Solar capacity outpaces coal in China

 

Source: Our World in Data

From EuroNews

China's solar energy capacity has surpassed that of coal-fired power for the first time ever.

"As of the end of July this year, China's installed solar power capacity reached 1.286 billion kilowatts," China's National Energy Administration (NEA) said.

"For the first time, photovoltaic installed capacity surpassed coal-fired power, becoming the largest power source category in China," it added.

The country's coal-fired power installed capacity, the energy body said, stood at 1.285 billion kilowatts [1,285 GW — a typical coal power station is 1 to 2 GW]

Solar generation rose 15.5 per cent in the first seven months of 2026 compared to the same period last year to 802.4 billion kilowatt-hours, about one-eighth of the country's total, the NEA said in another statement.

China, the world's largest emitter of greenhouse gases that drive climate change, has pledged to peak carbon emissions by 2030 and achieve carbon neutrality by 2060.

The NEA said China's installed solar power capacity and power generation "have maintained a steady trend of rapid growth," with it playing an "increasingly prominent role" in guaranteeing electricity supply and driving the energy transition.

Coal has been China's key power generation source for decades and a key driver of planet-warming emissions.

But the country's coal-fired power generation fell by nearly two per cent in 2025, despite rising energy demand in the world's largest emitter, data reviewed by the AFP news agency showed in February.

It marked the first decline in six years, with some analysts saying it was the first time on record that coal generation dropped at the same time as power demand rose.

China has seen an explosive growth in its renewable installation, with coal's share in its energy mix edging down in recent years.The country installed a record 315 gigawatts of solar power and 119 gigawatts of wind power capacity last year, over 80 per cent of total newly installed power generation capacity, according to the China Electricity Council.

EU countries are trailing behind China when it comes to renewables, partly because China started their transition to clean energy much sooner. [This seems incorrect. China's solar capacity on 2000 was just 0.03 GW, compared with 0.2 GW in Europe and 0.59 GW in the US.  China's capacity only exceeded Europe's in 2017.]  As an example, in 2023 China installed between 180 and 230 gigawatts of solar, compared to 58 gigawatts in all European countries combined.

China's ownership of clean technology parts and patents makes a big difference to how quickly and cheaply they can install, as well as cheaper labour.

China's energy grid is also more efficient at handling energy from multiple sources, where as Europe's grid has been called "outdated". Hybridisation has been recommended as a solution.

Remember, this is capacity, not output.   Solar output is constrained, often curtailed by the grid operator, because of excess capacity in coal.  China is still building coal power stations, despite low capacity factors, and electricity utilities have quotas to use coal power in preference to solar and wind.  For China to significantly reduce emissions, it will have to rejig the electricity market.  When it does, emissions should plummet.

US LNG exports are booming

 An interesting video from the FT (Financial Times, of London) about the boom in LNG exports from the US, mostly to Europe to substitute for the losses of gas from Russia.  It explains the process of creating LNG from natural gas, and shows how the US is now the world's largest exporter, with further increases likely.

Is the world locking in gas?  Prolly not, or at least not in the quantities implied in the question.  A grid powered by wind and solar will still need gas for cold, gloomy, windless periods  ("Dunkelflaute").    In countries with enough hydro, gas may not be needed, but even then gas will be necessary as back-up.  Until power-to-gas, i.e., converting surplus electricity to methane, becomes widespread, we will still need natural gas.  Producing surplus green electricity will require overcapacity in wind and solar, and we are a long way away from that now.  But by 2030, the need to curtail renewable output will be frequent, and in order not to waste it, we'll use it to make synthetic natural gas via the Sabatier process.  At that point, natural gas production will start to fall, and its place in the grid will be replaced by SNG.

California reaches record renewable output

 From IEEFA

California's solar and wind farms generated record volumes of renewable energy in the first half of 2022, producing at times more carbon-free electricity than the world's fifth-largest economy could consume.

Cutbacks [curtailments] of available wind and solar output on the California ISO transmission network, covering most of the Golden State and a sliver of Nevada, surged 79% in the first six months of the year to a record 2,063 GWh [2.1 TWh], according to an S&P Global Commodity Insights analysis of grid operator data.

The nearly 2.1 TWh of wind and solar curtailments in this year's first half, compared with roughly 1.2 TWh in the first half of 2021, mark a return to fast-expanding periodic excesses of CAISO-connected renewable energy after tighter market conditions in 2021 interrupted their rapid growth in 2020 and 2019.

The six-month total was 30% more than the prior annual high of 1,587 GWh curtailed in 2020. The first-half volume of idled renewable energy was also more than the combined net output of California's single largest solar and wind farms in 2021, according to S&P Market Intelligence data. Berkshire Hathaway Energy's 586-MW Topaz Solar Farm in San Luis Obispo County, Calif., and Pattern Energy Group Inc.'s 265-MW Ocotillo Wind Energy Facility in Imperial County, Calif., together generated about 1,740 GWh last year.

[Garrett Hering]

What could California do with its excess renewable electricity?  

