Renewables and Energy Technology

Wind turbines, solar panels, home battery storage - if it's discussion about renewable energy you're after, you'll find it here.

Wind turbines, solar panels, home battery storage - if it's discussion about renewable energy you're after, you'll find it here.

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Small Scale Bioenergy

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I'm currently working on small scale (<1MW) bioenergy systems to use wheat straw as fuel.  In Western Victoria hundreds of thousands of tonnes of straw are burnt each year as a way of removing from paddocks because there's no market for it.  The technology we are looking at is either gasification or steam cycle.  Gasification has an installed cost of around $2,500 per kW of electrical output and the steam cycle  systems are $3,500 to $5,500 per kW of electrical output.  The capacity factor of these systems is 90 to 95%.

As a comparison roof top solar has an installed cost of around$1,500/kW and a capacity factor of 15% (Melbourne).  Small scale wind has an installed cost of around $2,500 to $3,000/kW and a capacity factor of around 30%.  To achieve the same annual output as the bioenergy systems you have to install 6 times the kW's of solar and 3 times the kW's for wind giving an equivalent installed cost of $9,000/kW for solar and $8,000 /kW for wind.  To achieve some level of dispatchability you also require batteries which adds $2,000 to $4,000/kW to the installed cost. 
The bioenergy systems also produce 2 to 4 times the electrical output as heat.  If this heat is used to replace natural gas heating it pays for the cost of the fuel so you get the electricity for free.  Bioenergy is base load, dispatchable renewable energy that if installed as combined heat (can also be cooling) and power has a capital cost per kWh of annual output much lower than wind and solar.  

Why the fixation on wind and solar when we have so much biomass being burnt anyway?