PV Crystalox Solar, which makes silicon wafers for use in solar power, has more than doubled its first-half pre-tax profits because of strong demand and robust profit margins.

Shares in the company, which makes wafers from high-grade silicon for manufacturers of solar cells and panels, climbed 4¾p to close at 176¾p as pre-tax profits rose from €22.9m to €52.8m (£41.9m).