Somehow some models and data are mixed up - I assume you are talking about the GS105PE. In any case, the maximum power consumption is always specified including the maximum available PoE power.
GS105PE: Power Consumption (when all ports used, line-rate traffic and max PoE) - Worst case, all ports used, line-rate traffic, max PoE (W)
traffic, max PoE (W): 22.0 W. [1]
The rather academic PoE budget on the GS105PE encloses: "PoE pass-thru: 19W with 802.3at/7.9W with 802.3af input power" [2].
On the GS105PE, the available power also depends on the PoE power supply. With IEEE 802.3af just under 6.5 W are available at the connected PoE device, with IEEE 802.3at either once just under 13W or twice just under 6.5 W at the PD (Powered Device). At the switch this is 16.4 W or twice 7.2 W (line loss over 100 metres says hello). [3]
The switch requires 22 W - 19 W == 3 W under full switch power and the maximum cable lengths in pure GbE operation without PoE - this corresponds roughly to a 5 port GbE switch such as the GS105Ev2 [1].
Sources:
[1] page 8
https://www.netgear.com/images...
[2] Page 2, ditto.
[3]
https://kb.netgear.com/25541...
