Some truth to people who think we can be 100% renewable

[ERD50]

Many distribution lines run along the roadway. There's a potential for less infrastructure build out to the distribution grid. ....

But that's certainly no better in most cases than having the power produced right at a building. After all, the building itself is probably a pretty large power consumer, so the power only travels a hundred feet or so.

So if I'm generous, I might call that 'neutral', but not a benefit.

Regardless, it certainly isn't enough to over come the negatives. And each negative is pretty much a non-starter, right out of the gate (is that redundant?). Just a few to get the ball rolling...

1) Solar panels on a road mean being set at a sub-optimal angle. They will produce less energy than panels mounted on stands on a large flat rooftop. So you are already at a loss, and there is no way to make that up. Why would I want to even consider getting significantly less energy from those panels, unless there were positives that offset that.? It makes no sense. You can stop right there.

2) A road has (wait for it...) cars and trucks driving on it. These cars and trucks shade the panels. Again, that is energy that can never be regained. Why would we put panels in the shade, it's senseless. Again, panels on a large flat rooftop will not have trees or other shade encroaching on them. If you didn't stop at #1, stop now.

3) Covering the solar cells with a material to protect them? Cost, and there will be additional losses, that protective cover cannot be 100% translucent. Again, panels on a large flat rooftop will not have these issues. So why is this even being considered? Stop again.

I could go on and on, but unless someone has something that can even begin to compensate for those losses and costs, it makes no sense at all. And it is a waste, and is counterproductive to meaningful attempts to increase our Renewable Energy capabilities.

Allow me to make a parallel for illustration: A diesel engine can run on bio-diesel fuel quite easily. So suppose I told you I had a new design for a bio-diesel engine. This new design costs much more than the current engines even when mass produced, requires far more maintenance, is larger and heavier, and it will always be less efficient than the current designs, physics dictates it to be so.

Would you want to invest money to build prototypes? Why would anyone, there is not even a hint that this design is better than the alternatives.

But do you say "But we should support bio-diesel, so we should support this"? But why support it in this way, when there are better alternatives for bio-diesel use? It's just crazy. Solar roads are like that.

-ERD50

 

[samclem]

I could go on and on, but unless someone has something that can even begin to compensate for those losses and costs, it makes no sense at all. And it is a waste, and is counterproductive to meaningful attempts to increase our Renewable Energy capabilities.

No doubt. But I think the supporters believe that the road area is now just wasted square feet that might as well be put to good use in producing solar power. Even the most cursory analysis of the factors involved (esp the engineering reqmts of good roads/paving surfaces, the availability and advantages of other locations for PV panels, etc) should quickly put an end to any further consideration of the idea, but that didn't happen.

 

[NW-Bound]

About the peak demand power problem in Texas, the problem was acute because the Texas grid is somewhat isolated, and they cannot borrow from Western neighbor states.

About wind power in Texas, I found this:

Wind power in Texas consists of many wind farms with a total installed nameplate capacity of 25,629 MW from over 40 different projects. If Texas were a country, it would rank fifth in the world: The installed wind capacity in Texas exceeds installed wind capacity in all countries but China, the United States, Germany and India...

I found numbers for RE energy production in Texas last year.

Texas Wind Electricity in 2018: 75604 GWh
Texas Solar Electricity in 2018: 3348 GWh

Yet, the above numbers pale besides the total consumption.

Wind+Solar as Percentage of Electricity Usage in 2018: 18%


When more and more RE is generated and counted on, the variability of solar and wind generation will become even more critical. That's the problem with RE. We cannot control nature, and we do not yet have an economical way to store the huge amount of energy that we need.

 

[NW-Bound]

The shortage-induced sky-high price of electricity was worse in Texas than in California last week, due to the former's isolated grid.

It looks like Texas's problem could be alleviated by having more solar plants, due to the fact that the shortage happened in the afternoon when the ACs were cranking but the sun was also shining.

 

[samclem]

Storage of electricity is expensive, and probably gonna stay that way. And then you eventually hve to buy them again, and again. OTOH, transmission wires are also not cheap, but once you've bought them the recurring costs are low.

Stick with me here.

We don't need storage if we can reliably generate the power when needed. The US has a lot of real estate, and good neighbors north and south. There's weather diversity, so it's often windy somewhere in North America. As for solar--we've got the mid-day covered, and we have Hawaii and (esp) Guam as a location where the sum is still shining when Texas needs power. But the East Coast needs power in the morning, and we don't have much real estate to the east. Most of Western Europe is going to keep whatever they make, unless we work out a deal with them (they give us energy before the sun comes up here, we send them energy after the sun has set there).

