Solar and battery to make up 81% of new US electric-generating capacity in 2024

In the US, PV solar capacity factor is about 0.24 (partly because lots of people live near very sunny regions like California and Texas). The National Renewable Energy Laboratory claims that in some parts of the US utility-scale solar capacity factors are 0.33 [0]. Wind is about 0.36, Hydro also 0.36, Nuclear about 0.93 [1]. If you apply these capacity factors to the nameplate capacities (ignoring batteries), you get 58.5% solar, 19.7% wind, 15.1% natural gas, and 6.6% nuclear.

[0]: https://atb.nrel.gov/electricity/2021/utility-scale_pv

[1]: https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

Yes, correcting for capacity factor is essential if you want to compare potential energy generated over a year (which is perhaps not the most common use of these numbers). Gas generators are typically less than 50% capacity factor, and batteries should have course have a 0% capacity factor for comparison of energy created over a year

However, your capacity factors for solar are far too low, average CF is above 20%. There are roughly as many installs with CF>30% as there are with CF<15%.:

https://emp.lbl.gov/pv-capacity-factors

Also omitted from this view is the cost per MWh delivered to the grid. A great overview of the current state of the technology, including costs ($40/MWh), is here:

https://emp.lbl.gov/sites/default/files/utility_scale_solar_...

There's also a great overview of the state of batters here, where conservative estimates of lifetime cost of stored energy results in about $88/MWh:

https://www.nrel.gov/docs/fy23osti/85332.pdf

For the new nuclear cost, it's actually really hard to dig up, because it's a bit too embarrassing to the industry. But by taking the factors from this slide deck:

https://liftoff.energy.gov/advanced-nuclear/

And scaling the slide 14 numbers for $9k/kW overnight cost to the real cost of $15/kW at Vogtle, and we get nuclear costs north of $180/MWh for nuclear when including the new subsidies from Biden's IRA legislation (north of $200/MWh unsubsidized).

That’s not why it is done, it’s because this is reporting in capacity and that is the physical capacity being installed. That phrasing makes it sound nefarious, then you end with a fairly low solar range (which varies substantially and exceeds that in sunnier parts of the US).

Bit of an odd take. You could say the same, or lower, of capacity factors on peaking oil or gas plants in some areas that run for only a couple percent of the year. Nameplate and utilization are just different things.

Maybe worth noting that despite lower capacity factors and despite it being mid-winter, Texas (ERCOT) keeps setting solar output records because they’re installing so much nameplate[1]. It’s not like it does nothing.

[1] https://www.gridstatus.io/records/ercot?record=Maximum%20Sol...

Your range is wildly off for PV systems, concentrating solar thermal can be that low but it’s been abandoned for good reason. Utility scale PV solar in the US averages 0.246 with several solar farms in the US having over 0.32 capacity factors.

Ex: 0.328 from 2017 - 2019 https://en.wikipedia.org/wiki/Solar_Star While a nearby PV farm is only 0.275 (average 2015-2018) https://en.wikipedia.org/wiki/Desert_Sunlight_Solar_Farm and another in the middle: 29.7%(average 2015–2017, MS1) https://en.wikipedia.org/wiki/Mount_Signal_Solar Curtailment depends on the specific power purchase agreements so there’s some variability independent of the underlying technology.

The discrepancy around PV solar is largely the degree of tracking and location. Fixed panels have the same maximum, but even 1 axis tracking significantly extends how long a panel is producing the maximum power. 2 axis tracking allows even better capacity factor assuming nothing breaks, but at higher cost per kWh.

PS: Of note low capacity factor Solar installs are generally far smaller. It’s viable to install a little solar in Maine, but not at the same scale. https://spectrumlocalnews.com/me/maine/news/2022/11/17/const...

Why does nuclear not deliver closer to its ideal power output? Are nuclear plants really down 10% of the time?

Somehow, that is the latest pro-niclear / anti-renewables talking point. Not tgat people in field learn the principle of load factor in one of the first days of 101 lectures on the subject...

It least it is an evolution up from "solar isn't working at night" and similar deep and hot takes on the subject.

Keep in mind that looking at the capacity factor for nuclear vs solar/wind can be misleading as well if you don't take into account even more factors.

Renewables are composed of a wide mix of thousands of power plants. And these days the construction of renewables goes along with construction of energy storage and grid upgrades (even taking into account those costs, renewables are now competitive). So any failures/downtimes is smoothed out over both time and space.

