Archive for the ‘Electricity’ Category

Australia’s Energy Future

January 17, 2023

What are the likely prospects for electricity supply in 2023? In a nut shell, much higher prices, but we may avoid blackouts-just.


In April, Liddell coal fired power station will close. Data from OpenNEM shows an extra 2,827 MW of wind and 1,895 MW of solar farm capacity will come on line during the year, and as well rooftop solar will continue to grow rapidly. There will be an extra 154 MW of gas generation at Snapper Point in South Australia. There will be no change to hydro capacity. Figure 1 shows the changes in installed capacity from 2022 to 2023.


Figure 1: Installed Capacity

Across the National Electricity Market, generation and consumption are virtually the same (hydro pumping and battery charging accounts for much less than 1 percent.) Over 24 hours, daily consumption in Gigawatt hours in 2022 is shown in Figure 2.


Figure 2: Daily Electricity Consumption

Capacity factor is actual generation as a percentage of installed capacity.


Figure 3: Daily Capacity Factor

Note that in optimum conditions wind has a capacity factor almost as high as coal; low wind results in capacity factor dropping to 7.6 %. On average wind’s capacity factor is 34.9 %. Wind generation varies, and is mostly greater at night.


While there is a massive amount of solar generation each day, depending on cloud conditions, after sundown solar energy is virtually zero. At the early morning and early evening peaks, and all through every night, the amount of daily solar generation is irrelevant, and the nation relies on coal, gas, hydro, and whatever wind is available. When wind energy is very low, fossil fuels and hydro have to increase generation.


In Figure 4, projected consumption for 2023 is calculated from 2022 average capacity factors and 2023 installed capacity.


Figure 4: Projected 2023 Daily Consumption

Assuming there is no increase in demand in 2023- in other words, no population increase, no new electric vehicles or other gadgets, no economic growth- we can directly compare 2022 consumption with 2023. It is likely that the economy will slow, which might be the only thing to save the NEM. Here are three scenarios for 2023 after Liddell closes.


Figure 5: Third Worst Case

If we have a year with winds similar to last, on average there will be 6.8 GWhr less electricity per day. In 2022 there were 197 days when wind generation was below average. Of course, coal, gas, and hydro will easily increase generation to cover this shortfall, but at greater cost than 2022.


But that is the average day. We need to look at hour by hour demand and generation during each day.


Figure 6 is a plot of electricity supply by source for 30 minute periods for the week of 29 May to 3 June 2022.


Figure 6: Electricity Generation 29 May to 5 June 2022

Battery, biofuel, and diesel generation are not shown as they are tiny. Note the morning and evening peaks, the early morning base of about 19,000 Megawatts, and the daily solar curve, which decreases to virtually zero at local sundown.

Figure 7 shows the above data just for 2nd June.


Figure 7: Electricity Generation 2 June 2022

I am interested in electricity supply at 6.00 p.m. (the down arrow) as this is close to the daily peak. At 6.00 p.m. solar was irrelevant; and wind generation was extremely low all day- but wind generation can be much lower. In 2022 there were 18 days with less wind generation than that.


What if similar conditions occur in June 2023?


In the next figure I assume identical weather conditions- temperature, cloud, rain, and wind- and use the planned capacity increases for gas and wind, and the decrease for coal, to estimate generation for a similar day in 2023.


Figure 8: Second Worst Case- similar conditions to June 2022

773 MW short. Coal is already at its maximum output for the year. The shortfall can only come from hydro and gas. Gas can generate an extra 320 MW or so to equal the maximum for the year, and of course can go beyond this (theoretically, but impossible, an extra 4,255 MW to maximum installed capacity); hydro can contribute extra (theoretically, but impossible, an extra 3,454 MW to maximum installed capacity) – but there is a physical limit. This will drive prices even higher.


Which brings us to the Worst Case Scenario:


Worst Case: less wind than 2022 at peak times and anything less than maximum coal, gas, and hydro generation.


After April, electricity supply will be tight. If the wind blows strongly enough, we will be able to manage. Wind must be able to produce at least 1,100 MW every hour at peak times. However, the wind is unlikely to co-operate. Therefore, we will have higher prices.


