Why "baseload" is so antiquated

Hazelwood big battery. Source: Engie

Back in the 50s, electric grids everywhere had coal power stations backed up with peaking gas. Since coal power stations couldn't ramp up quickly (or economically) they tended to provide what was called "baseload". This was designed to provide a fixed supply of electricity to the grid, the level set at the point of lowest demand. The fluctuations in demand above that tended to be provided by gas, which can ramp up or down quickly.

Then along came wind and solar. Their output is driven by the weather. Peaks in supply didn't necessarily coincide with peaks in demand, although in hot places, the surge in demand because of a heatwave is now routinely met by a surge in output from solar. This required changes in how we run our grids. Most likely, we will end up with some over-capacity in wind and solar (estimates vary, but, say, around 20%) along with 4 to 6 hours of grid-wide storage.

Many still hanker for the old simplicities. The "Liberal"/National Party Coalition in Australia is very keen on nuclear. It doesn't matter that it's at least 50% more expensive even than new coal; or that new nuclear power stations in Australia won't start operating for, probably, at least another 15 years, which is a bit of a problem given that aging coal power stations will have closed down by then; or that even with 8 hours of storage with batteries (at current prices), wind and solar are 1/4 the cost of nuclear. But there is another problem with nuclear. It's even harder to ramp up or down than coal. And given the penetration of rooftop solar, the net demand on the grid (i.e., after rooftop solar) in east coast Australia now falls so low at midday that there simply is no space for GW-level baseload. (A situation already driving coal power stations to bankruptcy).

From Renew Economy

On Monday at around 5 pm (AEST), Victoria posted a new high for operational demand for the state’s grid of 9,581 megawatts (MW) in the midst of a record-breaking December heatwave.

Despite having two of its coal generation units off line, the state had little trouble dealing with the surge in demand because renewables were also delivering a record level of output.

Within 24 hours, however, the Australian Energy Market Operator, having spent much of the day issuing lack of reserve warnings for NSW and elsewhere, was back on line issuing a market notice of a different kind: warning not of a lack of reserve but of a lack of demand (minimum system load) for Victoria for Saturday, December 21.

The sudden switch from nearly too much demand to nearly too little demand is symptomatic of the dramatic changes that are occurring on the grid, and one of the fundamental reasons why most energy experts thing the idea of shoe-horning gigawatts of inflexible nuclear power capacity into the grid would be nuts.

The best to deal with such fluctuations, the experts say, is with flexibility – both in demand and supply – and most of that can be delivered by providing incentives to change the times when electricity is consumed, and ensuring fast reaction and flexible power sources, such as big batteries, can be deployed.

The warning for minimum system load cited potentially insufficient demand for Victoria at around 1pm on Saturday, with sunny conditions, high rooftop solar output, mild temperatures and the lack of business activity contributing to low operational demand.

The MSL notices are issued so that the markets can prepare a response. There are various options, but at the last resort AEMO can issue instructions to big batteries in that state (like the Hazelwood battery pictured above) to stand by on empty and get ready to charge – i.e. creating demand – if conditions warrant.

If that fails, there is a solar switch off mechanism, although that has limited application and is not popular, with either households or politicians and is seen as very much a last resort.

The MSL notice from AEMO – like another that was issued in early December – cited a forecast minimum demand of around 1,643 MW. The one issued for December 8 expected minimum load of around 1,250 MW.

This fits in with Tesla’s observations, in a submission to the federal nuclear inquiry, that most states in Australia, including Victoria, would struggle to support even 1 GW of baseload, or “always on” power because of the growing impact of renewables, and rooftop solar in particular.

It has warned that the federal Coalition’s nuclear power plan would result in “severe” constraints on rooftop solar – not just the occasional partial switch off in events like those cited above, but almost on a daily basis to accommodate nuclear power that does not like to ramp up and down.