That ~10% of the time that nuclear is down, you get 100s of MWs going down in a single region. France recently had several nuclear power plants go down at the same time, making them dependent on imports for a long stretch of time.

In terms of energy I think it's worth looking at the total net energy added.

The largest rate that nuclear ever grew was around ~200TWh for some years in the 80s.

Solar grew by ~300TWh from 2021 to 2022. Wind grew by ~200TWh. And the growth rate is still increasing exponentially.

For reference the world population grew from ~5 to ~8billion from the 80s until now, if you want to take that into account when comparing the growth rates.

I don't think there can be any doubt anymore that renewables will completely dominate the energy production in the future.

Here in Finland, the national power grid operator provides a live graph of how much that each source is outputting. Its kind of funny how solar produces almost no energy during the winter this far north. I'm very happy that we have that new 1,600 MW nuclear plant, so we no longer have to get that energy from coal.

https://www.fingrid.fi/en/electricity-market/power-system/

The LCOE of nuclear is very sensitive to its capacity factor.

Nuclear costs are set to skyrocket because for a larger and larger part of the day they will not be profitable as renewables undercut the price of power.

With a lower and lower capacity factor, new nuclear plants will never pay for themselves.

https://youtu.be/udJJ7n_Ryjg?si=m-F4DNn5MpNvycPA

> How much solar/wind/battery capacity can 34B USD buy!?

I'm guessing you'd run into space constraints pretty quickly. For one large project a nuclear reactor is incredibly compact compared to most alternatives except maybe hydro.

> How much solar/wind/battery capacity can 34B USD buy!?

According to How Big Things Get Done, at least 30B worth. Nuclear plants have some of the worst cost and time overruns for large projects, wind and solar some of the lowest (beaten only by roads).

And his theory as to why this happens, is that wind, solar, and roads are self-similar. Building the first 10% directly informs you on how to build the next 10%. Everything you learn along the way can be rolled back into the project in a feedback loop.

What you learn shingling a roof or building a nuclear reactor doesn't help this project all that much. It helps the next. And how many nuclear reactors does one worker build in their lifetime? 2? 4? That's not a lot of opportunity for process improvement.

> Those numbers are simply mind blowing. Why are these still built?

I'm guessing because there was no step in the process where it seemed like a better idea to stop construction and have spent whatever costs so far to get nothing of value, rather than accept the cost increase and end up with high availability, somewhat dispatchable generation.

There's not a lot of new projects in nuclear, because construction costs are high and subject to cost overruns as projects get delayed, and delays seem inevitable. That's why there's all the talk of modular nuclear and what not. If it was feasible to build these plants on time and on budget, the generation parameters are good --- doesn't use much fuel, tends to be available outside of scheduled maintenance, can modulate generation to follow demand, if the economics make sense (as-is, most of the plant expenses are fixed cost, so you may as well generate as much as you can to amortize the cost over more kWh)

What specifically is so expensive about the reactors? Having played the simulator[0] and now being an expert in running a nuclear power plant, the idea is "simple". Seemingly not much more complex than any other steam/heat power plant, so how do the costs run so high? Are the tolerances on everything turned to 11 to minimize chance of errors? Triple-checking all work?

As a point of comparison, the Large Hadron collider had a $9 billion budget, and that required a 27 kilometer circle to be dug.

[0] https://news.ycombinator.com/item?id=38515435

Network stability, night and bad weather hedging is a problem though with full solar/wind, isn't it? We still need a mix until tech is better to solve these problems.

> "I feel the same about the two big nuke projects in the UK (Hinkley Point C & Sizewell C). It makes no sense compared to solar/wind/battery."

Renewables are far cheaper, and can be built much more quickly. But there is an argument for (some) nuclear around energy security and diversification of supply. Batteries are great but can't really provide long-term storage (ie: multiple days/weeks). Do we want to rely solely on natural gas as a backup during the cold, calm, winter weather patterns which in some years can persist for weeks? Last year's energy crisis suggests maybe not. Or can we build enough interconnections and rely on imports from our neighbours?

Also worth considering that Hinkley Point C & Sizewell C are really only replacing existing nuclear plants that are shutting down. Even if both are built, the UK will still have only around half the nuclear capacity in the 2030s that we had in the 1990s.

