup system can be separate from the solar system• This could also be a generator only or have both inverter and generator• Can’t charge battery bank from PV array

Basic DC coupled grid-tie w/ Battery Backup (GTBB)

• The original and most common arrangement for grid-tie with backup• ~150 VDC array, charge controller, and battery-based grid-tie inverter• Protected loads panel for loads to be backed up

GTBB using 120vAC inverters with 120vAC loads

• Many grid-tie battery inverters are 120vAC single leg• These inverters also have only one AC input

• Transfer switch needed for running with a generator• Generator must have utility quality AC power output

• Inverter-based generator is required

GTBB using 120vAC inverters with 120/240vAC loads

• GTBB 120vAC system w/protected load panel and transformer for 240vAC loads• Use standard US house wiring at 120/240vAC• Grid connection and generator input is still only 120vAC

GTBB using 120/240vAC inverters with protected load panel

• Using a 120/240 split phase inverter with separate generator input is the most versatile and easy to use system

• A protected loads panel is still the best way to set up• Grid connection and generator input are both 120/240vAC

Whole house backup issues• NEC 702 5(B) requires a system that can power all loads if an automatic

transfer switch is used, − Exception for loads that are automatically disconnected − A 200 A service would require six Radian 8 kW inverters

• A Manual transfer switch only requires the system to power chosen loads− User must manually shut off non-critical circuits before switching− Manual transfer will leave the house in the dark until someone

performs the transfer

• If the inverter cannot power all the loads it will be overloaded and shut off, requiring a manual restart

• The input/grid-feed and output of the inverter must never be connected together− This will irreparably damage the inverter and may cause a fire− Connecting the input to the utility side of the meter is most common approach

Using a 4 pole transfer switch for a whole house backup system

• Power from the utility must be disconnected to install the transfer switch • The transfer switch must be manually activated to meet code, and larger

load circuits must be disconnected first • A 4 pole manual transfer switch may be hard to find

Using a line tie connection for a whole house backup system

• Line tie connection with fused disconnect and two pole transfer switch • Transfer switch must be manually activated to meet code

• Non-critical circuits must be disconnected first • Power from the utility must be disconnected to install the transfer switch

Whole house backup with automatic transfer switch

• Requires a backup system capable of powering all loads, or having loads automatically disconnected per NEC 702 5(B)

• 200A service requires six Radian 8kW inverters unless automatic circuit disconnects are used

• Requires a line tie connection to the utility

Array differences from direct grid-tie systems

• String sizing is smaller, commonly 3 modules in series

• Array wiring similar but more strings

• Generally strings are combined on the roof or near the array

• A PV combiner with circuit breakers is needed

• Short strings reduce shading impacts

AC coupled GTBB system

• Normally uses a protected loads panel • Uses both a direct grid-tie inverter and a battery-based inverter • Is useful when retrofitting an existing system• Is useful when a kWh production meter is needed • More expensive and complex, not all equipment is compatible

DC-Coupled System• PV array managed by

charge controller− 3 modules/string− Separate combiners

• Battery inverter actively manages export power− Exports power based on

battery voltage/state of charge

− Automatically disconnects from grid during outage

• PV array managed by grid-tie inverter− 10-14 modules/string− Integrated combiner

• Battery inverter passes export power through− Battery inverter uses GT

inverter output to charge or maintain battery bank

− Automatically disconnects GT inverter from grid during outage

AC-Coupled System

Advantages• Can make use of existing

GT inverter and PV array− Good retrofit solution

• High-efficiency export of surplus power− Can be better for backup

applications

• Distance between array and inverter can be greater− Higher voltage

• Requires 2 inverters− ~$1,200 more in equipment

costs for 7kW array

• Less efficient battery charging− Usually worse for off-grid

applications

• Not all GT inverters work well in AC-coupled mode− Battery inverter must have at

least 25% more capacity than GT inverter

− Check with GT inverter manufacturer for compatibility

Disadvantages

BATTERY BASICSBattery selection, sizing and maintenance

Lead Acid

Flooded Non-spillable(VRLA)

MaintenanceFree Maintenance

Absorbed GlassMat (AGM)Gel

• Lead calcium• Deep cycle 50%• 100 - 300 cycles

• Lead antimony• Deep cycle 80%• 300 - 2100 Cycles

• Lead calcium• High current

capable• Mid-cycling• 50 - 1200 Cycles

• Lead calcium• Immobilized electrolyte

• Deep cycle 80%•200 -1200 Cycles

FloodedFloodedFloodedFlooded VRLAVRLAVRLAVRLA

• Excess acid• Vented

• Acid - starved• Sealed (valve regulated)

Battery types

Pros• Higher cell capacities available

• Lower initial cost than VRLA

• Excellent cycle life

• Electrolyte is replaceable

• Less sensitive to overcharging

• Not sealed− Cannot be mounted on its side− Cannot be shipped by air− Requires spill tray & ventilation

• Maintenance required− Water must be added ~monthly− Equalization charge− Higher rate of self-discharge

• Subject to freezing

• Sensitive to shock and vibration

• Doesn’t reach full capacity for as many as 150 cycles

Cons

Flooded Cell

Pros• No maintenance

• Sealed− Can often be installed on its

side− Can often be shipped by air

• Better cycle life than AGM

• Wider temperature range than flooded

• Shock and vibration resistant

• Sensitive to overcharging

• Lower charge & discharge rates

• Slightly higher cost than AGM

• Lower capacity than flooded cell

Cons

Gel VRLA

Pros• Low maintenance

• Low self-discharge

• Cannot spill or leak − Can be installed on its side− Can be shipped by air

• Shock and vibration resistant

• Works well at low temperature

• Works in high-power applications

• Reaches full capacity in few cycles

• Sensitive to overcharging

• Few deep-cycle designs available

• Electrolyte cannot be replaced

• Higher initial cost

• Lower capacity than flooded cell

Cons

Absorbed Glass Mat (AGM) VRLA

Pros• Used widely in Hybrid vehicles and

portable electronics

• Good energy and power density − about 60% of Lithium-ion

• High cycle life at high cycle depth− Up to 3,000 cycles @ 80 to 90% DoD

• Tolerant of over or under charging

• Wide operating temperature range

• Flat voltage vs. state of charge curve

• No hazardous materials

• Moderately Expensive− 2 to 3 X price of lead-acid batteries

• Low cell voltage (~1.2 VDC)− More cells required per system

• High self-discharge rate

• Memory effect− Need to fully cycle about once per

month− Reconditioning is possible

Cons

Nickel Metal Hydride

Pros• Widely used in laptops, EVs and

handheld devices

• High power and energy density − High current tolerance compared to VRLA− Up to ~40 Wh/lb

