Bear Pit: now the sole domicile of politics at LuLa

[myotis]

Thanks for the link, Andrew. Now I understand why electricity prices are so low in countries which have prioritised the shift to renewables, such as the UK and Germany. (Joke      )

Electricity prices in the UK are primarily set by the price of gas and largely unrelated to production costs. 

In Scotland, all domestic electricity now comes from renewables and it's the cheapest (to produce) in Europe, but the most expensive in Europe to buy. It also costs 40% to 50% more to buy in Scotland than it does in London.

The numbers come from one of the smaller UK electricity companies ( I can't remember which one), a few weeks ago.  They were complaining about electricity prices being linked to gas prices

[Robert Roaldi]

Thanks for the link, Andrew. Now I understand why electricity prices are so low in countries which have prioritised the shift to renewables, such as the UK and Germany. (Joke      )

I did an internet search for the states in America which have the lowest electricity prices and what is the source of their electricity generation. Here's a list of four states that have the cheapest electricity generation.

There must be something that those LCOE estimates are not including.

1. North Dakota
In North Dakota, the primary source of electricity generation is coal, specifically lignite coal, which accounts for 55% of the state's electricity production. Wind energy is the second largest source, providing 36% of the electricity.

2. Wyoming
The primary source of electricity generation in Wyoming is coal. While coal-fired power plants still dominate, a significant and increasing amount of electricity is also generated from wind and natural gas, along with hydropower.

3. Louisiana
The primary source of electricity generation in Louisiana is natural gas, accounting for a significant portion of the state's electricity production. In 2023, natural gas fueled 76% of Louisiana's electricity net generation, making it the dominant source. The state also relies on nuclear power, which generated around 15% of electricity in 2022.

4. Utah
In 2023, Utah's primary source of electricity was coal, which accounted for 47.3% of the state's total generation. Natural gas followed as the second largest source, contributing 35.5%. Renewable sources (including solar and wind) made up 15.5% of the state's electricity generation.

Would coal be cheap if the producers/users weren't permitted to externalize costs, specifically pollutant/carbon effects? It's not so clear. The subsidies given to renewables are relatively easy to list, they show them in budgets. The 100+ years of subsidies to fossil fuel industries are less immediately obvious but that doesn't mean they're not real. What's the cost to American society of oil refinery pollution of the Louisiana coast. Who pays it?

We willingly pay more for modern medical procedures because they work better. The "cheaper" option isn't always the better choice.

[Ray]

Would coal be cheap if the producers/users weren't permitted to externalize costs, specifically pollutant/carbon effects? It's not so clear. The subsidies given to renewables are relatively easy to list, they show them in budgets. The 100+ years of subsidies to fossil fuel industries are less immediately obvious but that doesn't mean they're not real. What's the cost to American society of oil refinery pollution of the Louisiana coast. Who pays it?

We willingly pay more for modern medical procedures because they work better. The "cheaper" option isn't always the better choice.

Good point! The external costs of so many activities are difficult to quantify because of the complexity and uncertainty of the situation, and also because of human bias due to monetary incentives.

I consider myself to be relatively unbiased because I'm retired with no debts, own a 5 acre property which would allow me to feed myself if there were a major economic crisis in the future, and own no shares in any company.

I do my best to consider both the positive and negatives consequences on the environment, from human activities.
Pollution from oil spills, plastic waste, exhaust fumes from ICE vehicles and coal-fired power plants which don't employ 'state-of-the-art' emission controls, should be addressed, and are being addressed in developed countries.

Unfortunately, replacing fossil fuel use with energy from wind and solar is not as clean as you might think. A very large majority of solar panels and windmill parts are manufactured in China and other Asian countries which not only use fossil fuels during the manufacturing process, but also cheap labour.

Whilst it's true that some solar panels are manufactured in the US and Germany, for example, such manufacturing processes rely upon the importation of essential parts and ingredients from Southeast Asia.

From an internet search:

"While US solar panel manufacturers are increasing domestic module production, they still heavily rely on imported solar cells. A lack of domestic cell, wafer, and ingot manufacturing capacity in the US means that even with rising module production, many US panel makers are still dependent on imported components. The majority of crystalline solar cell imports come from Southeast Asia."

I suspect if all the solar panels, windmills, and Lithium batteries were manufactured in their entirety in the developed nations which use them, with all ingredients, such as rare earth metals, sourced from the developed countries, then the current Government subsidies for their installation and use, would rise dramatically. Wouldn't you agree? 

