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Comment by wscourge | Hacker News Reader

> They require more capital investment than solar or wind projects: $3,000 to $6,000 per kilowatt, compared with $1,700 to $2,100 per kilowatt for wind and solar. (However, a geothermal plant will produce between two and four times as much electricity as a wind or solar plant of the same capacity.)

Solar/wind: 1.7k - 2.1k / kW → N

Geothermal: 3k - 6k / kW → 2N - 4N

Looks like an investment no-brainer.

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Given the environment geothermalhydro is in and thus the equipment has to operate in, does it require more maintenance of the infrastructure? Presumably the steam would have different kinds of particles that could deposit accumulate and affect equipment (scaling)? Could be very manageable or could incur significant money to maintain. I don’t know, just asking.

I don't understand what that second sentence means. What do they mean by "capacity" if it's not electricity generation capability?

https://en.wikipedia.org/wiki/Capacity_factor

Capacity is the most they can produce at any given time. Solar only produces power during the day. Geothermal produces power 24 hours a day, without any regard for day or night. Therefore for the same “capacity” geothermal will produce more power per day because it produces for more hours a day at the same rate.

(This does not account for any complications such as the cost of that capacity or whether geothermal has other downtime to consider.)

D'oh, yeah, totally makes sense, thanks!

The napkin math factor I use is to get the average power you need to divide solar and wind's name plate power by about 4. So to get the same amount of total yearly energy as a 1GW nuke plant that runs 24/7 you need 4GW of solar. Because solar produces about 6 hours of power per 24 hour day.

From a capital cost perspective this is not nice at all. Too be fair upside of solar/wind is solar and wind farms don't go down for a year and a half of unplanned maintenance like nuke plants sometimes do.

Wind is rather better than 25%, most places where it is used.

Grid PV in a good location is more like 30% capacity factor. They typically use 1 axis tracking to collect more power in morning and evening due to the demand curve.

Ex: 32.8% https://en.wikipedia.org/wiki/Solar_Star

You need to account for cost of operation too

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