[monkeyfun]

There may not be a continuous fuel expenditure, but there is a maintenance cost for the grid infrastructure, keeping panels or turbines in good working condition, etc. -- not to mention the manufacturing costs and, since no organizations are currently engaged in microwave power transmission from solar-power satellites in space -- not insignificant associated monetary and opportunity costs to the land used.

Conclusion: yes, it's still a waste, unless that energy was surplus absolutely not going to be used for anything better or able to be stored, although even then the compute resources could have probably been used for more useful problems.