Solar capacity reaching up to 4.3 times peak load in sunny regions, and wind capacity of up to 2.1 times peak load in windy regions, would form the basis of a least-cost all-renewables resource mix in regions across the United States.
Those are the results of modeling by the energy firm Wartsila. The Finland-based firm used the Plexos resource planning model, together with technology cost projections for 2030 from Bloomberg New Energy Finance, to find the least-cost resource mix that would meet demand at all hours of the year.
Overbuilding enough renewable capacity to meet winter demand eliminates the need for seasonal storage. Overbuilding of solar implies substantial curtailment of solar generation during the summer, as shown in the image above, at the top of the hump.
“In all regions we have to overbuild solar and wind capacity, in many cases multiple times over the peak load,” explained Wartsila Power System Analyst Antti Räty. “This is purely the most economic option. Integrating a lot of flexibility into the systems allows us to take full potential of the installed renewables and keep the excess capacity to a minimum.”
Under the modeled resource plans, most Americans would get between 57% and 81% of their electricity from solar power, while wind power would provide up to 76% of electricity in windy regions.
Only four to ten days of multi-day storage capacity would be needed, depending on the region. That would require shifting only 3% to 7% of total generation to powering hydrolyzers, to produce hydrogen from water, and perhaps other technologies to produce a fuel from hydrogen. Fuel would be stored and later used to help meet electricity demand during stretches of the lowest solar and wind generation.
Substantial battery capacity would be needed in regions with the highest percentage of solar generation. In the Southeast, batteries would store up to 36% of annual generation for delivery after the sun goes down. In the windiest regions, battery capacity would be modest, shifting less than 10% of total generation.
A clean sheet
Wartsila’s modeling took a clean sheet approach, starting with only existing hydropower and geothermal units, and letting the model select the best mix of additional renewable and storage resources. Wartsila obtained data on hydropower and geothermal units from Lappeenranta University of Technology studies on 100% renewable energy systems.
If electricity demand were to increase without changing the load profile, the same proportions of each type of capacity would still be optimal, said Räty. The extent to which the load profile would change from electrification of transportation and heating was not evaluated. Electrified transportation may be able to provide flexibility to the system, Räty noted, as vehicle batteries may substitute for some grid batteries, and “smart charging could allocate more demand to times of high solar output.”
The modeling results will inform Wartsila’s consultative sales work, as “with our stakeholders and clients, we can together come up with solutions that will take into account what type of assets they should be investing in, and when,” said Saara Kujala, a Wartsila business development executive, in a company post.
Wartsila’s modeling results are available from an interactive map on a web page titled “Our Vision: 100% Renewable Energy.” Clicking on a region of a map brings up top-level results for the region, and then scrolling down provides further information.
Here are the optimal resource mixes selected by Wartsila’s modeling for U.S. states and regions, ranked by the percentage of solar generation:
Wartsila’s interactive map links to 145 countries and regions globally. In each one, “pivoting towards 100% renewable energy is possible” says a Warsila post.
Wartsila’s modeling corroborates the “overbuild/curtail” modeling results from Clean Power Research Senior Researcher Marc Perez and others.
Last fall, Vibrant Clean Energy modeled a low-carbon grid for Colorado in which electrification of transportation and heating allowed high levels of solar and wind on the grid, reducing costs for consumers.
Last winter, Mark Jacobson of Stanford and co-authors modeled a U.S. grid with electrified transportation and heating, powered by 2,000 GW of solar and 2,300 GW of wind, plus 3,300 GW of batteries and a large amount of flexible load. The modeled system yielded cost savings for consumers, largely from electrification of transportation and heating.
A Science journal article last summer examined rapid solar deployment, describing how to reach “a future with ~10 terawatts of PV by 2030 and 30 to 70 terawatts by 2050, providing a majority of global energy.”
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Seems that instead of curtailment of all that mid-day solar there would be incentives for EV charging, water heaters, maybe overcooling of houses and other load shifting.
The article says ” Overbuilding of solar implies substantial curtailment of solar generation during the summer, as shown in the image above, at the top of the hump.” . We have a Fresh water shortage and diverting any extra power to De-salinization plants allong our coasts durring the hot dry summers could not only give us more water, but provide incentives for more revenue in the overbuilding of renewables. You also have to remember that over the next 20 years, almost everybody will have at least one electric car in their garage to charge. people will do more driving and running of their air conditioners in the summer.
I have over built my off grid system 4 times my average usage to give me air conditioning and power electric heat instead of grid supplied natural gas and electricity for the furnace. How about a bypass on that gas water heater to and electric hot water heater durring the summer for the house and the pool?