“Given Australia’s world-leading solar and wind resources, and leading rates of rooftop solar PV, the power system’s minimum operating demand threshold becomes an upper ceiling for baseload supply to operate the power system in a secure and reliable state,” Tesla wrote in its submission.

“Increasing renewable penetration at these times further displaces baseload generation, reducing capacity factors and increasing the cost of supplying energy to consumers.

“The practical sizing of baseload generation is now significantly less than the minimum operating load.”

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.

16 hours of clean energy daily

 From Energy Storage News

San Jose Clean Energy, a non-profit electricity supplier in California, has celebrated the completion of a solar-plus-storage project which will ensure the delivery of carbon-free electricity during evening peak times.

The supplier held an online press conference on 2 February to officially inaugurate the Kern Solar and Storage Battery Project, which was brought online by developer Terra-Gen on 31 December 2021.

Under a 12-year power purchase agreement (PPA) signed with San Jose Clean Energy, Terra-Gen guarantees that 62MW of energy from the facility will be available to the supplier’s member-customers between 6pm and 10pm each day.

This is the period after solar production has tailed off for the day and evening demand for power from homes and businesses in San Jose, the largest city in Silicon Valley. The city is targeting becoming carbon neutral by 2030, which will make it the US’ first, and SJCE’s 350,000 customer accounts representing about a million people will be a big part of that, city mayor Sam Liccardo said at the press conference.

Liccardo said the 62MW of power is equivalent to about 20% of SJCE’s demand, but more importantly the project addresses the intermittency, or variability, challenge that renewable energy brings to the grid.

In effect, clean energy will be supplied from the project for 16 hours a day, seven days a week, SJCE director Lori Mitchell pointed out. It is also the first project to come online from a US$1 billion investment commitment into four large-scale solar and wind projects by SJCE, one of California’s Community Choice Aggregator (CCA) energy suppliers.

One of the next in that list will be another 100MW project by Terra-Gen, for which the CCA has signed a 15-year PPA, expected to come online during this year.

The Kern project is at the Edwards Air Force Base site in California’s Central Valley, in Kern County where many of the state’s large solar — and wind — farms are located.

Terra-Gen, which will own and operate the project, already has a 2GW wind energy power plant nearby, and the project for SJCE is part of a much larger solar and storage facility it is building at Edwards Airforce Base.

In fact the plant — or rather the vast complex — referred to as the Edwards & Sanborn project, is thought to be the world’s largest combined solar-plus-storage facility to date. Aiming to eventually reach 760MW of PV and 2,445MWh of battery storage, Terra-Gen closed US$804 million financing for its initial 346MWac PV and 1,501MWh of batteries in August last year.

Off-taker deals have been signed with a range of different parties, from corporates like Starbucks to other CCAs and some portions of the project have already been delivering.

Simon Day, VP and head of solar development at Terra-Gen said that for the SJCE deal, the developer built an oversized 118MW solar PV array at the site, as well as additional new battery storage.

It is also able to use other resources such as wind from the company’s portfolio to firm the delivery of clean energy for 16 hours a day, in what he described as a “groundbreaking” arrangement for the solar industry.

 

Aerial view of the project, built on land leased from Edwards Airforce Base. Leasing revenue will go towards maintaining the base’s mission, Terra-Gen’s Simon Day said. Image: SJCE / Terra-Gen.

16 hours baseload a day is great. And the remaining 8 hours can be covered by wind.  Unfortunately, the article doesn't give the cost (LCOE) but presumably it was competitive, i.e., even with storage.  Every day, we're getting closer to a grid which will no longer need fossil fuels.

A giga-battery for South Australia

 From RenewEconomy

French renewable energy developer Neoen has filed its development application for the huge $3 billion Goyder South wind, solar and storage project in South Australia which includes a proposed big battery than it nearly 10 times bigger than the expanded “Tesla big battery” at Hornsdale.

