Ozzies were promised free electricity.

 Australians were promised free electricity from 11 am to 2 pm, because we have so much solar.  Strangely enough, the electricity companies have managed to prevent us getting that free electricity.  Engineering with Rosie explains how they do this.  Isn't capitalism wonderful!

Plug-in solar is safe

Plug-in solar is a solar panel with an inbuilt inverter/transformer which converts the direct current (DC) of the solar panel into alternating current (AC) at the correct voltage of your home system.  All you have to do is put the solar panel in the sun, for example on a balcony or carport roof, and plug it in to your house's grid via a plug (socket).  It is widely used in Germany and other continental countries, some states in America have legalised it, and now it has been thoroughly tested in the UK, and found to be perfectly safe, provided it conforms to the regulations.

You can't run a house off a single panel, but it helps reduce your electricity bill, and it allows people who don't own their roof (flat-dwellers or renters) to share in the solar revolution.  A 400 watt solar panel (~1 metre x 0.7 metres) will provide about 1/3rd of your electricity demand during the solar peak (1-2 hours either side of local midday).  Portable house batteries (I'll do a post on them, shortly) will allow solar power to run your house when demand peaks, between 5-9 p.m.   In practice, many are at work when the sun is strongest, but need power at home in the evening.  So batteries plus plug-in solar will make a real difference to high electricity bills.

I intend to use a couple of plug-in solar panels to extend my rooftop panels when it is legalised in Australia.  I tried to add panels to the existing system on my roof, and was told that I would have to junk it entirely and pay for a brand-new system, even though what I had was working perfectly.  Insane—solar panels go on working for 30 years, though inverters only last 15.  But I had just put a new (larger) inverter in, and would have had to chuck that out, too!

This is a big step—plug-in solar is safe.  Your house won't burn down.  Electricians working on your electricity system won't electrocute themselves, nor will electricians working on the "poles and wires" in the street.  

After you've watched the video, check the comments too.  Some useful advice there.

Australia reaches 50% renewables

 

In Q4 2025, the percentage of renewables in Australia's main electricity market, the NEM, reached 50%, or to be precise, 49.9%.  This is the best quarter of the year for renewables' share because wind and sun are strong, but since it is spring, demand for electricity for air conditioning is low.   The average percentage of electricity demand provided by renewables for the whole year was just 42.9%, up from 5.8% in 2008.  The percentage of renewables in the NEM is rising by ~3.5% per annum, which means that we're still 16 years before it provides 100% of demand throughout the year.

All the same, it's a landmark.  In 2008, almost all the renewables provided came from hydro, and the growth of wind power was slow, because in those early days, it was more expensive than coal, especially existing coal power stations.  Governments, both state and national, provided high feed-in tariffs for rooftop solar, which in Q4 2025 provided an astonishing 17.6% of total electricity demand, even though subsidies for rooftop solar have now been withdrawn.  The rapid growth in rooftop solar led to everybody in the system becoming familiar with it, with the result that soft costs (permitting, etc.) are low.  A very successful policy.  Rooftop solar in Australia is much cheaper than in the USA because of this factor.  Obviously, the panels cost the same, it's the soft costs which are so high.

The Right has opposed renewables all the way, and even now that renewables are cheaper than even existing coal power stations, still is hostile.  For example, Queensland (run by a right-wing party) has banned new wind and solar farms, despite their cost advantage.  And at national level, the so-called Liberal Party and the Murdoch press continue to say that high electricity costs are because of renewables--they're not, they're because of gas.  And they continue to spruik nuclear, which in Australia is entirely unnecessary, and also insanely expensive, more expensive than new coal.

It seemed such a long way to go, back in 2008, and progress was so slow.  And yet, we are half-way there!  I hope that as solar, wind and batteries continue to drop in price, the transformation of Australia's electricity grid will accelerate, but here in Australia, as elsewhere, vested interests are doing their damnedest to stop it.  But the public knows that installing solar will save them money, and rooftop solar installations continue.  Outside Queensland, Labor-controlled states have fairly aggressive renewables targets, driving continued growth in wind and utility-scale solar.  

