This is absolutely wrong. Transmission is not a near zero marginal cost, and the cost to operate absolutely does depend on the design capacity, including the o

This is absolutely wrong. Transmission is not a near zero marginal cost, and the cost to operate absolutely does depend on the design capacity, including the operating voltages and number of sources and taps. Additionally, wider geographic distribution of power sources greatly increases the number of transmission lines and overall amount of right-of-way and materials needed per generated kwh. And because you can't assume a usage of near 100% of transmission capacity due to intermittent solar and wind, having to over-build transmission capacity reduces overall efficiency even greater, meaning even higher transmission costs for equivalent grid capacity.