The plan proposes a total of 1,200MW of wind energy, 600MW of solar PV, and 900MW/1800MWh of battery storage, an “extremely large” battery as Neoen describes it that will dwarf the 150MW/194MWh “Tesla” battery known officially as the Hornsdale Power Reserve.

Each stage would be delivered in three equal tranches of 400MW wind, 200MW solar and 300MW/600MWh of battery storage. Combined, they would generate around 4.8 terawatt hours of zero emissions power each year, nearly doubling the current output of wind and solar in the state, and taking South Australia close to the Liberal government’s net 100 per cent renewables target just on its own.

Neoen insists that the first stage is likely to go ahead regardless of any significant grid upgrades, but admits that the second and third stages would be contingent on the new transmission line between South Australia and NSW, known as Project EnergyConnect, going ahead. It will be located south of Burra, and north of Robertstown, where the new transmission link is expected to link to the state grid.

“The Goyder region in South Australia is home to some of the best wind and solar resources in the country,” the company says in its application.

“The Goyder South Hybrid Renewable Energy Facility is proposed to take advantage of these resources by combining wind, solar and energy storage in one integrated project. The facility will be capable of delivering a steady, reliable, dispatchable output of power throughout the day and night.”

Neoen says the wind facility will be made up of up to 163 turbines, suggesting a capacity of 7.3MW per turbine – by far the biggest announced in Australia to date. It says these machines will have a maximum hub height of 160m, a maximum blade length of 80m and an overall maximum height (tip height) of 240m.

The solar farm would be spread across 3,000 hectares, the lithium-ion batteries would deliver 900MW with two hours of storage, and associated infrastructure for connection to the electricity grid would include three substations, access tracks, underground connection cabling and transmission lines.

Neoen says the “extremely large battery” associated with the proposed project would be located on the South Australia end of the future EnergyConnect line and would, like the Hornsdale Power Reserve, provide crucial grid support functions to the state's energy supply.

“It would be available to assist the grid in the event of major disruptions,” it says, noting the key role that Hornsdale and other big batteries played in  keeping South Australia’s grid stable during the recent disruption to one of its major links to Victoria.

“The battery's key role, however, would be to allow Goyder South to provide 'hedge' contracts to consumers such as industrial customers or electricity retailers,” it says.

“These contracts guarantee customers a fixed power price 24 hours a day, irrespective of regional spot price fluctuations. This reduces the risk of power price fluctuations to large, energy-intensive industries and businesses such as mines, smelters, manufacturers and retailers.

It says the hedge contract market has previously been occupied exclusively by fossil fuel generators. “Goyder South would be able to provide these contracts at a much lower cost, and without the emissions, environmental damage and exposure to international fuel prices associated with gas generators.

“By combining energy production and storage, Goyder South would overcome the conventional critique of renewables that they are 'intermittent' and 'unreliable'. Hybrid projects such as this are the natural next step in the transition to a cleaner, cheaper, renewable economy.”

Neoen says wind in this region tends to blow most strongly at night, while solar is, of course, present during the day. The resulting energy output, firmed and smoothed by battery storage, would be able to closely match South Australia's average consumption profile.

[Read more here]

Three points: 

1. This project alone will take South Australia to 100% renewables.  No other region this size has reached 100% renewables except those with hydro (like Uruguay, for example, with 3.8 million people), or less populated regions embedded in a transcontinental grid (like Mecklenburg-Vorpommern, in northern Germany next to the Baltic Sea, with a population of 1.6 million, about the same as SA's 1.7 million)  That this push is being undertaken by a 'Liberal', i.e., right-wing government, is remarkable.
2. This kind of combined facility, with wind, solar and storage, is cheaper than separate facilities and is also better for the grid. It produces baseload power, and its output (after 'firming' by the battery) minimises fluctuations in grid voltage and frequency.
3. It was just a couple of years ago that the original 'big battery' which Elon Musk said would be built in 90 days or would be free was built.  At the time it was the largest battery in the world.  As Musk no doubt intended, its success has encouraged the roll out of many more big batteries everywhere.  Denialists mocked the big battery, but it has already saved South Australia from blackouts when the rest of the grid went down.  This new giga-battery will make the grid even more stable.

