Solar installations up 2/3rds this year

 From PV Magazine

BloombergNEF has released its updated solar market outlook for 2023, projecting that 413 GW of module capacity will be installed this year. This capacity will mostly be driven by China’s contribution of 240 GW, along with strong growth in many other global regions.

The quarterly update was provided via Bloomberg’s podcast “Switched On” in the episode, “Solar supply glut crushes margins but buildout booming.”

From BNEF (listen to the podcast, it's fascinating):

It’s a good news, bad news situation for solar right now. On the one hand, annual installations are continuing to break records, with China set to build almost as much solar this year as the entire world rolled out in 2022. But on the other hand, the industry is suffering from a supply glut, weighing on the prices and margins of module makers.

The reason why the forecast doesn't show a continuation of the exponential growth in new installations since 2010 is the difficulty of integrating lots of solar into the grid:  electricity prices get driven down to zero on sunny days, but zoom as night approaches.   The solution is twofold:  first, require solar farms to have 4 hours of storage; and second, to encourage wind and also CSP (concentrated solar power), which has 12 hours of storage.  That still leaves rooftop solar, and in this case, it would make sense for governments to subsidise not the solar panels but to encourage attached behind-the-meter storage. 

It's worth pointing out that China's new solar this year is almost as much as the whole world's installations last year.

Australia's first commercial vanadium grid battery

From the ABC (Australian Broadcasting Corporation)

Australia's first commercial vanadium-flow battery has been completed in South Australia's mid north and is expected to be running and exporting power by August.

Yadlamalka Energy has been undertaking the Spencer Energy Project at Bungama, outside of Port Pirie, where the 2-megawatt/8MW-hour battery is connected to a grid of solar panels.

The battery will store around 10 gigawatts of dispatchable solar power each year and charge from excess electricity produced by the solar panels when the sun is at its peak.

The power will be delivered to households at night when the grid loads are high from demand and when no solar generation is available.

Yadlamalka Energy chairman Andrew Doman said this would also be the first commercial use of the battery in the Southern Hemisphere.

"This is a battery that has significant advantages over lithium-ion ones; the most important one is the duration of this battery is four hours, unlike lithium batteries which typically last half-an-hour or two hours," he said.

"Introducing vanadium batteries will reduce peak energy prices in Australia.

"When electricity prices are negative, we'll be buying the electricity and that will help stabilise the grid, and when prices are high, we'll be selling power into the grid — that margin will have the effect to reduce prices.

The vanadium-flow battery was invented at the University of New South Wales during the 1980s.

Mr Doman said vanadium was ethically sourced as it was more widely abundant in Australia than other critical minerals like copper, nickel and cobalt.

The vanadium is then converted into an electrolyte which holds the ions and stores the electricity inside the battery.

University of Adelaide associate professor Nesimi Ertugrul will be monitoring the battery's performance and said the main difference between vanadium and lithium batteries was that the electrolyte could be replaced in a vanadium battery.

"That replacement simply makes them last longer," he said.

"Companies claim different life cycles for lithium batteries, but those life spans depend on environmental conditions as well as operating patterns.

"Lithium batteries last five to 10 years and vanadium batteries claim to last up to 20 years."

Associate Professor Ertugrul said lithium batteries were better for mobile objects like vehicles whereas vanadium was better suited to stationary conditions.

The vanadium-flow batteries are also non-flammable and are almost completely recyclable.

This text below is taken from the company's website:

Yadlamalka Energy comprises of co-located Vanadium Flow battery energy storage (2MW – 8MWh AC) and Solar Photovoltaic (PV) farm (6MWp DC), integrated behind a DC-coupled inverter. We want to commercialise breakthrough technology to help meet Australia and the world’s future energy needs.

Our first project Spencer Energy is located near Bungama Sub-Station, Port Pirie, South Australia, an area with very favourable solar radiation.

Spencer Energy Project will supply a combination of solar power and battery storage services to the grid. The vanadium flow battery will take advantage of the significant intraday price variation in South Australia to time shift power from midday to peak periods in the evenings and mornings.

The Project will also participate in the Frequency Control Ancillary Services (FCAS) market which helps maintain stability of the electricity system.

Through using breakthrough technology in the form of vanadium flow batteries, Spencer Energy Project, can deliver strong, economic infrastructure benefit to South Australia and at the same time support a low carbon economy.

Vanadium flow batteries are fully containerised, non-flammable units reusable over semi-infinite cycles, able to discharge 100% of the stored energy and do not degrade. In the words of Barack Obama “They are the multi-mega watt energy solution” and “one of the coolest things” he has ever spoken about.

Vanadium flow batteries have significant advantages over lithium in longer duration time shifting applications. The batteries will be able to discharge at a power of 2MW per hour for four hours. They are suitable for heavy cycling because, unlike lithium, they do not degrade.

The plan is to fully charge and discharge the battery at least once a day and possibly twice, depending on pricing conditions.

Spencer Energy Project, will contribute to solving the distributed and intermittent energy problems that exist in South Australia, which are expected to intensify as renewable energy sources are relied on more and more.

Yadlamalka Energy will monitor and report on the progress and outcomes of the first project, with the aim to continue to expand across Australia using this innovative breakthrough technology.

Largest vanadium-flow battery in the southern hemisphere.
Source: RenewEconomy

 Port Pirie is about 200 k's north of Adelaide and 50 k's south of Port Augusta (where a concentrated solar power plant is being built)  It all looks very green because it's mid-winter here in Oz, and it's the rainy season in the southern half of the country.

Concentrated solar power revived?

Concentrated solar power (CSP) looked like a really useful addition to the renewable panoply 5 years ago. It worked by using mirrors to concentrate sunlight on a central tower. The intense concentration of sunshine heated salts to ±600 C, melting them. The molten salts could be used immediately to drive steam turbines to generate electricity, or they could be stored to be used later for the same purpose. This allowed CSP to deliver 24/7 electricity, just like baseload. Only cheaper and cleaner.

However .... the most famous CSP plant, at Crescent Dunes in Nevada, failed, primarily because the tank where the molten salts were stored kept on cracking. It looked as if CSP would never be a reality, which was a great pity, because CSP is a fantastic complement to other forms of renewables.  Solar plus 4 hours of storage is cheaper than CSP, solar plus 10 or 12 hours of storage isn't.  And CSP is cheaper than new coal and much cheaper than new nuclear, while able to deliver baseload power.

But (perhaps) CSP is going to be resuscitated. An Australian company, Vast Solar, has tweaked the basic concept of CSP.  They have a 1MW pilot plant up and running, and they're planning to open a 30MW plant within a couple of years, with plans to expand that to 150 MW if it's successful.

When SolarReserve proposed a 150 MW tower Concentrated Solar Power (CSP) power plant for Port Augusta [Australia], the firm was fresh off completing Crescent Dunes, the world’s first attempt at utility scale tower CSP with storage. The startup was unable to get funding to build the Port Augusta project, but it was fully developed: SolarReserve had secured state government approval to build 150 MW of CSP with 1100 MWh of thermal energy storage and 70 MW of PV.

