The trick for making solar thermal electrical generation a reality is to reduce the cost of the solar thermal collector system to absolute minimum. Why? If one familiarizes oneself with the costs of putting such a system together – it becomes apparent why solar thermal electrical generation is not widely used. As elegant as solar energy is – the costs of putting together a working system are prohibitive.
The potential is there: 4 megawatts of solar radiation hit every acre of the Earth’s surface.
I just went through the design that weâ€™ve been evolving in the Solar Turbine Yahoo Group – where after some heated design debates it looks like weâ€™ve got an absolute winner. We now have a system design that costs $750 for all the materials for intercepting 30 kW of solar energy and focusing it on a 2â€ diameter receiver tube – with 48-fold solar concentration ratio. This cost does not include the heat engine or controlled feed-water delivery.
This is leagues beyond the initial designs of 16-fold concentration and $2000 cost. This appears to be a major breakthrough – and this is what weâ€™ll be building and testing beginning August 13 – when our team of 2 or 3 other people arrive here for the Solar Turbine Convergence at Factor e Farm. If this sounds good to you, bring a tent and join us for the two week design-build adventure.
Bottom line – if this works as proposed above – this may be a major contribution to realizing affordable, home-scale solar thermal electrical generation systems. Indeed, within the framework of an integrated concentrator thermal electric system – this would be at least 3 times less expensive than any available photovoltaic panel today – and I am aware of the work of Nanosolar.
Disclaimer – external consensus has it that such a performance prediction is highly suspect. Weâ€™ll report back in 3 weeks once weâ€™ve done the experiment. If you have insights on this, do contact us and provide further refinements to our thought process. For more information on the actual design described above, the best place to find out is the Google Group.