(Sharecast News) - Edenville Energy's annual loss widened as costs vastly outstripped revenue in what the mining company described as a challenging year.The AIM-traded company's pre-tax loss for the year to the end of December was £1.79m compared with £1.19m a year earlier. Revenue at £337,125 was less than a third of Edenville's £1.19m cost of sales.There were no year-earlier figures for these items. Edenville shares fell 25% to 0.047p at 09:38 BST.The developer of Tanzania's brownfield Rukwa coalfields said it was hit by heavy rain, lack of transport and a high percentage of fine coal from its production. It also had to make changes to increase capacity and buy extra mining equipment and had to take over construction of a plant because the contractor's work was not good enough.Edenville said operations got off to a good start in 2019 but a share offer that closed in February was poorly subscribed, leaving it short of funds to fulfil order and expand its operation. In April it succeeded in raising £510,000.Jeffrey Malaihollo, Edenville's chairman, said: "2018 was a significant but very challenging year for the company. We made substantial progress, becoming a revenue producing commercial coal producer for the first time, although it has taken longer than we had hoped to overcome the challenges we faced and reach the positive position we are now in."Malaihollo said the company was now generating revenue and had a wide range of customers and enough equipment to develop its current plant.