Hector, a new methodology for continuous and pattern-free heliostat field optimization

•Continuous heliostat field optimization is studied as an alternative to patterns.•Hector, a general method to support continuous field optimization, is designed.•Both versions of Hector, that divides the problem into subproblems, are developed.•Hector helps the same (any) optimizer selected to achieve better results.•The fields obtained outperform those obtained by the optimizer alone and patterns.