City of San Marcos Electric Utility

Texas Utility Interconnection & net metering rules

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Tariffs and interconnection rules move often. If something here is out of date or missing, tell us and we'll fix it.

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Net Metering AllowedYes
Line Taps AllowedNo
Load Taps AllowedNo
AC Disconnect RequiredYes

Net metering & export

Net Metering Allowed
Yes
TOU Utility
No
Post Solar Billing Method
Export Rate
Solar Export Type
Avoided Cost
Solar Export Rate Approx
0.06
Solar Export Value Notes
COSM will reimburse customers for energy “delivered to” the COSM distribution system at the avoided cost. Reimbursements will likely take the form of a credit on the customer’s monthly bill.
Rebates Offered
Yes
Deregulated
Yes
Allows Standby
No

Interconnection & taps

Approval Req To Install
Yes
Line Taps Allowed
No
Load Taps Allowed
No
Automatic Transformer Upgrade Size
0
Meter Aggregation Allowed
No

System size & offset

System Size Restrictions
20
System Size Restriction Type
AC kW
System Size Battery Included
No
System Size Includes Existing Systems
No
Offset Value
0
Offset Calculation Period
0
Industry Standard Watts Sqft
2
Inverter Oversize Restrictions
No
System Offset Notes

The proposed generation system does not expect to export more than 15% of total load on the feeder

Offset Calc Tool
Historical Usage

Metering & disconnect

Production Meter Required
Yes
Production Meter Position
Inv-Disco-PM-POI
Production Meter Labeling
Production Meter
AC Disconnect Required
Yes
AC Disconnect Labeling
Visible Lockable Labeled Disconnect

Plans & docs

Site Plan Reqs

Standard

SLD Reqs

Example SLD uploaded to files

  • PV>Inverter>Disco>PM>MSP>UM
  • Production Meter required between disconnect and POI. (Disconnect to bottom of PM, Utility to top)
Electric Service Reqs

AC Disconnect Required

  • Location of the disconnect switch must be approved by COSM.
  • Disconnect switch shall be easily visible, mounted separately from metering equipment and readily accessible.

Production Meter Required

Electrical Stamp Required
No
Equipment Approvals
California Energy Commission
Meter Num Req SLD 3LD
No
ESID Num Req SLD 3LD
No
Website
link
Phone
(512) 393-8000

Other details

Revision Required
Yes
Mod Swap Requires Planset
Yes
Compiled from public records, 2026. Tariffs and interconnection rules change; verify with City of San Marcos Electric Utility before you rely on this. The useful move: if an installer says you need a main panel upgrade, ask how these tap and interconnection policies were considered first.