Despite the opposition, we'll get to 100%, sooner than we got to 50%.

[If you want to play around with the data, you can do so here]

Golf courses take up more land than solar farms

Coal apologists are always going on and on about how solar panels will cover the whole world if we go solar and don't keep on using coal.  It is utter rubbish, of course.  And here's a nice chart showing how absurd it is.  By the way, 13% of all electricity in Australia comes from rooftop solar.  Yes.

 From Dr Paul Dorfman

A sobering look at key climate indicators

 From Dr Aaron Thierry

A sobering look at some key #climate indicators from last year - CO2 Emissions in 2024 - Record High Coal - Record High Gas - Record High Oil - Record High (tied 2019)

www.carbonbrief.org/analysis-glo...

CO2 Concentrations in 2024 - Record High www.noaa.gov/news-release...

Rate of Increase in CO2 Concentrations - Record High insideclimatenews.org/news/2404202...

Surface Air Temperature - Record High First year over 1.5°C above pre-industrial climate.copernicus.eu/year-2024-se...

Ocean Heat Content - Record High phys.org/news/2025-01...

Planetary Albedo (reflectivity) - "declined over the 25 years of precise satellite data" www.columbia.edu/~jeh1/mailin...

Earth's Energy Imbalance - "More Than Doubled in Recent Decades" agupubs.onlinelibrary.wiley.com/doi/10.1029/...

Rate of Global Sea Level Rise - "doubled during the past three decades" www.nature.com/articles/s43...

"Oil and gas annual upstream capital expenditures rose by $63 billion year-on-year in 2023 and are expected to rise a further $26 billion in 2024, surpassing $600 billion for the first time in a decade." www.ief.org/focus/ief-re...

This makes depressing reading, doesn't it?  Yet we are not helpless.  If we stop eating meat, we can cut emissions by +-30%.  You could become vegetarian, replace cow's milk with plant milks, and cut your personal emissions.  That is entirely in your control.  It's your choice.  

Second, you can replace your petrol car with an EV, if you can afford it.  In some countries, the sticker price for EVs is already the same as for ICEVs (petrol/diesel cars).   In others, you'll need an above average income to do it.  

You can put solar panels on your roof.  Again, that costs, so you need to have the money.  But if you do, you can cut your emissions, and help save the world.

And you can vote, for the greenest party available, even if it's not perfect.

WE. ARE. NOT. HELPLESS.  Do something.

Last 12 months hottest ever

The last 12 months have been the hottest ever recorded.  

This chart is from Our World in Data.  Look how the temperatures of the Northern Hemisphere have been rising almost twice as fast as in the Southern Hemisphere.   In fact, they are now more than 2 degrees above pre-industrial levels.  We have passed the 2 degrees "guideline" in the Northern Hemisphere.  

This is a terrifying chart.  After the last El Niño, temperatures were supposed to level off or even drop.  But they haven't.   

You would expect our leaders, political and corporate, to be concerned, to be panicking, even.  Yet they are not.  And a supine populace just accepts this.  

It's no good expecting anything to change unless we do it.  We can change our personal consumption to reduce emissions.  For example, we can become vegetarian.  We can buy an EV or a hybrid.  We can replace our gas/oil heating with heat pumps.   We can buy our electricity from green suppliers.  We can put solar panels on our roofs.   We can fly less.  Take public transport instead of driving everywhere.  

Of course, we might not be able to do all these things.  Solar panels have an upfront cost, even if you'll save by reducing how much electricity you'll buy later on.  Or there might not be green electricity supplies in your area.  But you can eat less meat and drink less cow's milk.  That won't add to your costs.  

And we can vote.   We can agitate and write letters to our local councils.  We can support parties which make climate change their priority.

It's up to us.  Don't shrug and say, "it's too hard."  Because if we don't act, we face imminent catastrophe. 

These anomalies are not relative to the period 1850 to 1899, which usually what is defined as being pre-industrial, but to the period 1861-1890.   The shape of the chart won't change, but the Y-scale will shift a bit.

