Household makes $5544 from 5.6kw Solar System....

Silver lining ... Mr Cooper checks the solar panels on his roof, which generate both electricity and income from selling power back to the grid. Photo: Dean Sewell

WHEN NSW brought in its generous solar panel subsidy scheme late last year, Aaron Cooper went big.

''As soon as we found out this policy wasn't means-tested, we just jumped,'' said the 37-year-old boilermaker. Last month Mr Cooper installed 32 American-made solar panels which take up most of the roof on his Berowra Heights home.

The 5.6 kilowatt system will run the lathes and welding equipment in Mr Cooper's shed, and heat an enclosure for 100 snakes he and his wife Ruth will keep out the back.

Mr Cooper, who studies venomous snakes as a hobby, has a licence from the National Parks and Wildlife Service to sell the reptiles, which can no longer be collected from the wild. He will also breed food for them such as crickets, frogs and mealworms.

Energy Australia estimates it will pay the Coopers $5544 a year under the state government's feed-in-tariff, at a rate of 66¢ per kilowatt-hour (kwh), based on the amount of electricity solar panels typically generate in Sydney. That should cover the couple's power bills well into the future, even though prices are expected to rise by up to 64 per cent over the next three years, and even assuming their power use doubles. Their bills were about $430 a quarter until now.

NSW's gross feed-in tariff, the highest in Australia, is guaranteed for seven years and should also quickly repay the almost $30,000 up-front cost of the system (not including renewable energy certificates worth about $7000, which the Coopers transferred to installer Blue Sky Energy).

''We wanted to cater for extra rises,'' Mr Cooper said. ''As long as we've got no bill, we're happy.''

But Mr Cooper is annoyed by his new smart meter - installed as a condition of connecting solar panels to the grid - which has seen his peak rate jump from about 16c/kwh to about 35c/kwh under a ''time of use'' regime.

He said that peak rate, charged between 2pm and 8pm weekdays, could jump to 64c/kwh by 2012 - almost as high as the feed-in-tariff. So-called shoulder and off-peak rates are much cheaper, of course, and Energy Australia said around 75 per cent of customers are better off under time-of-use metering, if they can switch to largely using dishwashers, dryers and pool pumps at night.

A typical saving would be $60 from a $1230 annual bill, an Energy Australia spokesman said.

Households are rushing to install solar panels to take advantage of the solar bonus scheme, which was announced last November.

A spokeswoman for NSW's Energy Minister, John Robertson, said the government hoped to treble solar panel installations in NSW, which would take the total to 33,000 homes.