We suggest a novel scheme for energy efficient, copious negative pion production: a stored proton beam collides with a thin metallic target producing primary π- and other shower particles. These high energetic secondaries produce further π- in external secondary targets. Estimations on energy cost per primary negative pion production for this scheme are given for proton beams and various targets. The secondary particle distributions according to momentum and angle are obtained with Monte Carlo simulation. The secondary neutron, proton and π+ efficiencies to produce negative pions are given. We find that a π- may be produced at a cost of 2.7 GeV in beam kinetic energy at Pp ≈ 4.8 GeV/ c using Be targets.