But to avoid blackouts:


Coal generators must produce at or above the 2022 maximum capacity factor, with minimal planned stoppages and no unplanned breakdowns.
Gas generators will have to increase supply- this will of course result in higher prices.
Hydro dams will have to stay full, with no droughts or floods.


Good luck with that.

(Source: OpenNEM)

Advertisement

Electricity Prices, Reliability and Ideology

December 10, 2022

So, apparently we will have electricity prices reduced by a cap on the price of gas and coal and by installing more renewables, and we will have more reliability by installing more batteries and hydro.  And Chris Bowen says anyone who denies renewables are cheaper is a liar “This crisis is caused by gas and coal prices, anybody who says it’s caused by renewables is lying..”

Time for a reality check.

All data has been downloaded from OpenNEM.

Figure 1 shows the fluctuation in daily generation of electricity for the National Electricity Market for the year from 3/12/2021 to 3/12/2022, as supply kept up with demand:

Figure 1: Daily electricity generation, NEM

There is a weekly curve with less demand on weekends, showing as the down spikes.

Figure 2 shows how generation was provided by all fossil fuels and all renewables including hydro and batteries:

Figure 2: Daily electricity generation, NEM, fossil fuels and renewables

(Renewable energy advocates will point out how renewable generation rose at the end of October to record levels.  Bully for them.)

Figure 3 shows the daily price of electricity for the same period:

Figure 3: Daily price of electricity

Note prices began to rise sharply in April and fell back again at the end of July, and there were several large spikes that had nothing to do with the price of gas or coal, but the realities of supply and demand.

So are renewables cheaper?  Well yes, apparently some are.

Figure 4: Average daily price of electricity ($ per GigaWatthour)

Clearly, diesel powered generators are by far the most expensive so are only used for small scale or emergency generation.  Black coal is in the middle, and solar power is cheapest.  Chris Bowen and other renewable advocates will NOT be happy to learn that brown coal is cheaper than wind.

The maximum price of electricity is reached when demand is high but supply is struggling to keep up- those spikes in Figure 3.

Figure 5: Maximum daily price of electricity ($ per GigaWatthour)

Renewables are cheapest, with coal next.  All others including hydro are above a million dollars a Gigawatthour.  Diesel is the stand out.

But how much of each is actually used?

Figure 6:  Average daily electricity generation

Coal is king.

Figure 7:  Maximum daily electricity generation

For short periods wind overtakes brown coal.

Figure 8:  Minimum daily electricity generation

The backbone producers of the NEM are the only ones visible- the others are backup only.

The next figures show plots of data at half hour intervals for the first week of December (1/12/22 to 8/12/22).

Figure 9:  Price per MegaWatthour by time of day (in an average early summer week)

This is the daily picture of supply and demand.  Maximum prices are reached in the early evening – 6 pm to 8 pm- and prices are lowest in daylight hours.  Notice that prices are frequently negative between 6.30 am and 4 pm.  Some generators are paying up to $50,000 per GWhr for the NEM to take their power.  They have to make up these losses when demand is higher.

How does this match with generation?

Figure 10: Total generation by time of day

Demand is highest in afternoons when air conditioners are working hard.  Demand is still above 17,000 Megawatts in the early morning hours.  That is baseload.  (The bottom two rows are Saturdays and Sundays, when people sleep in.)

Here is the problem for Chris Bowen and our energy ministers: how long until renewables plus storage can keep the lights on?

Figure 11: Total generation and renewables + storage by time of day

Not for a very long time, even on an average summer day, let alone if the wind fails, or there’s heavy cloud, or extremely hot or very cold weather.  What’s the point of “cheap” electricity if it can’t do the job?

Here’s why.

Figure 12: Solar generation by time of day

Most solar farms have panels that track the sun, so they quickly reach near maximum capacity.  Rooftop solar, being fixed, follows the irradiance curve.  But note that while solar electricity is cheapest, it cannot be bought for any price at night.

Figure 13: Wind generation by time of day

Solar power is predictable compared with wind, which can vary from less than 1,000 MW to over 6,000 MW.

