  In this paper we present alternative approach for Future Circular
electron-positron Collider. Current 100 km circumference design with the top CM
energy of 365 GeV (182.5 GeV beam energy) is based on two storage rings to
circulate colliding beams. One of the ring-ring design shortcomings is enormous
power consumption needed to compensate for 100 MW of the beam energy losses for
synchrotron radiation. We propose to use energy recovery linac located in the
same tunnel to mitigate this drawback. We show in this paper that our approach
would allow a significant, up to an order of magnitude, reduction of the beam
energy losses while maintaining high luminosity in this collider at high
energies. Furthermore, our approach would allow to extend CM energy to 500 GeV
(or above), which is sufficient for double Higgs production.
