Official Summary Text
N
o later than January 1, 2027,
this bill requires each
electric utility or electric project developer, owner, or operator within this state, regardless of public or private ownership or jurisdiction under the North American Electric Reliability Corporation
("
covered entity
")
to
conduct a technical assessment of all covered equipment to determine vulnerability to
geomagnetically induced current
s
("
GICs
")
.
The assessment
must meet all of the following objectives:
Utilize the waveform in Figure A.5 of IEC 61000-2-9, Edition 2.0, modeling a peak magnetic field strength of
20,000
nanotesla and corresponding electric field of
85
volts per kilometer
.
Assume transformers are fully loaded during GIC exposure
.
Account for transformer age and condition using ANSI/IEEE Standard C57.110 and IEEE Standard C57.91
.
Identify susceptibility to half-cycle saturation, GIC-induced harmonics, reactive power consumption, hot spot generation, and insulation degradation.
This bill prohibits
c
overed entities
from
rely
ing
solely on operational procedures such as load shedding or reactive power supply to mitigate GIC risk. Such procedures are not considered sufficient protection under this
bill.
As used in this bill, "covered
equipment" means any power transformer with a primary voltage of
100
kilovolts or greater and capacity of
25
megavolt ampere or greater, and any generator step-up transformer with a secondary voltage of
100
kilovolts or greater and capacity of
25
megavolt ampere or greater
.
REPORT
No later than July 1, 2027,
this bill requires
each covered entity
to
submit a report on the assessment to the general assembly, the governor, the Tennessee board of utility regulation, and the Tennessee public utilities commission.
The report must include, for each susceptible transformer and substation
, all of the following:
The transformer
(i) b
rand;
(ii)
place of origin, including nation where manufactured;
(iii) d
esign specifications, including windings and core configuration; winding impedances; winding DC resistances, specifying whether assumed or measured; and phase type, either single-phase or 3-phase;
(iv) c
apacity in megavolt-amperes; (v) voltage level in kilovolts; (vi)
a
ge; (vii) site location, redacted for CEII; (viii) purpose, such as generator step-up, autotransformer, step-down, converter, redacted for CEII; (ix) replacement lead time; and (x) replacement cost
.
Spreadsheet-formatted data and narrative analysis
.
Recommended solutions to protect the grid against GIC by preventing or reducing the half-cycle saturation of transformers
.
Total cost to implement GIC protection
.
Priority list of transformers by damage risk and critical infrastructure impact
.
Funding recommendations, including potential grant sources and rate recovery mechanisms.
This bill requires
CEII data, such as location and purpose, submitted under this
bill to
be handled in accordance with CEII protocols as defined in
this bill
. Location and purpose data must be redacted from public reports.
As used in this bill,
"CEII" means specific engineering, vulnerability, or detailed design protocols and procedures related to proposed or existing critical infrastructure, whether physical or virtual, that relate to the production, generation, transmission, transportation, or
distribution of energy, the unauthorized disclosure of which could pose a risk to the security, reliability, or integrity of the infrastructure
.
S
uch protocols are designated as confidential and exempt from public disclosure, as the
ir release could be useful to a person planning an attack or otherwise causing harm to the infrastructure.
Current Bill Text
Read the full stored bill text
SENATE BILL 2565
By Bowling
HOUSE BILL 2316
By Barrett
HB2316
012395
- 1 -
AN ACT to amend Tennessee Code Annotated, Title 4;
Title 7 and Title 65, relative to threats to electrical
assets.
BE IT ENACTED BY THE GENERAL ASSEMBLY OF THE STATE OF TENNESSEE:
SECTION 1. As used in this act:
(1) "Covered entity" means an electric utility or electric project developer, owner,
or operator within this state, regardless of public or private ownership or jurisdiction
under the North American Electric Reliability Corporation (NERC);
(2) "Covered equipment" means any power transformer with a primary voltage of
one hundred kilovolts (100 kV) or greater and capacity of twenty-five megavolt ampere
(25 MVA) or greater, and any generator step-up transformer with a secondary voltage of
one hundred kilovolts (100 kV) or greater and capacity of twenty-five megavolt ampere
(25 MVA) or greater;
(3) "GIC" means a geomagnetically induced current, also known as ground
induced current, resulting from naturally occurring geomagnetic disturbances or the late-
time component of a high-altitude nuclear electromagnetic pulse; and
(4) "Critical energy infrastructure information protocols," "critical electric
infrastructure information protocols," or "CEII" means specific engineering, vulnerability,
or detailed design protocols and procedures related to proposed or existing critical
infrastructure, whether physical or virtual, that relate to the production, generation,
transmission, transportation, or distribution of energy, the unauthorized disclosure of
which could pose a risk to the security, reliability, or integrity of the infrastructure; such
protocols are designated as confidential and exempt from public disclosure, as their
- 2 - 012395
release could be useful to a person planning an attack or otherwise causing harm to the
infrastructure.
SECTION 2.
(a) Each covered entity shall, no later than January 1, 2027, conduct a technical
assessment of all covered equipment to determine vulnerability to GICs.
(b) The assessment shall:
(1) Utilize the waveform in Figure A.5 of IEC 61000-2-9, Edition 2.0
(2025-05), modeling a peak magnetic field strength of twenty thousand nanotesla
(20,000 nT) and corresponding electric field of eighty-five volts per kilometer (85
V/km);
(2) Assume transformers are fully loaded during GIC exposure;
(3) Account for transformer age and condition using ANSI/IEEE Standard
C57.110 and IEEE Standard C57.91; and
(4) Identify susceptibility to half-cycle saturation, GIC-induced harmonics,
reactive power consumption, hot spot generation, and insulation degradation.
SECTION 3.
(a) No later than July 1, 2027, each covered entity shall submit a report on the
assessment conducted pursuant to Section 2 to the general assembly, the governor, the
Tennessee board of utility regulation, and the Tennessee public utilities commission.
(b) The report must include, for each susceptible transformer and substation:
(1) The transformer:
(A) Brand;
(B) Place of origin, including nation where manufactured;
(C) Design specifications, including windings and core
configuration; winding impedances; winding DC resistances, specifying
- 3 - 012395
whether assumed or measured; and phase type, either single-phase or 3-
phase;
(D) Capacity in megavolt-amperes (MVA);
(E) Voltage level in kilovolts (kV);
(F) Age;
(G) Site location, redacted for CEII;
(H) Purpose, such as generator step-up, autotransformer, step-
down, converter, redacted for CEII;
(I) Replacement lead time; and
(J) Replacement cost;
(2) Spreadsheet-formatted data and narrative analysis;
(3) Recommended solutions to protect the grid against GIC by preventing
or reducing the half-cycle saturation of transformers;
(4) Total cost to implement GIC protection;
(5) Priority list of transformers by damage risk and critical infrastructure
impact; and
(6) Funding recommendations, including potential grant sources and rate
recovery mechanisms.
SECTION 4. Covered entities shall not rely solely on operational procedures such as
load shedding or reactive power supply to mitigate GIC risk. Such procedures are not
considered sufficient protection under this chapter.
SECTION 5. CEII data, such as location and purpose, submitted under this act must be
handled in accordance with CEII protocols as defined in Section 1. Location and purpose data
must be redacted from public reports.
SECTION 6. This act takes effect upon becoming a law, the public welfare requiring it.