Rubbery nuclear cost estimates

The world’s largest crane lifts a steel dome onto Hinkley Point C’s first reactor building. The cost of building the UK’s latest power plant has soared. Photograph: Ben Birchall/PA

In Australia, the right-wing Coalition ("Liberal"/National Party) opposition, in government when Australia became the first country in the world to abolish a carbon tax, is enthusiastically spruiking nuclear power. Their numbers defy belief.

Here's part of an article from The Guardian:

The primary reason the world is not embracing nuclear energy on a grand scale is simple: cost (although in Japan’s case, it’s also about safety).

The Frontier Economics report, which the Coalition is using to make its case, is written in an opaque way that makes direct comparisons difficult. Essentially, the report admits that the capital cost of nuclear is $10,000/kW, while solar and wind are $1,800 and $2,500 respectively.

So how is it that the Coalition’s modelling suggests that a world where nuclear makes up more than a third of the east coast energy grid could possibly be cheaper?

It’s easy to come up with the answer you want when you base your modelling on rubbery assumptions.

Firstly, we should appreciate that even a $10,000/kW estimate for nuclear is considerably optimistic if we look at the experience of comparable countries over the past decade. The cost at the off-cited Hinkley C plant in the UK has, to date, risen to $27,515/kW. Three others – France (Flamanville 3), Finland (Olkilutoto 3) and the US (Vogtle) – are between $15,000 and $16,900. [In other words, nuclear in the West is a minimum of 7 times as expensive as wind and solar]

Delays have been a key factor in driving up the cost of nuclear power. The longer it takes to build and operate a plant, the higher the cost of finance. The Coalition believes we can overturn national and state legislation and acquire land and planning approvals virtually overnight. And then we’ll just install an ‘off-the-shelf’ nuclear power plant, ready to run.

By its own admission, having to tweak nuclear power plants so they operate at maximum safety and efficiency can blow out build times and costs. It beggars belief that the Coalition claims Australia, which has no nuclear energy capability, could ship, build and integrate into the grid with no challenges, with a 50,000-strong nuclear workforce appearing by magic.

There is no mention of the costs of extending the life of existing ageing coal-fired power stations, or the likelihood that these plants will increasingly fail as they reach end-of-life, raising energy costs as supply falls short and, increasingly, the likelihood of blackouts. And, apparently, nuclear waste can be transported and stored without cost.

The Coalition also argues that, because wind and solar energy are not always “on”, we’ll need to build a lot more capacity, along with transmission and storage. It calls this “overbuild”, but its assumptions have overegged what that need might realistically look like, especially as battery storage becomes cheaper over time (unlike the experience of nuclear) and of longer duration. [Battery pack prices have halved this year]

Finally, to arrive at these rose-tinted costs, the Coalition has had to cut back on estimates of the amount of energy we will demand over the next two decades by almost half what the Australian Energy Market Operator says we need. That’s because it’s assumed we won’t worry about EVs or electrification. [This has led the Coalition to claim that this will cut electricity costs by 44%.  They have deliberately confused capital cost with cost per kWh of output. Of course capital costs are 44% lower if you are going to produce 44% less electricity!] This is why the Coalition will undo Australia’s 2030 43% emissions reduction target, which we are set to get very close to, taking us back to our Morrison-era status of global climate pariah. [The Coalition plans to abolish Labor's 43% target] 

And this is the kicker. Under the Coalition’s plan, our modelling shows Australia’s domestic emissions will rise by around one billion – yes billion – tonnes, at a cost of $240bn to the economy, society and environment, based on Infrastructure Australia’s cost of carbon methodology.

Most commentators who are not creatures of the Murdoch media think that this is just a ploy to prolong the use of coal and gas.   If it will take at least 15 years to build out a nuclear fleet, in the meantime we will need to extend the lives of our coal power stations.   Since they are already long in the tooth, and will be very expensive to refurbish, that will mean building new coal power stations.  But new coal in Australia costs 3 times as much per MWh of output as new wind and solar backed up by 4 hours of storage.  Which is why no utility is interested in building new coal power stations.  