Alameda County Water District has a De-sal plant but because of the high cost of electricity from PG&E limits it’s usage to low salt content ground water rather than pulling salty water from the bay. If summer time energy was less expensive, then they could do more de-salinization durring the summer months when water is at a premium. We could also use that extra power and water to pump back underground to replentish the aquifer.
Let’s devise a plan that our chosen outcome is done even though it doesn’t have a chance in hell of happening!! s
Wartsila is getting silly here thinking their quality equipment will be chosen for H2 generation if it even came. The best use would be in a H2CCGT vs 40 Wartsila diesels and 60% efficient vs 50% and 10k% more upkeep on the diesels.
What is missing is the behind the meter storage, generation by homes, buildings, EVs which in 15 yrs will be the biggest storage and on demand generation as 50% or more of them store, generate their own and more to sell on demand.
At that point it doesn’t really matter what the rest of the grid is as behind the meter will soak up cheap power and generate expensive on demand power, solving the grid balance problem without FFs, H2.
To use the summer daytime excess solar, we should shift from charging EVs at home at night to charging during the day at work. We need an incentive program to encourage offices to build out charging infrastructure. It would be a great extra benefit to offer employees free at-work charging.
Note that the reported costs of 100% renewable energy plans – including the “143 countries” plan by the Stanford group – rely on a cost of capital (WACC) of only 2% for green energy investments in order to arrive at their headline “cheaper than BAU” claims.
If a 2% cost of capital was made available for deploying nuclear energy technologies, a completely decarbonised global energy system would be much less difficult and much less costly to achieve. Nuclear energy technologies require only one thousandth of the land and less than one tenth of the raw materials that green technologies require, which makes nuclear energy inherently less costly for people and nature than other energy sources.
In order to successfully address global warming and the energy challenge, it’s necessary to draw a line between bona fide scientific analysis on the one hand, and commercial or ideological antinuclear propaganda on the other.
Wartsila’s web page says: “What cost of renewable energy has been used in the modelling? Technological development has dropped cost of solar panels, wind turbines and battery energy storage dramatically in recent years, and similar development is expected to continue. All technology options have been priced at their expected costs at year 2030. The levelized cost of solar or wind energy depends both on the investment cost of the technology as well as the weather conditions in any specific location. Even if a solar panel costs the same in Finland and California, the LCOE (levelized cost of electricity) will be lower in California as the sun shines more and the same amount of solar panels will produce more electricity. In the modelling, the LCOE of solar energy ranges from 29 EUR/MWh to 74 EUR/MWh depending on the region, and LCOE of wind energy ranges from 25 EUR/MWh to hundreds of euros per MWh in regions where wind speeds are very low.”
Also: “Why are existing nuclear plants not included in the energy mix? The modelling is focusing on showing the potential of renewable energy sources, mainly solar and wind power. These are already providing the cheapest new bulk energy in most parts of the world and will likely do so all around the world in the near future. Nuclear power is incapable of providing the flexibility to balance variations in solar and wind power. The duration of existing nuclear plants’ lifetime depends on many factors, including politics, so to be clear they have been excluded from this study.”
Are you sure the Wacc is 2% or is it the social discount rate?
In his paper, page 110, “Assumed annual rate of return in utility calculations (%/year)” is 10% for low cost and 12% for the high cost.
I have my own issues with Jacobson’s paper, but I think you may have misread his paper. Please correct me if I am wrong.
Nuclear can be safe and be part of the mix with other renewables if we use the same proticoles that our Navy uses on nuclear vessels. Corportations and governments cut corners for profit or lower costs and we end up with nuclear disasters in nuclear genertion when back up systems fail. I feel we can make Nuclear safe and it must be part of our national grid.
The actual costs of the new NPPs (Vogtle in the US and Okiluoto in Finland) have gone far overbudget – tens of Billions of dollars, plus years of delays. It’s not antinukers, it’s huge cost overruns and delays that are preventing investors from building new NPPs. NPPs are not capable of competing against renewables. The land for wind turbines is not a problem – Iowa is getting a huge amount of wind power from turbines located on farm land. Offshore turbines need no land at all. And now they are designing floating solar panels to put on lakes and they are more efficient because the water keeps them cooler. And the solar panels lower evaporation losses. Win-win!
Shashwat Adhikari writes: “Are you sure the Wacc is 2% or is it the social discount rate?
In his paper, page 110, “Assumed annual rate of return in utility calculations (%/year)” is 10% for low cost and 12% for the high cost.
I have my own issues with Jacobson’s paper, but I think you may have misread his paper. Please correct me if I am wrong.”