But, then it hit me--Greenland!! Now it all makes sense! If we bought Greenland, they've got tons of land (as big as Western Europe) and only a small population. North enough so the day is longer in the summer--just when we need the juice the most. 21 hours of sun each day in June. They have geothermal resources and hydroelectric resources that are untapped.It's windiest there in the winter----send the wind, geothermal, and hydro power on the lines in the winter when the our way when the solar transmission lines have lots of excess capacity.

Sure, the transmission lines would be pricey. Maybe room temp superconducting will arrive. Or, with high enough voltage, all of the US could be run off a 12AWG extension cord.

I need to work through a few small issues (might need to modify the weather to reduce cloud cover over Greenland), but the hard part is done.

 

[explanade]

Why is the TX grid isolated?

 

[ERD50]

Why is the TX grid isolated?

So they are ready if they decide to secede from the Union?

-ERD50

 

[NW-Bound]

Because the Lone Ranger rides alone.

The local utilities that comprise ERCOT have pledged not to sell their power to interstate customers. As a result, the interconnection is exempt from most regulation by the Federal Energy Regulatory Commission, the Beltway agency that governs the transmission of electricity from state to state—say, by mandating transmission standards, or requiring that prices be listed in public forums....

See: https://slate.com/news-and-politics/2003/08/why-texas-has-its-own-power-grid.html.

 

[samclem]

Because the Lone Ranger rides alone.

Interesting. I wonder if Florida is also keeping the FERC out of their business in the same way. And maybe Alaska (seems that they wouldn't be "interstate" just for serving part of British Columbia)

I guess the utilities in Teas just absorbed those crazy-high spikes in electrical rates during the shortage (spreading the out to everyone)? If Granny Jones got a bill for $500 for the toast she made during the shortage, that would ruffle some feathers.

 

[NW-Bound]

I wonder how the sudden high cost is paid.

Although the entire state is tied together with that grid, each utility company knows how much he is pumping into the grid at each instant. He may not know how much his customers are drawing from the grid at that moment because the metering/reporting is not in real-time.

Together, the utility companies know how much they are short, but have to wait until later to know whose customers were overdrawing more than they could produce. It seems fair to me that the ones that produced less than their customers consumed had to pay the higher marginal cost for that last megawatthour.

They then in turn will have to collect from their customers. If the contracts are for fixed price, then they have to eat it and try to make up next year with a higher price.

I am really curious to know how it actually works.

 

[NW-Bound]

Come to think of it, if the incremental cost gets as high as $9/kWh as shown in the chart that I linked above, if you have a grid-tied solar system and take a sacrifice to turn off your AC so that your production all goes out to the grid, they should pay you that price.

For an average 5kW system, you stand to make $45/hour.

Heck, at that price if I could synchronize my RV genset to the grid, I would pump its 4kW production into the grid to make $36/hour. The fuel cost is 1/2 gal per hour. It's also a good deed to prevent a brownout.

 

[NW-Bound]

Here's something interesting.

Look at the spot price chart for Texas and California that I linked from Bloomberg in post #454.

Because Texas does not have a lot of solar power, its shortage occurs in the early afternoon due to AC usage, and they have a low-wind day.

California has plenty of solar power, so the shortage occurs later, when the sun already sets and the night has not cooled off.

That dovetails perfectly with the well-know "duck curve".

 

[Audie Murphy]

I am just a regular guy but let us look at something that is obvious and laughable about wind and solar. Where and how are they made and using what type of energy? Let us also ask this question. If there were no traditional energy sources, could people make all of the metal wire and plastic that goes into a wind turbine using the wind? Could the same group of people use the sun to make all of the components and miles of copper wire that go into solar panels (batteries?) using only energy from the sun?

Imagine on day one of a brand new wind turbine. Before it even starts spinning wouldn’t it be fair to say it has so many years of life. For the sake of argument, because I have no idea, but let say it can produce energy for 20 years. How many years should you have to run it to equal the amount of energy that went into its own production?

These contraptions are not efficient. They would not exist without oil and gas. They have serious issues with constant supply. And they cost more. Mostly, they just make people feel better but are all just a fantasy that end up in land fills eventually and don’t directly pollute but did so in their creation and their disposal. So we created a overly complex machine that pollutes in the beginning and the end but not when we look at it working just so people can feel good. Rube Goldberg comes to mind.

 

[jimandthom]

I am just a regular guy but let us look at something that is obvious and laughable about wind and solar. Where and how are they made and using what type of energy? Let us also ask this question. If there were no traditional energy sources, could people make all of the metal wire and plastic that goes into a wind turbine using the wind? Could the same group of people use the sun to make all of the components and miles of copper wire that go into solar panels (batteries?) using only energy from the sun?

