Gigawatts of capacity, I assume? What's the capacity factor of their investments, I wonder? E.g. how many GW-years of electricity do they generate in a year on average?
It's much more important these days to measure progress is integral terms like low-carbon energy generated/year rather than max low-carbon power when in ideal conditions.
It's even better to measure with things like lifecycle mass CO2-equiv/kWh avoided, which avoids traps of crediting things like forest combustion as "green" like drax does in the UK.
Fossil also has downtime, as does nuclear. It just isn't as frequent. But in some cases (reactor shutdown for instance) it can be much more sudden and long than the way wind and solar vary. And prediction of near future solar/wind availability is getting better all the time helping a lot in dealing with the variability.
I've been 100% off grid for two consecutive years in Northern Canada. We did have a backup generator but it wasn't used after the windmill went up. 48 KWh of storage was enough to tide us over any period without sun/wind.
I did some research to see if it would make sense as a homeowner and found it to be mostly not worth it.
You shouldn't attach it directly to the building because wind speed near surfaces slows down significantly. So you need a large pole which will make maintenance very expensive. You usually can't attach the pole directly to the building either because it isn't rated for such high forces.
Wind mills are also quite noisy so you probably want to have a huge amount of land to put it far away from the house.
The power produced rises to the power of two with the diameter of the rotor and to the power of three with wind speed. This means that you want an installation which is both large and high.
I built my own. 16' diameter, variable pitch, and silent as can be. The noise a windmill makes is closely related to the thickness of the trailing edge of the blades.
Have you done any write ups or posts on your build? Or do you have any suggestions of other posts about similar builds? Would love to learn more about what it takes to do this.
Are coal plants better because they have higher capacity factors?
Are they cheaper to run?
I mean obviously if you compare two coal plants that are otherwise identical, you'd assume the higher capacity leads to cheaper power and is therefore better. But once you are comparing coal to solar, its utterly meaningless out of context. Even in the near identical coal case, why not say "this one is cheaper" or some other measurement people actually care about?
Also it's mandatory to take care of the backup used when there is "no-wind/no-sun".
You can have your electricity share coming from renewable that is increasing, if in the end you have 30-40 of gaz/coal as a backup to handle the time when renewable is not producing you'll no go way further. Example: Germany.
Exactly. In some cases if you do the backup poorly (e.g. with gas like everyone is doing nowadays) you can get into situations where the gas plants run extra inefficiently due to frequent ramping and end up cancelling out a lot of the benefit of your wind and solar.
My favorite fun fact on this is that regular old nuclear plants can ramp up at down quickly, at 5% full per per minute! Most people don't know this. They often choose to not due it because fuel is a small fraction of their operating costs, but in a low-carbon capacity markets they could really shine. French and (previous) German reactor do it all the time.
Nuclear makes for such a good backup, you could just dispense with wind and solar altogether and still reduce total carbon output. That might be why they resist doing it. To some extent, the environmental movement has been overtaken by a corporate racket.
That is exactly my point. It is such a reliable energy it doesn't need any backup. You can skip solar/wind for nuclear. Keeping solar/wind for the margins, preserving a lot of land for other uses.
Some in nuclear like to call wind and solar a bridge technology for this reason. Of course we'll need to be more like the S. Koreans and Chinese on our builds before this happens in the west.
New battery backed solar is already cheaper than gas/coal in most areas. This is why the percentage of solar is exploding world wide while nuclear has stagnated. The economics just work out that way. In theory you hit an inflection point at X% wind/solar, but prices just keep falling so it hasn’t happened yet.
Germany made a huge sacrifice by subsidizing early and very expensive Solar to in a northern country to really kick things off. But they’re stilly paying subsides on those early installations.
> This is why the percentage of solar is exploding world wide while nuclear has stagnated.
No, solar is exploding because it's heavily subsidized, either monetarily or by other schemes like net metering. Nuclear has stagnated because it requires huge upfront cost, and stability in building new capacity.
No most of the planet. Including Nevada, Texas, … even much of South Dakota.
Look at a globe some time, most of the world is much closer to the equator than Germany yet battery backed solar still beats gas/coal/nuclear in parts of southern Germany.
PS: Nuclear, coal, and natural gas also receive plenty of subsidies. It turns out removing all subsidies from electricity production actually pushes wind/grid solar even harder. What it discourages is rooftop solar which isn’t a good fit for many locations.
Those are four states. We're currently without wind and have clouds in Pennsylvania where I'm visiting family, how do you propose we generate enough electricity and cover this coming weekend where there will be rain and clouds.
My list was hardly every state Hawaii and Florida are a great fit for solar.
As to PA, this time of year demand is very low as you need minimal heating or cooling. Similarly while solar output is low in stormy weather wind isn’t. Similarly the region has plenty of hydroelectric which can offset production from days with high wind/solar production to days with low wind/solar production.
Weather tends to be a tradeoff where hydro and wind improve just as solar and demand decline. In extreme cases like Washington state batteries are pointless and the ideal mix changes.
This is the real problem with renewables. You need to 20-30x them to get to real usage. Or have 100% redundant gas coverage, with giant political problems coming with it.