In a fit of ideological fantasy, Chris Bowen and our energy ministers think they can firm up renewable supply without using coal or gas.  Figure 14 shows hydro, battery, and biofuel generation on a typical early summer day:

Figure 14: “Green” firming by time of day

You can forget about batteries and biofuel (that’s mostly from burning bagasse in sugar mills during the crushing, so is only available for about eight months).   Hydro is the only source worth considering.

Figure 15:  Fossil fuel generation by time of day

Fossil fuels do the heavy lifting, 24 hours a day, helped by hydro. 

Figure 16:  Gas generation by time of day

Gas helps maintain supply when renewables fluctuate because generators can ramp up relatively quickly.  A lot of the time they are on standby, so have to make money when demand is high.

Figure 17:  Coal generation by time of day

Black coal generation can vary by nearly 50 percent in a few hours, every day.  They’re not designed to do that forever.  Break downs are more likely.  Brown coal is not as flexible as black coal but keeps up a reliable supply 24 hours a day.

There is a huge gap- about 10,000 MW- before renewables and storage can begin to provide for our needs.  Excluding coal and gas from firming supply- to maintain electricity supply when time and weather won’t co-operate- will make the task impossible.  Fossil fuelled generators have to make up for losses or lack of income when solar and wind supply is abundant by higher prices when demand is higher.  Supply and demand is the main reason for high electricity prices- but Chris Bowen and Albo have never run a business.

There is nothing but pain ahead, and things will get worse before they get better.

I’ve bought a generator.

(Source: OpenNEM)

Queensland’s Energy and Jobs Plan

October 1, 2022

Last Wednesday Queensland Premier Anastasia Palaszczuk released her $62 billion Energy and Jobs Plan

I can feel an election coming on.  This is pure political spin, pie in the sky stuff, that can’t and won’t work, designed to woo the city voters.  If I’m wrong and she’s serious, Queensland is in for big trouble.

However, part of it I can agree with.

It will involve building 1,500 km of 500 KVA transmission lines to strengthen the grid between north and south Queensland.  That I do applaud.

More from the statement:

The super grid will support 22 gigawatts of new wind and solar power, from between 2,000 and 3,000 more wind turbines and 36 million solar panels.

There will be another $2.5 billion to top up the $2 billion Queensland Renewable Energy and Hydrogen Jobs Fund.  That’s now $4.5 billion.

The government will finance 3 new wind farms, a new battery at Swanbank power station, and

A new hydrogen-ready gas peaking power station at Kogan Creek.

This project will provide power initially from gas blended with hydrogen with the future ability to use 100 per cent renewable hydrogen.

This will provide 3GW by 2035.

Pure hydrogen?  What can possibly go wrong?

Pumped Hydro:

However, the big ticket item is pumped hydro – $17 billion.  This will involve enlarging and redesigning Borumba Dam near Gympie to supply 2GW of electricity.  The major one is the Pioneer-Burdekin pumped hydro scheme.

Why am I concerned about this?

A sudden change of heart:

A government that is reluctant to build dams for agriculture (Rookwood Weir took years for approval) can suddenly build dams purely for renewable energy.

Poor record in dam building:

Let’s hope these dams are better designed and built than Paradise Dam, where 58% of the storage had to be released to lower the water height to a safe level. 

Effect on Community, Agriculture, and Environment:

The Pioneer-Burdekin project will involve two dams on the western side of the Clarke Range and a dam at Netherdale at the top of the Pioneer Valley.

Quoting from the Brisbane Times,   

A map of the site shows the lower reservoir — from which water would be pumped into higher dams to be released back down when energy is needed — would inundate a community of about 100 people, including cattle and cane farms, at the locality of Netherdale.

Figure 1:  Official map

I used to live close to Netherdale.  It is a beautiful part of the world, in most picturesque surroundings, in a high rainfall area.

Figure 2: Looking down the valley from Eungella

Figure 3:  Aerial image from Google Maps

To appease the greens and environmentalists,  no national park land will be affected- just farms, houses, and people.

In an indication that the Netherdale plan may not be politically viable, the government has announced that alternative sites are being considered “in the event the project is unable to proceed”.