1. Sell it to neighbouring states.  But their economies and populations are much smaller than California's.  The largest relatively close market is Texas, but for political reasons, Texas refuses connection to the US grid.
2. Store it using batteries.  California's battery banks are growing fast, but not fast enough to absorb this quantity of electricity.
3. Use it to make green hydrogen which can then be exported to other countries, either as Hydrogen, or, more effectively as methane or ammonia.
4. Live with curtailment.  Renewables are so cheap that we can afford excess capacity.

Terra-Gen’s 560MWh Valley Center Battery Storage Project, San Diego, California, which came online last month. Image: Terra-Gen.
Source: Battery storage load shifting up to 6GWh a day on CAISO grid

Solar more than coal for the first time

 If only for a short time.

From RenewEconomy

The combined output of rooftop solar and large scale solar farms exceeded that of brown and black coal generation for the first time in Australia’s main grid on Sunday.

According to energy analyst Simon Holmes a Court, quoting the OpenNEM data feed he helped establish, solar exceeded the output of coal at 12.35pm on Sunday, delivering a combined 9,427MW, or 41.2 per cent of demand, compared to coal’s combined 9,315MW, a combined 41.1 per cent.

It’s a significant landmark, reinforcing the scale and pace of the energy transition that has forced Australia’s two biggest utilities – AGL and Origin – to all but abandon the concept of coal generation as necessary “baseload” as they seek to adapt their legacy business models to wind, solar and storage technologies.

It wasn’t the only record to fall on Sunday, with fellow analyst Dylan McConnell, from the Climate and Energy College in Melbourne, noting that the output of coal had fallen to a record low, just as “instantaneous” renewable energy hit a new high of 56.2 per cent.

This was above the 56.1 per cent high set in April this year, but it was quickly eclipsed as the share of renewables hit a peak of 57.1 per cent of demand at 12.35pm. Wind was providing 13.2 per cent of demand at that time, and hydro 2.2 per cent.

Needless to say, prices fell across the board and all states had negative pricing events, particularly in South Australia, which is still constrained by the limits of transmission links to Victoria.

Wind and solar were providing around 100 per cent of all local demand in South Australia for much of the daylight hours, even though all its large scale solar farms – about 330MW of capacity at Bungala and Tailem Bend – and several wind farms turned themselves off to dodge the negative pricing events.

Another data logger, NEMLog, noted that the share of variable renewables, wind and solar, reached a record 54 per cent, which would have been 70 per cent were it not for curtailment (mostly due to dodging negative prices).

Negative prices also ruled for most of the day in Victoria where wind and solar provided for more than 60 per cent during the daylight hours, including a peak of more than 73 per cent in the early afternoon, also a record.

Indeed, NEMlog noted that without curtailment in Victoria, the share of wind and solar would have met 102 per cent of state demand, up from the record 99.1 per cent reached last week.

The obvious solution to the coal power stations' solar troubles is for them to put in battery storage, which would prevent them having to endure negative wholesale prices.  When prices are negative, they would shunt their output into the batteries, and sell the stored electricity when prices are high. 

Peak emissions closer than you think

Michael Liebreich is the doyen of energy change analysts.  He founded New Energy Finance which was bought by Bloomberg to become BNEF.  

I've taken extracts from this piece published on BNEF's blog.  (The emphases are mine)  If you don't want to read the whole piece, see my summary at the end.

I believe the new decade will see us hit peak energy-related greenhouse gas emissions and start to see a modest but meaningful decline. Just to be clear, we will not see the sort of decline demanded by the Intergovernmental Panel on Climate Change – a 20% cut by 2030 to keep temperature rises to 2C, a 45% cut to remain under 1.5C – but I would guess at a drop of around 5%.

Clearly that is not enough to put us fully on track to avoid appalling climate change impacts, and by 2030 we will have to admit 1.5C is out of reach. But it will be a game-changer: it will demonstrate to even the most pessimistic that we can bend the arc; it will end the feeling of helplessness and impending doom that has taken over our public discourse; and it will set us up for much more decisive reductions in the subsequent decades.

Optimism, therefore, but not without limits. It’s hard to be an unbridled optimist. Over the past decade, global emissions have risen by 15%. For one brief three-year period, between 2013 and 2016, they were flat – for the first time ever outside major recessions – but in 2017 they took off again, as the global economy boomed and China reverted to pumping cheap money into high-carbon infrastructure and building. Since then, emissions have been growing by around 1.2% per year.

[But,] while emissions grew 15% over the past decade, the global economy grew by 45%. On average, economic growth outstripped emissions growth by 2.4 percentage points per year.  [I.e, energy intensity fell by 2.4% p.a.] If that gap can be made to increase by just 1.4 percentage points, emissions peak, even in a growing economy. Increase it beyond that and we are over the hump: emissions will start to fall. Impossible pipe dream? Or something we will see in the course of the next decade?