You don’t get anything in seconds, but over years you just pay people to build them and they build factories just like you pay people to build equipment for other types of power plants.
New limits always show up with new scales. People will advocate dramatically scaling nuclear as if tens of thousands of people with the skills to operate them are sitting around with nothing to do. Lack of skilled workers is actually a larger limiting factor for nuclear than the few years it takes to build a single reactor and one of the reasons they can’t make a significant difference without at least a decade of lead time and more likely several. Current programs can teach people reasonably quickly, but you need not just students but more people trained to teach the material.
The trade off being the survival of the human race, and of course less money flowing into the hands of the Saudis, Russians, Exxon, and other corrupt organizations.
Care to put some numbers on the no wind/no sun scenario? As an example, the share of renewables in Germany never dropped below 30% last year and that only happened a couple of days. Average renewable contribution was >50%.
What is your source for this? I’m highly skeptical because it means there was never a time of low wind at night ir when it was cloudy. February 26th of last year sure looks like a lot less than 30% renewable. https://mobile.twitter.com/energybants/status/14973924637319...
There's also hydro (incl. imported from Norway) and biomass. Source for total renewable over time is here: https://www.zeit.de/wirtschaft/energiemonitor-deutschland-ga...
There might be spells during the day where this is less than 30%, but that's what short term storage would be there for. The nightmare scenario, often mentioned, is weeks of clouds and low winds, which does not seem to have occurred last year, at least. And even when it's cloudy you still have some solar.
By the way, I'm not arguing that all is well and everything is solved, I just hate this juvenile argument of "but what if it's cloudy and there is no wind for weeks", because that does not happen often, especially not on a continent-wide grid with lots of offshore wind power in one of the windiest seas in the world.
According to that source, this morning in Germany the total solar + wind + biomass energy production was under 410MWh, whereas gas + coal was around 8500MWh. Conservatively, _just the battery cells_ to make up for that shortfall _for just one hour_ would cost over $1B.
This isn't a once in a while issue that can be solved with a few batteries. We need revolutionary grid-scale storage tech to make renewables work. Current batteries are orders-of-magnitude too expensive and we have orders-of-magnitude too little manufacturing capacity.
The problem with these discussions is always that we are laymen using handwaving arguments to push for or against a topic. So useless all in all and just aiming for winning an argument instead of trying to solve a problem. Frustrating.
> the share of renewables in Germany never dropped below 30% last year
I find this very hard to believe. There was never a windless night all year? Not for an instant?
This[1] seems to disagree. There were plenty of times when wind + solar generation was 3GW or lower, where total usage was over 50GW.
If you look at all the electricity generated over the whole of 2022, about half came from renewables. But the grid doesn't operate on averages. Every load needs an instantaneous generation to match. And Germany regularly had times were wind + solar couldn't even meet 10% of demand.
I imagine that this is only for the grid production? If I charge my car with solar at home it won't move the meter, energy consumed by households with solar might not show up in the statistics.
In reality renewable contribution might be even higher, unless there is correction for this.
Can you elaborate? Are there significant differences in ratios of power produced to max power? Naively I would expect some scaling factor to apply in most cases, as regional and seasonal differences come out in the wash.
Huge differences based on region and technology. In California solar PV may generate 30% of its max capacity in a year due to nights and clouds, whereas in Seattle it may be well below 20% due to no sun in winter. Wind averages 35% due to lulls. Nuclear is about 92% (has to shut down every 2 years to refuel). Hydro often is run around 40% (depends on water availability).
So building 13.7 GW of nuclear capacity in a northern region could generate ~5x more clean energy per year than 13.7 GW of solar capacity.
Not sure if Apple is investing in nuclear or not. (:
Nameplate capacity is so vastly cheaper with solar it more than offsets that difference in all but the worst locations.
In Nevada you nuclear is means paying 10x as much to get a 90% capacity factor vs 30% for solar. So you build 3x as much solar and a ton of batteries and still cost less than nuclear while being able to follow the demand curve.
LCOE is vastly lower for battery backed solar, that’s why it’s so cheap. You also don’t need backup with batteries that’s the entire point.
Individual nuclear power plants are single points of failure and go offline randomly. Nuclear needs redundancy to ensure a stable grid which further increases its costs.
Transmission is again worse for nuclear because it’s so centralized. With solar you can locate it much closer to end users which cuts down on annual transmission losses.
Seattle is an extremely unusual location being both far north and very rainy. But that much rain provides plenty of hydropower which completely changes the equation.
A typical land-based wind turbine has a yield of about 25 to 30%, i.e. it produces about 25 to 30% of its maximum theoretical capacity. A typical offshore turbine produces 45 to 65% of the time (the bigger turbine, the better).
So installing 1GW of wind power onshore basically produces about half the actual power as 1GW offshore, off the bat.
Similarly yields of other renewables vary considerably (unsurprisingly, 1MW of solar panels produces twice as much power in Spain as in Germany).
It's much more important these days to measure progress is integral terms like low-carbon energy generated/year rather than max low-carbon power when in ideal conditions.
It's even better to measure with things like lifecycle mass CO2-equiv/kWh avoided, which avoids traps of crediting things like forest combustion as "green" like drax does in the UK.