But now; like SolarReserve’s other fully developed projects; Likana in Chile, and Redstone in South Africa, the Aurora project is under new ownership. Several years ago, 1414 Degrees purchased the project from SolarReserve and added a 140 MWh battery project. More recently, Australian CSP developer Vast Solar has purchased 50% of the project.

“Vast Solar’s long term plan is to build up to 150 MW of modular multi-tower CSP at the Port Augusta site, beginning with a 30 MW plant we expect to have online in 2025. What we intend to do afterwards is build a larger plant on the southern end of the site,” said CEO Craig Wood. That larger project would share site infrastructure, including the O&M team, the substation, some utility services and access roading.

The firm takes a novel (and award-winning) approach to tower technology that they believe can greatly increase the ultimate capacity of tower CSP. Instead of having a single tower with its solar heat fed by one solar field of heliostats, then running a steam turbine from heat stored in a co-located power block, Vast Solar will deploy multiple solar fields and towers that link together to make up a modular power plant.

In this technology, the solar field piping transfers heat to a shared grid-connected power block housing thermal storage and a steam turbine and generator. Though various approaches for multi-tower CSP have been researched, this will be the first commercial plant.

Wood spelled out the long term rationale; that a multi-tower approach enables the controllability and scalability of trough systems with the high temperatures and performance of central tower CSP. And allows for much larger CSP plants in the long run.

“Linking multiple solar arrays and tower receivers back to one central power block means you are able to build much larger plants,” he explained. “A CSP plant with a single central tower is ultimately limited to 100 to 150 MW.”

This is because as the size of the solar field increases, the mirrors at the outer edge which are typically a mile away from the receiver on the tower, deliver lower solar flux.

“So central tower CSP is limited in terms of the number of megawatt-hours of storage that it can have which ultimately means it is limited in terms of the cost down opportunity,” added Wood, who has both an engineering and finance background.
Nuclear inspires liquid sodium for heat transfer

Because Vast Solar intends its projects to be built in multiple units all connecting to one power block, it needs an effective heat transfer fluid that can be pumped from each tower to where it is stored and used in the power block.

The search for a fluid with excellent thermal conductivity – important in its heat transfer role but also in case something goes wrong and the fluid needs to be re-melted – led to Vast Solar pioneering an innovative heat transfer fluid for CSP, albeit one with decades of experience in the nuclear industry: liquid sodium.

“We went looking for something that would allow us to have that modular configuration in a very cost-effective way that also has high thermal conductivity,” Wood explained.

“Sodium boils at 883 C and solidifies at 97 C; so it has a wide operating range. In our system, with receiver outlet temperatures of up to 580 C, the sodium is just perfect in terms of the operating temperature range. We need a temperature range between 580 C in the receivers, and 300 C at the lowest, so this is right in the middle of what sodium can do while staying liquid.”

Another key benefit of using sodium as the heat transfer fluid from the receivers to the power block is that it, if something goes wrong and it freezes, it can readily be reheated to become liquid using heat tracing elements on the pipe.

“Once the sodium arrives back at the power block, we transfer that heat into thermal energy storage in a standard molten salt system and, when we need to, we use the heat from the salt to create steam to spin a turbine,” he said. So the heat is carried in liquid sodium, stored in molten salts, and finally used in the form of steam in a Rankine cycle turbine.

As did SolarReserve before them, Vast Solar has found that locals in this former coal plant town are very motivated, understanding that due to being a form of solar that has a thermal power block, CSP brings many of the same power station jobs back – but without the coal.

“Port Augusta is an interesting community with an industrial history, having previously been home to the two major coal fired power generators in South Australia,” Wood noted.

“So the locals understand the benefits of long-term well-paying jobs in a thermal power station like CSP. When the last of the coal-fired plants was announced for closure, the community organized a group called Repower Port Augusta to actively try to secure CSP for the town. People have figured out that PV and wind – while cheap – tend not to provide many jobs.”

Official support helps too, with the grid authorities actively trying to smooth the grid connection process. “The authorities have said to us that they’re pretty excited by the prospect of the steam turbine being installed in that location,” said Wood.

“As a thermal form of solar, CSP delivers its solar energy via a turbine. In the South Australian grid there is already a lot of intermittent renewable installed and, with more slated for installation, providing the ancillary services that turbines delivers is really attractive in that location.”

With energy delivery focused on morning and evening peaks, the CSP plant would have the high earning potential of batteries in Australia’s market-based grid, where prices can briefly shoot to a high price cap of $15,500 AUD.

“Regularly you’re seeing prices of upwards of $200 to $300 a megawatt-hour,” said Wood.

“There are definitely seasonal factors but also, particularly in South Australia, you’ve got a high volume of wind and a high degree of interconnection with the eastern states. If you get a coalition of circumstances such as not much wind and then an interconnector being constrained or down for maintenance, you do find extended periods of high prices.”

And here's an article about fixing the problem with the storage tanks:

A consortium has moved to patent a new tank design for the high temperature molten salt tanks used in thermal energy storage systems, like concentrating solar thermal power (CSP) projects.

Concentrated solar power systems use mirrors and receiving towers to gather and store the sun’s energy. The technology has had a disrupted history, from being hailed a great solution, to being wedged out by cheap solar PV combined with the finicky hindrances which detracted from CSP’s great advantage of dispatchability.

One of those finicky hindrances includes the molten storage systems’ hot tank, which had tended to leak because of thermal cycling and fatigue, resulting in substantial production losses for CSP projects.

Now, a consortium including Sydney-based Vast Solar, as well as CyD, Solar Dynamics, and Alia Energy Consulting and Critical Engineering, say they have jointly developed a tank design which addresses the issue, drawing on input from the Advanced Materials Team at the Australian Solar Thermal Research Institute (ASTRI), led by the Queensland University of Technology and Flinders University.

Dubbed the Flexitank, the consortium said it developed the new design by carefully analysing, understanding and learning from previous failures. The design increases the flexibility of the floor of the tank and mitigates the risk of failure associated with thermal cycles by absorbing the repeated expansion and contraction typically encountered in such tanks, the consortium outlined.

“Once we understood the tank failure modes and started testing the physical properties of the incumbent materials, we realised that flexibility is the key to overcoming thermal cycling and fatigue,” Vast Solar CEO, Craig Wood, said. “The economics of thermal storage are compelling, and we are delighted that our work will now deliver much needed reliability.”

“We are confident that the new design will substantially improve the operation performance of CSP systems moving forward,” Dominic Zaal, ASTRI Director, added. 

[Source of articles: Vast Solar's website] 

We'll see, won't we?  I was enthusiastic about CSP 5 years ago, and it all came to nothing.  These advances might yet bring it back from the dead, and it would be excellent for green electricity generation if Vast Solar succeeded.

