@MyNam3IsMark123 

Hi,

Is your goal to add TP-Link Powerline adapters to your sisters already existing Powerline network that consists of Netgear devices?

If yes, then please tell us the exact model of one of the Netgear Powerline adapters (best would be the one that is connected to the Telstra router). Devices usually have a sticker on their backside that contains this information.

Or are you planning to setup your very own separate Powerline network between the Telstra router and your backyard bedroom?

My sister has 5 Netgear Powerline 1000 (PL1000V2) adapters connected to the modem. She bought them here at JB Hi-Fi.

https://www.jbhifi.com.au/products/netgear-pl1000-100au-powerline-gigabit-adapter-kit

My goal is to add one TP-Link powerline adapter to my sister's already existing powerline network that consists of Netgear devices. I will need to get in the electrician to place a new wall outlet in the house near the modem and one in my backyard bedroom.

My sister has a separate powerline adapter for each appliance. One is connected to her laptop. The 2nd one is connected to her PlayStation 5. The 3rd one is connected to her Apple TV. The 4th one is connected to my mother's bedroom for her Apple TV. And the 5th powerline adapter is connected to her Nintendo Switch.

My sister and I share the same Telstra modem. We go in halves with the monthly bill. My bedroom is a good 30 metres away from where the modem is located in the house. I run a 100 foot ethernet cable from the modem to my bedroom and I wonder why my internet connection is often very slow. I am hoping to get rid of the cable and replace it with a two or three ethernet port TP-Link powerline adapter. Before I run out and buy this thing from Officeworks and/or get in the electrician to install new wall outlets, I just need to know if the TP-Link powerline adapter will work in my backyard bedroom and won't conflict with my sister's X5 Netgear powerline adapter setup.
 

  @MyNam3IsMark123 

According to the description from the seller the Netgear adapter supports the Homeplug AV2 standard, which is the same standard the TL-PA9020 uses.
So, theoretically they should work together.

Note that if data is transferred between two Powerline adapters of different speed grades, then the achievable speed will be determined by the slower of the two adapters. (the PL1000V2 in this case)

But now that you've mentioned you currently use an Ethernet cable I wonder what is wrong with that.

What sort of speed are you expecting from a Powerline connection over 30 meters?

Normally, Ethernet is the prime solution for fast and reliable network connections, while Powerline is considered more like a last resort.

Can you see any physical damage on that 30 meter long Ethernet cable?
Is it possible for you to test that Ethernet cable locally, I mean without relying on the Internet? (for example, connect two computers, one on each end of the 30m Ethernet cable and then transfer data between the two computers and see what the speed is and whether it is fairly constant)

Hmm. You have given me a lot to think about. I do find it somewhat off-putting that my sister's slower Netgear speeds will force me into accepting that speed despite buying a faster powerline adapter. I am glad that you mentioned this. It is something that never occurred to me. Thanks for that important bit of information.

I am happy with my current internet speed. Nothing is wrong with my Ethernet cable nor connection. Well, not now anyway. But by the looks of the cable where the sliding door keeps slamming into it, I don't think it will last very long. It's for this reason why I always have a spare ultra thin cable on hand. Because I don't think it's very smart to run this 30 metre cable along the ground, I think it may be best to get in the electrician and run it along the wall, and get him to drill a couple of holes through the brickwork.

I've changed my mind. I think I will continue using this Ethernet cable. All I really need to buy is an Ethernet splitter with one end running from my laptop and the other end running to my gaming console. The main reason why I came so close to buying the powerline adapter is because I'm fed up with always having to remove the Ethernet cable from my laptop to my gaming console and vice versa. I believe that buying a high quality Ethernet splitter should do the trick.

That should be it for now. Thanks for all your help. I really appreciate it. Take care :-)