I brought up capex because that is essentially the only thing that matters to datacenter customers. They want to comply with certain (very stringent) green stan

I brought up capex because that is essentially the only thing that matters to datacenter customers. They want to comply with certain (very stringent) green standards, and any opex savings beyond that are just not a big deal to them. You can't actually reduce redundancy because the loop can't reject any heat during the summer. Let's say municipality or utility company, if it's privately owned. Either way, you are making an investment that will take decades to pay off (all those pipes) and it is completely worthless unless one particular datacenter continues to operate.