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Comment by Akronymus | Hacker News Reader

The only problem I have with that, is that renewables can mostly only be treated as a bonus. Trying to rely on them for baseline power means you have to put out a LOT more capacity than you'd need with fossils.

IMO baseline being nuclear and the rest being mostly renewables (With HEAVY reliance on pumped storage power plants, as a sort of capacitor) is the way to go to minimize emissions.

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Renewables today are displacing energy 1:1. So, directly offsetting the fuel that would have otherwise been burned.

You're correct, that there is not a 1:1 reduction in fossil capacity through the construction of renewable capacity. But the fossil capacity is used less, as the marginal cost of the renewable energy is near zero.

Most pumped hydro today (at least in the US) was built during the nuclear build-out because nuclear can't easily be "load following." So, we had to build out additional infrastructure with low capacity factor.

IMO, tax emissions, let the free market figure it out.

For context: I live in austria, where we have the alps that provide a large amount of storage capacity.

Sadly we never got that nuclear power plant.

I wonder if Germany actually will start to decommision all nuclear plants in 2022. From what I've heard they had some insane corruption in storing waste and not the best reactor designs.

Your rumors are untrue. Germany has one of the best reactor designs (the Konvoi) which was the basis for the new European Pressurized Reactor (EPR).

Also, there is no corruption around storing waste because we aren't storing waste yet anywhere outside nuclear facilities which are supervised by the government and the IAEA.

Wow it looks like there has been some deep cleansing of articles about poor radioactive storage in Morsleben from a few reputable outlets. I'm not going to waste my life busting that censorship. Censoring those articles rather proves my point about corruption.

IAEA failed in Iran due to political posturing from europe. Europe has broken more than a few core international organizations. I'd rather not trust them to not cover up anything else for europe.

AFAIK they are already decomissioning nuclear plants. And replacing it with coal or gas. [1]

[1] https://cna.ca/news/germany-replaces-nuclear-coal-ghgs-skyro...

Germany could try to rely on the EU nuclear program but it's likely to be co-opted by France and their nuclear program.

> Renewables today are displacing energy 1:1. So, directly offsetting the fuel that would have otherwise been burned.

Except they are not. Otherwise Germany wouldn't be one of the dirtiest electricity producers in Europe.

I don't know why EE supporters keep ignoring the fact that any electricity not produced by wind and solar despite being needed will be produced by gas or coal which is why Germany is massively investing into new gas plants and a second gas pipeline to Russia (Nordstream 2).

You cannot solely rely on wind or solar which are intermittent and have a low energy density.

We have a solar array on the house. A lot of the Dc to AC solar inverters used in residential installs use the grid to match the frequency of the AC.

The downside is with no grid power the solar system doesn’t work to power the house. There are systems that can but they’re more money.

Take a look at online UPS systems. They convert incoming power to battery voltage, keep the battery charged, and output via an inverter that's made to run without being tied to the grid. They shouldn't be that costly if you can find them without large batteries, instead just hooking them up to your own.

Transfer switch to a very small inverter run off a battery; add your loads one-by-one and you should be fine during a prolonged outage (and as long as there is sunshine...)

can you directly use the DC as a reserve source? like, install car plugs in the house? there are lots of smaller everyday electrical gear for this standard

It's actually a much more interesting question than you might expect. Lots of modern appliances could run perfectly on DC of around the RMS voltage. For example the most modern fridges rectify the incoming mains to drive a brushless DC motor, this allows them to run at an appropriate speed rather than using bang bang control. Even an an induction hob, you might think it was most reliant on having an AC waveform but actually they need a much higher frequency so again they rectify the incoming mains.

Obviously it's not quite that easy, for example an oven uses resistive heating elements which would work fine on DC, however, the relay in the control circuitry wouldn't be able to switch a DC voltage.

That works for small cabins and lighting, as a 12v car outlet requires the same thickness of wire as a normal AC outlet. This is somewhat popular to do if you don’t need to use any high power appliances as then you can skip needing an inverter.

The 50% solution with CCGT making up for variability seems to be working just fine. Wind is a lot more consistent than you think, especially offshore. Does mean we're dependent on gas for the medium term.

Nuclear and pumped storage takes a very long time to build. The other storage systems are starting to make inroads - tiny ones so far, but growing rapidly. The "fast frequency response" market provides them economic support.

> The 50% solution with CCGT making up for variability seems to be working just fine. Wind is a lot more consistent than you think, especially offshore. Does mean we're dependent on gas for the medium term.

It does not work fine at all. Germany is one of the dirtiest electricity producers in Europe.

France emits 50 grams of CO2 per produced kilowatthour while Germany produces 400 grams on average:

> https://www.electricitymap.org

Germany also has the highest electrity prices in Europe:

> https://ec.europa.eu/eurostat/statistics-explained/index.php...

NASA also disagrees that gas plants are a good solution:

> https://www.giss.nasa.gov/research/briefs/kharecha_02/

That's because Germany still uses a lot of coal.

It seems to work, but this is about at the limit of what it can achieve - the UK is having to switch off renewable power sources increasingly aggressively to stop them from going any higher for grid stability reasons, and pay them quite a bit to do so.

The ability of utilities to incorporate renewables seems to have improved over the years. I'm sure it will only get better. In particular the approach of handling excess production by producing "green" hydrogen and storing it in the natural gas distribution network seems promising.

