Bioenergy facility

We are considering a bioenergy facility that generates:

• 24/7 dispatchable and controllable renewable energy 365 days a year.
• Approximately 4 million kilowatt-hours of renewable electricity. The equivalent of powering 267 households per year. 
• Enough renewable energy to power the facility itself, and the Byron Bay Sewage Treatment Plant. Any excess would be available for dispatch back into the grid.
• A nutrient-rich, low-carbon compost by-product for local farmland and small growers.

It creates:

• Local jobs created in the construction, operations and maintenance.
• Local processing facility for agricultural and commercial organic waste. 
• Local solution to waste management, reducing truck movements and distances travelled across the region.
• Improved management of sewage biosolids.
• Savings of approximately 3,402 tonne/CO2 per year for Council. The equivalent of keeping approximately 1,030 cars off the road each year. 
• A case study for others to follow in the search for future energy solutions while helping Byron Shire Council, NSW State and Australian Federal Governments meet renewable energy targets.

It reduces:

• Council’s use of grid electricity by 70%.
• Council's costs by taking its largest electricity user, Byron Bay Sewage Treatment Plant off-grid.
• Council’s total carbon emissions by over 20%.
• Council's overall electricity costs, creating the potential to increase funds for other local priorities.
• Landfilling of organics.
• The number of truck movements and distances travelled across the region, further reducing carbon emissions and impact on air quality and local roads.
• Australia's dependence on fossil fuels.

Council is considering this renewable energy project with the intention that there is no increase in rates for Byron Shire ratepayers. 

The estimated cost of the facility is approximately $15-20 million with payback estimated at between 10-20 years, dependent on grant funding. Council is submitting applications for Federal funding and if successful, will partially fund the project from its Sewerage Fund Capital Works Reserve. 

Council is considering this investment because it offers a secure cash flow that could potentially save ratepayers money in the future (generating long term revenue for Council through a compost product for the agricultural market as well as renewable energy generation), and it replaces existing Council-funded services but offers a longer term, and more environmentally sustainable solution. 

The feasibility stage of the project will address the business case risks compared to present business-as-usual conditions, and identify any issues to protect Council and its ratepayers. Councillors will consider the preferred option/s for financing and operation of the facility once the feasibility stage is complete.

Aerobic composting - oxygen, open-air, compost

Aerobic composting requires oxygen to decompose organic waste via naturally occurring micro-organisms. This process produces heat, water, carbon dioxide and small amounts of methane and nitrous oxide.

Typically aerobic composting uses grid electricity to power the aeration of decomposing organic waste. Composting is great but it still causes greenhouse gas emissions, which escape into the atmosphere as the process is usually carried out open-air. Aerobic composting, while far better than landfilling, does consume transport fuel and grid electrical energy.

Dry anaerobic digestion - no oxygen, contained, compost + renewable energy, closed loop carbon cycle

Dry anaerobic digestion decomposes organic waste in oxygen-free conditions. The organic waste produces carbon dioxide and methane.

The bio-methane can power a combined heat and power engine, which converts the biogas to renewable energy for storage or redistribution. There are very little fugitive emissions since the entire process is contained in enclosed structures and all gases collected for appropriate handling, ie. a closed-loop carbon cycle.

In summary

Both aerobic composting and dry anaerobic digestion produce valuable compost products and both produce approximately the same amount of physical carbon dioxide gas emissions. Dry anaerobic digestion also produces a renewable energy source and as a result, has a lower carbon footprint overall. 

No. The methane and carbon dioxide produced from the dry anaerobic digestion process are contained inside a pressure controlled facility. The biogas is not released into the atmosphere, so the environment is unharmed. 

The biogas is contained, collected and converted to renewable energy for using, storing or sending back into the electricity grid.