Flooding Danger:

This proposal is not just dumb, it is dangerous.  This is a high rainfall area.  Nearby Dalrymple Heights has no BOM data since January 2010, but had 1264mm in December 1990, 1246 mm in January 1991, and 1520mm in February 1991.  That’s 161 inches in 3 months.  In February 1958 there was 1737mm and in March 1955 there was 1804mm.  In a wet season with a cyclone knocking out wind and solar farms, and cloud reducing rooftop solar over most of eastern Queensland, all these three reservoirs will be overflowing and the Pioneer River will be in flood.  Any attempt to release enough water to “keep the lights on” will cause much greater flooding.  But that’s OK- it will be caused by climate change.

The Premier claims that this plan is proof the government is returning taxes to the regions, but the pumped hydro plan will do nothing for agriculture, water supply, or flood mitigation.  It’s purely for a renewable dream that can’t and won’t work.  Here’s why.

Limited Size:

The Pioneer-Burdekin hydro project will supposedly produce 5 Gigawatts (GW) for 24 hours, or 120 Gigawatt hours (GWhr).

The Borumba Dam will produce 2 GW, or 48 GWhr.

The next plots use data from OpenNEM.

Figure 4:  Total Qld Electricity Use to 29 September

In the week to 7.30 a.m. on 29 September, Queensland’s baseload electricity usage (generation less exports) was a touch over 5 GW, the lowest being 5.036 GW at 3:30 a.m. on Sunday 25th September.  That wasn’t to “keep the lights on”.  That was to run hospitals, electric trains, street lights, traffic lights, cold stores, mines, aluminium smelters- and all before sunrise or a normal working day.  Baseload power is the minimum amount of electricity that has to be maintained for 24 hours a day every day- that is at least 120 GWhr.  Pioneer-Burdekin could do that for just one day.

Figure 5: Electricity Usage for the Year to 27 September.

In the past year, Queensland’s average daily usage was 165.2 GWhr.  (That rose to more than 180 GWhr for most of summer).  Just 31 GWhr on average was produced by solar and wind generation, with up to 39.6 GWhr of solar on one day last summer, but only 4 GWhr on July 4 .

Our grand hydro “batteries” would last for just over 24 hours, at today’s usage. 

Inefficiency:

How efficient would the pumped hydro scheme be?  From the Premier’s own Statement:

Each megawatt of pumped hydro energy storage unlocks investment in another three megawatts of wind and solar generation.
That’s because more renewable energy is needed to pump water up hill during the day storing renewable power for when it’s needed.
Supporting around 21 gigawatts of renewables – or more than 150 new wind and solar farms.

There it is: to store 1 GW of existing renewable energy we need an additional 3 GW of wind (at about 33% efficiency) and solar (at 15 to 20% efficiency).

Transport and Industry Needs:

Further, we’re supposed to be transitioning to electric vehicles.  According to Budget Direct’s Fuel Consumption Survey & Statistics 2022 in 2021 Queensland used 3,343 billion litres of petrol (excluding diesel).  At roughly 9 KWhr equivalent per litre, if only 10% of cars are electric in 2035, another 310 566.5 GWhr of electricity per year would be needed. Include diesel and the figure is 1,020 GWhr. (I’m not confident about my calculation- but this will need a huge amount of electricity.)

And Queensland is meant to be supplying hydrogen for industry as well, so the demand will be much, much greater.

Conclusion:

I am pleased with the proposal to improve Queensland’s electricity grid.  However, the rest of the plan- especially the pumped hydro- is nonsense.

Hello, Anastasia- Queensland voters aren’t so gullible.  If it sounds too good to be true, it probably is.

Power Gaps = Blackouts

September 2, 2022

On Wednesday the Australian Electricity Market Operator (AEMO) gave a warning that should not have come as a surprise to anyone with half a brain, but it made the headlines, including at the ABC:

AEMO warns of power ‘gaps’ in Australia’s biggest grid within three years as coal exodus gathers pace

Planned coal fired power station closures and increasing demand will lead to shortages from 2025 in NSW, Victoria in 2028, Queensland in 2029, and South Australia early next decade.  Of course this is seen as a wake-up call that we need more renewables, more storage, and more transmission lines.  Sceptics will say “We told you so”.