• High cycle life at high cycle depth− Up to 3,000 cycles @ 80 to 90% DoD

• Expensive− $450 to $1,000/kWh

• mitigated by deeper cycling− Scale and technology improvements

expected to bring prices down

• Thermal management challenges− Operates between ~32 °F and 100 °F− Risk of thermal runaway fire− LiFePO and related chemistries less prone

to thermal runaway risk

• Requires sophisticated battery management system− Adds cost and design complexity

• Non-recyclable and hazardous− Disposal costs not typically included in

price− Hazmat shipping restrictions

Cons

Lithium Ion

Sodium-ion

• Uses common, non-toxic materials

o Stainless steel, manganese oxide, cotton, carbon, saltwater

• High cycle life at high cycle depth

o Up to 3,000 cycles at over 90% DoD

• Durable and abuse tolerant• Modest cost

o $550-600/kWho Likely to fall as technology

matures

• Bulk and weight similar to lead-acid batteries

• Voltage drops at lower state of charge

o Limits effective cycle depth• New technology with limited

manufacturing base

Pros Cons

Pros• Extremely long life with deep

discharges− Up to 10,000 cycles at 80% − Service life up to 50 years

• Not sensitive to partial state of charge

• Electrolyte does not take part in the reaction − Not prone to freezing

• Environmentally benign components.

• Expensive• Low cell voltage (~1.2 VDC)• Can be difficult to use

− Wide voltage range to charge or discharge

− Corrosive mist on charging - high maintenance

− Electrolyte replacement 10 years

• Low efficiency• High self-discharge• Bulky and heavy

− Similar to Lead Acid

• Flooded style with liquid electrolyte

Cons

Nickel‐Iron

Battery Voltage Impacts

• Fixed low-voltage inputo Inverter fed from steady

12/24/48 VDC from batteries

• Standardized interfaceo Most batteries work with most

battery inverters

• Inverter incorporates:o Transfer switcho Phase balancing

• Separate BOS required:o Charge controller(s) for PV

arrayo System controls and

enclosures

• Actively-controlled voltage inputo Inverter MPPT accepts range of

voltages usually 250-550 VDC

• Battery/inverter listed togethero Only specified inverters can be

used with each battery brand

• Inverter incorporateso MPPTo System controls

• Separate BOS required:o Transfer switch and autoformer

for backup applications

Low-Voltage Systems High-Voltage Systems

DoD vs. Cycle LifeDepth of Discharge

• Deep Discharging will shorten battery life

• Most lead-acid batteries designed for 50% DoD

• Deep-Cycle Batteries designed for up to 80% DoD− Shallower cycles will enable longer

life

• Never leave batteries discharged for more than a few days!− Sulfating of electrodes will

permanently decrease capacity

EnergyCell 200RE

EnergyCell HC Series

Battery Capacity

• Capacity = Ampere-hours provided to the load(s)

– Changes according to discharge rate, temperature, age, etc.

– 20-hour rating = 100% capacity = C20– 8-hour rating = 88% of C20– 6-hour rating = 84% of C20– 3-hour rating = 74% of C20– 1-hour rating = 59% of C20

• Batteries deliver less than 100% rated capacity when new.

– Poor maintenance will affect capacity

• Batteries self discharge if stored for long periods of time without being charged.

– The hotter the temperature the more self discharge

Temperature vs. Capacity

Series connection

Parallel connection

Battery Wiring

• Series: Voltage is additive; capacity remains same− Positive of Battery 1 is connected to negative of

Battery 2 and so on− Example: Two 12 VDC, 220 Ah batteries in series will

yield a 24 VDC, 220 Ah battery

• Parallel: Capacity is additive; voltage remains same− The positives are connected to each other, same for

negatives− Output leads must be from first and last battery for

electrical balance− Manufacturers typically limit maximum number of

parallel strings to three− Example: Two 12 VDC, 220 Ah batteries in parallel

will yield a 12VDC, 440 Ah battery

Common 48 VDC battery strings

Battery Charging

• Lead Acid Batteries should be charged after every use to ensure they are never stored in a discharged condition− If batteries are stored for extended periods of time they should be charged

approximately every 6 weeks− Between 105-120% of previously discharged capacity must be returned for

full charge− No need to fully discharge prior to charging− Charging should be temperature corrected

• Always use charge controller’s temperature sensor when available

• Flooded Batteries need to be periodically overcharged to ensure proper mixing of the electrolyte and avoid stratification− “Equalization” - deliberate, periodic overcharge to prevent electrolyte

stratification− Most charge controllers have an equalize charge setting− NEVER equalize sealed batteries!

Flooded AGM

Battery Charging Profile

Battery Voltages

Condition (@77F) Nominal Battery Bank Voltage

12 VDC 24 VDC 48 VDC

Fully charged – no load 12.7 VDC 25.4 VDC 50.8 VDC

20% charged – no load 11.6 VDC 23.2 VDC 46.4 VDC

90% charged – charging 15 VDC 30 VDC 60 VDC

Fully charged ‐ equalizing >15 VDC >30 VDC >60 VDC

Fully charged – under heavy load 11.5 VDC 23 VDC 46 VDC

20% charged – under heavy load 10.2 VDC 20.4 VDC 40.8 VDC

• Charging voltage must increase as temperature falls– Charging voltage must be higher in cold weather and lower in hot weather

• A battery monitor keeps track of amp-hours, voltage and temperature to determine state of charge

– OutBack FlexNet DC• Check battery voltages during any maintenance call

– This is often the first indication that something could be wrong

Battery Safety

• Always wear personal protective equipment when handling batteries− Chemical-resistant gloves, goggles

or face shield, acid-resistant apron and boots

• Keep flames, sparks or metal objects away from batteries − Use insulated tools− No jewelry− Do not smoke near batteries

• Neutralize acid spills with baking soda immediately

• Provide proper ventilation to prevent gas build up

Periodic Inspection and Cleaning

• Keep batteries clean and dry

• Check that all connections are tight

• Terminal protector should be applied to terminals to reduce corrosion

• Use a solution of baking soda and water to clean any acid residue on batteries or corrosion on the terminals

Battery Storage

• Batteries must be properly housed and sited

• Keep batteries in temperature-controlled space− Basements or garages are typical

• Battery enclosure must be ventilated− Active ventilation may be required for flooded

batteries in hot or tightly enclosed spaces

• Protect terminals from people, pets and falling objects

• Ensure that battery rack/enclosure meets any applicable seismic requirements for your region

• Breakers/Switches help improve safety when using and servicing batteries

HOW MUCH BACKUP DO YOU NEED?System Sizing

User Data You Will Need to Collect

• Protected loads− What loads does the user expect to run during an outage?− For each load, multiply the power draw by the hours it is used per day− For appliances, divide the Energy Star annual consumption kWh by 365

• http://www.energystar.gov/index.cfm?c=products.pr_find_es_products

• Peak load (Watts) − Sum of all loads that may be run simultaneously− Voltage the loads require (120 vs. 240 VAC)

• Hours/days of backup required− How many hours or days in a row will the loads need to run− Are outages likely to be accompanied by long periods of inclement weather?