Offshore wind could power the world

A sailing boat passes the Kentish Flats offshore windfarm. Photograph: Gareth Fuller/PA
Source: The Guardian

There are several carbon-free ways to generate electricity: hydro, onshore wind, offshore wind, solar PV (with either fixed or variable tilt), concentrated solar power (CSP), green methane and hydrogen (i.e., methane and hydrogen manufactured using wind and solar), biomass, nuclear fission (too expensive, too polluting) and nuclear fusion (not yet functional, except possibly for this).    The grid of the future will likely use all these methods, except for nuclear fission, because they complement each other.  The wind blows when the sub doesn't shine, offshore wind is less variable and stronger than onshore, CSP can deliver power 24/7, seasonal storage using green methane/hydrogen will cover week-long periods when wind and solar are low. 

From The Guardian:

Erecting wind turbines on the world’s best offshore sites could provide more than enough clean energy to meet global electricity demand, according to a report.

A detailed study of the world’s coastlines has found that offshore windfarms alone could provide more electricity than the world needs – even if they are only built in windy regions in shallow waters near the shore.

Analysis by the International Energy Agency (IEA) revealed that if windfarms were built across all useable sites which are no further than 60km (37 miles) off the coast, and where coastal waters are no deeper than 60 metres, they could generate 36,000 terawatt hours of renewable electricity a year. This would easily meeting the current global demand for electricity of 23,000 terawatt hours.

“Offshore wind currently provides just 0.3% of global power generation, but its potential is vast,” the IEA’s executive director, Fatih Birol, said.

The study predicts offshore wind generation will grow 15-fold to emerge as a $1tn (£780bn) industry in the next 20 years and will prove to be the next great energy revolution.

The IEA said earlier this week that global supplies of renewable electricity were growing faster than expected and could expand by 50% in the next five years, driven by a resurgence in solar energy. Offshore wind power would drive the world’s growth in clean power due to plummeting costs and new technological breakthroughs, including turbines close to the height of the Eiffel Tower and floating installations that can harness wind speeds further from the coast.

The next generation of floating turbines capable of operating further from the shore could generate enough energy to meet the world’s total electricity demand 11 times over in 2040, according to IEA estimates.

The report predicts that the EU’s offshore wind capacity will grow from almost 20 gigawatts today to nearly 130 gigawatts by 2040, and could reach 180 gigawatts with stronger climate commitments.

In China, the growth of offshore wind generation is likely to be even more rapid, the IEA said. Its offshore wind capacity is forecast to grow from 4 gigawatts to 110 gigawatts by 2040 or 170 gigawatts if it adopts tougher climate targets.

Birol said offshore wind would not only contribute to generating clean electricity, but could also offer a major opportunity in the production of hydrogen, which can be used instead of fossil fuel gas for heating and in heavy industry.

That this report comes from the IEA is telling.  It has in the past been far too conservative about the cost declines in renewables and about the rise in the penetration of renewables in the grid.  Good to see an analysis which is less favourable to fossil fuels.

There are no technological or financial impediments to de-carbonising our entire electricity grid.  The constraints now are political.

Chile to close 8 coal power stations

Tamarugal (Chile) CSP plant.  Source: Carbon Reduction Institute

From France24:

Chile announced Tuesday it would close eight coal-fired power stations over the next five years as part of a plan to switch entirely to renewable energy by 2040.

The closures, announced by Chile's conservative President Sebastian Pinera, account for 20 percent of the country's energy capacity, or 23,000 megawatts.

"The steps that we are announcing today are a concrete and real way of transforming words and commitments into facts and realities," Pinera said during a speech in the highly-polluted northern city of Tocopilla.

Chile, a net importer of energy, has relied increasingly on coal-powered electricity generation over the last decade, driven largely by the end of imports of natural gas from Argentina.
Imports were resumed last year under a new agreement with Buenos Aires, leading Chile to lessen its reliance on coal.

About 40 percent of Chile's electricity generation comes from 28 coal-fired power stations. The goal is to replace them all by 2040 and become fully carbon-neutral by 2050.

Pinera has pushed Chile's clean energy transformation drive first begun under his leftist predecessor Michelle Bachelet, favoring renewable sources of energy like wind, solar and geothermal stations.

The South American country will host the 25th UN Climate Change Conference, COP25, in December.

The shutdown of four coal-fired plants in Tocopilla -- as well as others in Iquique, Puchuncavi in the center, and in the southern city of Coronel -- will reduce annual Co2 emissions from the current 30 million tonnes (tons) to four million by 2024, the government said.

Once they are shut down, the plants will remain mothballed in a state of "operational reserve," ready to be called into service in an emergency at any time over the following five-year period, Pinera said.

Chile stepped in to host COP25 after Brazil withdrew following the election of far-right President Jair Bolsonaro, a notorious climate change skeptic.

Cutting out coal is one of the biggest steps we can take to cut emissions.  Even better if output from coal power stations is replaced with electricity from wind, solar and concentrated solar power.

Wild is the wind

The resource that could power the world.

A wind turbine blade at the Siemens Gamesa factory in Hull.  Source: The Guardian

A fascinating article from the Guardian:

The wind rips along the Humber estuary in Hull. It’s the kind that presses your coat to your back and pushes you on to your toes. “A bit too windy,” shouts Andy Sykes, before his words are swept away. He is the head of operational excellence at the Siemens Gamesa factory, which supplies blades – the bits that turn – to windfarms in the North Sea. At 75 metres long, they are hard to manoeuvre when it’s gusting.

Inside the vast factory hall, the blades lie in various states of undress. Several hundred layers of fibreglass and balsa wood are being tucked into giant moulds by hand. There are “naked” blades that require paint and whose bodies have the patina of polished tortoiseshell. Look through the hollow blades from the broadest part, and a pale green path, the tinge of fibreglass, snakes down the long tunnel, tapering to a small burst of daylight at its tip.

“Alice in Wonderland,” Sykes says. “That’s how I feel. That’s the emotion coming through. It’s 75 metres long. We know that. But stood here the perspective is just fantastic. It’s my favourite view.” Down this strange green rabbithole is a glimpse of a greener future, the possibility of a world powered by wind.

This is not as fanciful a vision as it once seemed. In the UK, the wind energy industry is celebrating. Last month, the cost of renewable energy dropped dramatically to undercut by almost half the government’s projections for 2025. At £57.50 (US$73) per megawatt-hour (MWh)[for offshore wind], it is far cheaper than the state-backed price of £92.50 awarded in 2016 to Hinkley nuclear power station. The speed of wind’s progress is extreme and inarguable.

The wind energy sector is certainly booming. Across the river from the Siemens Gamesa factory in Hull, in this long windy corridor of development on the east coast of the windiest country in Europe, there’s the Dong Energy hub, the screens of its operation room flickering with the data of wind captured by blades turning in the North Sea. Next month, the company will change its name – short for Danish Oil and Natural Gas – to Ørsted, after the celebrated Danish scientist who discovered that electric currents create magnetic fields, to reflect its near complete shift from black energy to green.

