I'm not assuming anything/anyone specifically but lean towards nation-state, anarchist, terror, etc.
A natural disaster such as a flare, earthquake, fire, etc. are a different story.
The radiation and electrical magnetic pulse from a solar flare could hamper equipment. However recent studies in the last few years by EPRI, INL, and ORNL actually show that much equipment would survive and equipment that did not would be localized.
While I don't disagree that transformers... let alone key transformer.. are critical. By disabling 9 transformers you cannot take down “THE GRID”. You could certainly cause havoc and perhaps take down sections of a grid, perhaps a large one such as new york city. But these would be localized. While ensuring that critical components are local and available is important much of this is being done in the energy sector. It’s not to say there simply are no replacements. However, the energy sector, including transmission, is made up of over 6000 separate organizations. Most of which are not federally controlled or controlled by the local government. Put simply they are for-profit companies. They are critical infrastructure and regulated by the gov, but not a part of.
Put short, this is a serious matter, but not in the way it is presented here. It would be a herculean effort to take out 1 let alone the suggested 9. Especially in a coordinated fashion. EVEN IF it was achieved.. This would only cause localized issues. Not takedown. “THE GRID”
This is a much larger discussion but a few things to consider:
1. There is no singular "grid". It just does not work that way. There are thousands of generation and transmission companies throughout the US. They all maintain there own “grids”. There is connectivity to provide ways to connect grids to sell/buy/shed power. But these connections are controlled and can be simply… disconnected.
2. Without going on a major diatribe on the many different attack vectors and inherent vulnerabilities in the energy sector…. Suffice to say.. The easiest and most sure way to take out a transformer is physical. They would need to be destroyed or disabled.
Digital/remote interference would require an immense effort and campaign… we are not talking breaching the 9 locations… we’re talking hacking millions upon millions of connected devices and coordinating load to take out a transformer or the grid as whole…. The coordination and effort necessary for either are staggering.
3. There are in fact spares and inventory… just not in the hands of the feds.
as aurizon stated you have to have an intermediary. There are several reputable email to fax services like fax.plus that will allow you to send up to 10 pages for free each page after that is .20 cents.
apologies, it's frustrating when you can't other forms of e comms.