• Sun-Hours per day during darkest month (kWh/m2/day)− This is the available solar resource− Use Winter Solstice time frame rather than annual average for best results


System Options you will need to Choose• Battery Type: Flooded, AGM or Gel

− Consider: Maintenance, shipping and storage requirements

• Battery bank DC voltage : 12, 24, or 48 VDC− Consider: Voltage of DC loads, size of system, available inverters− 48 VDC is generally most efficient and cost-effective for AC systems over 2kW

• Charge controller type: PWM or MPPT or AC coupled− Pulse Width Modulated (PWM) controllers

• Pros: Inexpensive ($150-$300) and compact• Cons: Low capacity ($500), larger

• Module Type: 36-cell, 60-cell or 72-cell− PWM controllers require 36 cell (nominal 12 VDC) or 72 cell (24 VDC) modules− Consider transportation and mounting limitations as well as cost

Load analysis: talk to your customer• Protected vs. non-protected loads: what do they really need?

− Refrigerator/freezer, lights, ventilation, TV/computer, cell phone charger, alarms

• Heating systems vary widely and may or may not be practical to back up− Air handlers can be a very large energy load, even if the heat source is gas − Electric water heaters can be a very large load

• How long do they really need the backup to last?− Batteries drive the total system cost more than the PV or inverter− The larger the loads and the longer they run, the more expensive the system will be − A 100 kWh battery bank (50 kWh/day for 2 days), is likely to cost about $20,000

• Can they add a generator if the backup needs to be larger or last longer?

• Manage the customer’s expectations!− “A protected loads panel is far more convenient and cost-effective than whole-house

backup”− Accurate load analysis is worth the time and will result in more satisfied customers − Ensure your customer understands how much energy they can expect from their

backup system and the risks of overloading it

Load Analysis

• Load Worksheet –‒ AEE Solar Design Guide and Catalog

For AEE

Battery Bank Sizing

• Battery sizing minimum for inverter power

• From OutBack Radian manual:− “To prevent the inverter’s charger from overcharging, the minimum

recommended battery bank size is 350 amp-hours for every Radian inverter/charger installed on the system”

− ”Systems intended to bridge short-term outages can use smaller battery banks. In these cases, the bank can be as low as 200 amp-hours per inverter However, the charge rate must be decreased to half the inverter’s maximum using the MATE3”

• One of the following conditions must also be true:– “The system is equipped with a backup generator that is programmed for automatic

start, – or typical grid loss is 30 minutes or less, or the loads are less than 2 kW”

• Other inverters have similar requirements

Battery Bank Sizing

• Daily energy consumption

− Sum the DC loads and convert to Ah− Sum the AC Loads and convert to Ah, then divide by inverter efficiency

• Limit total strings to 3 or less

• May need to try multiple different battery sizes

PV Array sizing

• Sizing the PV array for GTBB systems is similar to a grid-tie system

• Limits to array size: − 100% offset of electrical use− Available space − Budget

• At minimum, the array should power the backup loads for an extended outage

• Sizing for an extended outage needs to account for winter solar production unless the system will also have a generator

Charge Controllers

• Charge controllers for modern 60 cell modules must be MPPT type − MPPT = Maximum Power Point Tracking

• An MPPT controller will convert the input voltage to the correct voltage for charging the battery

• Array voltage must be higher than the battery voltage

• Charge controllers are current limited− A 4kW array will need one 80A change control for a 48 VDC

battery, but will require two controllers for a 24 VDC battery − 80 A x 48 VDC = 3,840 W, 80 A x 24 VDC = 1,920 W

• The PV array will rarely put out full rated power except at high altitude sites− Reasonable oversizing of array vs. charge controller can minimize

cost− Always have overcurrent protection between array and controller

PV Array Sizing (For MPPT Charge Controllers)

• String operating voltage must be between battery charging voltage and controller limit (usually 150 VAC)− Power will drop off dramatically if the charge point of the array

falls below the battery voltage

• A 48 VDC battery charges at 56 VDC or more − 2 modules x 26.1 VDC = 52.2 VDC − 2 modules in series will typically not charge a 48 VDC battery

• Most 60 cell modules will exceed 150 VDC in strings of 4

• A 48 VDC battery requires 3 modules in series only

• A 24 VDC battery can typically use either 2 or 3 modules in series

PV array combiner boxes

• Each parallel string of modules must have circuit protection − There is no current limiting electronics device between the battery and the combiner

box − Almost all modules now have a 15 A circuit rating

• The breakers in these circuits must be rated for the maximum voltage− Maximum voltage for many of these systems will be 150 VDC

• High-voltage charge controllers require higher voltage breakers or fuses

• All array circuits going to each charge controller must have a separate and isolated feeder to that charge controller

• Some combiner boxes have the capacity for two separate circuits− Multiple combiners may be more convenient for wire management

Inverter Sizing Considerations

• Inverter must meet the larger of array size or load size − The inverter needs to be large enough to power all of the loads that will

be put on it during a power outage − A grid-tied inverter also must handle entire PV array power − This connection does not exist for off-grid systems

• Will any loads require 240 VAC power? − Same as for off-grid systems

• Wire the protected loads panel for normal North American distribution of 120/240 VAC split phase or just 120 VAC?

• Will the installation use a backup generator? − Will it be 120 VAC only or 240 VAC?