Nuclear is the most clean energy that can be generated on-demand, solar and wind can only generate energy depending on the external conditions.

Batteries until today are not a viable solution.

When talking about the electrical grid you have to be able to generate energy in any amount whenever you want.

Regulation plays a significant role in cost overruns. Also we (should) expect the nuclear plants to work for at least a century while the panels and wind turbines last what, 5-15 years assuming no major storms damage them?

According to the NREL (National Renewable Energy Laboratory) in 2022 it cost approximately $1.06 per watt to install utility scale solar. So for the cost of the 1.1 GW Vogtle 4 reactor, utilities could have installed approximately 32 GW of utility scale solar. Obviously this is an extremely simplified and naive calculation that doesn't account for cost or availability of land, transmission infrastructure, battery or other energy storage, etc.

It gets really wild when trying to calculate the break-even point :)

> The one [solar] is useful all by itself

Not in a power-grid context; it'll over-volt the grid sometimes and under-volt it other times.

In the specific context of "understanding generation supply to a grid", working in terms of "load supplied by a system of solar & batteries" makes the math drastically simpler.

I think it's actually brilliant to include battery together with energy generation.

We know that when renewables become more than 20% of power generation, every GW of renewables you add should be matched by a similar order of magnitude of batteries.

So if we start reporting this way, you can immediately see if we're building enough energy storage or not.

If you wanted to make the amount of power actually produced comparable you could reduce the amount of reported GW of bother renewables and batteries by 50% so they add up to a realistic capacity number.

But capacity numbers are never really comparable anyway. Perhaps best to report raw numbers and assume readers are smart enough to understand that for every source you need to know the significance of what a "GW" means.

Like, a "GW" of a gas peaker plant does not mean much regarding how much energy it produces. That "GW" is actually much more comparable to battery energy storage "GW"

The question is whether such battery's charge/discharge cycle degrade faster than the return on investment.

For home use, break-even is an acceptable outcome, but not for commercial use like above. Is the price of battery low enough atm to make a return for such an investment?

This isn't really how batteries make money in the US right now, as I understand it. ~80% of battery revenue in ERCOT comes from what are called "ancillary services" [0] which is payment from the grid for being able to very quickly increase or decrease the amount of generation to ensure stability.

[0]: https://cimview.com/monthly-battery-revenue-in-ercot/

Last time I ran the numbers for this, price arbitrage alone using lithium batteries is not gonna be profitable.

Current lithium batteries are just too expensive, store too little energy and degrade too quickly for true grid-scale storage.

That’s why they typically offer services, other than price arbitrage, that actually makes building them make sense. There’s still no equivalent of a peaker plant using non-hydro storage.

Gemini took 2 years and cost $1.3B. Vogtle cost $34B for 2 units and took 12 years for those 2 units.

Edit: Gemini took 4 years from project submission and 2 years from construction start. Vogtle took 19 years from project submission and 12 years from construction start.

I agree that summing the two values to a GW seems disingenuous, but there are more scenarios than the two you described.

For instance, it's possible to discharge the battery during the day, as well. If peak load is in the afternoon, the plant could be charging the battery during the morning and mid-day when specific demand on that plant is less than 690 MW, then discharge the battery to have (temporary) output of 1 GW.

It seems like this thread has sparked a lot nuclear vs solar debate, but both have the potential to be net zero energy sources and most fault tolerant grids are powered by a multitude of sources. We should be aggressively building solar, wind, battery, and nuclear along with anything else that can reasonably be part of a net zero supply chain that produces electricity in the not too distant. They all have different tradeoffs and we shouldn’t be debating which is better than the other. Rather we should focus on what percent of each fit best balancing safety/resiliency/cost of adoption/long term operating costs. And this varies widely from region and changing over time. What’s need are formulas and frameworks for helping make these wildly complex decisions more straightforward.

And now look at number of solar and wind installed vs. nuclear. Take net numbers, as most nuclear capacity replaces decommissioned reactors in countries without a nuclear exit strategy.

I am too lazy too look up, and link, those publicly available numbers again....

Looking at a single plant isn't very interesting. Solar and wind are fundamentally more distributed so you're comparing apples to oranges. That distributed nature is both a good thing and a bad thing. Having just a few nuclear reactor go down at the same time in a single region can be problematic, as France recently experienced. Of course there are costs/upgrades associated with making large share of renewables viable at all, but those come with a more distributed and resilient solution.

