The Physics-Engineering-Cost (PEC) code has been updated to include blanket-shield design data, a new cost structure, new unit costs, and improved algorithms. It is used here to estimate component masses and costs for heliotron reactors, which have continuous helical coils like the Large Helical Device.

Relative to a "base case," we study how the cost of electricity (COE) varies with various parameters: central electron temperature, coil width/depth ratio, plasma-coil distance, plasma profile shapes, beta, maximum magnetic field, neutron wall load, net power output, plasma impurity content, plasma aspect ratio, and blanket lifetime.

The COE decreases strongly with increasing beta but tends to level out at beta values >6%. At a fixed output power, higher beta values make the reactor smaller, which decreases the energy confinement time, making ignition more difficult. The resulting COE estimates are compared with that of the Stellarator Power Plant Study.