Balance of System: Charge Controller Circuit Protection• Disconnects and circuit protection are required between

the PV array, charge controller, and battery− Battery string disconnects (right) can simplify

maintenance and trouble shooting

• A circuit breaker is normally used for 150 VDC PV circuits − This breaker should be rated at either the sum of the

combiner breakers or the maximum input for the charge controller

− Wire between breaker and the combiner box must meet or exceed the current rating of the breaker used

• The charge controller breaker and disconnect serves as the battery breaker− Must be rated for continuous duty − Can simply match the charge controller output rating − If the charge controller will be operated near its limit,

oversize the battery breaker slightly to avoid nuisance tripping

Balance of Systems: Ground and Arc Fault Protection

• Ground fault detection and disconnect (GFDI) is required for most residential systems − DC-GFDI or “DC-GFP” assemblies

• A DC-GFDI is simply a small breaker’s pole connected to larger breaker poles − The smaller breaker pole (usually 0.5 A) connects the negative array conductor to ground − This connection is the DC negative-to-ground bond − If the GFDI breaker trips from current flowing between negative and ground, it also

disconnects the PV array and/or charge controller

• The GFDI is traditionally installed between the array breaker and charge controller − OutBack also uses it between the charge controller and battery, serving as the charge

controller disconnect

• The 2011 NEC code also requires Arc Fault detection wherever voltage exceeds 80 VDC− Stand-alone arc fault detectors are not available at this time− Arc Fault protection is increasingly being built into charge controllers and array combiners

Lunch

Please be ready to continue by 1 PM

MAKING AC FROM BATTERIES

Inverters

Battery-Based Inverters

• Voltage sourced− Inverter builds its own waveform

• Fixed low-voltage input− Inverter fed from steady 12/24/48

VDC from batteries

• PV array MPPT provided by charge controller− Charge controller dictates string

size

• Modest efficiency: 75-90%

• Low-voltage single-phase output − 120 or 240 VAC

• Current sourced− Inverter uses grid waveform

• Actively controlled voltage input− Inverter uses MPPT and accepts

wide range of voltages

• Inverter provides PV array MPPT− String sizing dictated by inverter

• High efficiency: 95-98%

• Range of outputs− 240 VAC or 208/277/480 3-phase

Grid-Tie Inverters

Inverter Sizing• Find maximum AC load

− Identify and sum all loads that may run simultaneously

− Sum up total Watts – this is the minimum inverter continuous power rating

• Identify any loads with high start-up or surge current draws− Motors in compressors, fans and appliances− Gauss rifles/rail guns, electromagnets and other

large inductive loads− Largest surge load determines minimum inverter

surge rating

• Identify any loads that may require 240 VAC− 240 VAC often requires transformer or dual

inverters

• Be sure to consider inverter’s no-load-draw when sizing battery system and array

Inverter Sizing

• Size inverter for the larger of maximum load or for array size − During an outage, the inverter must be large enough to run all of the

loads that will run at the same time − The inverter must be large enough to process the full solar array into the

grid

• Per 2011 NEC 705.12(D)(2)Exception, the inverter grid feed current is rated at the continuous duty current the inverter can produce x 1.25 − The grid intertie breaker can be larger than the intertie circuit rating so

that the intertie breaker can handle the maximum pass-through current − 50A or 60A is a common breaker size for pass-through

• When a single 120 VAC inverter is used, the current for the grid intertie will be double that for a given system size compared to a direct grid-tie inverter running at 240 VAC − This may be a problem to meet 2008 NEC 690 64(B)(2), or 2011 NEC 705

12(D)(2)

Inverter Selection Considerations• Will there be an AC generator in the system?

− Be sure inverter has generator input for battery charging

− Be sure that inverter and generator are compatible

• Will the system connect to the utility grid?− Inverter must be “grid interactive” – these

inverters have internal transfer switches to comply with UL 1741/IEEE 1547 anti-islanding requirements

• Will the inverter be mounted outdoors?− Most battery-based inverters are only rated for

indoor use (NEMA 1)

• Do the loads include sensitive electronics or audio equipment?− Modified sine wave inverters may damage

certain electronics and will interfere with most speakers

GX/FX Series• 120 VAC input and output only

− An autotransformer can be used with a single inverter to produce 120/240 VAC split phase output, or 240 VAC input, but not both

− Inverter stacking not available with grid-tie

• Single AC input− External transfer switch required for

use with a generator − Few generators are compatible

• 120/240 VAC split phase input and output − Up to 10 Radian inverters can be

stacked for an 80 kW system • Radian inverters can be AC-

coupled using prewired GSLC• Radian inverters have two AC

input circuits− Compatible with most generators

Radian GS Series

Integration Hardware

• Over-current devices – breakers and fuses

• DC Ground-Fault Protection (GFP)

• Bus Bars

• Combiner boxes

• Grounding

• Generator Start Controls

• Amp-Hour Meters

• System Monitoring

BOS Balance of Systems, power panels

• A central location is desired to connect wiring and install breakers − There needs to be a DC load center and an AC load center, or one load

center for both AC and DC

• A battery-based inverter can have a very large current draw− Especially when battery voltage is lower

• The main DC breaker for these inverters is 125A to 250A − The inverter manufacturer or supplier will generally specify breaker sizes

• Otherwise, breaker size is generally max power output in watts divided by battery voltage x 1.5, but sometimes larger

• Wire size for battery and inverter circuits will commonly be AWG 2/0 or AWG 4/0 cable − Keep connection as short as possible to minimize voltage drop− Under 10ft is best

Power Systems

• Factory pre-wired power systems are available to simplify design and installation− Several common sizes & configurations

• Most power systems include:− Inverter(s)− Controller and networking devices− Battery monitor− Integration hardware and BOS− Enclosures, Breakers, GFDI, Bypass, etc.− Charge controllers (optional)

• AEE can provide custom configurations that are ETL marked to streamline inspections− Note that multi-inverter systems are shipped in

crates

System Controllers

• Automate battery management− Float and equalization charge timing

• Turn on/shut off inverters and/or generators according to time of day or battery state of charge

• Remote monitoring/control via Internet

Preconfigured GTBB Systems: Light Preserver

• 178 Ah battery bank (~7 kWh to 80% DoD)• 3.6kW power system - Enough to keep a refrigerator and a few lights on during a utility outage • 3.4 kW of PV - Enough to keep the battery bank charged indefinitely if loads are managed carefully