Germany needs 1.6 TWh of electricty per day. If you know the caloric value of methane for example, you will be able to calculate the amount of methane you need to synthesize to just store the electricity of one day which will be roughly 3.2 million gas trucks (45.000 liters each).

There is a reason why the UK is building or planning new nuclear power plants in Hinkley Point, Sizewell and Bredwell.

The German gas network can store 200TWh. I believe that power to gas has a bright future. Check out what Hydrogenics is doing. Also, storage doesn’t have to be day scale to be useful.

There's no need for baseline power in any power grid. The only type of power needed is peak power. You could run a grid on 100% natural gas peaker plants. The only reason to add baseline or intermittent power is if they're cheaper than the peaker plants or have some other advantage like being more green.

Yeah the base load debate seems to often get supply and demand mixed up. It's actually supply driven (old power plants are slow to start and stop and want a number to run at without wasting too much money).

https://www.abc.net.au/news/science/2017-10-12/renewable-ene...

"Technology has moved on from base load, and now you want flexible power. And that's what demand management, batteries and pumped hydro is," says Professor Andrew Blakers, director of the ANU Centre for Sustainable Energy Systems.

"If you have an increase in demand, a coal power station will take hours [to meet it], a gas turbine 20 to 30 minutes, batteries about a second, demand management about a second, and pumped hydro will take anywhere between 20 seconds and two minutes."

I meant environmentally independent power sources as being baseline power. Probably bad wording on my part.

You can not guarantee, no matter the capacity of power storage, that you never produce too little power over a long enough period.

This is the basis of my opinion that the closer to 100% renewable you get the faster the amount of additional capacity you need rises.

Something like 1/x over-provisioning[1] needed, where x is the percentage of environmentally independent power sources.

[1] Not sure if that is the right word.

Conventional plants need to be over-provisioned too, because of the possibility that one or more plants have a malfunction and have to shut down, possibly during a period of high load.

Put another way, it's probably more likely that they'll be some sort of equipment malfunction than we go an entire month with no wind.

Providing redundancy through independent mechanism (over-provisioning, storage, diverse sources) helps a lot.

But you're right. A grid that's 99% renewable with a natural gas peaker providing that last 1% will be a lot cheaper than a grid that's 100% renewable.

Working in that industry, my eyes roll whenever I see someone talk about "baseline" power.

You are right in that there is no such thing as "baseline" generation really. And thermal plants also need to be over-provisioned.

There is dispatchable and non dispatchable power, the former being plants that can alter output on demand.

Base-load is the point which the 24 hour cycle of demand doesn't go below. It's pretty much just a number.

Who occupies the base of the generation stack and will stay running during low demand, is the one who is cheapest. If wind is cheaper than nuclear, it will displace nuclear. The people who say "IMO we need nuclear for baseline and renewable for peaking" completely miss these facts.

The way it is going is renewable at the base of the stack and dispatchable power filling in the gaps, be that during peak or periods of low renewable output.

> The way it is going is renewable at the base of the stack and dispatchable power filling in the gaps, be that during peak or periods of low renewable output.

Very good idea to run gas plants with 490 grams CO2 per kWh instead of nuclear power plants with 12 grams CO2 per kWh, indeed.

France produces 50 grams of CO2 per kWh while Germany has 400 grams on average:

> https://www.electricitymap.org/

Your ideal model for producing electricity actually hurts the environment as the times where gas plants need to run are much more often than you think.

"dispatchable power" doesn't necessarily mean gas, it could mean storage.

Also nuclear is only weakly dispatchable, something the comment you replied to misses. So it is not suitable for filling the gaps.

A 100% nuclear grid will need dispatchable peak power as well, be it gas or storage.

> There's no need for baseline power in any power grid.

Go to smard.de, check "Market data visuals" and "Electricity consumption->Actual consumption" and you will be presented with the baseline which is never below 40 GWh in Germany at any hour.

Sure, baseline demand exists. But I'm talking about supply. If you have a system that can supply 120GWh at any time then it can also supply 40GWh at all times. If it can't supply 40GWh at all times then it obviously can't supply 120GWh at any time.

For the past two years (2018 2019) capacity factor of nuclear power in France has been around 70% mainly due to maintenance according to RTE (1)

For reference best UK offshore wind farm had 55.3% capacity factor in 2019 and UK offshore wind average capacity factor was 40.6% in 2019 (2)

(1) https://media.rte-france.com/bilan-electrique-2019-2/ 379.5 Twh produced, 63.1 GW installed, 68.7% capacity factor

(2) https://energynumbers.info/uk-offshore-wind-capacity-factors

Not far from so-called "baseload"

That's quite misleading though. You can choose and schedule maintenance slots so they don't overlap all at once. Much harder to do with wind, hence you get 0MW output at some times, and massive overgenereration at once causing very negative electricity prices.

Yes and sometimes you have unplanned 680 MW to 0 with "baseload" nuclear:

https://www.energylivenews.com/2015/12/15/unplanned-shutdown...

Wind is intermitent but predictable. Loosing a turbine will not make the plant production go to zero (albeit loosing transmission will but same for all power plants).

One nuclear reactor out of 57. Wow, that's really a problem.

On the other hand, we have times in Germany when wind and solar are producing less than 1% of their installed power.

Pumped storage, like all hydro can be the cause of major emissions depending on how much and what they flood. Anything with forest and suddenly they're actually worse than coal (in terms of Climate Change emissions, not the other nasty shit)

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