David Mills of Ausra
Image: COURTESY OF AUSRA, INC.
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Editor's note: This Q&A is a part of a survey conducted by Scientific American of executives at companies engaged in developing and implementing non–fossil fuel energy technologies.
What technical obstacles currently most curtail the growth of solar power (particularly solar thermal)? What are the prospects for overcoming them in the near future and the longer-term?
The biggest obstacles are ability to scale, long-term reliability and interruptibility due to clouds and the daily solar cycle. Ausra's core technology, the Compact Linear Fresnel Reflector (CLFR) system, is simple and robust. We are optimizing for the lowest cost of energy, not highest technical sophistication. This combination results in the best value to our customers and high reliability. CLFR uses an array of relatively flat mirrors that reflect sunlight to boil water in elevated tubes, producing steam that drives turbines to generate electricity. CLFR is also the most land-efficient solar technology. By using nearly flat mirrors, water/steam heat transfer, and commodity materials, we are also able to achieve significant cost savings and rapid deployment. Additionally, by using our special reflector geometry, we are able to have a greater density of reflectors in the area and use about half of the ground area of competing technologies. Our systems produce steam for stand-alone, large-scale solar power plants as well as to augment energy output and reduce emissions at existing conventional power plants. The steam can also be used for industrial applications, such as food processing and enhanced oil recovery. Unlike photovoltaic (PV) or other concentrated solar technologies, which lose output immediately when clouds come over, our technology has 20 to 30 minutes of stored capacity, so it can adjust to weather changes or other factors affecting the electric grid. CLFR hybrid plants (with natural gas boilers) can also provide firm capacity to the grid. We are currently proving our CLFR technology at our five-megawatt demonstration and test facility in Bakersfield, Calif. This is the first of its kind in the U.S. and the first large-scale solar thermal plant to go online in California in nearly 20 years.
Are there obstacles to scaling up solar power to serve a larger national or global customer base?
The biggest challenge to larger-scale solar is the ability to get project financing in today's tough credit market. We expect the upcoming year to be a challenging one, which is why we've accelerated Ausra's evolution from a project development company to a solar technology and equipment provider—expanding our customer base and reducing our capital and debt requirements.
Can the existing energy infrastructure handle growth in solar power? Or does that, too, need further modification?
Our current, aging transmission grid is built on a patchwork collection of local systems. We need to invest in a modern national transmission grid that can carry solar power to America's population centers to meet our growing demand for energy and to decrease the nation's dependence on foreign oil. Additionally, open land and superior solar radiation make the deserts of the American Southwest the best place to build large-scale solar power plants. But for those plants to provide electricity to the whole nation, we need a modern transmission grid that reaches those locations. We're encouraged that President Obama's economic stimulus package and energy plan places an emphasis on modernizing our nation's transmission infrastructure. We look forward to working with the administration and Congress to achieve that goal.
Given the current economic crisis, can your industry get the necessary capital (from public or private sources) to adequately finance its growth?
The economic downturn has left many of the financial firms that provide capital for commercial solar projects without taxable income and unable to utilize the solar investment tax credit (ITC) the way it was intended. We are encouraging Congress to monetize the ITC through mechanisms such as a long-term Department of Energy (DOE) grant. This will allow these firms to qualify for the tax credits and allow large-scale projects to be financed, built, and reach operation. But we have to be aware of the current environment, and we are very intrigued by PG&E CEO Peter Darbee's recent comments about building and owning solar power plants as opposed to purchasing solar energy from third-party providers. Utilities are now able to utilize the ITC and have the balance sheets to finance large power plants. Ausra can provide equipment to utilities to help deploy large-scale solar plants rapidly and cost-effectively. Our business model has also evolved and expanded to focus in the near-term on smaller, less capital-intensive projects that will provide power augmentation for existing coal and gas-fired power plants and provide solar-generated process steam for a number of industrial process applications. Our long-term focus will remain on providing equipment for large-scale power plants that utilities and independent power producers can own and operate. In the near-term, Ausra's evolution from a project development company to an equipment provider reduces our capital and debt requirements and allows us to increase our focus on further technology development and equipment sales.
From a strategic standpoint, which is the bigger competitor for solar: incumbent coal, oil and gas technologies or other alternative energy technologies?