Prices shown are subject to change

$9,891Ordered Item Item Description Qty Unit Gold Ext. Gold011‐02598 REC, REC280TP, PV MODULES, 280W, BLACK FRAME, MC4‐TYPE, SINGAPORE 12 215.60$ 2,587.20$ 015‐09822 SNAPNRACK, STANDARD RAIL SET, 122IN, BLACK, 6 PC 1 269.18$ 269.18$ 015‐09816 SNAPNRACK, STANDARD RAIL SET, 122IN, BLACK, 2 PC 1 101.46$ 101.46$ 242‐04015 SNAPNRACK, BONDING STANDARD RAIL SPLICE ASSEMBLY, BLACK 6 6.55$ 39.30$ 242‐02054 SNAPNRACK, BONDING MID CLAMP ASSEMBLY, 1.31 ‐ 1.77IN, BLACK 22 2.55$ 56.10$ 242‐02063 SNAPNRACK, BONDING UNIVERSAL END CLAMP ASSEMBLY 16 4.13$ 66.08$ 232‐01023 SNAPNRACK, STANDARD RAIL END CAP, BLACK 16 1.35$ 21.60$ 242‐02701 SNAPNRACK, BONDING L‐FOOT KIT W/ BASE AND FLASHING, BLACK L‐FOOT 16 7.84$ 125.44$ 242‐02101 SNAPNRACK, GROUND LUG ASSEMBLY, 6‐12 AWG 4 3.13$ 12.52$ 232‐01106 SNAPNRACK, WIRE RETENTION CLIP, COMPOSITE, BLACK 24 0.26$ 6.24$ 052‐09725 PV OUTPUT, HELIOS H4, MALE/FEMALE, 10/1, 50FT, 1000 V, PV WIRE 4 32.00$ 128.00$ 054‐03242 STRAIN RELIEF, 1/2IN, NYLON, 0.25‐0.27IN CABLE DIA, TWO HOLE, MALE PIPE THREAD, 6MM 4 3.20$ 12.80$ 052‐09126 CABLE CLIP, 10 TO 12 AWG PV‐WIRE EDGE CLIP, SST, 25 PACK 1 11.25$ 11.25$ 053‐03012 OUTBACK, STRING COMBINER, FWPV8, 8‐STRING 120A/600VDC MAX, NEMA3R 1 92.88$ 92.88$ 053‐03029 CIRCUIT BREAKER, DIN MOUNT 150VDC 15A, 1‐POLE, MIDNITE MNEPV15 4 9.60$ 38.40$ 033‐04091 OUTBACK, FP1 VFXR3648A, PRE‐WIRED POWER PANEL, 3.6 KW, 48 VDC, 120 VAC, 60 HZ, SINGLE 1 3,497.34$ 3,497.34$ 052‐02005‐R BATTERY/INVERTER CABLE, 2/0, 5FT, RED‐RR 1 52.00$ 52.00$ 052‐02005‐W BATTERY/INVERTER CABLE, 2/0, 5FT, BLK‐WW 1 52.00$ 52.00$ 040‐01171 OUTBACK BATTERY 200 RE 12V/178AH@20HR 4 422.10$ 1,688.40$ 048‐03001 OUTBACK, IBR‐2‐48‐175, INDOOR ENCLOSURE, PRE‐WIRED 1 1,001.65$ 1,001.65$ 188‐09100 HELLERMAN TYTON, 188‐09100, PREPRINTED LABEL KIT, RESIDENTIAL, UNDER 7KW 1 31.50$ 31.50$

Preconfigured GTBB Systems: Energy Provider

• 356 Ah Battery Bank (~14 kWh to 80% DoD)• 4 kW power system - Enough to supply up to two 15 A circuits during an extended utility outage• 4.2 kW of PV - Enough to keep the battery bank charged indefinitely if loads are managed carefully.


$14,840Ordered Item Item Description Qty Unit Gold Ext. Gold011‐02598 REC, REC280TP, PV MODULES, 280W, BLACK FRAME, MC4‐TYPE, SINGAPORE 15 215.60$ 3,234.00$ 015‐09826 SNAPNRACK, STANDARD RAIL SET, 162IN, BLACK, 6 PC 1 341.71$ 341.71$ 015‐09816 SNAPNRACK, STANDARD RAIL SET, 122IN, BLACK, 2 PC 1 101.46$ 101.46$ 242‐04015 SNAPNRACK, BONDING STANDARD RAIL SPLICE ASSEMBLY, BLACK 4 6.55$ 26.20$ 242‐02054 SNAPNRACK, BONDING MID CLAMP ASSEMBLY, 1.31 ‐ 1.77IN, BLACK 26 2.55$ 66.30$ 242‐02063 SNAPNRACK, BONDING UNIVERSAL END CLAMP ASSEMBLY 16 4.13$ 66.08$ 232‐01023 SNAPNRACK, STANDARD RAIL END CAP, BLACK 16 1.35$ 21.60$ 242‐02701 SNAPNRACK, BONDING L‐FOOT KIT W/ BASE AND FLASHING, BLACK L‐FOOT 22 7.84$ 172.48$ 242‐02101 SNAPNRACK, GROUND LUG ASSEMBLY, 6‐12 AWG 4 3.13$ 12.52$ 232‐01106 SNAPNRACK, WIRE RETENTION CLIP, COMPOSITE, BLACK 30 0.26$ 7.80$ 052‐09725 PV OUTPUT, HELIOS H4, MALE/FEMALE, 10/1, 50FT, 1000 V, PV WIRE 5 32.00$ 160.00$ 054‐03242 STRAIN RELIEF, 1/2IN, NYLON, 0.25‐0.27IN CABLE DIA, TWO HOLE, MALE PIPE THREAD, 6MM 5 3.20$ 16.00$ 052‐09126 CABLE CLIP, 10 TO 12 AWG PV‐WIRE EDGE CLIP, SST, 25 PACK 2 11.25$ 22.50$ 053‐03012 OUTBACK, STRING COMBINER, FWPV8, 8‐STRING 120A/600VDC MAX, NEMA3R 1 92.88$ 92.88$ 053‐03029 CIRCUIT BREAKER, DIN MOUNT 150VDC 15A, 1‐POLE, MIDNITE MNEPV15 5 9.60$ 48.00$ 033‐04080 OUTBACK, FPR‐4048A, 4.0 KW, 48 VDC, PRE‐WIRED POWER PANEL, 120/240 VAC, 60 HZ, FM80 1 5,936.70$ 5,936.70$ 052‐02005‐R BATTERY/INVERTER CABLE, 2/0, 5FT, RED‐RR 1 52.00$ 52.00$ 052‐02005‐W BATTERY/INVERTER CABLE, 2/0, 5FT, BLK‐WW 1 52.00$ 52.00$ 040‐01171 OUTBACK BATTERY 200 RE 12V/178AH@20HR 8 422.10$ 3,376.80$ 048‐03001 OUTBACK, IBR‐2‐48‐175, INDOOR ENCLOSURE, PRE‐WIRED 1 1,001.65$ 1,001.65$ 188‐09100 HELLERMAN TYTON, 188‐09100, PREPRINTED LABEL KIT, RESIDENTIAL, UNDER 7KW 1 31.50$ 31.50$