Largest wind/solar/storage facility in Africa

View of Mt Kenya near Timau, Meru county, Kenya
Source: This is Kenya

From IEEFA:

Japanese developer Eurus Energy and Australian-headquartered wind developer Windlab have signed a deal with Kenyan authorities to develop an 80MW solar-plus-wind-plus-storage facility in central Kenya. The Meru County Energy Park is being hailed as “Africa’s first large-scale hybrid wind, solar PV and battery project.”

According to news reports in The Standard and ESI-Africa, the US$150 million plant will comprise 20 wind turbines and 40,000 solar panels. The facility will be a public-private partnership, and the Meru County government will own part of the project once it is operational. Construction is due to start in 2021.

A memorandum of understanding (MoU) was signed between Windlab East Africa, Eurus Energy, the Kenya Investment Authority and Meru County government on Thursday 29 August at the Tokyo International Conference on African Development.

In June, a consortium of government and development financiers, including the World Bank and Dutch development institution SNV, unveiled a US$47 million pot for providers of off-grid domestic solar in rural Kenya.

I talked here about how Windlab is constructing a similar facility in Australia.  If you think about it, it's obvious that a combination of wind and solar will produce more stable output than solar alone, if only because the wind blows at night when the sun doesn't shine.  But since, even without that, wind and solar tend to be inversely correlated, the average of the two is less variable. If you add enough storage to the mix you should be able to get near baseload output.  For a developing country unfamiliar with renewables, a single plant producing output which mimics the output of a baseload power station is presumably easier to integrate into the grid.   Also, because the wind, solar and storage are all co-located, it'll be cheaper too. 

Afterthought:  Isn't that part of kenya stunning?  I want to go there!

Mind-blowing solar plus storage contracts

We all know that wind and solar are now cheaper than coal, and even in the USA, where gas is cheap, sometimes than gas too.  But the fossil-fuel spruikers will leap into words and point out that the sun doesn't shine at night and the wind doesn't blow all the time.  (We didn't know that.)  So the holy grail is wind or solar with enough storage to "firm" it, i.e., to provide the equivalent output to baseload power stations.  In Hawaii, a classic example of "island grids", the latest solar plus storage contracts now provide that, and significantly more cheaply than oil-fired power stations.  That is indeed mind-blowing.

From GreenTech Media:

This week Hawaiian Electric Company sent seven new solar-plus-storage contracts to state regulators. Six come in at record-low prices for the state, under 10 cents per kilowatt-hour.

The projects, which now await regulatory approval, would add 262 megawatts of solar and 1,048 megawatt-hours of storage distributed over three islands. The company said the projects will provide power “in place of volatile prices of fossil fuels,” which it quotes at about 15 cents per kilowatt-hour. 

Both the pricing and the size of the contracts are significant. 

“It’s hard to overstate the scale of this announcement,” said Dan Finn-Foley, a senior energy storage analyst at Wood Mackenzie Power & Renewables. 

Past solar-plus-storage prices in Hawaii came in at 13.9 cents per kilowatt-hour in 2016 and 11 cents per kilowatt-hour in 2017. One of the projects announced this week by Hawaiian Electric is more expensive than the latter price — 15 megawatts of solar and 60 megawatt-hours of storage at 12 cents per kilowatt-hour. But another 90 megawatts of solar and 360 megawatt-hours of storage came in at what Finn-Foley called a “jaw-dropping” 8 cents per kilowatt-hour. That means that from 2016 to 2019 solar-plus-storage PPA prices in the state dropped by 42 percent. 

Will Giese, executive director at Hawaii’s Solar Energy Association, called the pricing “mind-blowing.” 