First of all, the maths.  In 2017, a report by the World Resources Institute (WRI) showed that there were 49 countries, representing 36% of global emissions, which have already passed peak emissions [even though they have growing economies]. Almost the whole of the OECD is reducing its carbon footprint, even when you adjust for imports (something the ‘degrowth’ brigade pretend is impossible). The WRI expects a further eight countries, representing another 23% of emissions, to peak within the next decade.

Last week, in Paris, I attended the first meeting of the International Energy Agency’s Global Commission for Urgent Action on Energy Efficiency, of which I am a member. The Commission’s goal is to raise the rate of improvement in global energy intensity from its current 1.5% to 3% per year.

I have three main takeaways from the meeting: 1) energy efficiency is finally gaining recognition as a national priority in many countries, whether for climate or energy security reasons; 2) there is as much ‘low-hanging fruit’ today as there ever was; 3) there is a far better understanding of how to deliver improvements than a decade ago.

As we close out the decade, BNEF has concluded that around two-thirds of the world’s population now live in countries in which wind or solar are the lowest-cost ways of generating power. The world records for low-cost wind and solar are both now down to around $17/MWh. That is around a third of the cost of new gas-powered generation – even in the U.S., where there is a glut of cheap gas.  [Averages are of course higher, for both renewables and coal]

By 2030, I have no doubt whatsoever that the world record for low-cost onshore wind and solar will be below $10/MWh. It will probably be set in China, Morocco, Mexico or the Gulf states, who have been vying for leadership for the past decade. However, there is a chance it could be in India, Brazil, the U.S. or even Australia.

As we approach the final days of 2019, wind and solar are generating around 8.5% of global electricity. BNEF estimates that figure will be nearer 25% by 2030.

The biggest unanswered question, as renewable penetration grows, is whether the cost of managing intermittency will drop – with cheaper storage, growing demand-response capacity, business model innovation and smart policy design – as claimed by fans of renewables – or soar, as claimed by their opponents.
It’s a vital question, which will decide whether wind and solar can maintain their historical growth rates, or whether their penetration must soon saturate. All the main energy models are designed around the idea of renewable energy saturation: growth rates decelerating into the future – whether abruptly or slowly, but always markedly decelerating. The IEA’s central scenario, Stated Policies or SPS, has the combination of wind and solar reaching only 24% by 2040. BNEF’s NEO model, always more bullish, shows them at 39% in 2040 and 48% by 2050.

What if these models are wrong? What if learning, innovation and the co-evolution of demand-side industries continue to win the race against the physics of intermittency, and allow historical growth rates to continue for a few more decades?

Two decades ago everyone assumed that the cost of managing intermittency would soar after the first 5% of wind and solar entered the power mix; a decade ago we thought the inflection was 20%; now we know it is not this side of 40%. Modelling exercises around the world suggest that it is not until you reach 80% or more in any decently-connected grid that the cost of managing intermittency really starts to go vertical.  [But of course, by the time we get to 80% renewables, (a) storage costs will be much lower, and (b) overcapacity will be much cheaper]

To believe in a renewable energy singularity, the first thing to do is to extract all the latent flexibility in our current power systems, and then build more, in the form of power storage, demand response, long-distance interconnections and linkages with transport and heat. We’ll see a lot of that in the coming decade.

The second thing we need to do is learn to love overcapacity. As I said in a keynote in 2014, in a high-renewables system, overcapacity is not a bug, it’s a feature.

The average capacity factor of the world’s hydro plants is 42%; gas peaking plants 15%. Even so-called baseload coal plants run on average only 54% of the time. If technology is cheap, and demand or supply are intermittent, we overbuild. Wind and solar are no different.

Will we build many weeks’ worth of power storage, or hydrogen electrolysis, just to capture peak renewable electricity that would otherwise go to waste? In a word, no, because curtailment will be cheaper. Think about it: if your $20/MWh wind or solar suffers 33% curtailment, you know what happens? It turns into $30/MWh wind or solar – still half the price of power from any other source.

The third thing you would need to see if you want wind and solar to sustain their current growth rates is significant electrification of transport, (which I don’t think anyone doubts is on the cards – Daimler Benz clearly things so, for the first time in 135 years it is not working on the next generation of internal combustion engine) and heating (which, with global heat pump sales growing at 12% per year for the last decade, might finally be kicking off).

The fourth thing would be the electrification of industry and the generation of green fuels, be they hydrogen, ammonia or liquid fuels like methanol. It is hard to believe it was just 18 months ago that I wrote about this in Beyond Three Thirds: The Road to Deep Decarbonization, because there has been so much progress since.

BNEF’s seminal work on the cost of electrolysis suggests that green hydrogen (based on renewable power) will start to be competitive with brown hydrogen (from steam methane reforming of natural gas with no carbon capture) by 2030, and that by 2050 it will have a clear advantage. That means that, even in the absence of a carbon price, green hydrogen has the chance to eliminate the 5% of global emissions that currently result from fertilizer production and oil refining. A $20 carbon price would see it eat into the 2.2% of emissions from the global shipping industry. A $50 carbon price pushes green hydrogen into the 13% of industrial emissions from steel and concrete; and a $100 carbon price would take it into space heating, glass and other sectors. So the combination of cheap green hydrogen and a $100 carbon price will create an addressable market by 2050 of nearly 30% of global emissions. Neat.

