Monday, 20 June 2011

Solar Flagship Project Funding will also help Geothermal Power Generation

I was planning to continue on the geothermal renaissance theme that I started last week but an announcement by the government over the weekend caused me to reconsider. The federal government has announced three quarters of a billion dollars in funding for two major solar power stations that will go ahead in regional New South Wales and Queensland, one using photovoltaics and one using solar thermal power generation. The Solar Thermal project is based on the compact linear fresnel reflector technology developed by Australia's Dr David Mills, whose company Ausra was bought by Areva early last year.

The QGECE Heat Exchangers program was part of the solar thermal bid. The Solar Dawn consortium, led by Areva Solar, will now be building a 250 megawatt (MW) solar thermal gas hybrid power plant near Chinchilla. The consortium members are Areva Solar, CS Energy and Wind Prospect CWP. The project will be located near Chinchilla in Queensland, next to CS Energy's coal fired Kogan Creek Power Station and directly adjacent to the the Western Downs electrical substation. The solar plant output will be boosted by gas-fired power to ensure it can provide a “firm” dispatch to the grid when the sun is not shining, an important consideration for utility customers. Under the terms of the flagships criteria, gas will be limited to 15 per cent of its annual capacity, but in practice it could provide significantly more.

The following pictures how the solar radiation is concentrated onto a pipe to produce steam (AREVA web page) in the compact linear fresnel reflector (CLFR)technology..

Whatever collector technology is used to produce steam, a thermal power generator will have condensers and they will need to be cooled. The existing coal-fired Kogan Creek Power Station utilises air cooling. Initially the Solar Dawn Power Station will incorporate wet cooling (using treated water from coal seam methane) but will need to consider a requirement for transition to air or hybrid cooling in future years. To develop and test options for the consortium towards this end, QGECE will design and build a natural draft dry cooling tower test station on site that will be fed by part of the solar collector array. The objective will be to optimise air and hybrid cooling concepts (including natural draft cooling) for the main Solar Dawn Plant.

This is great news for the QGECE. We will be able to develop and demonstrate hybrid cooling techniques on a field-scale natural draft dry cooling tower. It is also great news for the geothermal energy sector since the results of this research will be immediately and directly transferrable to geothermal power generators that will need to use dry cooling but still have some limited to access to water that can be used on very hot days to help air cooling. On my last blog, I referred to the work at NREL, which shows that judicious use of water sprays can increase the power generation by 15% and bring the power generation close to the design-point value even on very hot days.

I will go back to geothermal renaissance theme in future blogs.

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