“With prices like these, it’s easy to understand the confidence of Hawaiian electric providers that their islands can hit 100 percent renewables ahead of the 2045 mandate,” said Finn-Foley. 

[Read more here]

Some notes:

1. These contracts are for solar plus 20 hours of storage, assuming a solar capacity factor of 20%, 16 hours at a capacity factor of 25%.  This is enough to provide baseload power.  Remember, apart from places like Las Vegas, the highest electricity demand is during the day--some 60%.  This suits solar power almost perfectly, with the only problem being that demand peaks after the sun does, requiring some 4 hours of storage to fill that gap.  The rest of the storage satisfies night demand.
2. The total cost is something like 9 cents/kWh or $90/MWh--for "firm" electricity.  This compares with oil at $150/MWh, coal at an average of $102/MWh and gas at $58/MWh (in the US--it's twice as expensive elsewhere)
3. The costs have fallen 42% in 3 years.  They will go on falling.  The gap between "firm" solar or wind and fossil fuels will only get bigger.
4. Such cost comparisons don't only apply to Hawaii, but to any off-grid community, such as mines, remote towns, other islands, etc.  In fact another 30% cost decline over the next couple of years (which is very likely) will mean that even non-islanded grids will find these costs very attractive.  Only fully-depreciated and paid-off coal power stations will still be competitive.  And they're wearing out because they're aging and will have to be progressively shut down over the next 20 years.  The future is renewables.
5. The utilities really like the fixed costs of solar (and wind) compared with variable costs of fossil fuels.  Regulators won't let them adjust their selling prices fast enough to compensate for swings in oil, coal and gas prices.  But with solar and wind, because they have no fuel inputs, the costs are fixed and known in advance.  Perfect.

Wind plus solar hybrid update

I talked about Windlab's hybrid wind/solar/storage Kennedy "energy park" here.  Cleantechnica has an update:

A world first renewable energy project has taken its first steps in Australia, with big-name companies Vestas, Tesla, and Windlab backed by Australia’s Clean Energy Finance Corporation partnering on a $160 million, 60 MW hybrid wind, solar, and energy storage project.

A flurry of announcements were published Thursday confirming the development of a 60 MW (megawatt) hybrid wind, solar, and energy storage by Australia’s international wind energy company Windlab. The AUD$160 million Kennedy Energy Park set to be built in central north Queensland as a joint venture between Windlab and Eurus Energy Holdings Corporation of Japan.

Kennedy Energy Park will be the first wind, solar, and storage hybrid generator connected to Australia’s national electricity network via a single connection point. It also serves as an industry-leading project demonstrating the complementary nature of the three technologies and proving their ability to work together. Vestas — who will provide the wind turbines for the project — describes the project as a “world first” of its kind.

The Kennedy Energy Park will consist of 43.2 MW worth of wind, made up of twelve Vestas V136, 3.6MW turbines; 15 MW worth of AC, single-axis tracking solar; and a 4 MWh Li Ion battery storage provided by Tesla.

Upon completion, Kennedy will be able to generate approximately 210,000 MWh of electricity per annum, which is the equivalent of enough electricity to supply over 35,000 average Australian homes.

[Read more here]

I estimated that they might need 3 hours of storage, but in fact they will have only about 10 minutes' worth.  Although the battery storage is enough to stabilise short-term fluctuations in output, it's not enough to provide the "load shifting" needed for the evening peak in demand.   I presume that the cost of battery storage remains a limiting factor.  To provide true baseload, they will need more storage, to wit, 72 MWh.  However, the new Kidston pumped hydro storage in N Queensland (a couple of hundred k's west of Kennedy) will have 2000 MWh of storage (more on that in a later post)

(As an aside, the last paragraph in the quote above suggests a daily household use of electricity of 16.4 kWh, a tad higher than my previous estimate of 15.9 kWh.  The shorter-range Tesla Model 3 will have a 50 kWh battery pack or 3 days' worth of power for the average Ozzie house.  The Tesla home battery, the Powerwall, has 13.5 kWh of storage, or enough to cover 19 hours of demand.  I suspect that most of the battery storage in Australia will initially be behind the meter)

Baseload from wind and solar

Those who are still wedded to coal (with an occasional foray into nuclear) keep on insisting that we need baseload electricity, and that wind and solar are too "variable" to allow us to rely on them.