In addition, the Coalition hasn't said what they're going to do about rooftop solar.  Rooftop solar, in summer, contributes 16% of total electricity supply, beating out all other sources except black coal.  Since old-fashioned nuclear power stations can't easily be ramped up or down, i.e., they're always "on", rooftop solar output will have to be curtailed to allow nuclear to keep running.  In other words, the money millions of people have spent installing rooftop solar to save on electricity bills will be wasted.  Not a winning proposition, for sure.

Globally, 80% want more climate action

It's tempting to rail against ordinary people when it comes to climate action. To blame mankind as a whole for its stupidity and greed. After all, we know that temperatures are rising, that heatwaves, droughts and floods are becoming much worse and more common.  So why is there not enough action? But ordinary people do want action. It is the politicians, the rich, the owners of oil companies, directors of companies who, while pretending to want action, do their best to stop it.


From Al Jazeera

Four in five people want their countries to ramp up efforts in the fight against climate change, according to a United Nations survey billed as the largest yet on the issue.

The UN Development Programme (UNDP) published the poll on Thursday, finding that a majority of people in 62 of the 77 countries surveyed said they supported a quick transition away from fossil fuels to clean energy.

These included the world’s biggest greenhouse gas emitters, with 80 percent in China and 54 percent in the United States supporting the move, though respondents in Russia were notably less keen, with only 16 percent approving.

“As world leaders decide on the next round of pledges under the Paris Agreement by 2025, these results are undeniable evidence that people everywhere support bold climate action,” said Cassie Flynn, UNDP global climate director.

Conducted in collaboration with Oxford University and GeoPoll, the survey posed 15 questions by randomised telephone calls to 75,000 people in 77 countries, the populations of which represent 87 percent of the world’s total – making it the biggest poll of its kind.

Overall, 80 percent of those polled wanted to see stronger commitments to addressing the problem, the clamour for action rising to 89 percent in poorer countries feeling the brunt of climate change.

Climate anxiety was higher in poorer countries like Fiji, where 80 percent are more worried about the problem compared to a year ago, followed by Afghanistan (78 percent) and Turkey (77 percent). Saudi Arabia saw the lowest increase in climate fears, with 25 percent more concerned.

Overall, the survey found 56 percent of respondents said they think about climate change at least once a week. Over half of those surveyed said they were more worried about climate change than last year, compared with 15 percent who said they were less worried.

Climate change is also changing people’s lives, with 69 percent of respondents saying that global warming had impacted major decisions, such as where to live or work and what to buy.

But Achim Steiner, head of the UNDP, said these concerns do not necessarily translate into electoral and consumer decisions.

He pointed to what he called a “perception gap” when it comes to climate action, summing up people’s typical reaction as: “I would do more. But the others won’t. So I will not do anything."

There are things you can do.  

You could eat less meat, especially beef and mutton, and drink less cow's milk.  The less, the better.

You could buy an EV or a plug-in hybrid (PHEV).  Yes, that can be expensive in the USA, because it’s just placed a penal tariff on imports of Chinese EVs and Chinese EV batteries, which are the cheapest in the world.   But in the rest of the world, EVs are plummetting in price.  As are electric 3-wheelers.   An EV will soon cost the same as a petrol car, outside the USA, anyway.   Make your next car an EV.

You can put solar panels on your roof (if you own your own property.)   If you don't, and can't, buy your electricity from a green supplier.   If we all insist of buying renewables from a green electricity utility, they will be forced to build more solar and wind farms.  Don't buy from a so-called green electricity supplier which claims its green credentials because it buys carbon offsets.  These are (mostly) a furphy, a scam. 

You could switch your heating from gas/oil to electric.  There's been some opposition to heat pumps because they supposedly don't work.  That's piffle; they do.  They cost more up front than gas or oil boilers/heaters, but they're cheaper to run.  Some polities provide subsidies to encourage the switch.

Together, all these steps will cut your personal emissions by 80%.  

And, most important, you can vote.  Don't be distracted by other policy issues.  Vote for the Party which is going to do most to cut emissions.  Even if in other ways they are imperfect.