Preconfigured GTBB Systems: Storm Rider

• 534 Ah Battery Bank (~21 kWh to 80% DoD), 8 kW power system, 6.7 kW of PV


$21,242Ordered Item Item Description Qty Unit Gold Ext. Gold011‐02598 REC, REC280TP, PV MODULES, 280W, BLACK FRAME, MC4‐TYPE, SINGAPORE 24 215.60$ 5,174.40$ 015‐09822 SNAPNRACK, STANDARD RAIL SET, 122IN, BLACK, 6 PC 2 269.18$ 538.36$ 015‐09816 SNAPNRACK, STANDARD RAIL SET, 122IN, BLACK, 2 PC 2 101.46$ 202.92$ 242‐04015 SNAPNRACK, BONDING STANDARD RAIL SPLICE ASSEMBLY, BLACK 8 6.55$ 52.40$ 242‐02054 SNAPNRACK, BONDING MID CLAMP ASSEMBLY, 1.31 ‐ 1.77IN, BLACK 44 2.55$ 112.20$ 242‐02063 SNAPNRACK, BONDING UNIVERSAL END CLAMP ASSEMBLY 16 4.13$ 66.08$ 232‐01023 SNAPNRACK, STANDARD RAIL END CAP, BLACK 16 1.35$ 21.60$ 242‐02701 SNAPNRACK, BONDING L‐FOOT KIT W/ BASE AND FLASHING, BLACK L‐FOOT 32 7.84$ 250.88$ 242‐02101 SNAPNRACK, GROUND LUG ASSEMBLY, 6‐12 AWG 4 3.13$ 12.52$ 232‐01106 SNAPNRACK, WIRE RETENTION CLIP, COMPOSITE, BLACK 48 0.26$ 12.48$ 052‐09725 PV OUTPUT, HELIOS H4, MALE/FEMALE, 10/1, 50FT, 1000 V, PV WIRE 8 32.00$ 256.00$ 054‐03242 STRAIN RELIEF, 1/2IN, NYLON, 0.25‐0.27IN CABLE DIA, TWO HOLE, MALE PIPE THREAD, 6MM 8 3.20$ 25.60$ 052‐09126 CABLE CLIP, 10 TO 12 AWG PV‐WIRE EDGE CLIP, SST, 25 PACK 2 11.25$ 22.50$ 053‐03012 OUTBACK, STRING COMBINER, FWPV8, 8‐STRING 120A/600VDC MAX, NEMA3R 2 92.88$ 185.76$ 053‐03029 CIRCUIT BREAKER, DIN MOUNT 150VDC 15A, 1‐POLE, MIDNITE MNEPV15 8 9.60$ 76.80$ 033‐04081 OUTBACK, FPR‐8048A, 8.0 KW, 48 VDC, PRE‐WIRED POWER PANEL, 120/240 VAC, 60 HZ, DUAL FM 1 7,590.00$ 7,590.00$ 052‐02005‐R BATTERY/INVERTER CABLE, 2/0, 5FT, RED‐RR 2 52.00$ 104.00$ 052‐02005‐W BATTERY/INVERTER CABLE, 2/0, 5FT, BLK‐WW 2 52.00$ 104.00$ 040‐01171 OUTBACK BATTERY 200 RE 12V/178AH@20HR 12 422.10$ 5,065.20$ 048‐03000 OUTBACK, IBR‐3‐48‐175, INDOOR ENCLOSURE, BATTERY RACK FOR UP TO 12 200RE BATTERIES 1 1,336.65$ 1,336.65$ 188‐09100 HELLERMAN TYTON, 188‐09100, PREPRINTED LABEL KIT, RESIDENTIAL, UNDER 7KW 1 31.50$ 31.50$

Preconfigured GTBB Systems: Ultimate Survivor

• 534 Ah Battery Bank (>12.5 kWh to 50% DoD), 8 kW power system, 8.4 kW of PV


$22,952Ordered Item Item Description Qty Unit Price Ext. Price011‐02598 REC, REC280TP, PV MODULES, 280W, BLACK FRAME, MC4‐TYPE, SINGAPORE 30 215.60$ 6,468.00$ 015‐09822 SNAPNRACK, STANDARD RAIL SET, 122IN, BLACK, 6 PC 3 269.18$ 807.54$ 015‐09816 SNAPNRACK, STANDARD RAIL SET, 122IN, BLACK, 2 PC 1 101.46$ 101.46$ 242‐04015 SNAPNRACK, BONDING STANDARD RAIL SPLICE ASSEMBLY, BLACK 10 6.55$ 65.50$ 242‐02054 SNAPNRACK, BONDING MID CLAMP ASSEMBLY, 1.31 ‐ 1.77IN, BLACK 50 2.55$ 127.50$ 242‐02063 SNAPNRACK, BONDING UNIVERSAL END CLAMP ASSEMBLY 20 4.13$ 82.60$ 232‐01023 SNAPNRACK, STANDARD RAIL END CAP, BLACK 20 1.35$ 27.00$ 242‐02701 SNAPNRACK, BONDING L‐FOOT KIT W/ BASE AND FLASHING, BLACK L‐FOOT 40 7.84$ 313.60$ 242‐02101 SNAPNRACK, GROUND LUG ASSEMBLY, 6‐12 AWG 5 3.13$ 15.65$ 232‐01106 SNAPNRACK, WIRE RETENTION CLIP, COMPOSITE, BLACK 60 0.26$ 15.60$ 052‐09725 PV OUTPUT, HELIOS H4, MALE/FEMALE, 10/1, 50FT, 1000 V, PV WIRE 10 32.00$ 320.00$ 054‐03242 STRAIN RELIEF, 1/2IN, NYLON, 0.25‐0.27IN CABLE DIA, TWO HOLE, MALE PIPE THREAD, 6MM 10 3.20$ 32.00$ 052‐09126 CABLE CLIP, 10 TO 12 AWG PV‐WIRE EDGE CLIP, SST, 25 PACK 3 11.25$ 33.75$ 053‐03012 OUTBACK, STRING COMBINER, FWPV8, 8‐STRING 120A/600VDC MAX, NEMA3R 2 92.88$ 185.76$ 053‐03029 CIRCUIT BREAKER, DIN MOUNT 150VDC 15A, 1‐POLE, MIDNITE MNEPV15 10 9.60$ 96.00$ 033‐04081 OUTBACK, FPR‐8048A, 8.0 KW, 48 VDC, PRE‐WIRED POWER PANEL, 120/240 VAC, 60 HZ, DUAL FM 1 7,590.00$ 7,590.00$ 052‐02005‐R BATTERY/INVERTER CABLE, 2/0, 5FT, RED‐RR 2 52.00$ 104.00$ 052‐02005‐W BATTERY/INVERTER CABLE, 2/0, 5FT, BLK‐WW 2 52.00$ 104.00$ 040‐01171 OUTBACK BATTERY 200 RE 12V/178AH@20HR 12 422.10$ 5,065.20$ 048‐03000 OUTBACK, IBR‐3‐48‐175, INDOOR ENCLOSURE, BATTERY RACK FOR UP TO 12 200RE BATTERIES 1 1,336.65$ 1,336.65$ 188‐09101 HELLERMAN TYTON, 188‐09101, PREPRINTED LABEL KIT, RESIDENTIAL, 7KW TO 15KW 1 60.20$ 60.20$