Let’s talk about the fifth driver of a potential renewable singularity: batteries. By 2030, EV batteries will cost around $65/kWh at the pack level. [Assuming a compound 15% p.a. decline, $65/kWh will be reached in 2024] That’s $6,500 for the battery in a full-sized vehicle with a range of 300 miles; $13,000 gets you a 600-mile range – certainly bigger range than my bladder can handle. [And the batteries in small 'city cars' with 40 kWh will cost just $2600] 

All the pinch-points in the mineral supply chain will have been long ironed out, and by 2030, all end-of-life batteries will be recycled – if there are any.

Yes, you read that right. Solid-state batteries may or may not have hit the market, delivering four-times the energy density, and launching swarms of electric planes. But there will certainly have been continued progress in lithium-ion technology towards the “million-mile EV battery”, which can deliver 10,000 charge cycles. It will make possible either cars with 50-year lives, ubiquitous vehicle-to-grid business models, or second-use applications at scale – or all three. Mindblowing.

Oh, and by 2030, you will not even remember about range anxiety – the same way you don’t remember that there were once insufficient modems to connect to the internet, or insufficient bandwidth for online video. 

Those who doubt the value of renewable energy in addressing climate change always point to negligible impact so far. Even at 8.5% penetration into power demand – and after investment of $2.7 trillion – wind and solar have only reduced global emissions by only around 2.5% from where they would otherwise have been. They have so far failed to absorb growth in energy demand.

That is to miss the point. As leading energy economist Professor Michael Grubb has pointed out in Conditional Optimism: Perspectives on Deep Decarbonisation, the key clean technologies are growing according to the dynamics of logistic curves, penetrating into incumbent technologies. Professor Grubb uses lots of fancy economics to forecast what might happen next. I’ll paraphrase: in a logistic curve penetration, the first 1% takes forever; from 1% to 5% is like waiting for a sneeze –it is going to be explosive, you just don’t know when it will happen; 5% to 50% happens much faster than you think – that is when the restructurings and bankruptcies happen.

No single “sneeze” will wipe out fossil fuel use across energy and transport; It will occur sector by sector, country by country. Over the past six years, LED light-bulbs have gone from less than 5% global market share to over 40%; coal power in the U.K. from 40% to a couple of percent; plug-in vehicles in Norway from less than 5% to over 50%. In each case, there was a slow start, an agonizing wait, and then the sneeze. Bless you!

What does all this mean for coal consumption? According to Global Energy Monitor (formerly Coalswarm), in the final 2.5 years of this decade, global coal capacity grew by an average of 56GW or 2.8% per year – which hardly looks like a harbinger of peak emissions.

India and China alone have between them a pipeline of 280GW of new plants, bigger than the entire current U.S. fleet and equivalent to 15% of current global capacity. However, this does not begin to tell the full story.

First, what really matters is not capacity, but how much coal is actually burned. Over the past decade, capacity factors for thermal generation have been falling around the world, in China’s case to record lows. Globally – not that you would know it from the mainstream news – coal consumption in the power sector has been flat since 2012; preliminary figures for 2019 show a drop of around 3%.

Just this month it was announced that over half of the power plants operated by China’s Big Five state-owned utilities are running at a loss. The government has plans for up to one third of them to shut by 2021, removing 15% of the country’s coal capacity. As for India, despite its 85GW pipeline, on average it has commissioned less than 10GW per year for the past three years. This September, Prime Minister Narendra Modi announced a push for 450GW of zero-carbon generation by 2030.

In the EU, eight out of 28 countries have already committed to phasing out coal by 2030; it will be entirely gone in the U.K. by 2025.  Germany, having prioritized the closure of nuclear over coal to date, will be off coal by 2038. The EU’s Green Deal, announced last week by new President Ursula von der Leyen, included 35 billion euros of support for Poland and other countries to get off coal.

In the U.S., despite promises to end the so-called “war on coal”, more coal capacity has been shuttered under President Trump’s first term than during any three years of the Obama administration.  Every publicly-quoted coal company has gone through Chapter 11 since 2016, as has privately-owned Murray Energy, whose CEO, Robert Murray, wrote the blueprint for the president’s energy policy. Not one new coal plant has been built since 2015. None are being built today, and it looks like none ever will be again.

Of course, coal is used outside the electricity sector, notably in heating and industry. That source of demand looks likely to carry on increasing for a few years at least.

Before 2000, the orthodox view of oil demand (and energy analysts always default to orthodoxy) was that by 2030 it would grow to around 130 million barrels. By 2000, oil demand was still expected to grow forever, but it would reach only 120 million barrels by 2030. By 2010, the accepted wisdom was still endless growth, but only 105 million barrels of demand by 2030. See the pattern? Oil demand growth consistently undershooting the growth predicted by experts.