Dong was among the companies that achieved the landmark price of £57.50, and Emma Toulson, who works in their Grimsby office, explains how they did it.

Since the government ruled out new onshore windfarms in England – a promise in its 2015 manifesto – energy companies have been forced offshore, making the UK the world’s offshore leader. Allowed to develop beyond the vision of land-dwellers who see windfarms as a blot on the countryside, the turbines have grown steadily larger, as have the farms to which they belong. Dong’s Hornsea Project Two will span 480 sq km, and Toulson’s PowerPoint outlines a large jagged blue diamond for Project Three and an even larger blue rocket shape for Four.

Toulson has a slide that shows one very clear reason for the falling cost of wind energy. Over time, the diameter of the blades have enlarged. A turbine commissioned in 2002 swept 80 metres; in 2005, that figure rose to 90 metres; in 2011, it was 120 metres. By 2020, it will be 180 metres.

Of course, the supply chain has improved, and there have been engineering refinements. But put baldly, wind energy costs less, and will go on costing less, because the turbines are growing taller and the blades longer. The manufacturers of these machines are in a race to produce the largest.

And yet despite the size of its gargantuan machines, the offshore wind industry is still in its infancy. Wind turbines may look alike, but as Garrad points out, “we are a long way from a design consensus”. There are fixed turbines and floating turbines, which can access deeper seas, turbines with gears and turbines without. The sight of three blades harmoniously turning has become commonplace. But there is no reason why offshore turbines should look like this. They could operate with a single blade (ruled out on land because one blade, whirring faster, is noisy), or with two blades (ruled out on land because an optical illusion makes them appear to pause as they pass the tower, flummoxing passersby). Offshore, there would be only the gulls to offend, and the people who will live, in four-weekly shifts, on the new accommodation vessels that are being deployed to manage the farms’ growing distance from shore.

Ken Caldeira is one of the two Stanford climate scientists behind the idea of a North Atlantic windfarm the size of India. To understand the significance of his discovery, he says, it is important to know that when wind turbines are arrayed in rows, the extraction of wind by the first row reduces the amount of wind available for the second row, and so on. Row by row, the wind’s potential diminishes.

To counter this effect, turbines need to extract energy from the wind that’s above them. What Caldeira found was that that is exactly what can happen in parts of the North Atlantic, where heat “pours out of the ocean”, causing greater “cyclonic activity”. But could a farm the size of India really be built in open ocean? “You wouldn’t want to,” he says. Better to have many very large ones (China currently has the largest). A wind power station that size “would be a climate change in itself”. For one thing, “pulling that much energy out of the sky shifts the direction of wind”.

“The total amount of power in winds globally is something like 50 times bigger than the total amount of power used by human civilisation,” Caldeira reckons. “If we were to power civilisation by winds, we would need to capture about 2% of winds today,” he says

[Read more here]

Elon Musk has said that the whole USA could be powered by a 100 by 100 mile square somewhere in the south west of the country, and the battery storage to "firm" that would require just 1 square mile.  The USA covers 3.8 million square miles.  In other words,  only 0.26% of the US's land area would be used for solar panels.  And that doesn't even count rooftops!

Area needed to power the whole US by solar.  Source: Inverse

The moral is clear: we have more than enough wind and solar resources to run our economies.  Because solar requires more storage than wind and because wind and solar are complementary (for example, the wind is stronger in winter when the sun is weaker), a blended grid with both wind and solar is the cheapest option.  To that we'll add some battery storage, some pumped hydro, and some concentrated solar power (CSP), and perhaps, in high latitudes, power-to-gas.

Lazard's 2018 electricity costings

Lazard has just published its latest LCOEs for different kinds of electricity generation.  In the chart below I compare the different costings, with some additions of my own.  I have used Lazard's data for everything except:

1. CSP (concentrated solar power), where it seems to me that Lazard is using the US experience, where no new CSP plant has been built for a couple of years.  However, Solar Reserve has won tenders for CSP plants outside the US, and I've used those PPAs for costings of CSP.
2. I've estimated storage costs using $400/kWh total cost of battery pack, plus engineering inverter(transformer) and grid connection.  This is what Tesla's "big battery" cost in South Australia. For cars, the battery pack currently cost $170/kWh,  Tesla and Envision Energy expect battery pack prices to reach $100/kWh by 2020 and $50/kWh by 2025.  I'm assuming (conservatively) that the battery only lasts 10 years, whereas it does seem as if at least Tesla's batteries will last much longer.  At $400/kWh, one hour of storage will add $4.60 per MWh (delivered) to the generation cost of electricity.  (Lazard's estimates for the cost of storage  are twice as high--I can't get my head around that yet, so I'll go with the "big battery" costings.)  
3. Wind plus power-to-gas is my estimate of the costs of wind plus long-term storage via power-to-gas, as I discuss here, and assumes that gas peaking using synthetic natural gas is used for 10 weeks a year.  The cost of producing synthetic natural gas will fall as the percentage of renewables in the grid rises because of increased curtailment.  Running power-to-gas plants when there would otherwise be curtailment will reduce its cost.  

Notes:

1. Green represents renewables, red, fossil fuels/nuclear, green/red stripes=mixed
2. These are unsubsidised data, however Lazard excludes the social costs (externalities) of fossil fuels.
3. "1/3rd each" is my calculation, and is 1/3rd wind, 1/3rd solar, 1/3rd CSP 
4. "Wind/solar plus 10 hours of storage" are Lazard's data plus $45/MWh for li-ion battery storage
5. Coal (marginal cost) is the cost of operation, excludes depreciation, interest, debt repayments
6. Coal (new) includes marginal cost plus capital costs for newly-built power stations    
7. These data, excl. my estimates of CSP, are for the USA.
8. Gas is 60% more expensive outside the US, pushing it up to "wind plus storage" cost levels. 

The first thing to note is that the marginal cost of unsubsidised coal is still, on average, cheaper than solar and wind.  There is a tax credit of 30% in the US which changes that, and the calcs would also be different if even a low carbon tax of $10/tonne of CO2 emissions were levied.  That would add roughly $10/MWh to the cost of coal-powered electricity.  However, some wind and solar (before subsidy) is already cheaper than the the marginal costs of some coal, and as the costs of wind and solar continue to fall, eventually existing coal's marginal cost will exceed wind and solar.  In 5 years even the most costly solar will be cheaper than the lowest marginal cost coal power station. (This decline will be partially offset by the ending of the 30% tax credit.)

Also, the marginal costs of wind and solar are near zero.  Grid operators will use renewables whenever they can.  The calcs for coal's marginal cost assumes it's used 24/7.  If renewables price it out of the market for just a few hours a day, even though nominally the operating cost of coal is cheaper than renewables, it will in fact become uneconomic.  Coal power stations cannot be turned off and on again.  As renewables expand into the grid, this factor alone will make coal uneconomic.

