Solar, Wind Renewable Energy

[NW-Bound]

OK, nowadays it's easier to look up the work of someone else's than doing it yourself.

One fellow has figured out that if we pump water between Lake Ontario and Lake Erie (linked by Niagara Falls), and can stand a 6-ft fluctuation of water level, we can get 10 Terawatthours of storage (ignoring conversion loss).

See: http://euanmearns.com/the-pumped-hydro-storage-potential-of-the-great-lakes/.

The annual electric energy consumption of Canada is 528 Terawatthours/year (2014). That of the US is 3911 Terawatthours/year (2015).

Not good enough for 1 day of use for the US!

 

[NW-Bound]

Reminds me of Atlantropa - damming the strait of Gibraltar.

https://en.wikipedia.org/wiki/Atlantropa

I like it! Using the Mediterranean as a huge reservoir. Whooeee!

This calls for a song: one of my favorites.

 

[TwoByFour]

Grid level energy storage is really the key for getting the world onto renewable, non-fossil fuels and there is a lot of research going on in the area. Somebody is going to figure it out and make a lot of money. Money is a powerful motivator so I am confident it will happen. It's just a matter of time.

While storing electrical energy as potential energy (raising water to a high level) is really simple it has significant environmental impacts. For instance, any existing hydroelectric dam can in principle be reversed so that solar/wind power is used to pump downstream water back behind the dam. But doing that means the downstream water is not available for fish or agriculture. In the Pacific Northwest (which is full of hydro power) that would be a non-starter.

I tend to think grid-level storage will be electro-chemical (like a LiPo battery) just on a massive scale. One interesting simple store is to use electolysis to separate hydrogen and oxygen, store those separately, and then push it into a hydrogen fuel cell to regenerate electricity. The latter is existing technology, just not at the scales needed. Stored hydrogen used in a fuel cell has about 10-100x (depending on the pressure) the energy capacity per unit volume, than LiPo batteries. Also, the energy density of water that would be used in a closed-system electrolytic storage system is about 0.6 KWH/liter of water. Compare that to the energy density in a potential-energy storage system, which is about 0.0003 WH/liter/meter. The latter is the energy one can derive by lifting one liter of water one meter up. It would take 3300 liters of water, lifted up 1 meter, to get even 1 KWH of energy. So electrolysis is going to be a much smaller storage system than a potential energy system. The problem with electrolysis is that the end-end efficiency is around 50% but there is work going on with boosting that.

 

[NW-Bound]

Yes, hydrogen and fuel cells should be promising, but I wonder why nobody talks about it recently.

There was an RV company that offered a fuel cell option instead of the common generator. It only produced something like 100W, but when accumulated continuously in a storage battery for an RV application would be quite adequate.

I thought that was cool. I checked back recently, and found that they dropped it. So there had to be some reasons.

 

[travelover]

Yes, hydrogen and fuel cells should be promising, but I wonder why nobody talks about it recently.

There was an RV company that offered a fuel cell option instead of the common generator. It only produced something like 100W, but when accumulated continuously in a storage battery for an RV application would be quite adequate.

I thought that was cool. I checked back recently, and found that they dropped it. So there had to be some reasons.

Coleman had a 1200 watt version all set to go back in 2002 but for some reason pulled the plug on it.



https://www.popsci.com/gear-gadgets/article/2002-01/yes-you-can-buy-home-fuel-cell

 

[TwoByFour]

I think for cars EV is probably the way to go since electricity is widely available. Hydrogen fuel cells need refueling stations, which there are none of, and it needs production and distribution facilities. But for grid-storage you don't need any of that since it would presumably be self-contained production/consumption. I think the main impediment now is efficiency. I believe that people are looking at catalysis to boost efficiency.

 

[Texas Proud]

Coleman had a 1200 watt version all set to go back in 2002 but for some reason pulled the plug on it.



https://www.popsci.com/gear-gadgets/article/2002-01/yes-you-can-buy-home-fuel-cell

I can see why it did not take off... $8K cost a $100 to refuel after 8 hours... and really not that much power...



A Honda or similar generator is much more practical and cheaper...

 

[NW-Bound]

+1

The AirGen Fuel Cell Generator is conceived as a backup generator, but at $7,995 the only buyers will be those who really need a secondary power source, perhaps for medical reasons. The 1.2-kilowatt unit could power a computer, phone, fax, and light for 8 to 10 hours before refueling.

.... the company is confident a $100 refill could be delivered anywhere in the United States within two days...

The $8K is high, but would not be bad if the unit has a long lifetime. The no-noise is a big plus. And the 1.2kW power is not really too bad, if it is paired with a battery/inverter setup to handle intermittent power demand surge.

The $100 for 10kWh is a killer. Nobody can afford that consumable price of $10/kWh, except for Bill Gates. And then, he would want a much larger unit to run his mansion.

