Wei Wu and Deborah Nansteel in “Penny.” (Scott Suchman)

I’m all for supporting new opera, but why put limits on it? This has been, to date, my biggest question about the Washington National Opera’s American Opera Initiative. Now in its third year, the initiative commissions young composers to write 20-minute operas, and then hour-long operas, with mentoring and workshops along the way. But does writing a 20-minute opera really prepare you to create a satisfying, hour-long opera?

Along came “Penny,” which premiered at the Kennedy Center’s Terrace Theater on Friday night, and said: Actually, maybe it does.

Douglas Pew, the composer, and Dara Weinberg, the librettist, wrote a 20-minute work, “The Game of Hearts,” for the program’s first season. With their hour-long “Penny,” they managed something that’s hard to achieve under the auspices of a program involving so many operatic cooks: originality. “Penny” isn’t pathbreaking per se; it’s just a story we haven’t heard before, told with compelling directness and through effective music.

Did I mention it’s about an adult autistic woman finding her voice? This may be one of the most interesting roles I’ve seen recently for a soprano — and Deborah Nansteel, a current member of the Domingo-Cafritz program, took it and ran with it. Nansteel’s voice always sounds to me as if it hasn’t fully opened up yet, but she sings well, and on Friday she also beautifully animated a difficult part.

Any opera creator tackling a contemporary subject has to answer the question, “Why are they singing?” “Penny” tackles this by making singing a part of the story line.

After the death of her uncle and guardian Raymond, Penny comes to live with her sister and brother-in-law, Katherine (the silvery-voiced Kerriann Otaño) and Gary, but the upheaval in her life causes her to shut down, rocking gently and keening to herself in a quiet vocalise. Martin, a friend of Gary’s, hears her and gets her, through singing, to start to communicate again, in a scene that could be hokey but was well enough handled actually to be moving instead (not least thanks to the ringing voice of Patrick O’Halloran, who seemed to be having fun playing a tenor on stage).

Pew’s score seemed to put subtle quotation marks around the scenes that were supposed to be sung, as opposed to those that were supposed to be spoken, while Penny’s interior monologues — rather, dialogues with her late uncle (delightfully and quirkily played by James Shaffran) hover in their own in-between realm, nudging at conventional melody while wandering in their own direction. If the strong opening seemed a brief nod to “La Bohème,” the different levels of musical characterization were far more than merely evocative, and they succeeded on a dramatic as well as a musical level. Anne Manson, one of the program’s mentors, conducted capably.

Weinberg had to take some narrative shortcuts to fit a lot of material into an hour, but her libretto created some strikingly round characters — an impression furthered by the stage direction of the Shakespeare Theatre Company’s associate artistic director, Alan Paul. Gary (Trevor Scheunemann) is a pianist who suffers from a neurological condition that’s affecting one of his hands (the words “focal dystonia” are not mentioned), and he wants to use some of Penny’s inheritance to pay for an operation. Penny’s social worker looks out for Penny’s best interests, her options and her autonomy. (Wei Wu, like Otaño and O’Halloran another current Domingo-Cafritz member, once again impressed with his resonant bass and increasingly authoritative stage presence.)

Programs like the American Opera Initiative can take on a quasi-prescriptive tone, with a whiff of antiseptic: This is what we ought to be doing. It’s refreshing, then, when they result in a piece such as “Penny” that simply works, not because we should like it, but because it has a story to tell.