We have recently been advised of situations where commercial PV solar customers have been caught by installing Solar PV systems not realising the impact on tariff structures. Essentially offending PV Solar companies have neglected to inform the customer that any changes to metering can invoke a tariff change. Basically there are new regulations that require a business electricity meter (NMI) with a demand greater than 75kVA or 100 amps to be on a demand tariff. We have heard of situations where this tariff change resulted in such an increase on their bill that it meant the Solar system was costing them rather than saving them. Therefore it pays to have an independent review of the Solar PV business case that considers and calculates the cost of any tariff impacts.
Further Reading: Consumer PV Guide | Clean Energy Council, 19/12/2012