How does SolarAPP+ address UL 9540A listed ESS equipment?
Under the 2021 International Residential Code and earlier editions, all contractors must obtain pre-approval from the AHJ to accept reduced spacing of individual ESS units. The AHJ could approve reduced spacing for equipment under UL 9540A, based on the manufacturer’s instructions demonstrating compliance with a UL 9540A Report. The contractor must then attest that they have received approval to use the specific equipment referenced in the UL 9540A report.
***New for the 2024 Model Residential Code, reduced spacings must be detailed in the manufacturer's installation instructions as determined by its listing to UL 9540:2020 edition 3. The standard provides guidance in 23.2, Large-Scale fire testing, and in Appendix E, Table E.1, Residential use ESS, on minimum separation distances from certain exposures and other ESS. The contractor is obligated to provide documentation at inspection to support the reduced spacing between individual ESS units. Reach out to the ESS manufacturer if you have trouble finding this information.
The inspection checklist will then ask the inspector to verify that the ESS has been installed per the manufacturer’s instructions or per the approved UL 9540A test Report, as applicable. An example of how this is shown on the inspection checklist is shown below.
| Manufacturer | Model |
Spacing Front to Back (inches) |
Spacing Side to Side (inches) |
Indoor Rated |
Additional Instructions |
Equivalent Room Volume |
| Canadian Solar | CSI EP CUBE |
3 |
8 |
Y |
N/A |
21.7m3 room size per 2 units |
| Canadian Solar | CSI EP CUBE 2.0 |
3.34 |
7.87 |
Y |
N/A |
21.7m3 room size per 2 units |
| Enphase Energy Inc. | IQBATTERY-5P-1P-NA |
6 |
3 |
Y |
N/A |
133 m3 |
| FranklinWH Technologies Co., Ltd. | aPower X [208V] |
N/A |
4 |
Y |
N/A |
100m3 room size per 3 units |
| FranklinWH Technologies Co., Ltd. | aPower X [240V] |
N/A |
4 |
Y |
N/A |
100m3 room size per 3 units |
| Generac Power Systems, Inc | PWRcell 2 APKE00076 |
36 |
18 |
Y |
NO |
9.6 cubic feet |
| Mango Power Tech Inc. | M Hybrid Inverter 12kW |
36 |
36 |
Y |
N/A |
8.53' X 6.23' X 4.27' |
| PhaseGreen Technology Inc. | PhG-ESS-5L-S |
39.37 |
36 |
Y |
N/A |
94.3" x 35.2" x 48.1" |
| PhaseGreen Technology Inc. | PhG-ESS-10L-S |
39.37 |
36 |
Y |
N/A |
94.3" x 47.7" x 48.1" |
| PhaseGreen Technology Inc. | PhG-ESS-15L-S |
39.37 |
36 |
Y |
N/A |
94.3" x 60.1" x 48.1" |
| PhaseGreen Technology Inc. | PhG-ESS-20L-S |
39.37 |
36 |
Y |
N/A |
94.3" x 72.5" x 48.1" |
| PointGuard Energy Inc. | PGHome-A-B |
19.69 |
11.81 |
Y |
40 kWh per single battery stack. |
Not specified |
| Renon Power | R-XL005011 |
N/A |
19.5 |
Y |
NO |
Not Specified |
| Renon Power | R-XL010021 |
N/A |
19.5 |
Y |
NO |
Not Specified |
| Renon Power | R-XL015031 |
N/A |
19.5 |
Y |
NO |
Not Specified |
| Renon Power | R-XL020041 |
N/A |
19.5 |
Y |
NO |
Not Specified |
| Renon Power | R-XL025051 |
N/A |
19.5 |
Y |
NO |
Not Specified |
| Renon Power | R-XL030061 |
N/A |
19.5 |
Y |
NO |
Not Specified |
| Sigenergy Technology Co., Ltd. | SigenStor-A-B |
19.69 |
11.81 |
Y |
No |
1011.81 sq.ft. |
| SolarEdge Technologies Ltd. | BAT-10K1P |
6.25 |
8 |
Y |
N/A |
1500 ft^3 |
| Tesla Inc. | AC Powerwall 3012170-xx-y |
1 |
10 |
Y |
N/A |
4' x 4' x 8' |
| Tesla Inc. | 1850000-XX-Y |
1 |
10 |
Y |
N/A |
4' x 4' x 8' |
| Tesla Inc. | 1707000-XX-Y |
1 |
4 |
Y |
N/A |
9.7' x 9.7' x 8' |
The SolarAPP Foundation maintains a database of UL 9540A reports that have been reviewed. Pertinent information about each report is listed below for reference. An AHJ may review the information and determine approval on a per-product basis. The foundation will update the database as we learn of equipment that satisfies the requirements of the 2024 International Residential Code.