[Robert Roaldi]

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Unfortunately, replacing fossil fuel use with energy from wind and solar is not as clean as you might think. A very large majority of solar panels and windmill parts are manufactured in China and other Asian countries which not only use fossil fuels during the manufacturing process, but also cheap labour..
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Why do you assume that I think that renewable technology is clean? Design is a cost vs benefits analysis. We just need to be honest about what the costs and benefits are. Most corporations' planning horizon is the next bonus cycle. The wider culture should take a longer term view. The two outlooks do not necessarily produce the same results. 

Nothing is 'clean'. Before the automobile, large cities were knee-deep in horseshit (I'm exaggerating about the knee-deep). Now we're knee-deep in cars instead.

Most discussions seem to always come down to A or B, as if all human concerns were as simple-mined as US elections with their arbitrary 2-party system. Our choices are more complicated than that. I'm sick and tired of this phoney framing. Gasoline-powered vehicles are good in some use cases. EVs are good in some use cases. Solar works in some locations, wind in others, nuclear in yet others, etc. Why pretend that there is a partisan fight going on when there actually isn't.

[Ray]

Why do you assume that I think that renewable technology is clean?

Okay! I'll rephrase it. "Unfortunately, replacing fossil fuel use with energy from wind and solar is not as clean as some people seem to think." Is that better? 

In order to get the public to accept the change to renewables, the politicians, the media, and many activist scientists, have to exaggerate the benefits of solar and wind energy, and downplay any negative consequences.

The benefits that are exaggerated are that renewable sources of energy are cheaper than fossil fuels, and cleaner because they don't emit that obnoxious pollutant called CO2, which is essential for all life, and has massively greened the planet during the past 30 years, according to satellite observations.

[digitaldog]

Okay! I'll rephrase it. "Unfortunately, replacing fossil fuel use with energy from wind and solar is not as clean as some people seem to think." Is that better? 

Some people don't think as much as they assume. Renewable energy is just that, renewable and compared to other forms of energy, clean. Of course, stuff needs to be produced for the technology. If it can’t be grown, it must be mined. The benefits are not exaggerated, and renewable sources of energy are cheaper than fossil fuels if you do a little research:

The Hidden Costs of Fossil Fuels
Published Jul 15, 2008 Updated Apr 18, 2025
The costs of gas, fuel, and other fossil fuels extend far beyond the gas pump or electric bill. Just ask a scientist.
https://www.ucs.org/resources/hidden-costs-fossil-fuels

[Rob C]

Well, today parts of Spain and Portugal are experiencing massive power cuts. Here in the Islas Baleares we are, so far, okay; supposedly, it’s simply an accidental loss with no malicious, external implications. However, the govt. also says it has ruled out nothing at this stage. Timely warning, all the same, of how easily things can go pear-shaped in just a matter of moments.

[Ray]

Some people don't think as much as they assume. Renewable energy is just that, renewable and compared to other forms of energy, clean. Of course, stuff needs to be produced for the technology. If it can’t be grown, it must be mined. The benefits are not exaggerated, and renewable sources of energy are cheaper than fossil fuels if you do a little research:

The Hidden Costs of Fossil Fuels
Published Jul 15, 2008 Updated Apr 18, 2025
The costs of gas, fuel, and other fossil fuels extend far beyond the gas pump or electric bill. Just ask a scientist.
https://www.ucs.org/resources/hidden-costs-fossil-fuels

"The benefits are not exaggerated, and renewable sources of energy are cheaper than fossil fuels if you do a little research:"

Absolutely true! If you do just a little research you will discover that renewable sources of energy are cheaper than fossil fuels. However, if you do extensive research you will probably discover research papers which falsify this claim and provide evidence that the unreliability of renewables to supply the energy when it's needed, makes it more expensive than fossil fuels, due to the expensive methods of backup storage, such as Lithium-ion batteries which also have a potential to spontaneously explode, the need for back-up fossil-fuel power generators which sit idle much of the time, the need for over-production of wind and solar power generation in order to recharge the battery storage system whilst simultaneously supplying electricity to the surrounding community, and the relatively short life-span of windmills and solar panels which have to be replaced every 25 years or so.

For those who are interested, I'll provide the following link to the Australian 'Institute of Public Affairs'.  It is registered as a charity with the Australian Charities and Not-for-Profits Commission.

