Net Metering and Interconnections

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Net Metering and Interconnections

• Home Energy Makeover
• August 16, 2008

Dan Harms, PE La Plata Electric Association
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Net Metering

• The Process
• Mechanics
• Examples
• Economics

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LPEA Net Metering Criteria

• For renewable systems under 25 kW
• Must be used to offset members load at same
  location

• Identical rate structure and components
• This includes any base charges

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Net Metering

• Allows a member to be billed for only the
  difference between what they generate and what
  they use
• Use the Grid as a pseudo battery bank

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Net Metering

• Member pays for net electricity consumed
  annually
• Excess generation purchased at LPEAs average
  wholesale cost each year

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Net Metering/Interconnection

• Member Benefits
• Eliminates need for batteries
• Reduces cost by eliminating second meter
• Increases economic value of system by up to 50
• Simple inexpensive mechanism to encourage
  renewable generators

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Net Metering/Interconnections

• Installations
• 65 Interconnected Sites
• 236,000 Watts
• 430,700 kWh of Energy Annually
• Value
• 43,000 each Year

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Local Net Metered Photovoltaic
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Local Net Metered Photovoltaic
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The Process

• Member submits Application for Interconnection
• LPEA approves application
• Member installs renewable system
• Member submits Certificate of Completion
• LPEA inspects system
• Applications - www.lpea.coop
• Go to Everything Green then Customer
  Generation then Interconnection Procedure

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Safety

• Inverter must be UL 1741 approved
• A system disconnect must be installed
• 10 kW or less a breaker will suffice
• Greater than 10 kW a visible disconnect is
  required
• All disconnects must be clearly labeled
• If disconnect not at the meter, a permanent sign
  must be installed at meter indicating precisely
  where the visible disconnect is located

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It is possible for a small generator to backfeed
LPEA lines at 7,200 VOLTS!
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LPEA Net Metering Mechanics

• One meter spins forwards and backwards
• Meter read a end of billing cycle
• If reading is positive
• Member is billed for amount shown on meter (Load
  - Generation)

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LPEA Net Metering Mechanics

• If reading is negative
• May March
• A zero usage read is entered
• Member is charged 12.75 base charge
• April
• Member is credited for amount shown on meter at
  average wholesale rate (currently 0.057/kWh)
• Member is charged 12.75 base charge
• If credit greater than base charge, check will be
  issued

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Example 1

• Members usage is 600 kWh
• Members generation if 500 kWh
• Meter reflects 100 kWh of usage
• Member is billed as though they only used 100 kWh
  that month

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Example 2

• Members usage is 600 kWh
• Members generation if 700 kWh
• Meter reflects 100 kWh of generation
• Members bill reflects zero usage
• Member has 100 kWh available for the next month

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Example 3

• Members annual usage is 6,600 kWh
• Members generation is 7,000 kWh
• Meter reflects 400 kWh of generation
• Member is credited for 400 kWh at 0.05 per kWh
  or 20.00
• However, monthly base charge is 12.75
• Member receives check for 7.25

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Net Metering Economics

• LPEA Rebates
• 2.00 per watt
• 3,000 cap
• Eighteen checks processed (2008)
• New Federal Tax Incentives
• 30 of system
• 2,000 cap for residential
• Renewed for 2009?

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Net Metering Economics

• Economics (Photovoltaic System)
• 2,000 watt system
• 10 per watt
• Installed cost 20,000
• Economics Energy Output
• 2,000 watt system
• Five hours per day
• 3,650 kWh annually

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Net Metering Economics

• Example

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Net Metering Economics

• Example
• Average life of system 20 years
• Without Incentives
• 0.274 / kWh
• With Incentives
• 0.206 / kWh

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What Does It All Mean?

• For LPEA Net Metered Accounts
• 500 Tons Less
• CO2 Emitted Annually

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