"The Boy Who Harnessed The Wind". Swan Theatre, Stratford-upon-Avon

The RSC’s new, Malawi-based musical is a story of a young boy standing up for himself, and a generational shift with an old king/young prince dynamic. The songs switch between Chewa and English. The movement is inspired by traditional folk dance. And it all takes place in a rural, African community surrounded by hyenas waiting for the chance to chow down on starving flesh.

Sounds familiar? The Boy Who Harnessed The Wind certainly doffs its kufi at The Lion King, but where Disney’s myth was about reclaiming a rightful throne, the incredible-but-true story of William Kamkwamba is one of innovation, perseverance, and uplifting a community in crisis. This is about a young inventor and, like him, it presses all the right buttons.

William, at the age of 13, excluded from school because his parents couldn’t pay the fees, and with a budget of zero, built a fully functional, electricity-generating windmill out of bits of rubbish. In so doing, he offered his community a way out of starvation in the lethal Malawian drought of 2001. This teenage Ion King went on to TED talks, university and international acclaim. You will never have so little as the nothing with which he created so much.

Kamkwamba’s story has already been told in book and film. What, if anything, does a stage musical add to the lore already available?

As it turns out, quite a lot.

First, clarity. Richy Hughes and Tim Sutton have simplified the story, and focused it on its emotional core: the tension between tradition and progress. William may be the central character, but the one who carries the sympathies of the audience, the one who has to evolve in order to survive, is his father Trywell, played with passion and dignity by Sifiso Mazibuko. Trywell knows how to till the land and pray for rain; he doesn’t trust education, much less electricity. All of his instincts are to force his wayward son to pick up a hoe and join him. Their battles, laced with paternal love and flickering independence, are the heart of this show, and it’s a heart that seems to encompass the quandary facing Malawi itself. In order to build the windmill, William has to persuade his father to give up his bicycle, and when, ultimately, he does so, the gesture has the symbolic weight of a nation behind it.

Next, song and dance. Sutton’s music is grounded in the parched earth of Wimbe, Kamkwamba’s home town. Unlike the Elton John/Tim Rice pop that made The Lion King so catchy but western-facing, the music here is all Afrobeats and ululation, and the dancing expresses pride, culture and life. Every swing of a limb feels loaded not just with rhythm but identity.

And thirdly, a musical brings a fairy-tale quality to a true account of struggle and pain. It pushes the story into mythical, unreal territory, somewhere over the rainbow but deeper into our consciousness. Shaka Kalokoh’s loping hyena and Choolwe Laina Muntanga’s Spirit of the Wind may be metaphorical presences, but we need metaphor to make sense of the madness around us, and they deliver it with savage, tender beauty.

And at the centre of all these intertwined skeins of dance, emotion and symbolism, is the poorest character of all: Khamba, a stray dog who is William’s constant companion. Khamba is a puppet, operated with astonishing skill by puppeteer Yana Penrose. Just like the windmill, he seems to be made out of abandoned odds and ends, but put together he comes to almost literal life. And when he dies, and Penrose lets go of his body before stepping respectfully away into the darkness, it feels like a soul departing.

The Boy Who Harnessed the Wind knows exactly how to harness our emotions: the scene when the ramshackle windmill finally spins, and the lights in the village twinkle into life one after another, feels as great an achievement as setting foot on the moon. And when this is followed up by projected documentary footage of the real William giving his TED talk in 2009, the switch from artificial to real is overwhelming. At the press night, Kamkwamba himself appeared at the end. That must have been quite a moment.

For all its heart and power, the show does have shortcomings. The set, which consists of a couple of rotating huts, a few semal trees, and a vaguely glimpsed sky in the background, feels a trifle cramped and tokenistic for the sheer size of the story. While I love the Swan Theatre, it may be just too small for the scale of this project.

And there’s a lot of boy before we get to the harnessing. The entire first half of the show is spent in setting up the lives of the village characters. Of course this is vital to establish all the stresses and strains of the community. But nevertheless, things only get really interesting once the famine bites in the second half.

But perhaps the most puzzling and frustrating decision made by the production is that, at its climax – the moment when the windmill creaks into life – it doesn’t deliver on its promise. Throughout the show, William says to his friends and family, ‘I can solve this’, ‘I can save us’, and ‘I can bring water from the clouds’. Dramatically, the script sets up the bringing of water as his absolute goal. But when the moment comes, the windmill very pointedly does not produce water, only light. And yet the characters all behave as if he has achieved what he set out to do. Later, there is a brief, wordless (perhaps bolted-on?) moment when they get water from a pipe and cheer. But it’s a corrective footnote masquerading as a secondary climax.

I know that, in reality, William’s first windmill did only produce electricity, and it was another six years before he was able to generate enough power to get water out of bore-holes. But from a theatrical perspective, in a feelgood, rags-to-riches fairy-tale like this, a little dramatic licence would perhaps have been acceptable. The lights twinkling on, followed by a cough from the water-pipe, and then the flow of water, would have been both a natural climax and the logical conclusion of everything that had gone before: the light of knowledge becoming the water of life.

So yes, there are a few structural weaknesses. But the emotional arcs of the characters, combined with the infectious creativity and energy of this production, more than compensate. What William Kamkwamba did is an inspiration for us all, a real-life embodiment of Kipling’s If. His father watched the things he’d given his life to, broken. His son stooped, and built them up with worn-out tools.