Britain's Drax switches on fourth biomass generation unit at Yorkshire power plant

LONDON, Aug 20 (Reuters) -

* Britain’s Drax said on Monday that its fourth biomass generation unit has started operations at its power plant in North Yorkshire

* Drax converted its first three coal units to use biomass between 2013 and 2016. It started the fourth unit’s conversion in June

* The cost of converting the fourth unit is below the level of previous conversions at around 30 million pounds ($38 million)

* Drax said it will now continue work to replace its remaining two coal units with gas-fired power generation units

* Proposals for these conversions has been submitted to the Planning Inspectorate and a final decision is expected next year ($1 = 0.7841 pounds) (Reporting by Nina Chestney, editing by Louise Heavens)