New Delhi: A contest organised by state-run National Thermal Power Corporation (NTPC), seeking ideas to dispose off close to 50 million tonnes of fly ash that it produces, has received entries from Tata Power, Berger Paints and Damodar Valley Corp, among others. India's largest power producer, which is engaged in the generation and sale of electricity, announced this competition last month with a top prize of Rs 5 lakh.