It's hard to tell if this photo was taken when the plant was being built, running, or being dismantled.
It is interesting that the Wikipedia page on Shale Oil
mentions new Zealand as one of the places where exploration and extraction took place in the 19th Century.
FROM THE WESTERN SOUTHLAND WEB PAGE; In 1899 a rich shale oil operation began, employing 200 men thus adding to the properity and population which reached 3,000 at its peak. The shale oil industry which produced an oil for lighting and a number of byproducts came to a sudden end in 1902. The excuse given was the adverse marketing conditions and the removal of duty on kerosene and paraffin oil. Mystery still surrounds the real reason! The closure of this important industry, coupled with less gold being discovered and the sawmilling industry moving further west saw the town slowly reduce in size. In the 1960s the town still boasted a movie theatre, three shops, an hotel and a dairy, plus a school, three churches and a Mission hall. It no longer does.