The second thing to note is that apart from existing coal with its low marginal cost, all the cheapest power sources are renewables, except for baseload gas.  (Gas is more expensive outside the US, so that's only true in that country.) Even allowing for 10 hours of storage, which would allow renewables penetration of 90%, renewables are cheaper than coal.  And even if we use power-to-gas to provide back up for the last 10-15%, it will still be cheaper.  I've been conservative in my estimates of how much power-to-gas would be needed, assuming that backup gas peakers would be required when the wind doesn't blow for 10 weeks a year.  Remember that the costs of renewables/batteries/CSP will keep falling as we move along the learning curve.

This is good news for the climate.  As I argue here, the chances are that emissions will start to fall soon, as battery costs decline.

Baseload power era over

Traditionally, electricity has been generated by giant baseload power stations--most often coal, but also sometimes nuclear.  There was some limited ability to scale production up and down slowly, but at peak demand, baseload had to be supplemented by peaking gas generators or, conversely, when there wasn't enough demand (between midnight and 5 a.m., for example) generators had to be disconnected from the grid and the power "spilled".  That was why in the old days, heating your hot water cylinder after midnight was encouraged.  At least that way some of the surplus power was used.

When renewables came along, they added a new complexity to managing the grid.  Initially, grid operators were afraid that even 5% of generation from renewable resources would cause the grid to crash.  In fact, thanks to good forecasting (we have a pretty good idea of wind speeds tomorrow or the day after, hourly, though not minute by minute) and growing experience and expertise, countries with 20, 30 or even 50% renewables in the mix have managed to maintain grid stability.  It remains true, though, that getting renewables to 70, 80, or 90% will require "firming".  This is where the variable supply from renewables is moved closer to the supply from baseload, using gas or storage--hydro, pumped hydro, batteries, and molten salt storage associated with concentrated solar power (CSP).  Actually, "firming" is better than baseload, because demand fluctuates during the day, and while baseload struggles to deal with that, gas can produce and storage can release electricity when it is needed.

The critical component is cost.  If renewables are cheap enough, utilities have a strong incentive to use them, provided the cost of firming isn't too much.  Typically, to date, most firming has been accomplished using gas peaker plants, but already, batteries are getting cheap enough that they are starting to compete head to head with gas. 

[Australia’s] Origin Energy says the cost of wind and solar farms has fallen so far it is now cheaper than the marginal cost of coal generation, and the company is moving on from the concept of “24/7 base-load”.  The assessment was made by Greg Jarvis, the company’s head of energy trading and operations.

“I have been in this game for so long … the one thing I have seen is just the cost of renewables really change the game,” Jarvis says. “It is amazing what we have been seeing. Renewables are cheaper than the marginal cost of black coal at the moment. They are very cheap.”

Jarvis puts the cost of solar in the mid $40s/MWh and the cost of wind at the low $50s/MWh. That cost of solar is around half the average price of wholesale electricity in most states this year. And with the falling cost of storage – this is likely to enable “firm” renewables to emerge as a serious contender to existing fossil fuel plants.

Jarvis also made it clear that Origin Energy has moved on from thinking about new generation in terms of “base-load”, which stands in sharp contrast to current government thinking and the conservative commentariat. Asked if Origin Energy had moved beyond the idea – promoted by the federal government and many in mainstream media – that reliability depended on 24/7 base-load power, Jarvis said: “Oh, a long time ago. The idea of base-load power stations is well and truly gone.”

He cited Origin’s recent investment in its last coal fire generator Eraring, and its efforts to make it more flexible so it can power down in the middle of the day so Origin can focus on cheap renewables, before turning up the power at peak times.

[Read more here]

When Jarvis talks about "marginal cost" I think he means "operating cost", i.e., the cost of running the plant ignoring depreciation and debt repayments.  He may also be excluding maintenance and repairs.  Total long-run cost is higher than operating cost.  But if operating cost of coal is below the total cost of renewables, then it's hard to justify continuing to use coal, even on a fully depreciated power station, let alone a brand new one.  Notice how Origin is trying to reduce power output over midday, when electricity from solar panels is pouring into the grid, but not in the mornings and afternoons.  But this is only financially feasible with an already-built power coal-fired power station.  With a new one, you'd want to run it to as close as full capacity as you can so that the constructions costs and depreciation can be spread over as much output as possible. 

The costs of wind and solar (new wind and solar) Jarvis quotes are also significant.  A year ago, Origin quoted average costs for new solar/wind as A$67.5.  Now, solar is in the "mid-40s" and wind in the "low 50s"--an average of below $50/MWh, which means that costs have fallen another 25% over the last year.

I've updated Origin's original chart below--the blue dot shows where costs/prices are now:

To everybody except those still living inside their right-wing echo chamber, it's very obvious that coal's days are numbered.  Origin is only making Eraring (which is fully depreciated and paid off)  more flexible as a temporary measure.  In 5 years, batteries will be cheap enough to make even varying coal power station output by as much as Origin plans to do, too costly.  So even existing coal power stations will be shuttered.  An increasing level of renewables in the grid will drive down wholesales prices until coal is unprofitable.

This is a pattern being repeated round the world.  It does mean that any new coal power stations built are likely to be "stranded assets".  Once the operating cost of coal exceeds the cost of renewables, keeping even new coal power stations going will just mean that the owners are digging an ever deeper hole for themselves.

California -- zero emissions from electricity

Crescent Dunes, a thermal solar plant near Tonopah, is the world’s first utility-scale facility to feature advanced molten salt power tower energy storage capabilities. Source: The Las Vegas Sun

We've mentioned this here before.  California has set a target of zero emissions from electricity generation by 2045.  The new target is 60% from non-carbon sources by 2030, and 100% by 2045.

In a move to solidify California's role as a world leader on climate action, state lawmakers voted this week to shift their state—the world's fifth-largest economy—to 100 percent carbon-free electricity by 2045.

The legislation now heads to Gov. Jerry Brown for his signature. Brown hasn't commented on it but is widely expected to sign the legislation as one of the crowning environmental achievements of his administration, which ends in January. The renewable energy commitment also comes on the cusp of a Global Climate Action Summit that Brown is hosting in San Francisco beginning Sept.12.

In a summer when California has been fighting record wildfires while facing off against the Trump administration's attempts to rollback climate policies, the state's Democratic-controlled legislature sought to double down on its commitment to shift away from fossil fuels.

"After a grueling year it has finally passed," tweeted state Sen. Kevin de León, the Los Angeles Democrat who sponsored the measure. De León, who is challenging fellow Democrat Sen. Dianne Feinstein for her U.S. Senate seat in November, was in the Assembly chamber on Tuesday to help round up the final votes needed for passage. The Senate approved the amendments on Wednesday and sent the legislation to the governor.

"Our state will remain a climate change leader," de León said.