 

[Texas Proud]

+1



The $8K is high, but would not be bad if the unit has a long lifetime. The no-noise is a big plus. And the 1.2kW power is not really too bad, if it is paired with a battery/inverter setup to handle intermittent power demand surge.

The $100 for 10kWh is a killer. Nobody can afford that consumable price of $10/kWh, except for Bill Gates. And then, he would want a much larger unit to run his mansion.

I am sure Bill already has a generator setup that can run his whole compound...


The Honda will cost maybe 20 cents per kWh... Bills will probably cost less...

 

[NW-Bound]

Well, Bill's estate is large enough that a 100kW diesel generator at the corner of his lot can't be heard at his mansion.

But maybe he wants to be green, and insists on a large fuel cell. Does anybody know?

 

[Bamaman]

My father worked for the government utility giant, Tennessee Valley Authority, as did both grandfathers, my uncles and aunts. At one time, they were the largest construction company in the world--building and maintaining their own coal fired and nuclear powerplants. They also have over 30 dams providing hydroelectric power.

Many of my fathers' friends were PhD's in Chemistry, and one had a law degree from Georgetown. They simply wrote the book on air pollution and what burning massive coal amounts does to the atmosphere. TVA's scientists have spent $ billions on hydrostatic precipitators and limestone scrubbers to get their powerplants as clean running as they are.

Unfortunately, Washington politics have gotten in the way, and we're seeing our coal fired steamplants shut down one by one. They are building natural gas generators and putting in solar farms along TVA's existing power lines--saving $1.2 million a mile that distribution lines cost. But it takes a bunch of mirrors and natural gas to make up for $.05 per KWH electricity coal power plants can make.

10% of U.S. steel imports goes into building windmills, and there has been so much corruption and failed producers operating on government loans and freebies. In our region, we don't really have enough wind to power windmills.

We are seeing a big improvement in U.S. industry. But prosperity takes electricity--massive amounts of electricity. I just hope we can keep up with the demand--at a fair price. I know our TVA electricity is up 100% in recent years, but is still much cheaper than most (except the Pacific NW.)

 

[folivier]

Uhhh, pumping water from one reservoir to a higher reservoir takes energy. True, this can be used to store energy but at what cost? It seems like the cost to pump may be as high as what is produced. So while this can be used to store energy for later use I don't see the practical use of it.
I think more "energy" should be spent developing tidal and current generators. That could be free energy.

 

[Totoro]

On intermittency: Belgium is facing electricity shortages in November because of their nuclear power plants showing defects that'll take months to fix properly and securely. So much for 'baseline' energy.

The issue with hydrogen in my view is on a basic level:

• High pressures needed to store it, which is also holding back e.g. natural gas quite a bit. Can't park in underground garages and not allowed access in some tunnels.
• Hydrogen is the smallest molecule out there, so it's a bit of a challenge to store it.
• No infrastructure to funnel it around available.

None of these issues batteries have to the same degree.

 

[Totoro]

Uhhh, pumping water from one reservoir to a higher reservoir takes energy. True, this can be used to store energy but at what cost? It seems like the cost to pump may be as high as what is produced.

Most things I could find is around 70% efficient. Not that great, but not bad either.

In addition, some sites don't have to be pumped to offer buffers. You just reduce dam flow in low demand and increase it in high demand. No efficiency penalty there. The issue with hydro is suitable sites and environmental concerns, not really efficiency.

Tidal plants are a bit similar: They don't offer storage, and also have location and environment issues. Also, a lot more expensive than dams at current costs (but improving I think).

 

[NW-Bound]

Energy storage is what we have been talking about.

Around the world, pumped storage has been in use for decades as the only way to store large amount of energy that is produced during the night for use during the day. This is so that we do not need to build more plants to run during the day, then shut them off at night. And we have been doing this, even if we get back out only 70% of the energy that we put in. It's routinely done for decades, even if laymen do not know about it.

With solar, it's the reverse. We want to store during the day to use at night. And going beyond, we will want to store for rainy days. And it takes a huge amount of storage that no one knows how to do.

Solar power is amazingly cheap right now, but there's no way to store it cheaply. I can buy a 300W solar panel for $100. If I have 67 panels, I can produce excess during the daylight hours to use for a 24-hr period. I would need a battery the size of the one in the P100D Tesla. I don't know how much its battery costs, but that's a $135K car.

 

[NW-Bound]

People take a lot of things for granted, such as electricity and tap water available on demand for 24/7/365.

When I was in Alaska, I saw that remote towns had to have their own diesel generators. While I was in Dawson City (in the Yukon, Canada), the power was turned off once for 1 hour during the lunch time. People expected this, so it was apparently a planned event. Perhaps the power plant needed a period off for maintenance (changing the engine oil or coolant?). They were not tied to a larger grid to "borrow" power.