In fact, readers may remember my post from 18 June titled “The Gap”, with this figure.

I have crunched the numbers for daily electricity consumption in the eastern states for the 12 months from 1 September 2021 to 31 August 2022.  Here’s that gap again, in GigaWatthours.

(The wobbles in the Total show the weekend drops and the Christmas- New Year “silly season”, the summer and winter demand peaks, and the spring and autumn “Goldilocks” periods.)

The gap is currently at the very least 307 Gigawatthours.  The average over 365 days is 418 GWhr- and we are supposed to be converting most of our transport to electric (or hydrogen!) in the next few years. 

Hydro produced a maximum of 99 GWhr.  Snowy 2.0 will only produce another 48 GWhr, and you can forget about batteries- minuscule.

Good luck with filling that gap.

How did fossil fuels compare with renewables over the past year?   The next figure shows the percentage of total consumption supplied by coal, gas, and wind plus solar.

Coal had a short period where supply dropped to 52.3%, but averaged 59.9% over the year, rising to 68.9% on Wednesday this week.  The plotted trendline shows a decrease of 0.9% over the year. 

Renewables decreased by a whopping 6.24%- so much for the renewable transition!

Gas filled the gap, with an increase of 6%.

Just so that you are clear that the crisis we narrowly avoided early this winter was NOT caused by unreliable coal fired stations, here is a plot of renewable supply expressed as daily deviation from the 12 month average- anomalies if you like:

Wind and solar were producing much below expected- and erratically- from mid-March to mid-July.

Finally, the next figure shows seven day averages of the major energy suppliers and the total, overlaid with price per MegaWatt.

The high prices coincide with gas and hydro increasing generation when renewables were unable to meet their average supply- let alone the increase in demand.

Mind the gap.

(Source: OpenNEM)

Cheap, Reliable, and Renewable: July 2022

August 2, 2022

Some more plots from the National Electricity Market (NEM) for the month of July to illustrate the problems we continue to face. Figures 1 and 2 are updates of similar figures from June, but Figures 3 and 4 are new and hopefully show the problem even more clearly.

Figure 1: July consumption: all sources (Gigawatts)

Note the dip in consumption every weekend is even more marked than in June.

Figure 2 shows the relative contribution of all major sources, (but including battery, if you can see it).

Figure 2: July consumption as a percentage of total: all sources

Coal usage increased mid month to provide over 60% of all electricity.  The contrast with all other sources is obvious.

For the next plot I calculated anomalies from the monthly means of all energy sources. I have calculated totals for Renewables (Wind and Solar) and for Coal, Gas, and Hydro- the main sources we rely on to keep our electricity system stable. To allow for days when total consumption was up or down, I subtracted Total energy anomalies from Coal, Gas, and Hydro.

Figure 3: July consumption anomalies: renewables and non-renewables

Figure 4 shows how Non-renewables are controlled by Renewables:

Figure 4: Coal, Gas, and Hydro as a Function of Renewables

Wind and solar can sell to the market as much energy as they produce, so on days (and hours) when they can supply more, coal, gas, and hydro must cut back. However, at those times when the sun doesn’t shine and the wind is not as strong, the shortfall has to be made up by non-renewables- and with gas in short supply, that means higher costs.

The average daily price in July was $376.73.

(P.S.- Hydro is normally included as a renewable, but really it isn’t. In drought years, there’s not enough water to power the turbines, and in wet years- like 2022- water release through the turbines causes downstream flooding, so needs to be curtailed.)

The Cost of Electricity

July 7, 2022

What drives changes in the wholesale price of electricity in the National Electricity Market (NEM)?  Here are some plots that may help understand the problem.

Figure 1 shows electricity generation and wholesale price for the 12 months to 3 July.

Figure 1: Total generation and price

The price had nearly doubled from August 2021 with no great increase in demand, but began to rise more and more sharply since the invasion of Ukraine on 24 February.  Figure 2 shows the percentage contribution to total generation of various sources since then.  I have included batteries for entertainment value.

Figure 2: Percentage contribution to total generation since the start of the Ukraine war.