We are actually seeking out coal and gas-fired power plants as potential customers. We can integrate our solar thermal technology into existing power plants to boost their energy output during peak demand with solar power and reduce their overall carbon footprint. Likewise, our direct, reliable solar steam generators can be used in a variety of industrial applications, including enhanced oil recovery, petroleum refining and food processing. We can help these types of companies lower their fuel and emissions costs. President Obama has made it clear that renewable energy will play a large role in his economic recovery efforts and in our future energy policy. Clearly a number of clean technologies will have the opportunity to thrive, but realistically, rooftop PV panels, as good as they are, will not be able to meet our energy needs on their own. We will need large-scale solar projects to meet our increasing electricity demands, and we feel that Ausra has a competitive advantage in being the most land-efficient and cost-effective form of large-scale solar.
Is there a cost target that you and others in your industry are aiming to achieve in, say, five years?
That is difficult to answer, due to the wildly fluctuating prices of oil and gas, construction materials, and the cost of capital. That being said, solar power has the benefit of a fuel source that is free—the sun. With the right tax policies, such as a mechanism for pricing the cost of carbon, there is no reason solar thermal power cannot be cost-competitive with fossil fuels in the near future.
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9 Comments
Add CommentEven if we have not yet fully solved the problem of solar or wind intermittence, these energy sources will save fossil energy sources and reduce greenhouse gas emissions when they function. For future generations, these savings will be appreciable.
Reply | Report Abuse | Link to thisThe problem of storage has been solved. Graphite blocks can store heat for very long periods with such great efficiency that some solar plants are being set up in Australia focussing the mirrors directly onto the graphite storage medium so that the heat can be drawn down as needed. That is, backup is not so much heat that is 'siphoned off' for use later, but THE central target of the power plant, enabling greater efficiency and baseload capacity.
Reply | Report Abuse | Link to thisCheck out Lloyd Energy systems in Australia.
http://www.lloydenergy.com/heatstorage.htm
Andasol-1 has been in operation for several months. It is a 50 MW power plant in Spain that can run at full power for 7.5 hours after sundown. The cost of power with storage is the same as the cost of power without storage. Obviously, it could be extended to operate 24 hours per day if that were required.
Reply | Report Abuse | Link to thisThis is brilliant stuff. Not only much more reliable and efficient than PV, but the concept is so simple it'll be much easier to implement on a large scale. I haven't had this good a reason to be optimistic about renewable energy in a long time.
Reply | Report Abuse | Link to thisHVDC (high voltage direct current) is obviously the best current solution to long-distance power transmission. It's well on its way to being implemented in Europe with a number of fairly large scale installations coming online in the next few years. The turf/environmental/production etc problems must be solved fast and well. Unless the US gives this the very highest priority, European technology and heavy engineering will blast it out of the water, regardless of how much protectionism is mobilized. Frinstance, imagine US companies being totally marginal in the competition to provide such countries as China, India, Iran or Russia with HVDC lines.
Reply | Report Abuse | Link to thisNo skin off my nose, and who outside the US really gives a damn ;-) - but in a development like this humanity needs all the scientific, engineering and manufacturing strength it can muster, even if it comes from the Great Satan.
They appear to be showing some CLFR technology on some of the news bulletins with Prime Minister Kevin Rudd(of Australia) lately!!!!?!?
Reply | Report Abuse | Link to thisIS there about to be some kind of big announcement some time soon?
My work on LED and photovoltaic cum electrothermal as well as on green coal makes me think he is right on track working with power supply industry. I offered to talk with Southern co.It seems they prefer to take money from govt. rather than improve their tech. He needs to combine my system of heat absorption... but..
Reply | Report Abuse | Link to thisI've been hearing quite a lot about the steam/heat transfer system (to increase efficiency) described in this article but can find little information comparing it's overall monetary cost compared to the storage of generated electicity via traditional means (ie batteries). How do the two compare side by side? I assume the steam transfer system poses next to zero enviromental risks as do batteries but in practical terms which one is cheaper? Can anyone assist?
Reply | Report Abuse | Link to thisRegards
Harry B.
<a href=”http://www.besthomeenergyguides.com/make-solar-power-generator.php”>Make solar power generators the easy way</a>
{Moderators could you please correct and remove if not allowable} Thankyou...
Reply | Report Abuse | Link to thiswww.besthomeenergyguides.com/make-solar-power-generator.php