At no point did it cross the experts’ minds that maybe the same trends that they kept missing would see oil demand peak, and then start to fall. When I first suggested it in 2015, it felt like a transgressive act.

Today, there is not an oil company in the world that is not talking about peak demand. Even Saudi Aramco’s recent IPO prospectus predicted “a levelling-off around 2035”. BNEF expects demand from light and heavy vehicles to peak in 2030; this is one of the rare times I depart (slightly) from its view. I see peak road transport demand around 2025; add in the growing areas of air transport, shipping and petrochemicals, and I think we’ll see peak oil this side of 2030.

So far, you will notice I have barely mentioned policy. The picture I have painted is a bit like the IEA’s Stated Policies Scenario: these trends, which should see emissions from fossil fuels peak by 2030, are what I see happening even in the absence of significant further policy in favor of climate action.

But, of course, there will be further climate policy – and lots of it.

In the U.K., the new Johnson government is committed to achieving net zero by 2050. At this September’s Climate Action Summit in New York, 77 other countries, 10 regions and over 100 cities announced their intention to follow the U.K.’s lead. As I write this, the EU has just unveiled its Green Deal, which is going to enshrine a 2050 net zero target in law, as well as a plan to reduce greenhouse gases by “at least 50% and towards 55% by 2030, in a responsible way”.

In Canada, Justin Trudeau hung on to government, albeit not his parliamentary majority, in this year’s General Election. The country is therefore the first to implement the sort of tax-and-dividend scheme that could be a model for carbon pricing in political economies where new taxes are all but impossible to impose.

In the U.S., climate is a key battleground for the Democratic Party Primary, but what is more interesting is that Republicans with an eye on political life after President Trump are finally conceding they too need a climate policy.

Even the international climate negotiations should be expected to deliver some level of positive mood music over the coming decade, despite the potential withdrawal of the U.S. from the Paris Agreement and the failure of the latest COP conference in Madrid, as I describe in the sister-piece to this article, Climate Wars Episode IV – a New Hope for the 2020s?.

So there you have it – the reasons why I believe we will see peak fossil fuel emissions during the coming decade. 

The small inset chart shows atmospheric concentrations of CO2, the larger chart annual increases in CO2 concentrations.

RCP means representative concentration pathway.  RCP2.6 would be consistent with a 1 degree C rise in temps, RCP4.5 1.8 degrees C.  Liebreich's analysis suggests something between RCP2.6 and RCP4.5.  If emissions only peak in the late 2020s, policy shifts as panic about climate change increases could lead to a much steeper decline thereafter.

To sum up:

• Renewables are going to get insanely cheap.
• Thermal coal demand will peak before 2030
• Peak oil is within sight
• The green hydrogen/methane economy will be cost competitive by 2030, and at $100/tonne carbon price, will replace 30% of emissions
• energy saving still has plenty of low hanging fruit.
• renewables overcapacity will be a design feature in electricity generation.
• CO2 emissions will peak before 2030, and by 2030, will be 5% lower than they are now

I've made a lot of these points before.  Liebreich makes them better, and with greater authority.

More storage? or more capacity?-II

I was inspired to write my previous article by two things.   The first was a tweet by Simon Holmes à Court a few months ago, showing a chart of the combined output of South Australian wind farms, which was flat, rather than fluctuating in line with the winds, because output had been curtailed by the AEMO (Australia's grid manager).    He said that it looked like the output of a baseload power plant.  It did, and it made me start to think, I wonder if having extra renewable capacity across the grid would deliver the same effect.

The second was this article in CleanTechnica.   And this chart from that article is illuminating:

The grey band shows the costs of electricity from the grid.  Obviously, without a carbon price, or factoring in the cost to the environment of carbon emissions, new generating capacity must be cheaper than the average cost of the grid now to be taken up.  The red line A shows how, without storage, renewables are much cheaper than grid parity.  As we increase capacity in renewables, the costs rise steadily, because of curtailment.  By 60% curtailment, they start to increase above grid parity. 

The blue line shows the cost of battery storage.  With zero overcapacity in generation, we need a lot of storage, to cover those rare days when there is no wind and no sun and strong demand.  As we add more renewable overcapacity, it falls from 6 times grid parity at zero overcapacity/curtailment to below grid parity, because the extra capacity reduces the need for storage.

The black line shows the total cost, i.e., represents the sum of the blue and the red lines.  And the result is counter-intuitive: as we add surplus capacity up to point C, the average cost of capacity plus storage doesn't increase—it falls.   (Note that the authors call it dynamic curtailment because it changes as supply and demand positions change.)

Their costings are lower than mine.  But the conclusions are the same—we could run a grid on 100% wind and solar, by planning for overcapacity.  We don't need nuclear or other baseload power, which is not to say that legacy nuclear and hydro plants won't be useful.  The siren voices which insist we need nuclear to reach 100% renewables are wrong. 