On 12 June the AEMO intervened in the market and set a cap on prices.  Prices were claimed to have risen because of the shortage of gas and coal and the failure of coal generating sets.  Certainly coal’s contribution had fallen from around 60% of total generation to the low 50s over the three week period leading up to the intervention. 

In this post I analyse how the price of electricity varied with changes in the energy mix during the period of rapid rise.

As both price and generation was changing, it is necessary to remove the trend in price to get an accurate analysis.  Figure 3 shows the price of electricity from the day after the Ukraine invasion to the day after the AEMO price cap, fitted with a 2nd order polynomial trend line. 

Figure 3: NEM wholesale price

Figure 4 shows the detrended price timeseries.

Figure 4: NEM wholesale price detrended

This shows that the price was becoming more volatile.

Now I look at the contribution of each main generation source in relation to the average wholesale price of all electricity (detrended).  In each, the line at zero represents the actual trend.

Figure 5:  Price and percentage contribution of solar generation

As solar generation increased by one percent, the price decreased by $1.63 per Megawatt.  That would be excellent news if the sun shone 24 hours a day.

Figure 6:  Price and percentage contribution of wind generation

Again we see the cost decreasing with more renewable generation- $4.23 less for each extra percent of total generation.  However, the plot also shows the converse- when there is little wind the cost is much greater.

Figure 7:  Price and percentage contribution of hydro generation

Great faith has been placed in the necessity of having pumped hydro as a store of renewable energy, but Figure 7 shows that the cost increases by $7.77 for each extra percentage point of total need that hydro back up provides- well above trend. 

Figure 8:  Price and percentage contribution of gas generation

Gas is in short supply and very expensive, so the cost of providing each additional percentage point of the total generation is $11.08. 

Figure 9:  Price and percentage contribution of coal generation

Here’s something the renewables industry and the ABC won’t tell you.  The wholesale price of electricity actually decreases as the proportion of coal generation increases.  As well, price volatility decreases.  Above 62% the average price across the network is relatively stable, varying by +/- $100 per Megawatt.  Below 62% the price becomes more and more volatile.

As more and more renewables come on line, coal usage will drop, to apparently near universal acclaim.  Figure 10 shows how wind pushes out coal:

Figure 10: Percentage contribution of wind and coal

But there was no new additional wind capacity during this period.

And Figure 9 above shows cost and price volatility will increase as reliability decreases.

How should we keep prices down, and maintain reliability?

Coal is your friend.

Cheap, Reliable, and Renewable

July 4, 2022

(or How Not To Run An Electricity Grid)

Here are some plots from the National Electricity Market (NEM) for the month of June which may illustrate the problems we will continue to face.

Figure 1: June consumption: all sources (Gigawatts)

Note the dip in consumption every weekend.

Figure 2 shows the relative contribution of all major sources, (but including battery, if you can see it).

Figure 2: June consumption as a percentage of total: all sources

You may note that coal stepped up mid-June to produce 60% of all electricity.  The contrast with all other sources is obvious.

The next plots show June monthly average, maximum, and minimum for all major sources.

Figure 3: June consumption Average, Maximum, Minimum

Note that while coal ranged from about 300 to 350 GW, wind ranged from almost half coal’s minimum to very little.

Figure 4: June consumption Average, Maximum, Minimum as percentages

Coal stands out for its consistency.  And with all the rooftop solar and solar farm expansion, solar cannot produce 10% of our power needs.

The next figures compare coal with renewables to show the daily fluctuation, that is, how much the electricity generated (and consumed) each day compares with the one before.

Figure 5: Percentage daily change in electricity consumption: coal and total

The close match between coal and total consumption is obvious.  Coal’s daily percentage changes (above that of the total) on the 2nd, 13th, 16th, 17th, 18th, 21st, and 30th June correspond to the fall in renewable generation – especially wind- on those dates, as Figure 6 shows for coal and wind.

Figure 6: Daily change in coal and wind consumption (Gigawatts)

The contrast is even starker when expressed as a percentage:

Figure 7: Daily percentage change in coal, wind, and solar consumption

Coal can change on a day to day basis by 20 to 30 percent.  Wind can decrease by 76 percent or increase by 326 percent from one day to the next.  What a way to run an electricity grid!