In his paper Jacobson writes:
“Social-cost analyses are performed from the perspective of society rather than from the perspective of an individual or firm in the market and hence must use a social discount rate rather than a private-individual discount rate, even for the private-market-cost portion of the total social cost. To maintain consistency with the fact that our analysis is a social-cost analysis, we therefore use a social discount rate of 2% (1%–3%) for estimates of all our costs, both private and external, and for both WWS and BAU energy (Note S37).”
Although Jacobson states here that he also grants a 2% WACC to his BAU reference plan, he does not, because his BAU reference does not (re)calculate BAU unit energy costs from the ground up to correspond to his low WACC, but instead he assumes “todays costs” and projects them forward.
Jacobson also assumes there is no increase in energy efficiency in his BAU reference, and no transition to nuclear energy that could solve climate and air pollution costs at least as well as his WWS scenario could. On his method of comparing costs, Jacobson writes:
“Third, most analyses look at the cost per unit energy rather than the aggregate energy cost per year. This problem is significant because a WWS system uses much less end-use energy than does a BAU system.”
What’s significant is that a lot of people are citing Jacobson’s work as supposedly proving that excluding nuclear energy reduces the cost and increases the speed of addressing global warming, but clearly, the opposite is true and Jacobson finds himself forced (again) to put several fingers on the balance in order to hide that fact.
J. van Dorp, MSc, Nice catch on the discount rate. It looks like he has changed his discount rates from the 2015 California WWS paper, where he used private discount rate (PDR). That being said, public financing in Euros is super cheap and could be a 1-3% depending on the tenor.
> What’s significant is that a lot of people are citing Jacobson’s work as supposedly proving that excluding nuclear energy reduces the cost and increases the speed of addressing global warming, but clearly, the opposite is true and Jacobson finds himself forced (again) to put several fingers on the balance in order to hide that fact.
Well, his whole argument is that we can solve the problem with Wind-Water-Solar, hence that is why he doesn’t look at nuclear.
I think the biggest issue is that policymakers are not adept at understanding the assumptions of this paper and try to rush regulations over it.
A key problem with Nuclear energy is that not all countries will be allowed to own/use it due to geopolitical issues. There are many countries that will be considered by the G7/G8 as dangerous thus preventing them from ownership of the projects or require foreign intervention in the usage.
Another example is India, where nuclear projects are still going up and there is a push from the international community to deregulate requirements.
I’ve been using photon excitation from the fusion reactor in our solar system for 15 years, just 93 million miles away. The question becomes not why aren’t we building more nuclear power plants or why we aren’t spending more money on ITER, but why “we” make it so hard? Propaganda? Really, REALLY?
If there was just this thing to allow solar PV to keep the lights on after the sun goes down, I would call that invention a battery. This battery would be used in a smart Energy Storage System. Oh, yeah, we have that too. So, why does it have to be so hard?
Czarnobyl and Fukushima
I’m not sure I see the sense in 4.3 X peak with solar or 2.1 X wind. I approached this differently in MISO, where the hourly generation from 17,225 MW’s of wind was available from 2017, to compare with the actual hourly load. I took the actual data and multiplied every hour of the year by various numbers to examine the fit with consumption. At 6.5 times the current mix MISO would see 50% of total electricity with 0.7% generation above consumption (available to be stored). At 9.5 times, generation by wind alone was 73.7% of consumption with 9.52% available to store. MISO didn’t have hourly generation data for a year from solar in 2017, and if anyone knows where a large grid resource is quantified hourly for a year with both wind and solar data I’d really like to know where it is (Ned.Ford@fuse.net).
We can reach a few easy conclusions from this analysis, which has the advantage of starting with known information so that the power available for storage can be parsed from that: Solar is obviously a desirable fit with wind. I’m aware that this may not be as good in other regions, but it is so incredibly good in MISO that I think we ought to temper the enthusiasm. We also need to understand that the target is not 100% renewable electricity, but abut 180% renewable electricity, since we need enough electricity to provide for all the non-electric fossil fuel uses, and the nuclear plants which age out and are too expensive to replace in kind, which I estimate will be 99% of them by 2050. Any lower fraction is gravy from a climate perspective.
Note this article from this week’s Science Magazine https://science.sciencemag.org/content/368/6491/566.2 which emphasizes the role of cheap renewable electricity in replacing fossil fuel chemicals and plastics with renewable chemicals made from air and water. It is a real wild guess as to whether we are going to need much storage at all, or if the best mix will be excess wind and generation using a large share of dispatchable load instead of storage.