It's up to us, and most of us want to do something.  You can make a difference.  Start today.

Flexible export limits for rooftop solar

From RenewEconomy

South Australia has become the first state in Australia, and possibly the first in the world, to roll out flexible export limits for homes with rooftop solar panels at scale.

On July 1, new rules came in that mean all new solar systems must be technically compatible with flexible export limits of 10kW.

The new system requires modern inverter technology to be installed with rooftop panels so that exports can be remotely controlled and ramped up and down, to better suit the needs of the grid and manage new concepts such as minimum demand.

Flexible exports are promoted on the basis that distributed network service providers (DNSPs) can avoid switching them off altogether, as is being proposed in Queensland, or proposing hard and inflexible limits on rooftop solar exports, which has been usual practice around Australia.

The new system does not apply to existing rooftop solar systems nor will it apply to those which export nothing to the grid.

Exemptions apply for battery storage systems until March 1, 2024, SA Power Networks says.

Currently, all homes in Australia with rooftop solar can’t send more than 5kW of electricity back into the grid. These fixed limits were to prevent rooftop PV from overloading the grid during the day.

A trial, first mooted in 2020 by SAPN and rolled out in 2021, showed that most customers were capable of exporting up to 10kW of electricity 98 per cent of the time. The other option instead of flexible limits was a hard cap of 1.5kW at all times.

The remaining 2 per cent of the time when the local network became congested, the energy regulator could scale back exports.

It also means during emergencies, such as storms affecting electricity distribution, SAPN may not need to rely so heavily on the Big Solar Button, the Remote Disconnection and Reconnection (RD&R) emergency backstop for rooftop solar as remote control gives the DNSP more options.

Solar Analytics CEO Stefan Jarnason expects Victoria to be the next to shift to flexible exports he hopes by late 2024 — provided Western Australia doesn’t make a surprise move first — followed by New South Wales or Queensland in the next two years.

Solar Victoria said in May that it wants all new inverters sold through its Solar Homes rebate program to be flexible exports-ready from 1 March next year.

“The main thing it opens the door to is larger solar systems. Previously people were putting on 5kW solar systems, now the average is 9kW,” Jarnason says.

“When you electrify your own home, an electric car, hot water, air conditioning, cooking, ideally you want 20kW. This opens the door to that, and on those days when there’s too much in the grid that can be throttled back. There is literally no downside, unless you own a coal power station.”

The new rule won’t suit everyone: it won’t benefit people with rooftop systems smaller than 5kW, but anything over 7kW is definitely better off, Jarnason says.

Rooftop solar even with export limits has been the largest source of downwards pressure on power prices over the last five years.

Jarnason expects the new technology, which will let even more 5-10c/kWh electricity into the South Australian grid, will be even more influential on local power prices.

It has taken South Australia time to introduce the new rules, as investor manufacturers needed to be given time to build appropriate software.

The rule was supposed to come in on 1 December last year but was delayed to give inverter manufacturers more time.

At the time only a handful of inverter models from a small number of manufacturers met the requirements for flexible exports, using the SwitchDin Droplet, but companies Fronius and SMA were designing “native” inverter software for their inverters.

Chinese inverter company Sunglow got its compliance tick in May.

South Australia gets 18.6% of its electricity from rooftop solar, one of the highest percentages in the world, with all renewables totalling 60.3% so far this year.

Rooftop solar's dominant summer

From RenewEconomy

Rooftop solar systems across Australia set a new record across the Summer, supplying more of Australia’s electricity than brown coal and dispatching more energy to the grid than all other renewable energy sources.

New figures published by Australia’s Clean Energy Council on Tuesday show that small-scale rooftop solar systems provided 14 per cent of Australia’s electricity needs during the summer months.

Total rooftop solar output during summer reached 8,046GWh across more than 3 million homes, up by an impressive 19.5% on the previous year – an increase likely spurred on by a surge in solar installations as consumers seek to escape rising energy bills.

The strength of rooftop solar’s role during Australia’s summer is demonstrated in the fact that it outperformed brown coal as well as all other renewable energy sources including grid-scale wind farms and solar farms.