One thing you can say about renewables: they can be relied on to be unreliable.

Blowin’ in the Wind

June 22, 2022

The energy crisis seems to be ongoing- the new normal apparently.  Is it the fault of old, rundown coal fired power stations with breakdowns?  Is it the fault of greedy, profit hungry energy suppliers gaming the system?  Is it the fault of the Ukraine war pushing up coal and gas prices?  Is it the fault of the previous coalition government for not having the correct climate policy, resulting in not enough investment in renewables?  Or all of the above?

Nope.

Breakdowns last week in under-funded power stations didn’t help, nor a shortage of high priced coal and gas.  And you can’t blame companies wanting to keep their income above their costs. 

But no amount of climate ambition, and no possible amount of renewable capacity, could have averted the problems we’ve had last week and are likely to continue to have.

Figure 1 shows our electricity consumption for the two weeks from 3rd to 17th June. 

Figure 1:  All NEM electricity consumption 3- 17 June

Coal is the heavy lifter.

Figure 2 shows the main energy sources as a percentage of the total usage.

Figure 2:  All sources as a percentage of NEM electricity consumption 3- 17 June

Note again it is coal followed by daylight- and I don’t mean solar!  Note also that coal’s relative contribution increased despite breakdowns and supply difficulties.

The next plot shows the percentage contribution of fossil fuels and all non-fossil sources- batteries, hydro, wind and solar.  I’ve also included the negative contribution of pumped hydro, when dams are refilled using excess electricity- except on 13th and 14th when it was too expensive.

Figure 3:  Fossil and non-fossil generation as a percentage of consumption

Renewable energy advocates like averages- they hide a multitude of sins.  Here are the averages of all sources for each 30 minutes of the day for the last two weeks:

Figure 4:  Average 30 minute NEM electricity consumption 3- 17 June

Coal varies between 12,000 and 16,000 MW per half hour as it responds to the twice daily peaks in demand, and the daily peak in solar output.  Solar is useless for meeting baseload around 4:00 a.m., or either of the daily peaks.  Wind averages a touch over 4,000 MW all day so is also no help with extra demand.  Battery discharge at peak times can barely be seen.  Gas and hydro vary at similar rates to meet demand when needed, though gas output remains higher throughout the night.

How reliable was wind generation, which averaged over 4,000 MW per half hour?  Here is a plot of actual wind generation at 30 minute intervals from 3 June to 17 June:

Figure 5:  Actual wind generation 3- 17 June for each half hour

“Fickle” is not an adequate description.

Of course renewables can provide 18,000 MW at maximum capacity- but at the wrong time of the day.  When the need was greatest, they could provide only 6,880 MW- and 90% of that was hydro.

Our entire electricity generation, including fossil generation, depends on the reliability or otherwise of renewable generation.

Our energy crisis last week was not caused by breakdowns, fossil fuel prices, greedy power companies, coalition governments, or lack of investment in renewables.

It was caused by a lack of wind.

Figure 6:  Actual wind generation 3- 17 June

We are hostages to the weather.  Bob Dylan was right.  The answer is blowin’ in the wind.

(Source: OpenNEM)

The Gap

June 18, 2022

Here is a simple plot to demonstrate the challenge facing our new government, and all future governments, if they want to transition to a zero carbon economy.

This is the gap between all non-fossil fuel generated electricity- solar, wind, and hydro- and total consumption in eastern Australia over the past two weeks (3rd to 17th of June) for every 30 minutes of the day.

That gap- 12,000 to 16,000 MW for base load and 16,000 to 30,000 MW for peak load- is now filled by gas and coal.  Snowy 2.0 will only provide an extra 2,000 MW of storage.

That’s just for electricity- don’t forget electric vehicles and hydrogen!

(Source: OpenNEM)

The Real Cost of Renewables

June 13, 2022

Electricity prices are increasing, we know.  Here is a plot of electricity prices across the eastern states in the National Electricity Market.

Fig. 1:  NEM Prices 2009-2022

There is a shortage of available coal and gas generation, resulting in record prices.

