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Comment by The_rationalist | Hacker News Reader

Do you know any city that have a majority of it's energy that come from renewable? Are there any smart grid that really works, that manage the absence of solar energy the night, the load balancing, etc without just pumping nuclear energy at the moments where solar/etc can't keep up with the electrical demand?

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In the US, the NWPP (Washington, Oregon, Idaho, Nevada, and part of some other states) is 47.2% hydro, 8.6% wind, 3.4% nuclear, 0.7% geothermal and 0.5% solar = 60.4%. CO2 emissions come out to 651 pounds per megawatt.

https://www.epa.gov/energy/power-profiler#/NWPP

California doesn't have as much renewables in their fuel mix, but they get better emissions per megawatt, since they burn less coal: https://www.epa.gov/energy/power-profiler#/CAMX

As far as I can tell, upstate New York has the lowest carbon emissions per megawatt in the United States, 294.7, thanks to lots of nuclear and hydro: https://www.epa.gov/energy/power-profiler#/NYUP

Put another way the NW with 60% renewable is 3x higher than NY, which mixes its hydro with Nukes and avoids the use of coal.. If you assume 60% renewable with natural gas as the peak/remainder then your still 2x higher than France.

These graphs prove the failings of modern "green energy" because all that hydro was built 50+ years ago, and if instead of fighting Nukes and getting coal plants the environmentalist would have embraced Nukes we wouldn't really be talking about CO2, particularly if the widespread use of breeders brought the price down so that buying electric cars made sense without the huge subsidies both in purchase price and electric charging.

Put another way, making electric cheaper via modern fission would make electric cars more appealing than the unsustainable subsidy models currently in use.

This argument annoys the hell out of me. Renewables gave gone from too exoensive to cheapest over a time short compared to the lifespan of our generating infrastructure. So the installed base is zombie tech, not what would be installed today.

There many water dams which feed whole cities

Dams are literally terrible in terms of ecological impact. The sooner they are all gone the better.

as opposed to figuratively terrible?

The ecological impact of dams is totally local, but the ecological impact of CO2 is global. If we were to power the entire earth with hydro, the local damage to ecosystems would be a very small price to pay indeed.

Dams are obviously better than fossil, but I think a case can be made that fusion would be better than dams.

Also, using a fossil plant is harmful, using a dam is not. The damage was done when it was built.

I've seen arguments that some dams where the water level varies a lot produce a lot of GHG's due to decaying plant matter.

But yes, in general compared to fossils it certainly wins.

Any specific good material that I could read more on this?

A lot of the impact can be mitigated by building fish pass channels, building new habitat such as compensation channels, and controlling the rate of change of water levels.

We really should stop using the same word for two things with such different characteristics.

Hydro/geothermal: nice steady power but not easily available everywhere.

Wind/solar: available everywhere but variable output.

Obviously it's easy to run a city on "renewables" if you have a convenient dam, but if you only have wind/solar it's more challenging.

How big of a city? Does 1.6 million people count? If Auckland, New Zealand runs on 80% renewable electricity which is certainly a majority in my books.

How about an entire country?

https://www.ecowatch.com/iceland-worlds-largest-clean-energy...

>Today, all of Iceland’s electric power is generated by hydropower and geothermal energy, and about 95 percent of the nation’s heating demands are warmed by geothermal means.

https://www.sciencealert.com/costa-rica-has-been-running-on-...

>Costa Rica ran on 100 percent renewable energy for 76 straight days between June and August this year, according to a new report, demonstrating that life without fossil fuels is possible - for small countries, at least.

This is the second time in two years that the Central American country has run for more than two months straight on renewables alone, and it brings the 2016 total to 150 days and counting.

Thanks but I'm looking for non local renewable energies, geothermal and water dams are great but they will not save the world.

All of Norway...

https://en.wikipedia.org/wiki/Electricity_sector_in_Norway#M...

Do you know any city that have a majority of it's energy that come from renewable?

Montreal runs on hydro

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