Retrofit Systems

Ordered Item Item Description Qty Unit Gold Ext. Gold053‐03012 OUTBACK, STRING COMBINER, FWPV8, 8‐STRING 120A/600VDC MAX, NEMA3R 1 92.88$ 92.88$ 053‐03029 CIRCUIT BREAKER, DIN MOUNT 150VDC 15A, 1‐POLE, MIDNITE MNEPV15 6 9.60$ 57.60$ 033‐04080 OUTBACK, FPR‐4048A, 4.0 KW, 48 VDC, PRE‐WIRED POWER PANEL, 120/240 VAC, 60 HZ, FM 1 5,936.70$ 5,936.70$ 052‐02005‐R BATTERY/INVERTER CABLE, 2/0, 5FT, RED‐RR 1 52.00$ 52.00$ 052‐02005‐W BATTERY/INVERTER CABLE, 2/0, 5FT, BLK‐WW 1 52.00$ 52.00$ 040‐01179 OUTBACK, 106RE, AGM BATTERY, 12V, 100AH AT 20HR 4 204.35$ 817.40$ 048‐03005 OUTBACK, IBE‐1‐48‐001, INDOOR ENCLOSURE, BATTERY ENCLOSURE & WIRING FOR UP TO 4 1 505.85$ 505.85$

Ordered Item Item Description Qty Unit Gold Ext. Gold053‐03012 OUTBACK, STRING COMBINER, FWPV8, 8‐STRING 120A/600VDC MAX, NEMA3R 1 92.88$ 92.88$ 053‐03029 CIRCUIT BREAKER, DIN MOUNT 150VDC 15A, 1‐POLE, MIDNITE MNEPV15 6 9.60$ 57.60$ 033‐04080 OUTBACK, FPR‐4048A, 4.0 KW, 48 VDC, PRE‐WIRED POWER PANEL, 120/240 VAC, 60 HZ, FM 1 5,936.70$ 5,936.70$ 052‐02005‐R BATTERY/INVERTER CABLE, 2/0, 5FT, RED‐RR 1 52.00$ 52.00$ 052‐02005‐W BATTERY/INVERTER CABLE, 2/0, 5FT, BLK‐WW 1 52.00$ 52.00$ 040‐01171 OUTBACK BATTERY 200 RE 12V/178AH@20HR 8 422.10$ 3,376.80$ 048‐03001 OUTBACK, IBR‐2‐48‐175, INDOOR ENCLOSURE, PRE‐WIRED 1 1,001.65$ 1,001.65$

$7,364

$10,419

• 356 Ah Battery Bank (~8.5 kWh to 50% DoD), 4 kW power system (

Retrofit Systems$21,790

• 534 Ah Battery Bank (>12.5 kWh to 50% DoD), 8 kW power system (

WINNING DEALS WITH READY-TO-GO SOLUTIONS

Selling Battery Backup

Battery Backup Does Add Cost

• Battery backup functionality adds about $2/W to equipment costs‒ This varies with battery vs. PV array size

• Additional labor is required to install the batteries

• Depending on customer needs, household circuits may need to be rewired

• Many customers who would like backup will not have the cash to pay for it

• Financing battery backup systems has been a challenge – but it is getting easier

A battery backup PV system costs twice as much as a grid-direct PV system…

Debt Financing (Loan)

• User owns the equipment–

• Equipment choices not restricted

• Terms from 1 to 10 years

• Payments often more than electricity savings

• Payments fixed

• Installer must be credit-worthy and in business for 2 years or more

• Installer pays points on loan to offer attractive package

• Standardized nation-wide

3rd-Party Owned (Lease)• Investment fund owns equipment

• Equipment options limited by ASL

• 20-year terms

• Payments less than or equal to electricity savings

• Payments often escalate over time

• Installer must meet stringent financial and business volume requirements

• Installed price effectively capped by lease terms

• Only available in certain states

Debt Financing Options

• Home Mortgage Refinance• Homeowners can refinance their home loan and take out additional funds to

pay for the GTBB system• Fannie Mae now offering specific program for solar and energy improvements• Offers low rates and tax-deductible interest payments, but is complex and can

take months to complete

• Home Equity Line of Credit (HELOC) or 2nd Mortgage• Homeowners with sufficient equity can take out a traditional secured bank loan• Offers modest rates and tax-deductible interest, but is not universally available

• Title I Loan (i.e. Admiral’s bank Solar StepDown Loan)• Up to $40,000 available to pay for GTBB system• Secured by bank lien on property (no equity or appraisal requirements)• Can be re-amortized once incentives are received• Rates tend to be higher than for equity-based loans, but no contractor fees• https://www.admiralsbank.com/renewable-energy-lending/for-contractors/

AEE Sponsored GreenSky Trade Credit Program• Unsecured consumer loans for up to $55,000

‒ Reduced APR loans with terms up to 12 years‒ 0% interest loans with terms up to 5 years‒ Up to 12 months same-as-cash financing

• Contractor fees used to buy down APR ‒ 12 month same-as-cash loan has a 4.5% contractor fee‒ 10-year loan at 6% has a 9.85% dealer fee

• Easy processing‒ Paperless Internet or phone applications/approvals‒ 640 minimum FICO score‒ Dealer initiates payment as milestones are reached‒ Payments processed as Mastercard transactions (subject to processor fees)

• Get special product rebates with AEE sponsored program ‒ http://greenskycredit.com/dealerapplication‒ Use Sponsor #: 358

Consumer Value Proposition

• Light Preserver 3 kW GTBB System– Installed Cost: $21,750– Loan Terms: 10 years @6% APR– Payments: $250 per month– Bill savings: $40 per month

• Assumes $.12/kWh rate

• Storm Rider 6 kW GTBB System– Installed Cost: $43,500– Loan Terms: 10 years @6% APR– Payments: $500 per month– Bill savings: $80 per month

Installer Value Proposition

• Light Preserver 3 kW GTBB System– Selling Price: $21,750– Equipment Cost: $10,147– Financing Cost: $2,487– Contractor fee plus MC processing– AEE Rebate: $250– Installation Margin: $9,384

• Storm Rider 6 kW GTBB System– Selling Price: $43,500– Equipment Cost: $21,185– Financing Cost: $4,937– AEE Rebate: $700– Installation Margin: $18,078

Optimize Your Sales Process

• Address Budget and Goals at the beginning!