Green methane in the gas grid

How power-to-gas works
(Source)
erneuerbare Energien=renewable energy;  Wasser=water; Wasserstoff=hydrogen
Erdgasnetz=natural gas grid; Strom=electricity; Wärme=heat
  Mobilität=mobility; Kohlendioxid=CO₂;Katalysator=catalyser; Elektrolysator=electrolyser

One of the ways we can reduce emissions is to produce synthetic fossil fuels.  We can do this by taking "green" hydrogen, running it with carbon dioxide at pressure and temperature over a catalyst, to produce methane.  "Green' hydrogen is produced by electrolysing water using surplus electricity from renewables.

This is an energy intensive process because the bonds between hydrogen and oxygen are very strong.  But, if you use power which would any way be "curtailed" (i.e., when the grid operator says there in too much electricity being generated and fed into the grid and forces wind or solar farms to temporarily disconnect from the grid) then the cost is low.  If, in addition, you don't need to concentrate CO₂ from the atmosphere. but already have a concentrated supply, for example, from the exhaust stack of a gas power station, then the cost is negligible.  Only the capital cost of the plant is relevant.

By the way, "brown" hydrogen is produced from coal, and "blue" hydrogen from natural gas.  Neither of these is carbon-neutral, and if they are used to fuel a hydrogen economy, then the hydrogen economy isn't carbon neutral either.  Which is surely the whole point! If, however, "green" hydrogen is used, although CO₂ will be produced when it is burned, it will have already been drawn from the atmosphere to create the synthetic methane in the first place, so will not be adding to atmospheric levels of CO₂.

Two points.

First of all, in high latitudes, there will be a need for seasonal storage, and batteries will likely be too expensive for a week or two of storage, for a couple of decades yet.   Gas via legacy peaker plants will be the obvious way to fill these gaps.  And the gas grid in most developed countries (a) already exists and (b) has several weeks of storage capacity.   Synthetic natural gas won't add to carbon emissions.

Second, there will inevitable be curtailment in any renewable grid.  Yes, we will have batteries, yes, high voltage connectors between regions will be built, but just as with the fossil-fuel grid now, there will be much more capacity than we will on average use, just to ensure that when demand is high (or supply low because of the weather), there is enough power.  This will mean that output from wind and solar farms—when for example there are strong winds or sunny days or both—will often be curtailed.  If instead of being curtailed, the unneeded electricity is used to create synthetic natural gas (SNG), the cost of SNG will be lower than natural gas, despite the energy cost.

From ArsTechnica:

A Düsseldorf, Germany-based energy company called Uniper announced last week that it sent methane made from renewable hydrogen into the local natural gas pipeline.

The methanation plant in Falkenhagen that made the synthetic methane opened in May 2018, and the plant's operators began testing the process to combine renewable hydrogen with carbon dioxide from a nearby bioethanol plant.

The synthetic methane is sent into the local natural gas pipeline, where it's used along with traditional natural gas. "Today, the plant produces up to 1,400 cubic meters of synthetic methane (SNG) per day, which corresponds to approximately 14,500 kWh [kilowatt hours] of energy," a Uniper press release noted. 

Uniper's Falkenhagen-based methanation plant combines the renewable H2 from Store & Go's nearby electrolysis plant with captured CO2 from the nearby bioethanol plant, combining the two molecules to create methane (CH4), the primary ingredient in natural gas. That process also creates heat as a byproduct, which is used at a nearby veneering plant.

A big advantage of this methanation project is that it can leverage existing natural gas infrastructure, allowing vehicles, residences, and other customers to indirectly use renewable energy for fuel and heat.

The methanation plant receives renewable hydrogen (H2) from a nearby plant that has harnessed excess wind and solar power for electrolysis-based hydrogen synthesis since 2013. The renewable-hydrogen project is run with help from Store & Go, a European Union-funded research program that recently partnered with CO2-capturing startup Climeworks to build a synthetic methane plant in Troia, Italy.

[Read more here]

From pv magazine:

Vattenfall-led consortium plans 50 MW power-to-gas project in Germany.

The energy company plans to build the “HySynGas” project in the Brunsbüttel Industrial Park with ARGE Netz and MAN Energy Solutions. The consortium wants to establish a power-to-gas hub for cross-sector decarbonization in northern Germany.

ARGE Netz, MAN Energy Solutions, and Vattenfall announced a plan on Thursday to set up a large-scale power-to-gas project in an industrial park in Brunsbüttel, northern Germany. The facility will produce green hydrogen and synthetic gases (SNG) from electricity generated by nearby solar and wind plants.
It is expected that the green hydrogen will contribute to cross-sectoral decarbonization. It could be used as fuel for buses or ships, as well as in gas power plants and other industrial sectors. 

The aim of the partnership is to establish a unique power-to-gas hub for cross-sectoral decarbonization in northern Germany, Vattenfall said in a statement. The partner companies have also applied for funding from the Federal Ministry for Economic Affairs and Energy to build a related R&D laboratory.