This chart, which references the new Kennedy wind plus solar plus storage project by Windlab in Queensland's far north, shows how closely you can produce near baseload output from a combination of these two different renewables.

Source: Windlab Prospectus

The pine green shows measured daily output averaged over one year from wind, the dark blue from solar, and the top of the green shows the combined averaged daily output from wind and solar.  The black line shows averaged daily demand in Queensland.  The times of day when supply from wind plus solar is "above" the black line (they are on different scales) more power is being produced than is needed, while when the top of the pine green line is "below", it's the reverse.  So storage is needed; the batteries charging up overnight and discharging from midday to about 10 p.m., with the maximum "gap" at about 6 p.m. when everybody gets home and turns on the aircon and the kettle, before wind speeds have picked up.

Well, say the baseload promoters, you don't need storage with baseload, because it's always there.  Have another look at the chart.  The red line on the chart represents hypothetical baseload output from, say, a coal-fired power station.   There would be too much electricity produced between 10 p.m. and six a.m., and too little between 1 p.m. and 10 p.m.  You would still need storage. Or you would need peaking gas plants from 1 p.m. to 10 p.m., and you would have to wastefully vent steam from your coal power station to prevent the grid overloading between 10 p.m. and 6 a.m., because you can't quickly dial down (or up) the heat output of a coal power station to meet variations in demand.  Both very expensive.  In fact batteries would be really useful to a grid with 100% baseload electricity generation too.  The only difference between a 100% baseload and a 100% renewable grid is that you you would need roughly twice as much storage capacity.

The three key objectives to consider are cost, reliability and carbon emissions.  A 100% renewable grid with a mixture of wind and solar produces no carbon, and will (with enough storage capacity) be completely reliable.   All good, but will it be cheaper?

That depends on the cost of storage and how much you need.  The new Tesla Powerpack utility-scale battery costs US$109/MWh (back of the envelope calcs, using the costings revealed by Elon Musk for the South Australia battery bank)  Reading off the chart, you'd need storage equal to half of demand for 3 hours and 20% of demand for 5 hours, or a total storage of 2 and a half hours of daily demand.  Let's say 3 hours, to be safe.  Wind and solar are half the cost of coal, even ignoring coal's CO2 emissions and lethal pollution.  Wind is A$55/MWh, solar (at that latitude) A$65/MWh. Assuming capacity factors of 40% for wind and 25% for solar, about 80% of the output will be wind, 20% solar, so roughly A$57 for the electricity output.  Cost of storage in A$ is $145/MWh (US$109 /0.75)  You'll need 3 hours total storage to cover 24 hours demand, so that's $145/24*3, or  A$18/MWh.  Total cost = A$57 + A$18, or $75/MWh⧫.  New coal is A$110/MWh before a carbon tax, and that ignores the storage needs of baseload ($9/MWh?) or the cost of gas peaking power plants, and venting steam at night (X$/MWh??)  So, A$75 vs A$120, or a 40% discount for renewables over coal, with zero carbon emissions and complete reliability.

A combination of wind plus solar with storage can provide baseload, more cheaply and much more cleanly than coal can.  There is no case for baseload coal.  Existing coal power stations will keep going until they wear out, but there will be no need for new ones to be built.





⧫ Incidentally, the same price that the new CSP plant in South Australia will be selling its output to the SA government.  But the CSP plant will provide 8 hours of storage.  CSP still a lot cheaper than batteries.