To equip solar energy plants atop private houses in Chandigarh, the Union Ministry of Renewable Energy has given its approval to the Union Territory administration. However, the Union government has curtailed the number of such plants from 300 to 230.    The cost of the 1 kw plant will be roughly around Rs 1 lakh and Rs 1.40 lakh with battery. A resident will get 30 per cent subsidy to set up the plant.    The UT administration said that it has received the nod last week. Public notices will be issued and if more than 230 residents opt for the facility, it will hold a draw of lottery to select the private person intending to set up solar energy plants.    As per the availability of space of houses, solar plants of three categories, 1 kilowatt, 2 kilowatt and 3 kilowatt, would be provided to residents. One kilowatt plant requires 100 square feet area and would be able to generate 1,300 to 1,400 units of electricity in a year.    Tenders would be advertised within a week for selecting competent companies and later impanel them from where people could buy the equipment.