Imagine on day one of a brand new wind turbine. Before it even starts spinning wouldn’t it be fair to say it has so many years of life. For the sake of argument, because I have no idea, but let say it can produce energy for 20 years. How many years should you have to run it to equal the amount of energy that went into its own production?

These contraptions are not efficient. They would not exist without oil and gas. They have serious issues with constant supply. And they cost more. Mostly, they just make people feel better but are all just a fantasy that end up in land fills eventually and don’t directly pollute but did so in their creation and their disposal. So we created a overly complex machine that pollutes in the beginning and the end but not when we look at it working just so people can feel good. Rube Goldberg comes to mind.

I will agree that wind etc have "manufacturing" costs but in reality so does oil and gas, it just doesn't magically appear out of the ground. It also has to be transported through a variety of means.

Oil and gas fields also have limits on the life of productivity and the infrastructure to move the product has limits on useful life.

The highlighted part talks about polluting at the beginning and the end for wind etc.

Seems to me that oil and gas exploration, production, delivery pollute at beginning and the end and also during the use of the fuel.

Just as the world has moved and is moving from burning manure/peat/wood to coal to oil/nat gas so to will it move on from burning fossil fuels.

And someday we will start transitioning from wind, PV etc, unless you believe that everything that can be invented has been invented.

 

[NW-Bound]

Of course windmills and solar panels require energy to manufacture.

But if over their useful operating life they produce enough electricity to save more oil and gas than it takes to make them, then it is definitely a worthwhile trade.

I think the tough problem is not being able to store energy for cloudy and calm days.

 

[Nemo2]

Of course windmills and solar panels require energy to manufacture.

But if over their useful operating life they produce enough electricity to save more oil and gas than it takes to make them, then it is definitely a worthwhile trade.

Not that I know a damn thing about any of this, but how does disposal of inoperative/non-repairable panels/windmills factor in (including environmental impact)?

 

[NW-Bound]

Windmills would be scrapped for metal, not too differently than we do with cars.

Solar panels are mostly aluminum for frame, and a piece of glass. The thin solar cells themselves are mostly pure silicon. There's a sheet of plastic backing, which is minuscule compared to the plastic we throw away in milk jugs.

 

[Nemo2]

Windmills would be scrapped for metal, not too differently than we do with cars.

Solar panels are mostly aluminum for frame, and a piece of glass. The solar cells themselves are mostly pure silicon. There's a sheet of plastic backing, which is minuscule compared to the plastic we throw away in milk jugs.

Thanks!

 

[dixonge]

Re: solar roads

https://bigthink.com/technology-innovation/france-solar-road

Tl;dr - big failure

 

[Alan]

Shared household battery storage

There is a new energy company and concept that has been approved by the regulator in the UK this year. We considered signing up with them when we had our solar panels and battery storage installed earlier this month. However, the installation costs would have been £12k instead £7.5k and the company and concept is brand new so we decided not to go for it since they only went online in April this year. We can always update our batteries in future years if this new technology really works and the grid is able to cope. The system we have also includes a smart meter that prices exports to the grid every 30 minutes.

In a nutshell, they use AI in conjunction with the batteries to maximize the battery utilization in conjunction with variable tariffs. For example, home batteries store electricity during hours of sunlight and discharge during periods when the sun is not shining. Mornings are high demand as folks get ready for work but in winter months there is no sunlight early mornings so the batteries charge up during the night when electricity is cheap.


https://www.solarplants.org.uk/social-energy-explained-who-what-and-why-we-have-partnered-with-them/

Social Energy allows you to utilise your solar energy
Social Energy builds on the concept of grid-sharing which is a term that is being used more often when talking about battery storage. Grid-sharing is the idea of batteries with shared software sending energy between each other. This decentralises the grid, reduces reliance on suppliers and prevents waste of energy.
By using machine learning to predict household load and generation, Social Energy aims to use its software to export and import at the best prices. The battery comes with a grid monitoring box which constantly sends data and information to the Social Energy cloud.
The software is an intelligent digital technology, it creates a customer profile for you and records your usage pattern for the grid. It accurately anticipates your solar generation by incorporating the size of the system and accounting for weather forecasts 24 hours in advance. This allows you to use all of your free energy produced by the solar system at the best possible times maximising your savings. But it also means any energy you wouldn’t normally utilise can be drawn by Social Energy so you can earn too.

 

[Music Lover]

The list of everything wrong about a 'solar road' is longer than the roads they've installed. This isn't something we need to build to "see how it works", any more than Count Ferdinand would need to actually build a dirigible out of lead to see if it would fly. A few simple calculations and analysis would tell you there are better alternatives. Could make a great rock/blues band though.

