Comment on Renewables blow past nuclear when it comes to cheap datacenter juice
Aatube@kbin.melroy.org 3 weeks agowdym the github is complete crap? it has everything you mentioned you wanted to look at. and wouldn't a too-low estimate for nuclear costs give extra validity to the claim that microgrids are much cheaper?
humanspiral@lemmy.ca 3 weeks ago
what is .nc file format? their csv data has no cost numbers.
It is much cheaper. Everywhere. But the modeling done in this instance can still be completely incompetent.
Aatube@kbin.melroy.org 3 weeks ago
is this not cost? https://github.com/ryanjenkinson/data-centre-modelling/blob/main/notebooks/costs_2020.csv
https://stackoverflow.com/questions/36360469/read-nc-netcdf-files-using-python. and regardless, is a single file you don't understand that is clearly read by the notebooks as input solar data enough for you to evaluate competence‽
humanspiral@lemmy.ca 3 weeks ago
github.com/ryanjenkinson/…/model.ipynb does give model details, but doesn’t use that cost file directly.
some mistakes…
inflates 2021 costs to 2025 for all technologies. Solar has depreciated, and wind maybe did not go up in price. A bigger deal is no distribution costs. Offshore tall AF wind turbines are cheapest power in the world, if you build an island/raft at the bottom of the turbine to drink the power, and that is only scenario where they are part of a microgrid. They cost much higher than solar due to HVDC lines, and transformers to use “normal” current. Current conversion equipment in general also not included.
The gas costs overall are very low. Ridiculously low is fixed opex 1/4 that of wind. insurance about the same as solar, when people can get burned or poisoned “easily”, and mile wide craters have occurred at gas plants. No fuel delivery markups on futures prices, or infrastructure costs to deliver it. If it’s going to be 5%-20% capacity factor, delivery by truck is no infrastructure, but high fuel costs. Fuel delivery/handling for low capacity use makes coal look better. Fixed opex requires people operating 24 hours and emergency shutoff standy people.
Battery modeling is bad. Model uses constraint/linear programming to find a mix, but battery range is capped at 600mwh, with wind and solar at 2000mw, and so can fill battery in 20 minutes. Claim that at 600mwh, you only need gas for 5% of power, makes a gas plant a complete absurdity relative to a utility grid connection. A good battery size is 2 times the maximum charge rate.
SMR modeling is extreme joke. Based on 540mw reactor which simply is not even SMR. Normal big reactors are 1gw. They save substantial costs by having 4 to 8 on a site. The $55/mwh ($80 in 2025) figure from earlier is just variable/fuel costs. $5/watt construction costs not serious. no reason to ever expect under $15/watt. Neither of the numbers scale down to 120mw either, and nuclear is simply not a 24/7/365 capable energy source, even if you want your datacenter to be. If you need 12 hour maintenance windows, you need 1440mwh of battery systems that you will hardly every use. Nuclear was always stupid to consider, and a grid connection with possible exporting generation assets on site is the way to go.
Capacity factors for wind of 0.61 is high due to invalid offshore use. With 1400mw wind, and over 800mw wind per hour, a 120mw datacenter is horribly mismatched. Solar of 0.11 is 2.5 hours/day production. It’s a reason to have datacenter outside of UK, but onshore/onsite wind+solar can work for the right UK site. Solar for “off grid” in north should go for lower total capacity factor by maximizing tilt for winter production. Easy to get a full day’s power 9 months of the year, and find way to monetize surpluses. Grid exchange for datacenter application, smart. For datacenters, all electronics run on DC, which means they can all run off batteries, and everything else charges batteries.
The starting point with behind the meter renewable power with bidirectional grid connection is production required for maximum use + export on a 120mw transmission line per day = 5800mwh. 2600mwh battery to discharge up to 120mw all day is also 24 hours of operation power. Summer solar in UK will reach 8 hour days, and many 7 hour days. Onshore Wind averages 6 hours, but can hit 20 hours in a day. Model is $1.5m/mw wind, and $500k/mw solar (excluding grid connections) at capacity factors favours more solar. Natural DC power also favours solar. Wind has less land footprint, and could benefit from being on the north side, with (idk) solar panels helping rare south winds funnel up to the blades. The winter capacity factors are much higher for wind, and worth more than 3x the cost in winter. Other factors is export value of our electricity. A renewable future means higher night prices, and even in UK, higher winter prices. 24 hour huge battery means profit from day 2, 3 day ahead forecasts arbitrage.
The right model is 7 hours solar + 6 hours wind = 5800mwh (summer peak). and 6 hours wind + 1 hour solar = 1300mwh which is hoping for 50% self generation in bad solar winter days, but average wind. 200mw of wind and 650mw of solar at winter optimized angle gives 1850mwh on bad solar average wind winter day, and the 5800mwh summer maximum on mnay days with some curtailment possibility. up front power costs are $390m batteries, $325m solar, $350m wind = $1.065B. Over 1twh non curtailed self production per year. For 10% ROI on power production (nevermind datacenter companies having 5% cost of capital), $100/mwh is both export revenue needed and cost of internal power (which if you only needed 5% ROI/or financing burden is $50/mwh). This is lower internal costs than grid or just variable SMR power costs, and can often undercut competing supply for even higher profit. This is same annual production as 120mw 24/7 SMR, but that has $1.8B+ capital costs, and $180/mwh breakeven energy value (before the extreme variable/fixed operating costs). A 120mw fossil plant does mean just $30/mwh capital cost retrieval, but the operational costs are at least $60/mwh. OP Model underscores these heavily. The renewables approach achieves lower internal power costs + big profit opportunity from electricity trade. The variable costs of fossil fuel plants means they can’t just run 24/7 into a market price that loses them money, and so it only makes sense for datacenter to not share fossil power with rest of society.
Aatube@kbin.melroy.org 3 weeks ago
thanks for the detailed analysis!
i'm curious though, https://en.wikipedia.org/wiki/Small_modular_reactor#List_of_reactor_designs says the design with the largest output is just 940 MWe and the second-largest output 600 MWe, are you sure they should be at least 1 GWe or am i reading something wrong?