“There is no doubt with inflation and cost of living pressures, people are turning to rooftop solar in record numbers,” said Kane Thornton, chief executive of the Clean Energy Council.

“Thousands of Australians are switching to rooftop solar and seeing their benefits to their hip pockets and the environment. In fact, payback periods for rooftop solar are now at near record-low levels, at 3.4 years for a 7kW system.

“We’re seeing a fundamental shift; consumers are becoming energy generators, making their own clean energy, reducing their bills and taking on the electricity companies.”

State by state, South Australia remains the country’s leading example of the role rooftop solar can play, but is being closely chased by New South Wales which was the most improved of all the states.

The smartest renewable rooftop system

From Just Have a Think

 A rooftop combine wind and solar system with twice the efficiency of normal rooftop solar and 6 to 10 times the efficiency of small wind turbines.  Very interesting.

 

My comments:

• Because the solar panels are bifacial and all the equipment is painted white to reflect as much of the light back up to the underside of the panels, and because the cooling wind under the panels stops the panels heating up on sunny days, the efficiency of the solar is double the norm for rooftop solar.
• The "roof" of panels and the arrangement of wind turbines focusses the air flow, making these wind turbines exceptionally efficient.  Rooftop small wind turbines are not nearly as efficient as giant turbines, making home wind turbines uneconomic.
• The LCOE  over 25 years is 8 to 12 cents per kWh.  That's more expensive than the LCOEs of utility-scale wind and solar, but this system is competing with the retail cost of electricity, not the wholesale price.  The average retail price of electricity in Europe is over $0.25 cents per kWh (including taxes); in the US it was around 11 cents/kWh in 2021, before gas prices jumped in response to Russia's invasion of Ukraine, and in Australia, the average retail price of electricity was (US) 19 cents/kWh.  
• The Eindhoven installation provides 85% of the building's energy requirements.  If the building were 2 or 3 stories shorter, it would be 100%.
• These distributed generation facilities should benefit the residents of the building, but ownership of the machinery belongs either to the landlord of the building or to the body corporate.  This complication will have to be resolved for this to work, given the retail/wholesale price difference.
• Wind and solar together go far towards producing a stable baseload electricity output.  Adding in 4 hours of storage would make it even better.  Charging the residents' EVs when there is surplus power available would make the building and its occupants more or less independent of the grid.
• A very clever system which would be worth installing on all buildings of 4 storeys or more with flat roofs.

114% increase in UK rooftop solar

From Solar Power Portal

The Microgeneration Certification Scheme (MCS), has released its latest data showing that 130,596 solar photovoltaic (PV) systems were installed in UK homes last year – a 114% rise from 2021.

This figure made up the majority of the total 163,341 MCS certified installations, marking the highest annual deployment since 2015, which saw 200,000 installations.

The standards organisation for domestic renewable energy and heating technology also reported the highest annual increase of certified contractors in 2022 at 780 – more than double the net increase from 2020 to 2021.

67% of these contractors are certified for electricity generating technologies, demonstrating the growing demand for domestic solar in the UK.

Battery storage had a similarly promising year. Launching its battery installation standard in November 2021, MCS reported that 50 certified contractors and 269 installation were reported in 2022.

“We're pleased to report our second strongest year since 2015, illustrating the sector’s upward trajectory. We had an incredibly busy 2022 and the data confirms the progress we’ve made. The future of small-scale renewable installations is becoming increasingly important, and we continue to play a crucial role in the decarbonisation of the UK's homes,” said Ian Rippin, CEO at MCS.

“The growth we’ve seen in domestic renewable electricity systems over the past year may also give some insight into the growing consumer reliance on home-grown energy in the UK during the cost-of-living crisis. As electricity prices skyrocket, more people are turning to renewable solutions to generate their own power at home.”

The plunge at the end of 2016 was because of the end of a subsidy incentive.
The spike in March 2019 was due to the announced closure of a feed-in tariff scheme.

