I'd like to suggest transmission tower icon.
Try the radio-tower icon.
Thank you for your help, but radio-tower it's different what I need. I'm talking about electricity transmission towers.
@oengenheiro what is the purpose of this icon?
I guess something along:


The purpose of this icon is to identify an energy source.
Example: An IoT/SmartHouse software (personally thinking Home Assistant) can show energy supplied from local installed solar panels (mdi:solar-power) and from the energy supplied from the public energy grid (insert name of the proposed icon)
I'm also looking for this icon.
The first suggestion from @CoDEmanX would be nice.
great work @goyney! thank you soo much for addressing this issue 馃槃
Can I possibly suggest you make the top horizontal crossarms thinner ?
MD guidelines require 2-pixel width lines. So, I don't believe so.