Latest and greatest solar powerplant online

[cbr]

http://www.enn.com/business/article/45743

So let me get this straight, latest and greatest solar plant, smack dab in a desert, and it requires capex of $30,000 per household served (at best) to get going? Even if there were zero o&m costs and an infinite life span, that would be, what, a 10 year payout? This is really bad news for present viability of solar.

[thriftyandboringinohio]

Re: Latest and greatest solar powerplant online

Here's a cost study for new conventional power plants running on natural gas. Rather than dollars per home serviced ( a rather dodgy calculation full of assumptions), the results are in dollars per kW or $/MW, which is probably a better measure for comparison

http://www.brattle.com/_documents/Up.../Upload971.pdf

The subject solar plant is rated at 100 MW.

Note also that the subject solar power plant is not photo voltaic; it's parabolic concentrating mirrors generating steam for a turbine-generator machine.

[thriftyandboringinohio]

Re: Latest and greatest solar powerplant online

I took a little time to run rough numbers for natgas vs that solar plant skimming through that report.
Solar plant seems about 7 times more expensive to build.

But fuel is free forever.

Combined-cycle natgas runs at 50% to 60% overall efficiency ( btu of fuel input compared to kW electricity output)
I was too lazy to slog through the arithmetic converting natural gas energy input cost into electrical power output, so I looked it up directly in another report
http://www.fas.org/sgp/crs/misc/RL34746.pdf

So if we examine the fuel cost of a 100 MW natgas combined cycle plant I find

$30.57/MWhr x 100 MW x 12 hour/day sunshine x 365 days/yr = over $13 million a year fuel savings for a half the day solar plant compared to a half the day natgas plant.

Both plants have annual downtime, so that's a rough number. But it appears substantial and ought to be considered in the comparison.
Of course, the whole comparison is apples-to-oranges, because one of the first concentrated solar steam plants in the world will be more expensive to engineer and build than a conventional power plant.

There is no apparent reason the solar plants should be vastly more expensive. Both plants have a turbine and a generator in a building full of control and power distribution equipment. The natgas plant has combustion and emissions equipment while the solar plant has acres of mirrors.

[c1ue]

Re: Latest and greatest solar powerplant online

But fuel is free forever.

That's not quite true.

Solar plants - even the thermal ones - still have maintenance and depreciation expenses.

A major expense for thermal solar plants is keeping the mirrors clean.

The scale of the build was also much higher than you might think at first glance:

http://gigaom.com/2012/08/07/a-mirro...nto-high-gear/

This is Ivanpah, one of the largest solar thermal farms in the world, which when switched on in 2013, will use 170,000 mirrors to concentrate sunlight onto three massive towers to produce solar electricity.

...

There’s already 40,000 of the planned 55,000 mirrors installed around the first tower of Ivanpah — called Ivanpah 1 — which will sell its power to utility PG&E. Ivanpah 3 will also sell power to PG&E, while Ivanpah 2 will supply Southern California Edison.

...

The construction effort is unusual to say the least. The site has boasted three heavy lift cranes that can lift 90 tons of materials. Ivany says there’s only 22 of these cranes in existence in the world.

...

Energy storage and natural gas turbine technology will help the solar farm deliver closer to baseload power (meaning it could run more like a 24/7 coal plant) with greater power reliability than a solar panel farm.

This last part is interesting - I wonder just how efficient this 'storage' is.