Rocky Point is riding out the drought with comfort as it relies on reclaimed water.

Queensland's Rocky Point Green Power electricity generation plant is green by name and by nature, using everything it can lay its hands on. By Kellie Morle.

While the ongoing drought has signalled disaster for many electricity generators, Rocky Point Green Power at Woongoolba in Queensland is enjoying a few windfalls, not least those provided by higher black energy prices. Since 2005/06, the average price per megawatt hour of electricity on the east coast grid has risen from $28.12 to $52.14 last year, with the current financial year climbing even further up to $73.31.

Rocky Point is a cogeneration plant that burns wood and green waste and bagasse (sugar cane waste) to generate electricity, steam and hot water. A third of the electricity is used by the neighbouring sugar mill during the harvest crush, usually from July through November, and the rest sold to the grid. Outside the crush about 95 per cent is sent to the grid.

General manager Peter Shaw says other factors contributing to the plant's runaway success include improvements to on-site technologies and infrastructure, a huge increase in available biomass fuels, a steady income stream from abatement certificates and some handy pocket money from by-products.

The Rocky Point Sugar Mill has been there for more than 100 years, originally owned by the cane growing Heck family, who also saw the value in reusing bagasse to generate steam and a small amount of electricity, about 3MW.

Stanwell Corporation took over and in 2002 spent $50 million replacing the old high emission boilers with more efficient high-pressure boilers.

The makeover also introduced recycled wastewater from the Beenleigh Water reclamation facility and expanded fuel feedstocks to include organic municipal waste.

It became the Rocky Point Cogeneration Plant, with value-adds such as organic sugar production and distillation of fuel alcohol, ethanol. Last year, private equity group Babcock and Brown and National Power forked out $5.12 million for the plant and renamed it Rocky Point Green Power.

Buoyed despite drought
Shaw is obviously buoyant about the high prices but says it's a bonus and not part of the business plan, which is aiming for other improvements.

Still, two examples illustrate the impact of water restrictions on the state's generating capacity – and why Rocky Point is riding high. Earlier this year, Tarong Energy announced it had reduced generation by 70 per cent at its 1,400MW power station at Nanango to conserve water in Boondooma Dam. And CS Energy's 480MW coal-fired Swanbank B Power Station had its water allocation from Wivenhoe Dam reduced in line with level five water restrictions.

With Queensland providing about a quarter of the National Electricity Market's (NEM) requirements, the restrictions will continue to impact along the east coast. While rainfall levels have ticked upwards, NEMMCO predicts at the worst up to 2,200MW of generation capacity will be unavailable in late 2008, more than five per cent of total installed capacity.

On the other hand, the completion of CS Energy's Kogan Creek Power Station Project later this year will help. The 750MW air cooled plant at Chinchilla will use 90 per cent less water than a conventional power station. Late 2008 should also see some improvements in supply when the Western Corridor Recycled Water Scheme reaches Tarong.

While the drought serves Rocky Point in some aspects, Shaw is predicting a shorter crush this year due to low rainfall. He says sufficient green and wood waste will cover any bagasse shortfalls.

Going with green power
So what other gains are being made at Rocky Point? The company has not renewed its electricity supply contract with Queensland government-owned Energex and has instead gone with private retailer JackGreen, whose Green Power scheme is reporting significant uptake from consumers.

So far, half a million Aussies have opted for greener power.

The plant gets its green waste from local councils such as Caboolture and Maroochy, with the rest coming in the gate, along with wood waste from demolition companies, builders and flooring manufacturers.

Shaw estimates in the past year the amount of waste available has grown exponentially, from about 120,000 tonnes on Stanwell's watch to 300,000 tonnes today.

"We've got there just by telling people we are here and what we do. Obviously, there is a need out there and it is just coming our way," he says.

He adds even more waste will be accessible once the northern councils catch up with their southern counterparts, which have introduced higher landfill costs in a move to stimulate just the sort of activity already underway at Rocky Point.

Stanwell's 2006 annual report talked up the crush of 2005 and down the outages the plant experienced. But historical figures show an average of 94% availability for the years 2004 to 2006, a figure the new owners have already improved upon.
Shaw elaborates: "We've had to spend a lot of money on the plant to solve the problems that Stanwell couldn't."

Win-wins all round
The quality of the fuel is up due to more stringent screening of the fines, which reduces the dirt going through the boiler. The amount of calcium precipitating in the pipes and vessels has been reduced. Maintenance times, and therefore downtimes, have been cut from one day every 10 to one a month, and a clarifier is on its way, which should push that out to one day every three months.

Significant corrosion and erosion of high temperature boiler pressure parts from chlorine has also been reduced.

"The screening we do on the fuel takes out the leafy, grass clipping parts and leaves us with more cellulose type material, and we have a ready market for the fines from the screening process (great for compost), so it's a bit of a win-win all around," Shaw says. "Also, ash is on-sold to one of the mulching people as it's filled with minerals and sterile."

The plant improvement bill stands at about $8 million and will also cover a new road, weighbridge, boiler air heater, fan, tubing, grinders and some sheds to protect equipment from dust.

Shaw says greenhouse caps and credits that are likely to be imposed on the generators under a national emissions trading scheme will make Rocky Point look even more handsome. Meanwhile, abatement certificates from NSW, Queensland and the Federal Government are being cashed in.

Shaw is watching with interest the general move away from burying everything in landfill to everyone seeing the benefits of recycling or burning waste.

"I still take the view that we recycle carbon," he says. "Most of our carbon is from living material. It's not as if we are digging up coal and burning
our ancient carbon... Everything we get is a diversion from landfill and therefore represents a decrease in methane emissions."