The lines company said solar electricity users connected to its network had been subsidised by other power consumers so a lift in charges was needed. Solarcity is asking the Electricity Authority to stop Unison's solar tax on the grounds that it wrongfully disadvantaged customers and breached the Electricity Industry Participation Code.
Solarcity chief executive Andrew Booth said Unison's solar charge was likely to result in fewer people installing solar panels, leading to less take-up of renewable energy and continued reliance on fossil fuels such as coal and gas.
Unison business assurance general manager Nathan Strong said the company informed the Electricity Authority of its intentions to introduce a new distributed generation price category prior to its introduction. He said it would work with them during their review of the alleged breach.
Meanwhile, Mr McGrath said many people invested in solar to reduce their power bill and some did so for environmental reasons. Those environmental concerns weren't as significant in New Zealand as elsewhere because 80 per cent of the country's electricity was generated sustainably.
Mr McGrath said many people were away during the day when solar power was being generated.
They could export the power which wasn't being used back into the national grid, at almost wholesale price, or store it in a battery.
There was a cost associated with batteries but they allowed more access to solar power electricity generated, said Mr McGrath.
Nationwide, there were 9533 solar connections at the end of March, up on 5760 at the same time in 2015 and 2712 the previous year. According to the Energy Efficiency and Conservation Authority, the main barrier to the uptake of solar energy was its cost. Solar generation made up only 0.1 per cent of the country's renewable energy.
Future savings appeal
Rotorua's Alan Dick says ever-increasing electricity prices are one of the reasons he went solar.
He opted for an expensive monocrystalline panel system because it best suited the size of his roof and his power requirements.
The monocrystalline panels were also more efficient over their lifetime.
Mr Dick said the type of system he installed was "financially marginal" but allowed him to have control over future pricing.
He remained on the grid in case of several days of bad weather during the winter.
Mr Dick said he was happy with his system, which he'd had for nearly two years.
He expected more people to install photovoltaic (PV) panels as time went on, partly because of the way generators were charging for electricity.
