There are many good places to get advice on the ideal word count for a particular category of book. This post by agent Jennifer Laughran is one of them. The post is from 2011, but the advice is still good.
The 100,000-word psychological barrier for debut authors, mentioned at the end, is real. I battered my own head bloody against it for a long time. I have an extensive Excel spreadsheet of word counts for well-known books, including many debut books of famous authors. Damn few of those debut books were longer than 100,000 words, although many later ones by the same authors were (robust sales give an author a lot of leeway).
Remember, the slush pile for the average reputable agent is so enormous that there are probably several “deal killers” the assistants are told to watch for and instantly hit the “reject” button without further examination. I suspect “over 100,000 words” for a new author is one of them.
Maybe you’re looking at your 150,000 word debut novel and saying that each and every word is essential. This is probably not true, but if you think it is, and you’re determined to go ahead at that length, do it with your eyes open and knowing that you’re setting the bar much higher for getting it published.