Electrical engineer. Born in Edinburgh, ones of the Haldanes of Cloan and a cousin of J.B.S. Haldane (1892 - 1964), he was educated at Edinburgh Academy and the Royal Naval College, Dartmouth. He served in the navy during the First World War and was present at the Battle of Jutland in 1916. Haldane then read physics at Trinity College, Cambridge, working under Prof. Ernest Rutherford at the Cavendish Laboratory. He went on to work as a consulting electrical engineer, first with C. A. Parsons and Company and later with Merz and McLellan, going on to become a partner in that firm. Haldane helped to establish the British national electricity grid, worked on the first UK-France electrical interconnector and promoted geothermal power in New Zealand. He also installed a pioneering heat pump of his own design at his home Foswell House in Perthshire.
Haldane served as President of Institution of Electrical Engineers (1948) and won its James Watt Gold Medal (1953). Haldane was inducted into the Scottish Engineering Hall of Fame (2021). He died at his Perthshire home and lies buried in Auchterarder.