[Read more here]

This is actually quite a slow pace of transition.  Currently renewables provide 29% of California's electricity.  So to 2030, that's a transition of 2.6% per year, i.e., 2.6% of fossil fuel generation capacity will need to be retired and replaced with renewables.  From 2030 to 2045, it would be 2.7% a year.   Actually, it's even less than that, because of existing hydro-electric power.  But I'm being conservative and assuming hydro diminishes as global warming steadily dries out the SW of the USA.

How will California do this?

• More solar.  All new homes in buildings under 3 stories high will be required to have integral solar.  Plus, given California's solar resources, there will be more solar farms in California and across the border in Nevada
• More batteries.  Batteries are still too expensive for time-shifting, i.e., storing power from midday for the evening demand peak, but they are excellent for synthetic inertia, for stabilising the grid, and for providing some additional supply at peak demand times.  Falling battery costs will mean that the role of batteries will steadily increase.
• More concentrated solar power.  The Crescent Dunes CSP plant across the border in Nevada uses mirrors to focus sunlight to melt salts.  The stored heat is then used to drive turbines to provide power in the evening and at night.   The company which built the Crescent Dunes plant is planning one 10 times as large nearby.  The cost of CSP has halved over the last 5 years.
• Less nuclear.  The Diablo Canyon nuclear power plant is scheduled to close in 2025.  It produces about 9% of California's electricity.  
• Less gas.  This will be hard.  Gas is ideal for firming the variable generation from wind and solar.  Replacing it will require other forms of storage: batteries, pumped hydro, molten salts.  However, California may be the first place to use power-to-gas at a large scale.  That's where  surplus renewable energy is used to electrolyse water into hydrogen and oxygen, and the hydrogen, with CO2, is then passed over a catalyst at high pressure and temperature to produce methane, which can be burnt without adding to atmospheric CO2. 

Even while California is switching to a 100% green grid, its transport will also be transitioning to EVs.  By 2045, 100% of California's car, lorry and bus fleet is likely to be non ICE (internal combustion engine)

California has already cut its emissions even while growing strongly.  As it often has in the past, it will again be leading the world.

Life after coal

Port Augusta, South Australia (Source: Wikipedia)

From The Guardian:

The largest solar farm in the southern hemisphere lies on arid land at the foot of the Flinders Ranges, more than 300km north of Adelaide. If that sounds remote, it doesn’t do justice to how removed local residents feel from what currently qualifies as debate in Canberra.

As government MPs and national newspapers thundered over whether taxpayers should underwrite new coal-fired power, mauling advice from government agencies as they went, residents of South Australia’s Upper Spencer Gulf region have been left to ponder why decision-makers weren’t paying attention to what is happening in their backyard.

In mid 2016, this region was on the brink, hit by the closure and near collapse of coal and steel plants. Now it’s on the cusp of a wave of construction that investors and community leaders say should place the region at the vanguard of green innovation – not just in Australia but globally. There has been an explosion in investment, with $5bn spread over the next five years. There are 13 projects in various stages of development, with more than 3,000 construction and 200 ongoing jobs. The economy of this once-deflated region has been transformed and those who live here are starting to feel hopeful again.

The Port Augusta mayor, Sam Johnson, a 32-year-old former Liberal [in Oz, that means conservative] member, is continually surprised at how resistant some are to the idea that the energy environment has changed. “You might choose to ignore what’s happening here now because we’re out of sight, out of mind, but the reality is that what’s happening here is going to be happening on the eastern seaboard in the next 10 years,” he says.

In simple terms, the Upper Spencer Gulf transition story goes like this. Port Augusta was a coal town, home to the state’s only two lignite – or brown coal – plants, Playford B and Northern. Playford B, ageing and failing, was mothballed in 2012. Northern, the larger and younger of the two, closed in May 2016 when owner Alinta Energy decided it was no longer economically viable. The Leigh Creek mine that supplied it, by then offering up mostly low-quality coal, shut at the same time. About 400 workers at the plant and the mine lost their jobs. Roughly a third retired, a third found other employment locally and a third had to leave town to find work.

At the same time, further around the gulf, the steel town of Whyalla was teetering precipitously after the owner, Arrium, put the mill in voluntary administration facing debts of more than $4bn.

Two years on, the Port Augusta city council lists 13 projects at varying stages of development. And Whyalla has unearthed a potential saviour in British billionaire industrialist Sanjeev Gupta, who not only bought the steelworks but promised to expand it while also spending what will likely end up being $1.5bn in solar, hydro and batteries to make it viable.

Gupta says the logic behind his investment in solar and storage is simple: it’s now cheaper than coal.

If you have time, read the whole article.  The 13 projects include Australia's first concentrated solar power (CSP) plant, its first salt-water pumped-hydro storage system, a combined solar/wind/storage farm which will deliver baseload electricity, and the southern hemisphere's largest solar farm.  And by the way, all these projects will take South Australia's renewables as a per cent of its electricity demand to over 80%.  This will be the highest in the world for a region which has no hydro power.  Notice also in the table in the article that almost all the projects include storage of one kind of another, as you would expect with renewables penetration at this levels. 

The Labor Party in SA lost the last state election, and before the election, the Liberals [i.e., the conservatives] were very hostile to the energy transition that Labor had been pushing.  Now that they're in office, they have flipped, and are supporters of the shift.  They also support the construction of a a new high-voltage interconnector to NSW to sell SA's surplus power into the NSW electricity market, which is the largest in the country.

Concentrated solar power getting dirt cheap

Concentrated solar power (CSP) can produce power 24/7, just like a coal or nuclear power station.  It does this by heating molten salt to 1000 deg F (538 deg C) during the day when the sun is shining then using the molten salt to drive a turbine overnight when it's dark.  Its costs have fallen by 2/3rds over the last 4 years. CSP in sunny places is now cheaper than coal, produces no emissions or pollution, yet nevertheless provides base-load electricity. 

Source: Big Think

It's not 100% "firm", because prolonged cloudy weather will impact production, but then again, coal power stations often "trip" without warning.  The way the grid has always coped with this in the past is to have excess capacity, so that the loss of one generator can be offset by turning on another.  And the risk is reduced by having diversified supply sources.  For example, the wind often blows when the sun isn't shining, and it blows more in winter when sunlight is less.

Hinkley Point: Worse and Worse

Under an agreement between the Government and EDF Energy, ironed out in 2013, Hinkley is guaranteed to earn £92.50 for every megawatt-hour (MWh) of energy produced through a combination of wholesale market prices and a levy on consumer energy bills. 

At the time Government said this would require top-up payments totaling £6bn via energy bills to meet the "strike price", but falling market prices have widened the forecast gap every year since then. 

Two years ago the cost was estimated at £13bn before it spiralled to over £30bn under fresh analysis from the public spending watchdog last year. 

The latest forecasts have revealed that EDF’s bid to build the first new nuclear plant in a generation could cost energy bill payers £50bn over the life of the project, well above the £6bn bill estimated in 2013. 

