Quote:
Originally Posted by Wobs
Fair enough.
"Table 4 provides a breakout of the CSP technical potential for these counties, and shows the statewide CSP technical potential to be approximately one million MW of capacity."
http://www.energy.ca.gov/2005publica...2005-072-D.PDF
Total energy demand for California is forecast to be about 65GW in 2010
Now consider that that potential solar capacity is not what will actually be supplied, and you’ll see that its contribution will be small.
While it can have a back up of 13 hrs (which is great), the amount of energy that it can provide over the course of say, two days will be significantly lower than the plant’s total capacity, as it can’t store and supply at full tilt at the same time.
From April 2008:
"Concerns about long-term water availability and consumption patterns are real and growing in importance in the U.S. west. As indicated on page 3-12 of the draft report, BLM applications for over 45,000 MW have been received in California. The vast majority of these identified sites are in arid and semi arid areas where near term water availability is often challenged, let alone 20 year commitments.
As a result, the base trough plant design, capital cost, energy production, and capacity contribution should be based on dry cooling, sized to address the summer season 12 p.m. to 6 p.m. ambient air temperature and humidity characteristics associated with each CREZ.
Several very recent studies and reports present widely different capital, O&M and levelized MWh costs associated with solar trough plants. We respectfully suggest a rationalization take place between these studies to understand how and why these levelized cost differences exist. "
And from the same report:
"If dry cooled trough plants cost more to construct per MW of capacity as a result of required design changes, typically have higher operating costs and demonstrate significant performance degradation when operating in the desert where 100 - 115 degree F plus summer temperatures are coincident with peak demand hours, all other things equal, why wouldn’t they show significantly higher levelized costs and a lower peak season capacity contribution than similarly rated wet cooled trough plants? "
http://www.energy.ca.gov/reti/steeri...irst_Solar.pdf
"Water usage at power towers is comparable to other Rankine
cycle power technologies of similar size and annual performance."
http://www.nrel.gov/docs/gen/fy98/24496.pdf
Its clearly worth asking questions, as when you're fed ideal numbers, you run the risk of being mislead. |
Why wouldn't the costs be higher ? They probably would be higher, but fossil fuel based energy is likely to be even higher, based on global demand projections against supply. Oils at $130 a barrel today. Some say we are past peak oil at affordable cost. We don't even have a carbon tax yet and look at oil. Clean coal will cost more. All fossils are being squeezed and the US appears in near recession.
Solar Thermal power plants can have as much backup as they deem optimal. Plants can vary the size of collector array, concentrator, storage and generator. It just costs more money. I remember reading that tests around 10 years ago, found that around the 14 hour storage was optimal in terms of kWh cost before cost started to be less competitive. This however was back in days when oil was a third the price of today and energy was cheaper per kWh etc.. back then. The whole cost dynamics have changed significantly since then.
On cost alone it would likely be more optimal to have more storage and I suspect over 20 hours of storage. Also they don't have to operate at 6 kWh per sqm sites. If they accept 5 kWh sites it simply means it costs more to operate. Almost 30% of the USA gets 5 kWh at least. That's allot of square miles of land when you only need 92 square miles of 6 kWh sites, equating to about 110 square miles of 5 kWh sites, at a 16.6% reduction in output. Naturally dispersed as smaller sites. If power prices are rising yearly 5% or higher, that the 5 kWh cost overhead will be leveled in the market place within about 3 years.
The plants will function optimally on cost by being supplemented with fossil fuel backup, even though technically they could function near all year around, the cost would be unreasonably prohibitive in the winter months.
Give it 5 years and see where the cards fall. If they fall anything like what's on the visible horizon, it's almost a given that renewables like Solar PV and Thermal will grow strongly. In future, everything will cost more, but fossil fuels even more so. Cheap energy is all but over, but clean energy mandates will help further drive growth in renewables of varying kinds, Solar Thermal included.
As I indicated, Solar Thermal technology works. Cost is the only significant barrier impacting on growth and cost is trending in favour of renewable energy of varying kinds, including Solar Thermal.