The aim is to increase the use of renewable energy and reduce CO2 emissions in a range of sectors with green hydrogen. “The project is a central building block for a holistic energy transition and at the same time lays the foundation for the power-to-gas hub in northern Germany,” said Frense.

The consortium has already secured a number of well-known customers, such as the Volkswagen Group, various logistics firms, municipal utilities and other local companies.

According to Oliver Weinmann, managing director of Vattenfall Europe Innovation GmbH, “the technology is ready for use and the companies want to invest in the green energy future.” He said that an electrolyzer for the production of green hydrogen with at least 50 MW of capacity will be built at the industrial park, as well as facilities for the production of synthetic methane, with a capacity of at least 40 tonnes per day.

In Rotterdam, the Gigawatt Elektrolysefabriek project was also recently launched. The researchers from that project aim to start generating green hydrogen at the the gigawatt scale from 2025.

[Read more here]

My ray of sunshine

Off grid--by Dionne Gain, The Age

From Elizabeth Farrelly at The Age:

Although the term “solar system” usually refers to our heliocentric colloquium of planets, asteroids, comets and assorted gravity-tethered junk it could equally designate the arrangement of wires, batteries and photovoltaic panels that hover above my head as I write. I can’t tell you how much I love it, my little solar system.

Each day, rain or shine, it is fully replenished (after its overnight fridge-running duties) before breakfast is done. I can charge all devices, run a fridge and a vacuum - run the heater all day if I like - at zero cost to self or planet. In more than three months, the batteries have never dipped below three-quarters full.

It’s not cutting edge or anything. Slinky, certainly, with a neat box of lithium-ion batteries and a wee animated readout tracking the photons, letting you monitor charge-rate, usage, feedback - even remotely, via app, from a thousand clicks. But it’s not earth-shattering. Not the artificial photosynthesis of which science is now capable. Yet still it strikes me, every day, as a kind of magic.

All this is less evident with urban solar because it’s often just an adjunct to grid-type power, of which the true costs are hidden – dissipated communally and amortised over time. Here in the country things are much clearer. Just to connect, although the poles and wires are easily visible from my desk window, they wanted to charge me $50,000. And that’s before I started paying through the nose for the power itself, at rates increasing with every disillusioned consumer who deserts to solar.

Fifty thousand bucks. My generously proportioned solar system cost less than half that - and thenceforth is bountiful, clean and free.  We can wrench the coal from the ground, burn it in a way that pollutes the air, wastes water and heats the globe, transport it vast distances via wasteful and uglifying wires. Or we can sit with our hands out and silently collect what nature gives us gratis. You can have a clunkety-clunk diesel generator, a filthy coal-fired power station or this sleek and silent on-site engine whose only moving parts are photons in and electrons out. You choose.

More energy strikes the earth in an hour than the world can use in a year. Scientists have calculated that to generate the necessary 15 terawatts of carbon-neutral energy would use only 0.17 per cent of the earth’s surface – a country the size of Venezuela or Namibia. Obviously, this incident energy is not evenly distributed. On the other hand most of it falls on the poorest countries – Africa, India, South America. So my question is this.

Our politicians blather on about how we have to dig, sell and burn our filthy coal to drag the world’s poor out of misery. We’re awfully bloody sorry about climate change, and the island nations we’re drowning, but honestly it’s the only way to end poverty. Blah blah.

Yet Elon Musk says 100 Tesla Gigafactories (producing low-cost lithium-ion batteries) like his Nevada model could “transition the whole world to sustainable energy”. So why wouldn’t they just do that?

Why can’t the rich countries see that ending poverty by driving climate change is madness? That their greatest calling, for themselves, their grandkids and the so-called “third” world is to provide free, clean energy forever?

Why don’t they bundle their aid budgets together and just build these factories, these massive arrays – a hundred, two hundred. Honestly, whatever. Just bloody do it.

[Read more here]

To provide electricity to a home which is off-grid, you require more resources than you would for one which is connected to the grid.  This is because the demand on the grid from millions of consumers averages out.  I don't put my kettle on at the same time as my neighbour.  Similarly, the supply of electricity from renewables also averages out.  The winds in western Victoria blow at different times and strengths to the winds in eastern Victoria.  At any given moment, sunshine levels are different across the state and the continent.  If there are adequate interconnectors to distribute power from one end of the state to the other, the need for storage is reduced.   Moreover, having a mixed supply from wind and solar also means that less storage is needed.  That's hard to do cost-effectively for a single off-grid house, as small wind turbines are much less efficient than large ones. 

Yet, even without being connected to the grid, the author has had no shortage of electricity.  Note that the three months she talks  about (July, August, September)  are the coldest months of the year in Australia, which means that even using heaters she has had enough power to run her house. 

The implication of this is obvious.  If a single household can go off grid, clearly the whole grid could be run using renewables.  This is so obvious that I always wonder that denialists can't see it.  With the right level of storage, with interconnectors, and with some "excess" capacity (see below) we can move to 100% renewables without blackouts.