"The Institute of Public Affairs is an independent, non-profit public policy think tank, dedicated to preserving and strengthening the foundations of economic and political freedom."

https://ipa.org.au/publications-ipa/research-papers/the-ruinous-cost-of-free-energy-why-an-electricity-system-built-on-renewable-is-the-most-expensive-of-all-options

Here are some relevant quotes:

"Australia previously benefited from some of the lowest consumer electricity prices in the industrialised world, but it now has some of the highest.

This paper shows that an electricity supply system built on a foundation of baseload generation – that which provides power 24/7 to the grid to meet base energy needs – results in the lowest Total System Cost.

This invalidates claims that renewable energy is the cheapest form of energy.

That may be true in particular locations at particular points in time, but at the system level a system built on renewable energy would be the most expensive – by far – of available options.

Contrary to popular belief, coal-fired power plants do not have a predetermined life. They can be refurbished periodically and remain in service for an indefinite period. The benchmark for comparing costs is not a hypothet-ical fleet of new coal plants: it is the fleet of already existing coal plants.

Thus the lowest cost system is the one we have, and the next lowest cost system is one built on new baseload power plants, whether they be coal or nuclear.

The levelised cost of energy (LCOE) of any generation type does not reflect Total System Cost."

[degrub]

Except as they state in the paper, the cost profile and conclusion does not include the penalty cost of CO2 and other positive feedback gases from combustion.  How severe that penalty is and will be is not well known but there are a few models out there. A bit trite, but a reasonable explanatory paper.
"
19 Note that any claim that broad (or even narrow) environmental impacts have been
reduced would need to be assessed rigorously, not at the margin, but in depth at
the broad system level. The stated aim or public policy justification of rooftop solar
PV promotion programmes is to reduce CO2 emissions. As that is a global issue, its
success or failure can only properly be assessed at the global level. Such assess-
ment includes the effects across the whole power system in which the panels are
installed, and the wider effects up the supply chain through manufacturing up to
raw materials, and end-of-life outcomes. Such an analysis is beyond the scope of
this paper, which is focused on the costs within the power system.
"

[digitaldog]

"The benefits are not exaggerated, and renewable sources of energy are cheaper than fossil fuels if you do a little research:"

Absolutely true! If you do just a little research you will discover that renewable sources of energy are cheaper than fossil fuels. However, if you do extensive research you will probably discover research papers which falsify this claim and provide evidence that the unreliability of renewables to supply the energy when it's needed, makes it more expensive than fossil fuels, due to the expensive methods of backup storage, such as Lithium-ion batteries which also have a potential to spontaneously explode, the need for back-up fossil-fuel power generators which sit idle much of the time, the need for over-production of wind and solar power generation in order to recharge the battery storage system whilst simultaneously supplying electricity to the surrounding community, and the relatively short life-span of windmills and solar panels which have to be replaced every 25 years or so.

The "however" and "probably" above are based on little to no evidence. As for the levelized cost of electricity (LCOE), I will provide some with examples of solar, wind and others:

[digitaldog]

Solar-Plus-Storage: The Fastest, Cheapest Way To Meet Surging Power Demand
Construction crews are building this technology combination across America at record levels – solar-plus-storage composed 84% of new U.S. grid capacity installed in 2024, adding 37 gigawatts of solar generation capacity and 10 GW of utility-scale storage capacity. The reason behind solar-plus-storage’s surge is clear – they’re the cheapest technologies and the fastest available to bring online.
https://www.forbes.com/sites/energyinnovation/2025/03/18/solar-plus-storage-the-fastest-cheapest-way-to-meet-surging-power-demand/

Solar Power Is Reaching a Critical Tipping Point in the U.S. From hyperscalers to smart tracking tech, the U.S. solar industry is charging ahead despite political and financial headwinds.
In 2024 alone, the U.S. installed 50 gigawatts (GW) of solar capacity, enough to power roughly 38 million homes. Solar accounted for 84 percent of all new electricity generation added to the grid. About nine out of 10 new power plants built last year were solar farms.
https://www.inc.com/soren-kaplan/solar-power-is-reaching-a-critical-tipping-point-in-the-u-s/91170660