It was a fact of life, and the locals were not bothered.

 

[atmsmshr]

Electricity- makes our modern life comfortable with the convenience of a switch or wall plug.

The devil is in the details of generation. Like the modern wonders medicine, no one source is a best fit for all situations.

As a nuclear engineer - I know there is some spot in the energy mix for nukes, but politics and regulation not allow that in western democracies.

PWR technology is frozen in time to 1975.

Atom

 

[ERD50]

Quote:
Originally Posted by folivier
Uhhh, pumping water from one reservoir to a higher reservoir takes energy. True, this can be used to store energy but at what cost? It seems like the cost to pump may be as high as what is produced.

Most things I could find is around 70% efficient. Not that great, but not bad either. ...

But as I pointed out earlier, 70% round-trip storage efficiency means you need to put $1.43 worth of energy into the system to get $1.00 worth out of the system. So you've had a significant increase to the price of that power, even before you add the cost of amortizing the storage system itself, plus any operating costs. Operating costs are probably low, I imaging the capital cost/loans are the primary factor by far, but those are not cheap, or the San Mateo system would have gone in, but it got cancelled...

Ahhh, some info:

https://www.hydroworld.com/articles...l-pumped-storage-hydro-from-ferc-license.html

400 MW capacity, $1,5 Billion. I'm not fining a MW hour rating offhand, but from what I recall, this was a few hours of storage, just to fill gaps in the "Duck Curve", as solar wanes and demand increases late afternoon, early evening. But a (probably generous) SWAG of ~ 4 hours at peak capacity gets us to a nice round ~$1 per watt-hour (1.6BWhr/$1.5B) investment. Hmmm, not sure where to go from there.... do we figure a home uses ~ 1KW average draw, so ~ 4 kWh storage required per home? So $4K investment per home, which would be an added ~ $20/month on a 30 year note? Plus increasing the cost of that electricity by 1.43x?

How does that compare to buffering with additional NG plants, I think that's the question?

-ERD50

 

[NW-Bound]

But as I pointed out earlier, 70% round-trip storage efficiency means you need to put $1.43 worth of energy into the system to get $1.00 worth out of the system. So you've had a significant increase to the price of that power, even before you add the cost of amortizing the storage system itself, plus any operating costs. Operating costs are probably low, I imaging the capital cost/loans are the primary factor by far, but those are not cheap, or the San Mateo system would have gone in, but it got cancelled...

Ahhh, some info:

https://www.hydroworld.com/articles...l-pumped-storage-hydro-from-ferc-license.html

400 MW capacity, $1,5 Billion. I'm not fining a MW hour rating offhand, but from what I recall, this was a few hours of storage, just to fill gaps in the "Duck Curve", as solar wanes and demand increases late afternoon, early evening. But a (probably generous) SWAG of ~ 4 hours at peak capacity gets us to a nice round ~$1 per watt-hour (1.6BWhr/$1.5B) investment. Hmmm, not sure where to go from there.... do we figure a home uses ~ 1KW average draw, so ~ 4 kWh storage required per home? So $4K investment per home, which would be an added ~ $20/month on a 30 year note? Plus increasing the cost of that electricity by 1.43x?

How does that compare to buffering with additional NG plants, I think that's the question?

-ERD50

4kWh storage per home? Not here in the Southwest.

I just looked at the highest daily usage of my home.

Total over 24 hrs: 100kWh
Highest hourly usage: 6.6kWh between 5PM-6PM due to heat soak
Lowest usage: 1.5kWh between 7AM-8AM, due to thermal lag

This was on July 7, when the average temperature over a 24-hr period was 103F (39.4C). Daily high: 120F. Daily low: 90F. Even at night, the hourly power consumption was 3.8kWh between midnight and 1AM, when the outdoor was still at 100F.

My home is just about average here at 2,700 sq.ft. I close off the vents to the 4 unused bedrooms. Thermostat is set at 79F. AC is 15-year-old. Pool pump and electric water heater are on timers to run only during off-peak hours, but that is to save on money, not on kWh.

 

[NW-Bound]

Lithium batteries are very efficient energy storage devices, with round-trip efficiency as high as 99% under the right conditions. Of course there's also energy loss in the electronics for the charger/inverter.

The main problem is cost. For home use, 2 Tesla Powerwalls can be used to store 27kWh, at a cost of more than $15K after installation. It's warranted for 5,000 cycles, if I remember right.

For larger-scale installations, they have the Powerpacks that store 100kWh/unit. That's the same capacity as the largest Tesla car battery. The price is reported to be around $400/kWh.