[Read more here]

Nuclear is the only generating technology with a inverse or negative learning curve.  With every other technology, as installations rise, costs fall.  As you can see in the chart below, as cumulative nuclear installations have risen, so have costs (measured in constant 2004 dollars).  This is the opposite of what is happening with wind, solar, batteries and concentrated solar power (CSP), which are all falling precipitously in cost.  For example, in Germany solar has fallen from 40 Euro cents per kWh  in 2009-2011 to 5.9 cents/kWh now.

If I thought nuclear power would stop global warming, I would grit my teeth and support it.  But for the same cost we can get 2 or 3 or 4 times as much electricity from renewables, and we can get it more quickly.  The world could get to 50% renewables in 10 years, if we wanted to.  With nuclear, we might not even have started construction in 10 years.  Which is why, I suspect, hard and soft denialists are such enthusiastic supporters of nuclear.  Because it requires continued reliance on fossil fuels.

Source

See also:

How much does nuclear cost

Nuclear melt down

Nuclear Power

Renewables just keep on getting cheaper

(Source; click to enlarge)

In Mexico:

Twice in 2016 Mexico held two renewable power auctions that raised significant investor participation. 

The most recent, in September, saw 23 winning bids out of a pool of 57 to build renewable projects worth $4 billion for 2,871 megawatts of new capacity. More important, the average price at the auctions was US$33.47 per megawatt hour, (MWh) 30 percent less than prices from a previous auction in March. In the September auction, 54 percent of the supply was awarded to solar projects and 43 percent to wind farms. 

The March auction drew 69 prequalified bidders and awarded 18 projects with a total of 1,691 megawatts for solar and 394 for wind. The a average contract price was $47.60/MWh

(Source)

In Chile:

According to media reports, Mainstream Renewable Power Ltd. and Empresa Nacional de Electricidad/Chile SA won more than two-thirds of the electricity supply auction in Chile. 

Meanwhile, Solarpack set a new record-low solar bid at 2.91¢/kWh ($29.1/MWh). That beats the 2.99¢/kWh bid a Masdar Consortium provided for an 800 MW solar power project in Dubai earlier this year. 

Mainstream has won rights to supply 3.7 TWh of electricity every year (30% of the auctioned electricity), while Endesa, a subsidiary of Enel, will supply 4.9 TWh (40% of the auctioned electricity). There was a significant correction in tariff in this auction compared to previous one. The average tariff bid in the auction declined 40% to US$47.59 per MWh compared to the previous auction. 

To supply the contracted electricity Mainstream will develop 7 wind energy projects with a total capacity of 985 MW. To achieve this capacity, the company is expected to invest $1.65 billion over the next 5 years. Electricity generated from these projects will be sold at tariffs between $38.8 per MWh and $47.2 per MWh.

(Source)

In Abu Dhabi:

The United Arab Emirates has seen yet another record-breaking solar power tariff bid. Abu Dhabi received the lowest-ever bid for a solar PV project at a shocking 2.42¢/kWh, taking back the title of cheapest solar power project from Chile. 

Abu Dhabi Electricity and Water Authority received a total of 6 bids for the proposed 350 MW solar PV project planned to be built in the town of Swaihan, Abu Dhabi. Out of 6 bids, the lowest ever bid of 2.42¢/kWh has been submitted by the JinkoSolar–Marubeni consortium. The results of the tender are not out yet, as authorities will now evaluate the proposals for technical and economic viability. 

The current bid of 2.42¢/kWh is the lowest so far globally, and by quite a bit — it is shockingly low. This bid is 20% lower than the previous record bid of 2.91¢/kWh submitted at an auction in Chile last month. 

The second-lowest bid in the Abu Dhabi tender was reportedly not much higher, at 2.53¢/kWh, and was submitted by a local firm. These bids also beat the 2.99¢/kWh bid (shocking at the time … and still to some extent) submitted by a Masdar-led consortium for an 800 MW solar PV project in Dubai. 

The Abu Dhabi solar park was initially planned for 350 MW. However, media reports state a possible increase in project size, as bidders were allowed to bid for larger capacities. The final capacity of the solar power park may well increase to 1 GW.

(Source)


Some points:

• These, like South Africa, are mid-ranking developing countries.  Their electricity demand, contrasting with the situation in developed countries, is still growing.
• Solar costs have more than halved in two years.  More than halved.  In two years.
• These prices are already irresistibly cheap.  And they're going to get cheaper.  If electricity demand is expanding, the new generators built are not going to be coal-fired.  They're going to be wind and solar.  In developed countries, it's harder.  Even though renewables are cheaper than new coal, often much cheaper, existing coal power stations look cheap, because they're fully depreciated.  So the switch to renewables is constrained, though it is happening, especially where generation is highly competitive, for example in the USA.  The good news is that most of the coal generating fleet in developed countries is past its design life, and major refurbishment is not worth it.  New capacity (as it already is in the US) will be renewables plus gas, and coal-fired power stations will be progressively retired.
• This means that coal demand has peaked, and that emissions from burning coal have peaked too.  Coal is the biggest contributor to CO2 emissions.  It's very likely that within 20 years there will be no coal-fired power stations.  Anywhere.  And that's without a carbon tax.  Introduce a $30 per tonne carbon tax and coal generators are toast.
• It also means that despite Trump and his gang of climate-denying, oil- and coal-loving cabinet, despite the Republican cognitive dissonance about global warming, the renewables revolution is irreversible.  For a start, it's happening now in developing countries including China, not just rich developed countries.  Second, even in the USA, the switch to renewables is being driven not just by regulation, but by price.  And the states in the "wind corridor" might vote Republican but they're also very fond of their wind turbines and the cheap power they generate.
• These developing countries and the US are installing both wind and solar, even though solar is cheaper, because the two together minimise the storage needed.  For now, the variability of renewables supply will be compensated for by gas.  In future, storage (CSP and batteries) will take the place of gas peaking power plants.  So demand for natural gas prolly hasn't peaked.  Yet.
• The reverse auction (i.e., targeting the lowest not the highest price) is an extremely effective method to slash renewables costs. Are you listening Australia?  Germany?
• I keep on saying this, so I'm beginning to sound like a record (remember them?) with a scratch.  But there are now no technical nor economic reasons  why we cannot aggressively switch electricity generation to renewables.   Global temps are rising by 0.2 deg C per decade.  Even though global CO2 emissions have probably peaked, they're not falling fast enough. We need to stop making excuses, stop listening to the lies of the denialists, and move.

How much land for solar?

The latest rather feeble tactic I've seen from a denialist is to assert that we can't switch to renewables because they'd take up too much land.  It's nonsense of course.

From Ramez Naam

We’ll probably never power the world entirely on solar, but if we did, it would take a rather small fraction of the world’s land area: Less than 1 percent of the Earth’s land area to provide for current electricity needs.