No other energy source came close to matching solar’s rate of growth in 2024 – in numbers
Solar generation for the first 11 months of 2024 increased by over 26%, while new solar generating capacity added in November was the second-highest monthly total ever reported, according to new data released by the Federal Energy Regulatory Commission (FERC) and the US Energy Information Administration (EIA).
New solar capacity easily surpassed all other energy sources during the first 11 months of 2024, followed by wind, according to the SUN DAY Campaign, which reviewed the data.
Solar was 81.4% of new capacity during the first 11 months of 2024 and 98.6% in November alone. According to FERC’s latest “Energy Infrastructure Update” report (with data through November 30, 2024), 25,817 megawatts (MW) of new utility-scale solar generation was placed into service in the first 11 months of 2024 – 81.4% of the total.
In November alone, solar added 4,132 MW representing 98.6% of all new capacity added, making it the second-largest monthly expansion, behind only December 2023 when 4,979 MW were added. Moreover, November was the 15th month in a row that solar was the largest source of new utility-scale generating capacity.

I rest my case on solar. But as to the costs and why the above is happening, at least in the US is simple. "More than 80 percent of the country's energy infrastructure is owned by the private sector, supplying fuels to the transportation industry, electricity to households and businesses, and other sources of energy that are integral to growth and production across the nation".
https://www.cisa.gov/topics/critical-infrastructure-security-and-resilience/critical-infrastructure-sectors/energy-sector
https://www.energy.gov/articles/economic-impact-oil-and-gas

[Jonathan Cross]

Solar-Plus-Storage: The Fastest, Cheapest Way To Meet Surging Power Demand
Construction crews are building this technology combination across America at record levels – solar-plus-storage composed 84% of new U.S. grid capacity installed in 2024, adding 37 gigawatts of solar generation capacity and 10 GW of utility-scale storage capacity. The reason behind solar-plus-storage’s surge is clear – they’re the cheapest technologies and the fastest available to bring online.
https://www.forbes.com/sites/energyinnovation/2025/03/18/solar-plus-storage-the-fastest-cheapest-way-to-meet-surging-power-demand/

Brilliant, Andrew
  !!

Jonathan

[Ray]

In November alone, solar added 4,132 MW representing 98.6% of all new capacity added,

A new capacity which:
1. Used a lot of fossil fuel in its construction, delivery and installation.
2. Will last about 25 years, and will present enormous recycling costs in the future.
3. Uses land which could be used for other productive purposes.
4. Provides electricity around 25% of the time, on average, in sunny areas, and less in many other areas.

What could be better!   

[digitaldog]

A new capacity which:
1. Used a lot of fossil fuel in its construction, delivery and installation.
2. Will last about 25 years, and will present enormous recycling costs in the future.
3. Uses land which could be used for other productive purposes.
4. Provides electricity around 25% of the time, on average, in sunny areas, and less in many other areas.

1. Voltaire, the French writer, said, “The best is the enemy of the good.” Or to answer your query:  “He that is good for making excuses is seldom good for anything else.” —Benjamin Franklin
2. So what? As for recycling, not a problem: https://www.solarcycle.us
3. So what, and: Birdlife more abundant on well-managed solar farms than on arable farmland, finds RSPB study
https://www.countryfile.com/farming/birdlife-more-abundant-on-solar-farms-than-arable-farmland
4. Wrong, so wrong: learn about BESS technology AND the advantages!
Grid-Scale Battery Storage Is Quietly Revolutionizing the Energy System
This energy storage technology is harnessing the potential of solar and wind power—and its deployment is growing exponentially.
Energy storage is the peanut butter to the chocolate of renewable energy, making all the best traits about clean energy even better and balancing out some of its downsides. But it’s also an important ingredient in grid stability, reliability, and resilience, helping ensure a steady flow of megawatts during blackouts and extreme weather.

The most common use is frequency response. The alternating current going through power lines in the US cycles at a frequency of 60 hertz. If the grid dips below this frequency when a power-hungry user switches on, it can trip circuit breakers and cause power instability. Since batteries have nearly zero startup time, unlike thermal generators, they can quickly absorb or transmit power as needed to keep the grid humming the right tune.

Grid batteries can also step in as reserve power when a generator goes offline or when a large power user unexpectedly turns on. They can smooth out the hills and valleys of power load over the course of the day. They also let power providers save electricity when it’s cheap to produce, and sell it back on the grid at times when demand is high and power is expensive. It’s often faster to build a battery facility than an equivalent power plant, and since there are no smokestacks, it’s easier to get permits and approvals.