If you want to compare impact on actual energy generation, look at the growth in total net numbers:

The largest rate that nuclear ever grew was around ~200TWh for some years in the 80s.

Solar grew by ~300TWh from 2021 to 2022. Wind grew by ~200TWh. And the growth rate is still increasing exponentially.

For reference the world population grew from ~5 to ~8billion from the 80s until now, if you want to take that into account when comparing the growth rates.

All the nuclear energy production plants in the world ever built have the same capacity as the amount of solar generation built just last year. So your comparison doesn’t make much sense, nuclear is dead in current energy market, it makes sense only for producing fissile material for nuclear bombs.

Presumably you can discharge the batteries while pv is also producing at full tilt.

But that'll rarely happen.

I absolutely hate the current state of energy reporting in general. The writers of these articles are not even trying to make sure they report accurately.

E.g. the battery stats: Is it MW or MWH? Both are very different and the distinction is important. A battery that can deliver 380MW but only for 10 mins is pretty useless.

In some scenarios the solar is only deployed because of batteries being deployed in the same network. The batteries are providing energy when the sun is down.

It seems that the thing they're measuring is the amount of instantaneous power that all the new "sources" could deliver at once, assuming they're able to deliver right then, and at max-output-power. In other words, it's an optimistic measure, but it's not meaningless.

From the purposes of grid operation, batteries serve both generating and load functions.

Having a complete catalog of generating capacity is a standard metric that EIA tracks. So even though batteries can also consume from the grid, it really does make sense to add them to the list of "generation," at least according to the purpose that this generation metric has always served.

It’s even a bit funnier than you put it since on net they consume electricity due to round trip efficiency losses.

This also can provide something of an interesting discussion with local authorities when trying to site a battery somewhere that has banned new “generating” technologies (typically targeted at wind and solar), since batteries are consuming electricity and can be likened to transmission infrastructure (or physical trade assets which I think some people are enjoying playing with).

Yes, absolutely, this compound effect is very important. Also interesting is that with every EV that gets added to the grid this effect improves even for the ones that can't deliver the power back later if it is economical to do so. They effectively serve as capacitors.

Thanks for the correction, "new" was accidentally dropped while trying to squeezed the original title into the allowed number of characters.

I saw that qualifier also. Does anyone know what percent of total capacity will be new next year (or better, what percent of total capacity will be solar next year)?

81% of *new* capacity planned for *this year*

Trends are often easier to understand from a rolling average or derivative.

Electricity might also seem fungible but even near optimal conditions a rule of thumb of 1% power lost per 100 miles (~160km) of distance. https://en.wikipedia.org/wiki/Electric_power_transmission#Lo... Thus the value of any installations should be rated by their distance to loads and load capacity under typical operating conditions. Solar is probably a good pair against AC units. Base load plants are still desirable.

Wind is strange, because there is more maintenance and more upfront cost, but the amount of energy you get from a windmill is enormous.

Panel and battery prices have come down such that transmission losses, natural disasters to farms, last mile power lines in storms, etc become bigger concerns comparatively.

I think the end-use solar and battery model makes more and more sense every year from a consumer perspective.

No. Transmission lines are too expensive, it's cheaper to put solar panels in non optimal locations.

https://caseyhandmer.wordpress.com/2020/12/27/the-future-of-...

https://www.spglobal.com/marketintelligence/en/news-insights... ("US Interconnection Queues Analysis 2023")

https://www.eia.gov/todayinenergy/detail.php?id=55960 ("Renewable generation surpassed coal and nuclear in the U.S. electric power sector in 2022")

https://pv-magazine-usa.com/2022/11/02/u-s-to-deploy-550-gw-... ("U.S. to deploy 550 GW of new renewables by 2030")

China deployed more solar last year than total US solar generation capacity, so while work, it can be done.

https://www.reuters.com/business/energy/chinas-installed-sol... ("The country built in excess of 216 gigawatts (GW) of solar power this year, the data indicated, underscoring the scale and pace of China's solar build out.")

Currently, the U.S. PV manufacturing industry has the capacity to produce PV modules to meet nearly a third of US domestic demand.

https://www.energy.gov/eere/solar/solar-manufacturing

I think wind dominates hydropower now

https://www.eia.gov/tools/faqs/faq.php?id=427&t=3

Say you don't understand exponential growth without saying you don't understand exponential growth.

