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#power#nuclear#plants#load#coal#baseload#lot#generation#cost#gas
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Discussion (19 Comments)Read Original on HackerNews
Yet pumped hydro storage was originally implemented in the 70's because nuclear of the time couldn't do peaking power. It was envisioned as a way to move cheap nuclear power generation from the nighttime lows to daytime peaks.
Baseload is just a cost optimization. We need a power system that meeds demand 24/7/365. If we've done that then we've also provided baseload, by definition.
Technically, what grids mostly need now that we have a lot of intermittent producers and consumers of energy is not a lot of very inflexible generation (which is what baseload boils down to) but a lot of flexibility in the grid that can be switched on/off and is able to rapidly adapt to changing supply and demand.
The grid doesn't need gas plants that are running 24x7 and burn a lot of expensive gas when there's more than enough power being generated through the day from wind and solar, which tends to be a lot cheaper.
But because that's intermittent, you still need other sources of power. The traditional interpretation of that is "baseload" i.e. the stuff that used to provide most of our power (coal, nuclear, and gas).
But in the last few years we have a new alternative: batteries. This grew from next to nothing a few years ago to hundreds of GW of capacity. Soon TWs. Batteries can smooth out the peaks and dips and switch from charging to discharging in a few milliseconds. You might still need some other power beyond that but now you can carefully plan when to bring backup power online and take it offline again once it is no longer needed.
Modern gas plants can switch on and off relatively quickly and are very suitable for providing tha backup power. Modern coal and nuclear plants can do that as well but are just a lot less attractive due to their higher cost. And if you are not utilizing backup plants most of the time, their cost is really important.
Power that is 1) very expensive, and 2) can't be switched off easily or cheaply, is kind of a the opposite of what is needed. That's what baseload amounts to. It's the exact opposite of what is needed.
A thing that's often overlooked in discussions like this is cables. Cables can move power around. And interconnected grids like the European or Chinese grids make use of that to deal with highly localized peaks and dips in energy due to weather and daily and seasonal changes in availability of e.g. sunlight. An east west cable can time shift power in early morning and late evening. A north south cable can move solar power from places close to the equator to places further away from it. There are some cable projects being planned to connect Africa to Europe, Australia to Singapore, and Canada to Europe. Cables + batteries deflate a lot of the economical argument for needing baseload.
Okay, but that isn't really base load. That's the other thing. Base load is real. It's statistics.
Base load was a useful concept in the 1960s when the cheapest power plants couldn't follow load and so you needed to find the right mix between base load and the more expensive generation. Now that the old power plants are not the cheapest we don't care about it even though it statistically still exists.
In the 90's/00's when Germany and Denmark decided to start decarbonizing their grid, the sane choice would have been nuclear. At the time it was the cheapest zero carbon viable electricity source. (Geothermal may have been cheaper at the time, but wasn't viable to power their entire grid).
But instead they decided to massively overpay for wind & solar. This bootstrapped the insane cost reduction we've seen in wind & solar over the last 30 years. Today solar & wind are significantly cheaper than natural gas, and orders of magnitude cheaper than nuclear.
> coal (see Germany)
Which dropped from 55% of electricity from coal in 1990 to 23% today. From 400 million tons to 130 tons.
I can expect that a well-built nuclear plant might not have a catastrophe in my lifetime. But when the consequences are so long-lasting it seems prudent to avoid them entirely. One misbuilt reactor or one governmental regime that rolls back safety regulations and you end up with irreversible consequences. Given the tendency of corporations to “race to the bottom” and abandon safety, and the general unwillingness of the US Government to give proper attention to potential catastrophes (like climate change), I don’t believe that we as a society can handle the responsibility of nuclear reactors. I wish we could have nuclear safely; I don’t trust us to be safe, so I’d rather we not have nuclear at all.
> The gap in understanding comes with the second factor: belief that it is inherently more efficient to match this load with big thermal generation.
> This comes from a historical contingency, where large stable loads matched very well with traditional coal-fired and nuclear power plants. These burn coal (or fission) to heat water, creating steam that then drives a turbine to generate electricity.
> In both cases, getting the water up to temperature can take hours, and these plants do not handle fluctuations in demand well. They are much more efficient running steadily at a given rate. But, when operated at that steady rate, these large plants were historically some of the most cost effective available.
> As a result, in most places a layered system of generators was built with large, slow-but-efficient coal and nuclear plants designed to serve the ‘baseload’ that would always be required. On top of this, faster-but-more-expensive gas, oil, and hydroelectric generators were layered.
This model doesn't make sense. Suppose you have an existing setup with some coal plants and some oil plants. The coal plants like to stay on; the oil plants are more indifferent.
There's a baseline load reflecting the amount of power demanded at almost all times of the day or night in whatever region contains this setup.
Now we add some more coal plants. They like to stay on. They hate turning off.
What will happen is that the local baseline load rises to accommodate the greater supply of power. Also, the price of electricity will go down.
It just isn't the case that the amount of power people consume within any given region is independent of the power supply to that region! The baseload is set by the amount of power being delivered; it's logically incoherent to try to determine what level of inflexible power generation will meet "the baseload". Almost any level will.
Lots of folks don't know that coal and gas fired plants are able to turn down their power generation more than 90% (i.e., "ten to one turn down"). It's definitely true that cold restarts take a while. However, they often rather quickly and dramatically change their power output profile while running.
Maybe. Electric companies used to have policies that encouraged that. Most people are asleep between midnight and 6am, so if you used a lot of electric at that time they would give you a large discount on electric costs. However most people would not get up at 3am to take shower even if it would save $20/month (must be a really high flow shower to save that much). However those policies have changed over time as now the electric company is going to give discounts if you can use power when the sun is bright or the wind blowing (depending on where they get their power).