Batteries have already proven useful for overstressed power networks. As temperatures reached triple digits in Texas last year, batteries provided a record amount of power on the Lone Star State’s grid. ERCOT, the Texas grid operator, didn’t have to ask Texans to turn down their power use like it did in 2023. Between 2020 and 2024, Texas saw a 4,100 percent increase in utility-scale batteries, topping 5.7 gigawatts.
https://www.wired.com/story/grid-scale-battery-storage-is-quietly-revolutionizing-the-energy-system/

What could be better!   

Try telling us. Do tell us a less expensive AND cleaner means of generating electricity if you can, sir. Seems you have a lot to learn about renewable energy benefits.

[digitaldog]

Fossil fuels are terrible for the environment. Is mining critical minerals any better?
In short, yes. But we have to actively work to avoid repeating the abuses of mining for coal and other fossil fuels.
The most mined resource today is coal, with around 8.7 billion tons produced in 2023 alone. We need fossil fuels in such large quantities precisely because they are fuels, continuously shoveled into power plants to generate energy. By contrast, solar panels and wind turbines require a fixed quantity of metals only during the construction phase—and once built, they can produce energy for several decades without additional inputs. Because of this, experts agree that the world will actually see a net decrease in energy-related mining if we replace fossil fuels with metals-powered technologies.

There are also many opportunities to extract minerals from the waste of existing mines that were originally built for different purposes. Research by mining and sustainability expert Tim Werner of the University of Melbourne has estimated that waste from a single Canadian zinc mine could supply several years’ worth of global demand for indium, which is used in solar cells, and there are already efforts to recover cobalt from old lead mines in Missouri.

Most importantly, perhaps, while fossil fuels can only be burned once, many minerals can in principle be used many times over. The Netherlands study estimates that we could slash energy-related mining demand by an additional third in the 2050 net-zero scenario if we were to massively upscale recycling of EVs, wind turbines, and solar panels.
https://www.fastcompany.com/91310932/fossil-fuels-are-terrible-for-the-environment-is-mining-critical-minerals-any-better

As for coal, those who worry about water use: According to the Department of Defense National Energy Technology Laboratory (NETL), a wet recirculating cooling water system for a 520-MW coal-fired power plant uses about 12 million gallons of water per hour.
Power generation has been estimated to be second only to agriculture in being the largest domestic user of water.[1] To produce and burn the 1 billion tons of coal America uses each year, the mining and utility industries withdraw 55 trillion to 75 trillion gallons of water annually, according to the US Geological Survey.
https://www.gem.wiki/Water_consumption_from_coal_plants#:~:text=According%20to%20the%20Department%20of,gallons%20of%20water%20per%20hour

Fracking consumes a massive amount of water. In the United States, the average can run between 1.5 million and 9.7 million gallons of water to frack a single well, according to the United States Geological Survey (USGS).

Now Ray can pipe in on what energy source he feels is superior to solar or wind renewables and costs less to produce; what could be better!

[Jonathan Cross]

Re Climate change and electricity production
I read of the move to deny climate change and promote fossil fuels by the administration in America.  It makes me wonder why so many scientists across the world and rising temperatures and retreating ice are being ignored.

Scotland has been quoted in this thread and there are stats available about electricity production there
https://www.scottishrenewables.com/our-industry/statistics
Wind is much used and hydro is also a renewable source.  I have been up and down glens with several hydro generators at various points in each river. Wind is classified as an intermittent source, but pumped storage can be used.  50 years ago we went round the Ben Cruachan scheme,
https://www.drax.com/about-us/our-sites-and-businesses/cruachan-power-station/
 and this can get up to full power in 30 seconds to deal with variation in demand.
Dinorwig in Wales is another example of a large pumped storage scheme,
https://www.engie.co.uk/power-storage/dinorwig-power-station/
 It is interesting that large oil platforms for use at sea were built at Cromarty in Scotland.  Those facilities are now building wind turbine towers so continuing to provide jobs. A huge floating wind farm project has been approved off Aberdeen,
https://greenvoltoffshorewind.com/onshoreplanningapproval/

Norway is virtually all renewables, nearly all hydro, 88%, with 11% wind.
https://energifaktanorge.no/en/norsk-energiforsyning/kraftproduksjon/
It also has pumped storage so the majority of its electricity supply is flexible rather than intermittent.

I would have thought that America with its mountain chains and desert areas has plenty of scope for hydro, solar and wind electricity generation, so I fail to understand wanting to cling to the old polluting finite fossil fuel technologies.

Jonathan

[digitaldog]

would have thought that America with its mountain chains and desert areas has plenty of scope for hydro, solar and wind electricity generation, so I fail to understand wanting to cling to the old polluting finite fossil fuel technologies.

