Keep Your Old Miners

To protect your value one must be prepared to hash against a 51% attack. It is a far flung outside near impossibility at the moment. But there may come a time. Miners are self defence.

Even if its not many hashes it is still honing your skills. 

Maybe the marginal energy use versus hash will have an effect considering energy prices would theoretically rise during an international style hash war. This would be a sanction like method we are all too familiar with at the moment.