The US has three separate grids: east, west, and Texas. Who are oddly separatist about their badly managed energy system.

Solar is the generating, batteries are the capacity

That's not the main use of grid batteries. The main use of batteries is 1) to soak up power that is otherwise not needed when there's too much of it. 2) to deliver that power back when there's too little of it. This is something that happens very often for typically short amount of times (hours). Batteries help smooth this out.

The mistake you are making is only thinking about when there's not enough power. The real challenge is dealing with the very regular situation that there's too much of it. That's energy that is wasted and lost.

Batteries improve the capacity factor of renewables (the percentage of time they are useful).

So, do electricity cables. Shortages and surpluses are highly localized. Germany for example has the problem that the demand is in the south and a lot of wind generation is in the north. So, they are curtailing wind power when there's too much wind and are firing up coal plants in the south because they lack the cables to get the power from where there is too much of it to where it is needed. When Texas had it's blackouts, other states had plenty of power. But Texas is not connected to those states by cables. So they had no way to get the power delivered. So, blackouts happened.

Long term storage is much less relevant currently and a market in it's infancy. The overwhelming majority of grid batteries is for dealing with short term dips and peaks in power generation. Most setups don't provide more than a few hours of power at best. But they can switch between charging and discharging in milliseconds and do both at high capacities.

This is why lithium ion is popular in this space. It can deliver or soak up a lot of power very quickly. You can put cells in series or in parallel depending on the use case. You add more cells to deliver more power more quickly. Not necessarily for longer. You can configure the same 1gwh of cells to deliver 100mw of power for 10 hours or 2gw for half an hour. Most of these batteries are configured for high capacity charging/discharging and relatively short storage.

There are some long term storage solutions emerging as well of course. Redux flow batteries are a good example where there's a fixed size cathode and anode and reservoirs of electrolyte that are pumped around. You can scale these by simply using larger reservoirs. They are cheap and can hold many days/weeks of power. Just add larger tanks. The caveat, is that the power delivery is a constant and typically low.

Looking through LCOE+[^1] and references to old reports[^2], it looks like solar used to be significantly cheaper, and wind a surprising dip in cost last 12-18 months. It's now on par if not less for onshore wind across the board. [^1]

[^1] https://www.lazard.com/research-insights/2023-levelized-cost....

[^2] https://www.quora.com/Which-is-more-expensive-to-build-wind-...

My knee jerk thought is that you have to work significantly harder to secure land for windmills. They have to be distributed such that you require huge tracts of land and/or to secure rights to install a tower on someone else's property. Each of those towers then need additional transmission lines.

While solar might generate less energy per unit area, it is at least condensed so that you could get away with buying a plot and fully exploit the area. You can add additional (unconnected) plots as cheap land becomes available.

I could also see the advantage that solar has quite limited opex after installation. A fleet of windmills may require significantly more resources to keep operating after years of service.

The US is a bit behind in catching up with the rest of the world on this front. There are some positive exceptions like Texas where they figured out quite early that it's cheaper to power refineries with renewables than with fossil fuel. So, Texas has a lot of solar and wind at this point. And why not, it's a sparsely populated state that is very suitable for tapping into both.

The complacency in the rest of the US of course has a lot to do with the fact that there's a very loud and active pro fossil fuel lobby that kept insisting coal was the future even while a lot of coal plants were going out of business. A lot of states invested in gas plants instead of wind generation because of that too. And now that renewables are clearly cheaper, a lot of those investments are starting to look pretty bad.

Not necessarily a problem; recall that the way economics works is the market will have marginal businesses that are on the verge of being unprofitable to run - so seeing some borderline cases is not troubling.

It looks like solar is finally becoming economic; so it is reasonable that the marginal producers right now will be solar farms. But assuming the price trends continue businesses will start to appear that make good money.

Although there does seem to be a serious risk to grid stability. Most of the energy emergencies in the last few years have been linked to areas that invested heavily in renewables.

Some important businesses are just terrible investments. Airlines come to mind; they always seem to be one minor downturn away from insolvency.

There is just no barrier to entry in the market.

You can get a small PV going for a few hundred bucks, and it scales more or less linear from that point on.

And cost to entry is reducing over time

By discharging energy when the grid operator calls for it, having charged when there was excess energy on the grid (typically what would’ve been wasted as curtailed renewables).

They form a voltage potential between their anode and cathode.