A particular issue is the proposed abolition of the avoided cost of transmission payment (ACOT), which delivers around $158 per customer to King Country Energy.
The payment is made to generators who supply homes and businesses through local lines which are not directly connected to Transpower's network, avoiding the cost of transmitting on the main grid.
Foster said the removal of this payment would have a major impact.
"Potential removal of the ACOT also means a number of upgrades King Country Energy is investigating - each of which has potential to positively affect peak demand and security of supply - are now at risk," he said.
Foster added that the overhaul of its Wairere Power Station where $2.73 million was spent to remove three old turbines and replace it with a single new turbine in 2014 would have been unviable under a regulatory regime that had removed the ACOT payment.
He believes the overhaul will diminish distributed generators like his.
"If this proposal goes through, distributed generators will be dependent on Transpower's perspective of their worth, and quite simply, that means the Electricity Authority has handed responsibility for the status of distributed generation to the grid operator," he said.