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Comment by thoughtsimple | Hacker News Reader

That's 16 birds a day. Unless the birds are endangered, that seems like a relatively small number for 390 MW of mostly green power.

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74 MW of solar power in 2015 (up by a factor of about 1.4 from 2014 but still only about 2/3 the planned output). At the cost of $2.2B, and 3500 acres (14 km^2) of steel and precision-ground glass and wilderness.

The Ivanpah facility was built on public land, not wilderness.

What makes public land not wilderness?

In this context, it's a US federal government designation for protected land. http://wilderness.org/article/wilderness-designation-faqs

The word does also mean in some contexts any land that is undeveloped, so the meaning can be overloaded.

Update: The 74 MW figure is given by EIA as "net solar generation". The plant also burns natural gas, and made slightly more power in total (which still rounds to 74 MW on average for the year). In particular, it burned 564,814 mcf of natgas, which is worth 9 MW in our existing fleet of combined-cycle power plants. But Ivanpah made < 1 MW out of it, according to EIA.

It's unclear how EIA is partitioning the plant's output. If we use the total generation and subtract the potential (or CO2-equivalent) value of the natgas, it made only 66 MW from the sun.

Wikipedia cites 652,375 MWh of "solar only" production in 2015, with natural gas consumption listed separately. That works out to an average 74.4 MW output from the sun alone.

https://en.wikipedia.org/wiki/Ivanpah_Solar_Power_Facility#I...

Out of curiosity, why did you subtract the potential natgas from the actual solar output, instead of the actual gas output you just cited?

It's not clear how the natgas output is being measured. It's used to bring the working fluid up to temperature. Either the true solar output is lower than stated or the plant is using natgas extremely inefficiently (getting 0.9 instead of 9 MW of it). In the latter case, it's still a cost of obtaining the solar energy that should be accounted for.

Wikipedia has the total and solar-only figures switched, as can be seen by visiting the citations given. The solar-only figure is 644,506 MWh.

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