The sweet spot for electrolysers will, instead, be cheapest possible inefficient units, because the power to drive them will have "marginal cost zero", i.e. be

The sweet spot for electrolysers will, instead, be cheapest possible inefficient units, because the power to drive them will have "marginal cost zero", i.e. be free, coming from production in massively over-provisioned solar farms in excess of immediate demand. Capital cost dominates because of intermittent utilization.