Sustainability is a fiduciary responsibility. If we would become stewards, then we must recognize the role of fiduciary in the deployment of resources.
We are entitled to private property for the sake of consumption and investment but not for extraction and waste. Our resources are assets, and our assets don't belong to us as owners but only as stewards -- to use but not to exploit.
As such our natural resources are given to us in trust, as a fund, for which we have a fiduciary responsibility not unlike the values that would have been in effect had we been made trustees of some financial estate. We owe it to our children, yes, but the truth is it doesn't belong to us in the first place. It belongs to God.
When the power utility gets returns for helping the utility's customer base produce electricity rather than to demand it, and to lower the demand for electricity rather than to promote increases in its demand, it is behaving like a steward that measures its corporate mandate in terms of how much it's leaving on the table rather than how much it's taking off of the table.