At the same time, the perspicacious Yen foresaw that the expansion of Keelung Harbor would create new opportunities for the coal fuel market. Therefore he went into business with Japanese to actively develop the coalfields in northern Taiwan, where output eventually accounted for two-thirds of all coal produced on the island and the region boomed for half a century.
同時，眼光銳利的顏雲年看準基隆港的開發將帶動煤礦燃料市場，因此與日人合作開發北台灣煤田，煤產量佔全台三分之二，譜寫了半世紀的礦業風光史。