What about cost?  The author doesn't give the details of the panels and battery she installed, but  6.5 kW of solar panels would cost $4000, and a Tesla 13.5 kWh Powerwall would cost about $15,000 fully installed.  She says the cost of her installation is "less than half" $50,000, so that would fit.  I don't know how much electricity her house consumes, but the average is something like 20 kWh per day, which means that even with only a 13.5 kWh battery she has never run out of electricity.   On the other side, her cost savings would average $4000 a year ($2200 for the electricity and $1800 for connection) -- she will never pay another electricity bill.  And her installation will have paid for itself in 5 years.  No wonder the utility companies are petrified of household solar + storage and say it needs "regulating" because it's "unstable".

Note that 6.5 kW of solar panels would produce far more power than the house needs every day in summer (35.3 kWh in January) and the panels will have to be automatically disconnected from the house's internal power grid to prevent damage and fire.  This is the equivalent of curtailment at grid level.  One way to ensure there is enough power from renewables is to overbuild capacity and then curtail output when supply is greater than demand.  In effect, this is what the author has done on her house.  But this adds to costs, though overcapacity is typical even with conventional power stations in order that all likely demand levels can be catered for.  A future grid powered by renewables would also have inbuilt additional capacity for the same reason.

To get equivalent levels of storage from the grid would mean 16 hours of storage capacity would be needed.  That would add US$70/MWh to the cost of the underlying electricity at current battery costs.  This is slightly more expensive than coal, according to Lazard's LCOE estimates.   But the cost of batteries is falling fast.  In 5 years' time, storage will cost 1/3rd of what it does today.  Which means that 16 hours of grid-wide storage would add just $23/MWh to the cost of electricity.  In other words, still a little pricey now, but cheap in 5 years and even cheaper in 10.

Quacking the code

[Hat tip to Climate Denial Crock of the Week for the clever title.]

Here's a short video from Vox which explains the difficulties the rising penetration of solar is creating for the managers of the grid.


Before the widespread adoption of rooftop solar, the (Californian) electricity demand curve looked like this:

There was a morning ramp up and then another ramp up in demand from 6 pm to 10 pm.

But as rooftop solar spread, the daytime net demand (the demand visible to the grid operator CAISO) fell each year and is forecast to continue to fall.

This produces a curve which looks like a duck, hence the "duck curve" or "peaking duck curve".  As you can see, from the point of view of the grid operator there is a huge surge in demand in the evening, made up of an actual increase in demand and a tail-off of rooftop solar generation.  This requires that peaking gas plants need to be started up to cater for the demand.  Peaking gas is expensive, because you need to pay for the plant maintenance, depreciation and debt repayment from just a few hours of use each day.

It produces a second consequence too: overgeneration.

 
Because baseload power generators (coal and nuclear--the tan line in the chart above) can't really be scaled up and down or switched off over midday when solar supply peaks causing net demand to drop below supply from baseload generators, output has to be curtailed.  I.e., any generator which can be switched off will be asked to.  Otherwise the grid would burn out.

The solution to those dual problems is of course storage.  If storage is cheap enough then it would pay utility-scale solar farms to install storage.  When the grid operator requests that output into the grid be curtailed, the solar farm would just switch its output from the grid to its batteries.  And when net demand ramps up in the evening, the solar farm would simply supply it from the power it stored earlier in the day.  By the way, this applies to wind too, even though wind farm output doesn't fall off at night, because the grid operator will ask any dispatchable power supplier to shut down when supply is excessive, even when it's not its fault.

So how much storage would be needed?  Well, from the POV of the grid operator or any individual wind or solar farm, any storage would be better than nothing if it's cheap enough.  A renewable generator would reduce curtailment and the grid would reduce the need to ramp up expensive gas peaking power plants.  But to remove or significantly flatten the peak of the duck curve plus remove the need for curtailment would require 4 to 6 hours of storage. 

And how cheap is cheap enough?  1 hour of battery storage costs about $4.5/MWh, 6 hours about $27.  The cost of wind is $30-$60/MWh, the cost of solar $43-$53/MWh.  But it depends on the wholesale price, which fluctuates during the day.  The cost of peaking gas is $156-$210/MWh, and of course the need to use peaking gas would drive up the wholesale price in the evening demand peak.  So a solar or wind farm installing battery storage would avoid curtailment (=zero income) at midday while earning (potentially) $150/MWh plus in the evening.

The big battery in South Australia has shown what is possible, and already wind farms in that state (60% renewables penetration) are retrofitting battery storage to avoid the costs of curtailment and to take advantage of evening peak wholesale prices.  As battery costs fall--and they should halve over the next 3 years--this will become widespread wherever the penetration of renewables rises enough to either require curtailment or to affect wholesale prices.  Also, as batteries become cheaper, households and businesses will install behind-the-meter storage, thus eliminating the daytime net demand decline.

The duck curve, curtailment and the evening ramp up would be a major problem in the absence of cheap storage.  But with cheap storage, batteries will soak up daytime sunshine so avoiding curtailment while reducing the need for peaking gas in the evening.