 

Costs of running an EV in the UK

 From a Twitter thread by Katy Duke

Fuel costs of running an ICE v BEV updated yesterday. There are 3 BEV consumptions + av. cost pa. Have been on night tarrif from @OctopusEnergy for just a week! ICE costs 21.98p per miles, BEV is 1.79p per mile on night charge.

This is the lowest priced dealer EV locally https://drive-green.co.uk/used_evs/2011-peugeot-ion-km11umc/… £5895. HP £6685 = £127 pm + £590 deposit = £1525 pa

2011 Peugeot iOn EV

Replies to her tweet pointed out that some shopping centres and supermarkets offered free charging, so the public charge costs could be lower. Note also, that maintenance costs for EVs are lower than for ICEVs, because they have ten times fewer moving parts.  In Australia, electricity is also cheap at mid-day as well as late at night, because we have more solar than the UK, which relies much more on wind.  Obviously, that means that when demand is low, late at night, but supply continues, because the wind blows at night, the wholesale price of electricity plunges.   A good time to charge your car and heat your house. 

And if you have your own solar panels, you can charge your car, effectively for whatever your feed-in tariff is (in Oz, feed-in tariffs are low)  Also, how good it is to be able to buy a second-hand EV, thanks to early subsidies which increased sales years ago.  Australia has hardly any second-hand EVs, so cheap up-front entry to the EV world isn't possible here.  For that, blame the right-wing LNP government, recently, thank goodness, comprehensively voted out of office.

Rooftop solar to meet 3/4 of demand by 2026

Rooftop solar, Australia

 From IEEFA

Rooftop solar systems are going to have such an impact in coming years that they will meet up to 77 per cent of total grid demand on occasions within five years, sending minimum operating [i.e., net] demand down to levels that had never been contemplated until recently.

The Australian Energy Market Operator says the pace of rooftop solar is increasing beyond its own expectations and homes and businesses will likely add at least another 8.9GW by 2025, on top of the existing capacity of 14GW.

This will have a major impact on prices, demand and the operations of the grid. These solar systems alone could supply up to 77% of total electricity demand at times by 2026 in the four mainland states that are part of the National Electricity Market (South Australia, Victoria, NSW and Queensland).

“As a result, minimum operational demand across the NEM mainland is expected to drop to a record low of 4 to 6GW by 2025, down from 15GW in 2019,” AEMO says.

This is a real Ozzie success story, which has happened despite the Right's slavish devotion to their fossil fuel masters.  And it happened because a leftish government introduced subsidies for small-scale/rooftop solar.    The subsidies drove rapid take-up, and this in turn drove down the before-subsidy costs in a classic learning curve virtuous cycle.  These days, one can put 5 kW of panels on one's roof for ± A$5000 (US$3500). It also made people aware of renewables; so much so, that when one talks about solar, everybody thinks one means rooftop solar.

The tremendous growth of rooftop solar (3 GW in 2020 alone) has meant that some aging poles-and-wires street infrastructure is stressed on sunny days, and the grid operators, ever alert for more cash, are trying to get a "solar charge" introduced because "it's not fair".  Ignoring of course that the wholesale price of electricity has been driven down by the jump in renewables in the system, reducing electricity costs for everyone, not just those with rooftop panels.   Meanwhile, on hot, sunny days, local solar actually saves the wider grid from being overloaded (and shutting down) when all the aircon units on individual houses are run., because typically, it's sunny when it's hot.  Duh.      

The obvious solution to overloading the poles and wires, which in fact existed when I put in my first set of solar panels a decade ago. is a smart meter, which disconnects the solar panels from the grid when the voltage on the local grid rises too high, stopping the grid from burning out.   

The key point I want to make though, is this: Australia went from zero solar to 77% (on sunny days) in little over a decade.  Similar subsidies and targets could drive behind-the-meter household storage to high enough levels to stabilise the grid; and also EVs to 100% of sales.  Within 15 years.  Subsidising/incentivising a technology which has a steep learning curve drives very rapid increases in installations.  Not gonna happen in Oz, given our troglodytic backward LNP government, so don't hold your breath.

