Solar companies are starting to blame network owners for ratcheting up costs for new solar customers to slow the rapid uptake of rooftop panels and protect their businesses.

Huon Hoogesteger, founder of Smart Commercial Solar, which offers solar systems to business customers, said network owners were seeking to hold back the growth of renewable energy because they were "afraid" of the potential of the industry to cut their revenues.

Connection costs may threaten the uptake of rooftop solar by businesses. Credit:Glenn Hunt

The network industry rejects the claims, with lead spokesman John Bradley, head of the Energy Networks Association, calling it "fundamentally wrong".

"Networks are actually keen to support the integration of solar because solar integrated into the network can help to lower our cost of delivering services to customers and help to defer augmentation [of the electricity grid]," he said.