I haven’t read the Wartsila paper yet, so I don’t know what they are assuming for future load, but my 180% is based on an accurate conversion for gasoline and diesel which is amazingly low. The conversion from gasoline to electricity captures a massive amount of efficiency, and the 40% of petroleum which presently becomes gasoline will be replaced with 12 to 20% of our current electricity generation. I assume similar efficiency for the conversion of furnaces to heat pumps, based on reported cost savings. That makes 180% an informed guess. I haven’t compared my numbers to peak demand in MISO, but I’ll see if I can do so. But my immediate conclusion is influenced by my knowledge that a balance of about 50:50 wind and solar is going to make the most sense in MISO, and probably most other places. We need to re-examine the value of onshore wind in light of current prices in places like Georgia and Florida. The current public data is 2009 vintage, and reflects costs more than double the current actual costs, and that makes a huge difference in what is economically prudent.
(A little aside to the nuclear fanatics: Compare the cost of Vogtle with 2% interest rates to the cost of wind and utility scale solar with any interest rate you think is reasonable in the same context, and tell me why you don’t think the Vogtle plant is already causing a surge in private solar construction, and won’t massively stimulate utility interest in wind and solar, including the Vogtle owners). We can build utility scale solar in Georgia with power output under 2 cents per KWh, and Vogtle won’t be able to recover its costs without interest for less than 18 cents per KWh, and forget a return on the investment).
Desalinization is just one of the many uses for dirt cheap renewable electricity. I don’t know how to rank them and I expect the market will do a dandy job of that. But I can’t see solar plus storage being cheaper than wind by itself just about anywhere, and solar plus storage must be cheaper than wind by itself to make it sensible to build much more than 50% solar.
Thank you for a thought-provoking article. This is some of what you provoked. The Science article is thrilling to me, because me and a couple of friends have been kicking these ideas around for several years without a clear sense of how widespread that sort of thinking has become.
BLUF: There won’t be big savings through electrification of transportation.
Like Ned, I’m also from Georgia. I’m on the outskirts of the Atlanta commuter bubble. I’m no expert in the field; just an interested layman. I didn’t follow the links to other articles. What stood out to me here was the repeated emphasis of customer savings through electrification of transportation, without much substantiation. I don’t see it. If this model were built out today, I would have to get in line to finance a Tesla to have solar electricity help reduce my transportation costs. As someone who only buys used cars for lots of reasons, I can tell you that they’re not in my price range, and won’t be for years to come. I can’t see financing $30,000 for four years to save $2,000 in gasoline per year.
I’m not arguing against the big picture. I’m just pointing out what seems to be missing or misrepresented, and how the macro trickles down to the micro. Americans have been trained since WW2 to be big commuters, and shocking amounts of lobbying dollars have been spent to keep it going. We’re not going to be redesigning many of our cities for people to use electric trains and buses anytime soon. When anyone can go down to the local used car lot and pick up a long-range BEV for under $10,000 is when we will really see transportation savings nationwide and beyond.
On the freight side, I think the revolution may be closer. Self-driving unmanned electric semis running cross country from terminal to terminal will soon be cheaper than human drivers. They could convoy two feet apart at 45 mph all night long without a hiccup and charge during the day on the excess. Making the far left interstate lane “Trucks Only” will speed up the legal and liability process, which is the real bottleneck. Human drivers could drive electric semis the last mile to the final destination, which is the hard part for computers. This gives many of the efficiencies of rail freight while keeping the flexibility of roads.
Patrick your observations are valid, encompassing the roll out of BEV needs two real things. More energy density for the weight of the battery module, so chemistries need to become lighter, longer lasting, cheaper to manufacture and more energy dense with charge/discharge cycles in the 20,000 range. The second, we really need to get a handle on distributed charging infrastructure and a national if not a World charging standard. The higher the D.C. buss voltage the less current necessary for the same power output and when using regenerative braking, the more harvest of motor regeneration back into the battery. At 800VDC one could fast charge at almost the same rate fueling an ICE vehicle has now. So, the BEV driving “experience” would be the same with pretty much the same operating schedule as an ICE vehicle. Most mini-mart gas stations have “commercial” power feeds that could feed several 800VDC fast charge stations. As the market is trying to find its momentum, used and wrecked BEVs become available on the aftermarket and are being used for many purposes. This is creating a secondary overhaul and retrofit of BEV technology to “classic” vehicles which is also bringing along the eCrate motor concept. This is where one buys an (eCrate) motor with the electric motor, inverter, mounts, adapters, wiring harness. Your decision is just how big of a battery pack do you need?
Patrick, please check the used prices for almost any mainstream EV other than a Tesla and I think you will be pleasantly surprised. Tesla is great but if you are budget-minded and not looking to impress your neighbors/coworkers than a used Bolt, Leaf, or similar will be much cheaper than the list price, partially because the tax credits applied to the original buyer factor into the used market as well.
If there will often be huge excess electricity, desalination!
Membranes also much better!
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