-ERD50

Well...maybe the person that first suggested a solar road doesn't care if it's a good idea or not...maybe they just wanted a lucrative government contract.

Going green/renewable can pay very very well...regardless of whether or not it works. And you often have the added bonus of relaxed environment regulations...kill one duck in a 5 gallon oil spill and heads will roll but kill endangered birds with wind turbines on a daily basis and no one is held accountable.

 

[ERD50]

By using machine learning to predict household load and generation, Social Energy aims to use its software to export and import at the best prices

That makes me wonder about what algorithms NW-Bound is using for his off-grid Solar/storage/mini-split-AC system.

If I understand correctly, he's doing it to avoid the peak time-of-day rates. The primary goal would be reducing the main AC usage during peak rate times.

But it occurred to me that he might also want to limit charge/discharge of the battery, since there are losses, and some 'wear' on the battery. So another priority might be to run the mini-split direct as much as possible, and leave only enough storage to run the mini-split to the end of the peak period.

Seems like this could get pretty sophisticated, including some weather prediction?

-ERD50

 

[NW-Bound]

I am still observing the power generation and my consumption pattern, and slowly realize what enhancement I can use, at least for the summer season.

What I learn is that my 5.5 kW solar array typically produces about 25 kWh each summer day. It is about 10% short of what it could be, due to shading in the afternoon by the neighbor's trees. That is less than 1/3 of what I used to consume on the average each day in August.

The above generation just barely matches my storage battery of 22.5 kWh. In the peak of the summer, the mini-split has to run 24 hours, albeit at a reduced speed in the early morning hours. Over 24 hours, it uses more than the 25 kWh from the solar array. Hence, I usually find the mini-split getting transferred back to the grid some time in the night.

In the morning, about just 1 hour after dawn, the array already produces enough to bring the battery voltage to the point the transfer switch cuts the mini-split back to solar power. The mini-split is usually using less than 700W in the morning.

Then, as the sun rises and more power is produced, up to 4.2 kW peak, the surplus power goes to charge the battery. The max power consumption of the mini-split is 1.4 kW, so there is plenty of power surplus although it is not enough to fill up the battery. I do not want to charge the battery to full either, in order to maximize its life.

The goal is to use all of the power that the panels can produce, as I cannot pump it into the grid for "storage". And I want to use as much of it during the peak hours of 2PM-8PM, when the cost is $0.24/kWh, not during the off-peak when it is just $0.07/kWh.

Hence, I do not care to save much power to use beyond 8PM. In midday, when the battery is sufficiently charged, the fridge is switched over to run off solar. And it usually stays on the battery until 8PM.

In the early summer when it was not as hot and the AC did not work as hard, I even had enough power to dump it onto the electric water heater in midday.

Using solar power for water heating is actually not desirable for me, as my main AC still turns on during the day. It just runs less often. The water heater is on a timer, and it has enough storage to cruise through the peak period (and we know to avoid using a lot of hot water during that time). I would rather use the solar power for air conditioning, but cannot power the 5-ton AC without expensive hardware.

The obvious use of more solar power during the peak hours is to have another mini-split. Then, I will need to time everything just right, in order to not use the grid at all during the peak hours. If I do not have enough solar generation, then I could keep the mini-splits off the solar in the morning, in order to get the battery more charged up to cruise till 8PM. In the worst case, I may even have to precharge the battery overnight to arbitrage the difference between the 7c and 24c costs.

All this will wait to be figured out until next summer, when I have the 2nd mini-split. But before that, I still have to see what happens in the winter when the cooling requirement is a lot less than the heating, but solar generation is also reduced.

Right now, with 1/3 of the power coming from solar, I have been able to save 1/2 of the electric bill by using the solar power during peak hours. My August bill was $333 last year, and should be about $165 this year. It would be lower with another mini-split, but with a diminishing return.

 

[samclem]

Thanks. This game clearly calls for a super bit of software to do the optimizing. And I do think weather prediction/anticipation could be part of it.


Is it practical to do any thermal load shifting with the AC (e.g. pre-cool habitable space, or thermal mass in the habitable space to "bank" some "coolth" in the period when you are getting good solar output but the outside temps haven't yet soared and thermal load is still being delayed by your wall/roof insulation)? Your condenser is also more efficient in the morning before the outside temps climb high.

 

[NW-Bound]

Precooling the home does help, and is actually recommended by the power company.

However, I do not want a large temperature swing, and use a setting change of 2F.


PS. Using weather forecast to predict and plan for electric power consumption has been done by utility companies all these years. We just take a lot of things they do for granted.