Chiwetel Ejiofor has made his debut as writer-director, and the result is exhilarating and rather inspiring – a story of success against the odds, of ingenuity and resourcefulness, of a father and son painfully coming to terms with each other. Ejiofor brings a real sensitivity and empathy to this material, as well as some bold, fluent storytelling.

He has adapted a 2013 memoir by the Malawian engineer William Kamkwamba, which told the remarkable story of how as a teenager he provided electricity for his village by designing and building a wind turbine, hooked up to a simple bike-type dynamo. Ejiofor has exercised a little creative licence here and upped the narrative stakes, by making this turbine vital for pumping otherwise inaccessible well water for the drought-stricken village’s crops, and in doing so battling against his father’s angry realisation that his kid has done what he could not. But Ejiofor’s creative interventions are entirely justified. They speak to the larger ideas – the pain and confrontation involved in trying something radically new.

Ejiofor himself plays Trywell, a man consumed with fear that he will be found wanting as a father and farmer; Maxwell Simba plays his smart, observant son William. Aïssa Maïga is Trywell’s wife Agnes.

The village is plunged into poverty and hunger. Exploitative, predatory landowners make derisory buy-out offers to families like William’s; government politicians are cynical, violent and corrupt. In the midst of all this, William has a natural aptitude for technology, and with just a school library book called Using Energy, he realises that he can save his village.

Simba shows a maturity in his performance to match Ejiofor’s. This absorbing story is shot with athletically strong light and colour by cinematographer Dick Pope and the performances are intelligent and forthright. When those turbine blades turned, I felt like cheering.