You won’t actually renew the visa. You will obtain an extension of stay based on retirement and you will need to either have the necessary funds in a Thai bank or else get a letter from the US Embassy where you state that you meet the income requirements. I am sure that you are aware that if you make a border run just prior to the enter before date you will get an additional year on your non imm o-a visa which will postpone all the above. And of course you still need to perform the 90 day reports.
also, if the terms are considered interchangeable a person may google Thai Embassy requirements when they plan on dealing with a Thai Consulate, and could be irritated and surprised.
Dakota Anderson each country has a single Embassy in the other country and depending on the size of that country it may also have one or more consulates. Sometimes the consulates cannot perform all the duties of an embassy. “An embassy is a permanent diplomatic mission (read: a delegation of diplomats) led by an ambassador. The term is often also used for the physical building they occupy, but that's more correctly termed a chancery. A consulate is a government delegation led by a consul.”