Using get_the_excerpt() Before The Loop

So you are basically also looking for a fallback in case your excerpt is empty? I suppose this question/answer could be helpful for you: “get_the_excerpt() with fallback like the_excerpt()“. It describes, how to build your own “excerpt” in case there is none – like this:

$excerpt = get_the_content();
$excerpt = esc_attr( strip_tags( stripslashes( $excerpt ) ) );
$excerpt = wp_trim_words( $excerpt, $num_words = 55, $more = NULL );

In your case you would probably add the ID to it: $excerpt = get_the_content(1);. I don’t know if your SE privileges allow this, but should probably add “I’m looking for a solution for when has (the article) no defined excerpt / the post_excerpt is empty” to your question to clarify what you are actually looking for…