Rooftop solar pushing out coal

From IEEFA:

One of the most common questions among people concerned about climate change and cleaning up the energy grid, is what small contribution they can make. Will adding rooftop solar make any difference at all?

The answer is most certainly yes. The latest quarterly report from the Australian Energy Market Operator contains little doubt – the increase in rooftop solar, and in large-scale solar plants, is pushing coal out of the daytime market.

According to the Quarterly Energy Dynamics report for the December quarter, the changes in generation sources for the main grid were quite marked.

The biggest increase – and remember this is not average output, but the average increase in output – came from rooftop solar, which in 2019 posted a record installation rate of 2.13GW (for sub 100kW systems). Rooftop solar at its midday peak posted an average increase of more than 1.5GW over the quarter, showing the real impact on the generation mix.

The coal generators most affected by the increase in solar output – both rooftop and large-scale – were Eraring in NSW, where output declined by an average 231MW, and Gladstone and Stanwell in Queensland, where the average middle of the day output declined by 246MW. Other coal generators might also have been affected, but their output was interrupted by so many outages – both planned and unplanned – it was hard to tell.

In Queensland, the increased output of rooftop and large-scale solar has resulted in a changing pattern of charging by the state’s biggest pumped hydro facility at Wivenhoe, which is now under new ownership by the government owned CleanCo. Under its previous owner, CleanCo pumped mainly at night, supporting coal generation, but with CleanCo it is now doing most of its pumping during the day, soaking up the excess of cheap solar – the so-called solar duck curve – and helping prevent prices going negative.

Rooftop PV reaches grid parity in EU

From PV Magazine:

If all the rooftops across the European Union able to host solar arrays did so, 680 TWh could be generated, providing 24.4% of the political bloc’s current electricity consumption.

That is the chief finding of a paper entitled A high-resolution geospatial assessment of the rooftop solar photovoltaic potential in the European Union, published on the ScienceDirect website.

The authors of the study combined geospatial and statistical data to assess the technical potential of rooftops for solar energy deployment on every building in the EU. The model, which also used machine learning, was used to quantify the total available rooftop surface for PV systems.

The methodology helped the researchers identify EU markets where rooftop PV could generate electricity at a very competitive levelized cost of energy.

“Specific countries such as Germany, France, Italy, Spain stand out in the maps as they host the highest economic potential that translates to more options for advantageous investments,” stated the paper, adding, electricity retail prices of €0.30-0.169/kWh meant rooftop solar could offer electricity savings of 49% in Germany, 44% in Spain, 42% in Italy and 23% in France.

Eastern EU member states such as Bulgaria, Hungary, Romania and Estonia, however, were cited as markets with very low retail electricity prices, of €0.095-0.12/kWh.

The rooftop PV analysis identified nine markets where grid-parity is some way off as a result of cheap grid power and all of them are in Eastern Europe: Romania, Poland, Hungary, Czechia, Slovakia, Croatia, Lithuania, Latvia and Estonia.

By contrast, Portugal was highlighted as a market with very favorable conditions, including high solar radiation, good financing availability and high retail electricity prices of around €0.22/kWh.

[Read more here]

Remember that rooftop solar is more expensive than industrial- or utility-scale solar because of economies of scale, and because utility-scale solar can use variable-tilt/tracking solar panels which increase yield by 20% or so, plus produce a "squarer" output profile than fixed-tilt solar because they shift to face the sun during the course of the day.   On the other hand, the price point is also higher, being offset against the retail not the wholesale cost of electricity. 

I have already looked at how onshore wind could provide ten times Europe's electricity needs, and how offshore wind could power all of NE Europe.  Rooftop PV could provide 25%, and large-scale PV even more.  There'll be no shortage of electricity even in a 100% green Europe. 

As can be seen from the map above, it would prolly make sense to put Europe's solar farms in Spain, North Africa, the south of France, Italy, Greece, Turkey and SE Europe, where solar resources are greater.   The offsetting cost would be the construction of HVDC (high-voltage direct current) interconnectors between these regions and northern Europe.  Rooftop solar doesn't have that problem, because it's located right next to the demand for electricity.