From Wikipedia:

A May 2015 article in Forbes magazine calculated that using a Tesla Powerwall 1 model combined with solar panels in a home would cost 30 cents/kWh for electricity if a home remains connected to the grid (the article acknowledges that the Tesla battery could make economic sense in applications that are entirely off-grid). US consumers got electricity from the power grid for 12.5 cents/kWh on average. The article concluded the "...Tesla's Powerwall Is Just Another Toy For Rich Green People." Bloomberg and Catalytic Engineering also agreed that the Tesla system was most useful in places where electricity prices are high.

There are however a number of such locations, including Hawaii and other remote islands that generate electricity with shipped-in or flown-in fuels. Residential California PG&E customers pay as much as 40 cents/kWh if they reach Tier 3 in electrical usage.

 

[travelover]

I can see why it did not take off... $8K cost a $100 to refuel after 8 hours... and really not that much power...



A Honda or similar generator is much more practical and cheaper...

With that logic, private jets, million dollar motor homes or Teslas, for that matter, would not exist. And run that Honda generator in your bedroom and you won't wake up. A fuel cell will just make water.


I'd love to see fuel cells successful, even if just for recreational use.

 

[Texas Proud]

But as I pointed out earlier, 70% round-trip storage efficiency means you need to put $1.43 worth of energy into the system to get $1.00 worth out of the system. So you've had a significant increase to the price of that power, even before you add the cost of amortizing the storage system itself, plus any operating costs. Operating costs are probably low, I imaging the capital cost/loans are the primary factor by far, but those are not cheap, or the San Mateo system would have gone in, but it got cancelled...

Ahhh, some info:

https://www.hydroworld.com/articles...l-pumped-storage-hydro-from-ferc-license.html

400 MW capacity, $1,5 Billion. I'm not fining a MW hour rating offhand, but from what I recall, this was a few hours of storage, just to fill gaps in the "Duck Curve", as solar wanes and demand increases late afternoon, early evening. But a (probably generous) SWAG of ~ 4 hours at peak capacity gets us to a nice round ~$1 per watt-hour (1.6BWhr/$1.5B) investment. Hmmm, not sure where to go from there.... do we figure a home uses ~ 1KW average draw, so ~ 4 kWh storage required per home? So $4K investment per home, which would be an added ~ $20/month on a 30 year note? Plus increasing the cost of that electricity by 1.43x?

How does that compare to buffering with additional NG plants, I think that's the question?

-ERD50

To me the cost of storage needs to be compared to the cost of production... IOW, why spend billions of dollars on a means for storage might be able to make a few plants that can produce the same amount for less... now, that is if the cost of production is cheaper than storage...


BTW, many many years ago I had a friend who worked at a power plant.. it was a backup plant for Houston and for the years I knew him did not produce electricity... they made steam which they sold to industrial users, but the generators were not used... and they once did some kind of service on the unit that cost $20 mill...


He said it was there just in case... and to help reduce the cost they had to pay to other producers...



I am with you.... I do not see us getting to 100% RE without a huge amount of regular production waiting to come online when it is not there...

 

[Texas Proud]

With that logic, private jets, million dollar motor homes or Teslas, for that matter, would not exist. And run that Honda generator in your bedroom and you won't wake up. A fuel cell will just make water.


I'd love to see fuel cells successful, even if just for recreational use.

Nope, private jets make sense to the rich, so does million dollar motor homes... but they offer a level of luxury that the person is buying... if they can get that level of luxury cheaper I would bet they would....



An $8K fuel cell does not make sense for say 99% of applications... it cannot run the fridge or freezer, it cannot run and AC.. it has limited applications... now, if you are on some kind of medical device that needs electricity then it might make sense, but I would first use batteries for that and if it were me I would invest that $8K on a whole house generator that run on NG so I do not have to fill it up....


And why would I run the generator in the bedroom? I can run it outside as it is quiet... and it will run the fridge or a small AC....

 

[Totoro]

How does that compare to buffering with additional NG plants, I think that's the question?

Gas peakers end up at $0.16 per kwh according to Lazard in 2017 on the low end. Interestingly, solar thermal with storage is at $0.10 low end according to them.

Pumped hydro is harder to find: $0.19 in 2015 Lazard, $0.17 in 2017 but unclear what it actually means, $0.26 is also mentioned and Irena estimates $0.10. Note this isn't large hydro (one way only - no pumping), which has $0.03 on the low end.

Most other forms of battery are around $0.30 and above it seems. Which surprised me that it was that low. Two more halvings in cost are needed, that'll be a while longer.

Sources:
https://en.wikipedia.org/wiki/Cost_of_electricity_by_source

 

[Walt34]

And why would I run the generator in the bedroom? I can run it outside as it is quiet... and it will run the fridge or a small AC....

The small portable generators cannot be used in the rain - at least none that I'm aware of. That would be a market niche for the fuel cell to run a small medical device that is essential but doesn't use much power.

No carbon monoxide to think about, probably near silent in operation, and the exhaust is water. The refill cost is problematic but if it's only needed a couple/few times a year that would not be a deal-killer.