• Your customers don’t know what they need, they know what they want

• Budget and price always matter, don’t shy away from it, address it early on and help the customer shape their goals

• As early as possible, introduce your potential customers to your standard system offering

• Help your customer understand the financial cost of not having uninterrupted power− Food spoiling− Alarm System− Sump Pump− Cost of a hotel in a natural disaster


What not to say (because it takes way too much time)

“Mr. Customer, we have lots of options available, tell me more about what you would like to backup and I will create a custom system for you…”

Why?• Customers will tell us what they want, not what they can afford• Customers will get excited about their goals, and we have to crush them the

second we start talking about price• We have to start saying ‘no’ to their goals once we hear their budget, instead

of saying ‘yes’


Instead, say…“Mr. Customer, we have 3 options available, (1)We have a small system which just backs up the bare essentials. It costs

$22,000 or $250/month(2)We have a large system that backs up the majority of your everyday home

needs. It costs $44,000 or $500/month(3)We could design a custom system to power whatever your home requires. The

starting cost is about $30,000 and it really depends on what you want to do.

Based on your budget and goals, which one would you like to talk about in more detail?


• With budget defined, discuss Customer goals and determine which system is right for them − Power Budget− Equipment placement− Additional electrical work –adders!

• By making the backup discussion efficient, you can offer it to virtually every customer− “Without battery backup, solar panels on your roof won’t do you any good if the

power goes out” − “Extreme Weather is only getting more extreme…and more frequent”− You can finally offer a solution that everyone and their brother always wants to hear

about….

Help Your Customer Determine Which System They Need

• What are the goals for this solar electric installation?− What would you like to be able to power if the grid goes down?

• What is the price you put on having safe, reliable power for your home and family?− How much are you spending on electricity each month?

• How much has your usage changed since you moved into this house?− Do you expect your usage to change going forward?

• What are you looking for in a solar contractor?− What are the primary criteria for choosing a solar contractor?

• Take notes• Use 80/20 rule• Summarize situation and impacts

Present Solutions/Close

• Present/build your proposal− Offer multiple options based on their budget

• ASK, ASK, ASK!!! (Probe, Probe, Probe!)− “Does this make sense?”

• Identify ‘buying questions’− “If we signed a contract this week, how long would it take to get started?”− “If we wanted to move forward, how much is the deposit?”

• Present installation timeline

• Identify action items and deliverables

• Ask for the business

Ask for the Referral

• Explain your referral program: “We would rather invest inour clients than in marketing companies”

• “Which of your friends or family would be interested in hearing about this?”

• “I am going to be visiting other homes in this area, I want to make sure you get credit for any neighbors you know, can you give me the names of any neighbors you think would be interested and I’ll talk to them before sending out the mailers so you get credited for the referrals.”

• “If you’re pleased with how things have gone so far, would you be willing to write a review about us on Yelp/Google/Angie’s List, and let us post a picture of you and your system on Facebook/Pinterest/Preppers.com?”

Keep Improving

• Practice really does make perfect− Role play− Mock negotiations

• Repetition− Following this process will not be easy at first; stick with it and

perfect your talk track

• Seek feedback from peers and clients

MANAGING CUSTOMER EXPECTATIONS

Communicating Limitations

Communicate with Your Customer

• Does the end-user know what to expect from the system?− Limitations− Maintenance requirements− Warrantees and service agreements− Consequences of operating outside system parameters

• What your customer doesn’t know, could hurt you− “The system you designed failed, again...”− “You never said I would have to replace the batteries...”− “You said that circuit was backed up, I should be able to plug in my hair dryer...”− “...I’m calling the Better Business Bureau!”

Or

System Limitations

• System Power Budget – Overload the inverter and it will shut down− How many things can be run at once?− The difference between a hair dryer and

a small fan

• System Energy Budget – Drain the batteries too much and they will die− How many Watt-hours can be used?− Bad weather may impact how much

energy you can use

• Install a monitoring system − Be sure the end-user knows how to read

it!− Do you have remote access to read it

too?

Maintenance Requirements

• Battery bank maintenance− Ensure batteries are fully charged at least once every 2-3 days− Ensure batteries are clean and protected

• PV array maintenance− Ensure modules are free of dust and/or debris− Clear out any critters, leaves, etc. from underneath array

• Power system maintenance− Check for error signals and/or review monitoring system information

Warrantees & Service Agreements

• Module Warranty/Power Guarantee− Typically 10 to 25 years, covers replacement parts only− Common exclusions: close to salt water, physical damage, out of spec

mounting

• Inverter/Power system warranty− Typically 2 to 5 years, covers replacement parts only− Common exclusions: overload conditions, insufficient battery bank, generator

fault/surge, lightning

• Battery warranty− Typically 2 years or less, covers replacement or prorated refund− Common exclusions: lack of maintenance, DoD over 80%, insufficient

recharge, overload conditions, overcurrent conditions

• System warranty/Service agreement− This is the expressed or implied workmanship warranty you offer as an

installer

Consequences of Misuse

• What happens if:− User adds loads that weren’t designed for?− PV array is disabled due to weather or damage?− User “adjusts” the system?− User fails to maintain batteries?− No one interacts with the system for 3 months?− The user is replaced?

• Clarify (in writing) what is your responsibility and what is the user’s responsibility− Be sure the owner/user understands it

Maintenance Agreements

• Get paid for the work you’ll have to do anyway

• Maintenance agreements provide many advantages− Sets expectations of both user and installer− Provides added revenue stream for installer− Ensures that system is properly maintained

• What to include in your maintenance agreement− Online monitoring, which you check at least weekly

• e-mail alarms can be set up with many monitoring systems− Annual or semiannual site visit

• Battery checkup• Module cleaning• Overall system checkup/test• Discuss any new loads the user is considering “I’m going to buy an EV”

Additional Resources

• AEE Solar Youtube Channel‒ Recorded Webinars and conference

presentations‒ Product intro and review videos

• Rooftops & Wrenches Podcast‒ Monthly Q&A with AEE Tech Team‒ Find us on Stitcher and iTunes‒ Listen directly on AEESolar.com

• AEE Solar Live Training Events‒ Annual Dealer Conference‒ Regional Workshops‒ Webinars

• OutBack Power Training‒ Certificate Training Program

grid-tied battery backup workshop...• december 2014: arizona’s srp rolls out mandatory demand...

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