The second to last column tells us that, weighted by how much electricity they actually produce, large solar PV facilities need 3.4 acres of total space (panels + buildings + roads + everything else) for each Gwh of electricity they produce. 

That leads to an output estimate of 0.294 Gwh / year / acre, and virtually the same total area, around 50,000 square kilometers in the US, or 0.6% of the continental US’s land area.   

[....] 

So, consider that: 

1. The built environment in the US (buildings, roads, parking lots, etc..) covered an estimated 83,337 square kilometers in 2009, or roughly 166% of the area estimated above. (Likely this area would not be as efficiently used, of course. But it could make a significant dent.) 

2. Idled cropland in the US, not currently being used, totaled 37.2 million acres in 2007, or roughly 150,000 square kilometers, roughly three times the area needed. 

3. “National Defense and Industrial” lands in the US (which includes military bases, department of energy facilities, and related, but NOT civilian factories, powerplants, coal mines, etc..) totaled 23 million acres in 2007, or roughly 93,000 square kilometers, nearly twice the area needed to meet US electricity demand via solar. Presumably much of that land is actively in use, but it gives a sense of the scale. 

4. Coal mines have disturbed an estimated 8.4 million acres of land in the US. That works out to around 34,000 square kilometers, not too far off for the estimate from solar, and doesn’t include the space for coal power plants. And coal currently produces around only 40% of US electricity and hasn’t been above 60% in decades. To scale coal to 100% of US electricity would have required far more land than is required to meet that same demand via solar. Other analysis says the same: Counting the size of coal mines and their output, solar has a smaller land footprint per unit of energy than coal. 

And the solar estimate of ~50,000 square kilometers, of course, is with solar systems already deployed. It doesn’t take into account the possibility of future systems with higher efficiencies that could reduce the land footprint needed.

Read more here.

It's a bit more complicated with wind farms.  According to this piece from NREL (doing for wind what this piece did for solar):

Excluding several outliers, the average value for the total project area was about 34 ± 22 hectares/MW, equal to a capacity density of 3.0 ± 1.7 MW/km2.

This implies an output of  about 3.1 GWh/acre/year from a wind farm.  But unlike solar farms, farming can continue on the ground even as the turbines turn overhead.  If you read the NREL article in full, you'll see the problems they had estimating actual land use, and their calcs are correct only if you assume the land can't be used for anything else.  This snippet from this article about UK wind farms says:

A standard wind farm of 20 turbines will extend over an area of about 1 square kilometre, but only 1% of the land is used for the turbines, electrical infrastructure and access roads. The rest of the land can be used for farming or natural habitat.

My guess is, if you allow for the fact that most of the land in a wind farm has two uses, once again, even if we were to get 100% of power from wind farms, it would still only take about the same as solar: under one percent of land area.

Moral of the story: no, we will not be constrained by the availability of land from switching to renewables.

CSP on steroids

The Crescent Dunes CSP facility, via PowerMag

CSP stands for 'concentrated solar power', with 'with storage' always understood.  In fact, the Ivanpah CSP plant, which is the biggest in the US, doesn't have storage, but the Crescent Dunes facility at Tonopah  in Nevada has 10 hours' worth.  You can read an excellent detailed article about the Crescent Dunes plant here.

On a normal day, Crescent Dunes begins generating power around 10 a.m., reaches full power around noon, and stays there until 10 p.m. to midnight per the terms of its PPA, which calls for 12 to 14 hours of generation a day. This helps NV Energy meet peak evening demand, and Crescent Dunes shuts down as that demand falls late at night. 

But that’s only what it’s contracted to do for the utility. The PPA, in fact, doesn’t exploit the plant’s full capabilities. By reducing its net output slightly, Crescent Dunes can actually operate 24 hours a day, banking excess thermal energy while the sun shines and using it to generate steam all night. As a proof of concept, SolarReserve ran the plant for a continuous 120-hour period during July. While doing so, it was able to maintain full power for most of the day, only ramping down to about 60% power during the early morning hours. 

SolarReserve has an array of new plants in various stages of development that will be less expensive and even more efficient than Crescent Dunes, Smith said. Two near-term examples will move substantially past what the company has achieved in Nevada. 

The 100-MW Redstone project in South Africa, which breaks ground this fall and will incorporate 12 hours of storage, should see about a 30% decrease in construction costs from Crescent Dunes, as well as reduced construction times. The 260-MW Copiapó project in Chile, with 14 hours of storage, plans to bid its power at under $70/MWh, without subsidies. That plant, using two solar towers and an additional 150 MW of PV generation, is being designed from the ground up to operate as a 24-hour-a-day baseload facility.

Other projects are in the works in China and Australia, Smith said. “We have an agreement with Shenhua, China’s largest coal generator, to build a 10-tower facility, and another agreement with State Grid Corp. to build another 10 towers, though they may not be all on the same site.” 

[Read more here]

SolarReserve is planning a new CSP plant in Nevada, which will be the largest solar plant in the world, more than 10 times larger than the Crescent Dunes one:

The race to build the world's largest solar power plant is heating up. California-based energy company SolarReserve announced plans for a massive concentrated solar power (CSP) plant in Nevada.   

SolarReserve CEO Kevin Smith told the Las Vegas Review-Journal that the $5 billion endeavor would generate between 1,500 and 2,000 megawatts of power, enough to power about 1 million homes. That amount of power is as much as a nuclear power plant, or the 2,000-megawatt Hoover Dam and far bigger than any other existing solar facility on Earth. 

SolarReserve's Sandstone project involves at least 100,000 mirrored heliostats that capture the sun's rays and concentrates it onto 10 towers equipped with a molten salt energy storage system. The molten salt, heated to more than 1,000 degrees, then boils water and creates a steam turbine that can drive generators 24/7. 

Compared to photovoltaic arrays, the appeal of CSP systems is that solar power can be used after sunset. 

"It's really the ability to provide renewable energy that's available on demand 24 hours a day," Smith told NPR. 

[Read more here]

This single plant will provide about 4.5% of California's peak electricity needs.

Note that the electricity from the first CSP plant, Crescent Dunes, was contracted at $US135/MWh, after subsidy, but that the Chile plant costs US$70/MWh, though that includes PV (photo-voltaic, i.e., solar) panels which would reduce the cost.  The big advantage of CSP over battery storage is that the CSp tanks containing the molten salts don't degrade over time as batteries do.

Lazard costs the cheapest CSP at US$119/MWh, and PV with battery at $92/MWh  (although I question their battery degradation rate of 1.5% per annum; I think that's way too low.  But they are more expert at this than I am).  The costs of both technologies  are falling fast, and I'm not sure which will win out in the end.  Probably we'll use both, PV plus batteries at homes and small businesses, CSP at utility level.  Whichever wins, in sunny places around the world there will be no technical or economic difficulty switching to 100% renewable electricity generation.

[P.S.  Some have expressed concern at birds who are killed flying through the concentrating beams.  The fewer birds incinerated, the better.   Fortunately, they've fixed that problem]