A major issue is our grid, the location of facilities (here in my hometown, NIMBYers are trying to stop a clean energy facility due to their silly fears of BESS systems), and infrastructure. For example, in NM, some want rooftop solar that cannot get it due to a lack of feeders to move the electricity onto our grid:
https://www.krqe.com/news/investigations/new-mexican-homeowners-continue-to-struggle-connecting-to-solar-systems/
This despite 300 days of sunshine a year! In the case of a solar farm + BESS facilities, a paramount concern and need is proximity to the grid to supply electricity to the grid. The idea that solar or wind farms can just go anywhere is wrong.

[Jonathan Cross]

A major issue is our grid, the location of facilities (here in my hometown, NIMBYers are trying to stop a clean energy facility due to their silly fears of BESS systems), and infrastructure. For example, in NM, some want rooftop solar that cannot get it due to a lack of feeders to move the electricity onto our grid:
https://www.krqe.com/news/investigations/new-mexican-homeowners-continue-to-struggle-connecting-to-solar-systems/
This despite 300 days of sunshine a year! In the case of a solar farm + BESS facilities, a paramount concern and need is proximity to the grid to supply electricity to the grid. The idea that solar or wind farms can just go anywhere is wrong.

I take your point about the grid, we are different in Europe.  But what about domestic solar to run aircon, water pumps and sprinklers?   BESS systems are coming in here, nobody seems to have fears.  It is interesting that there is a huge substation near Inverness (c 1 x 1/2 mile) that collects electricity from renewable sources in Northern Scotland where the population density is low, converts it to high Voltage AC and exports it via overhead lines and pylons to Southern Scotland and Northern England, up to 200 miles.  I understand it may well handle the electricity from the floating wind farm off Aberdeen some 80 miles out to sea 60 miles more on land to the substation.  There are also subsea cables between the UK and France and also or wil be between the UK and Norway.

Is there no scope for commercial renewables to supply cities like Tucson and Phoenix from just outside?  And what about renewables to provide the power to generate hydrogen that can be transported away by tanker as may well happen in Chile.

Jonathan

[digitaldog]

I take your point about the grid, we are different in Europe.  But what about domestic solar to run aircon, water pumps and sprinklers?   

Not sure I understand the question. Again, in parts of the US, a limitation of domestic solar for all home power needs is the grid needed updates.

BESS systems are coming in here, nobody seems to have fears.

Where you live, peope are more sensable and able to accept facts and data, not FUD it seems. EPRI's Battery Energy Storage System Failure Incident Database, which compiles information about stationary battery energy storage system (BESS) failure incidents, lists only 91 worldwide from 2011 to 2025. 38 are solar Intergration. No fire has escaped a facility to burn anything outside it, further emphasizing its rarity compared to other fire incidents. Fact check: (https://storagewiki.epri.com/index.php/)

Is there no scope for commercial renewables to supply cities like Tucson and Phoenix from just outside?

Arizona has two community solar farms. Tucson Electric Power has a 1.6 MW community solar farm southeast of Tucson.SRP's largest solar power plant, CO Bar Solar, is under development northwest of Flagstaff, Arizona. It was supposed to be completed in 2024, not sure if its on schedule. And: https://americas.rwe.com/our-energy/solar-energy/solar-projects-and-locations/mesquite-solar-complex/

[Jonathan Cross]

Not sure I understand the question. Again, in parts of the US, a limitation of domestic solar for all home power needs is the grid needed updates.

Not sure I understand your comment either!  Perhaps there is a fundamental difference in the way the systems work.  Here, if a house is off grid, then solar power can supply electricity to save a petrol generator.  It is possible to get generators that will kick in automatically if the other source can't cope. 

If a house is on grid here, i.e. gets electricity down wires from a supplier, solar will work with it.  If the solar system can cope, then it is used.  If it cannot cope then the supplier electricity is used.  The supplier meter just records what is used from that source.  It all happens with no human input.   

BESS here works by storing electricity when there is spare solar or the supplier (we call it mains) electricity tarriff is cheap, e.g. at night.  It will then release electricity if the solar can't cope.

It's all great fun, and, like when changing an LED bulb, it seems you need a PHD to work out the fixing, screw or bayonet, what wattage and lumens, and what colour temperature. This is all without going into heat pumps which we are being encouraged to do!

Jonathan