Fig. 2:  NEM Coal & Gas Prices 2009-2022

Of course wind and solar are much cheaper:

Fig. 3:  NEM Wind & Solar Prices 2009-2022

See?  Renewables are cheaper.

Not so fast.

Figure 4 shows electricity consumption for the eastern states last week (Friday 3 June to Friday 10 June).

Fig. 4:  NEM Total Consumption 3 June – 10 June

Note the daily cycle between baseload and peak load.  Figure 5 is a plot of consumption for each 30 minutes of the day:

Fig. 5:  NEM Total Consumption by Time of Day

The baseload- the minimum amount of electricity to meet the needs of streetlights, hospitals, smelters, and households- occurs every day between about 3.30 a.m. and 5.00 a.m., and last week was from 20,600 to 22,300 MW.

Peak load rose to 35,386 MW.

Figure 6 shows how wind and solar performed last week:

Fig. 6:  NEM Wind & Solar Consumption 3 June – 10 June

The bleeding obvious is that while solar provided more than 10,000 MW for 30 minutes on Saturday 4 June, it produced absolutely zero every night.  Wind never reached 7,000 MW.

That’s the reason we need storage.  If we can store the excess from solar, we could use it to supplement wind when needed.  Much money has been invested in large scale batteries.  However, batteries provided a maximum output of 324 MW last week- pathetic really.

We do have hydro-electricity, mainly in Tasmania and the Snowy Mountains.  Figure 7 shows how hydro contributed last week:

Fig. 7:  NEM Hydro Consumption 3 June – 10 June

Hydro helped twice a day at peak times, and also provided a substantial supply in daylight hours- over 2,000 MW on 8 June.  The previous week- at 6 p.m. on Thursday 2 June- wind could manage only 3% of the NEM load, and hydro provided 19.33%, or 5,382 MW.  Last Thursday 9 June at 6 p.m. hydro provided 5,519 MW.

That’s why we need more storage.  Forget batteries- the only realistic storage is pumped hydro, where excess off-peak electricity is used to pump water to storage dams.  Wivenhoe Dam in Queensland has been doing this for 40 years.

So the politicians dreamed up Snowy 2.0.  This scheme, whose timeline for completion has blown out to the end of 2026 according to Chris Bowen (Weekend Australian June 11-12), will cost 4.5 billion dollars to build, plus another $1.5 billion to $2 billion for extra transmission lines.

 “Snowy 2.0 will provide an additional 2,000 megawatts of dispatchable, on-demand generating capacity and approximately 350,000 megawatt hours of large-scale storage to the National Electricity Market. To provide context, this is enough energy storage to power three million homes over the course of a week.”

That’s a cost of $3.25 million per MW.

That’s the “good” news.  Now for the interesting news.

As we saw above, baseload last week was 20,000 to 22,000 MW- and winter has only just started.  If fossil fuels are removed eventually, baseload at 4 a.m. must be met by some combination of wind and hydro as there is no sun at that time of day. 

The current hydro capacity is 9,285 MW.  Snowy 2.0 will provide an extra 2,000 MW.

The current installed capacity of wind generation is 9,202 MW- and that is going full bore day and night, with optimum wind conditions and no stops for maintenance.  32% of capacity is the average reached.

The total installed capacity of wind, current hydro, and Snowy 2.0 is 20,487 MW.  That is still short of baseload with winter to come, and peak load last week was 35,386 MW.  That doesn’t allow for population increase or economic growth either.  Where will the extra 15,000 MW of wind powered and pumped hydro electricity come from?  It’s an impossible dream.

But wait, there’s more.

Here’s the bad news:  Hydro electricity is the most expensive electricity in Australia- more expensive than either coal or gas.  In May 2022 it reached $315.91 per MW.

Because it is rapidly despatchable it is sold at times of very high demand, so the operators get top dollar.  Much more than coal or gas.

Figure 8 shows the average price of hydro for each month to May 2022.

Fig. 8:  NEM Hydro Prices 2009-2022

The real cost of renewables will include the cost of storage and emergency supply.

Don’t hold your breath hoping for electricity prices to come down.