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SFOGuy (Member Profile)

Houston Helicopter Officer Lands and Tackles Suspect

Ladybaby "Give Me Money"

eric3579 (Member Profile)

radx says...

Yap, wheat and rye, mostly. Some maize. It's been a week since the last snow fell, but it remained cold enough to maintain a thin layer on top of everything.

Those wind turbines on the second picture were in the process of going offline. There's hardly any wind at all. Solar panels are working splendidly though, cloudless sky all day and perfect working temperatures.

eric3579 said:

Snowy! Are those crop fields?

The Howmet TX: Rethink Everything

oritteropo says...

According to the entry in Jimbo's big bag'o'trivia, there's a second turbine that drives the wheels (and an electric motor for reverse).

newtboy said:

I want to know more about how it works. It seems like they're saying it's direct drive off the turbine (with no clutch? Really!?), but then they are able to stop the wheels with the brakes while the turbine is spun up...so how does that work?
Looks like fun, and an interesting idea.

The Howmet TX: Rethink Everything

newtboy says...

I want to know more about how it works. It seems like they're saying it's direct drive off the turbine (with no clutch? Really!?), but then they are able to stop the wheels with the brakes while the turbine is spun up...so how does that work?
Looks like fun, and an interesting idea.

blackfox42 (Member Profile)

Real Time - Dr. Michael Mann on Climate Change

newtboy says...

Well, allow me to respectfully say that you (and he) are wrong.
Absolutely I would still save money without the grid. I already have paid to have a small battery bank in my system (>1KWH), so it wouldn't cost me much more to be completely grid free. As it is I barely send power to the grid, as I use most of my electricity as I produce it by doing housework during the daytime. (EDIT: If @Asmo did that, maybe just by using timers on large appliances to run them during the daytime, he would save a lot more, like up to 4.5 times as much as he saves today.) In the short run I would not save as much as I do currently, because I would need to buy more panels and a larger battery bank, and the batteries would need replacing sooner, but it would still be a huge savings in the end over buying grid power. The suggestion that it's not economically viable without the grid is simply wrong.
Once flywheels become popular, it will be far cheaper than it is today to store your own electricity, I'll probably get one to replace my batteries when they eventually die.
EDIT: A micro-hydro system could also store the power cleanly, but requires 2 large storage tanks, one raised as far as possible above the other, and a pump/turbine to move the water. For those with the space, that seems a good solution for power storage, and it's how some electric companies do it on a large scale already.

EDIT: I did the math, and to be completely grid free would cost me about $3000 more, and the upgrade would pay for itself in 2-3 years. Hmmm, now you've got me thinking.....Oh yeah, I forgot, my system can't run my large welder, the electric oven and stove together, or the hot tub directly, that's why I stuck with a grid tied system in the first place, I use too much electricity at once sometimes. Solar systems DO have some limitations, mine can only put out 6500 watts at once, max.

bcglorf said:

I think Asmo has a bigger point. You aren't counting the cost of effectively using the energy grid as a personal storage system for energy you produce. If you were to cut your line to the grid and replace it with your own storage, would you still be saving money over just being hooked up to the grid? Asmo is suggesting that you would no longer be saving money by doing that. Moreover, by pointing that out he is making the obvious extension that in that case solar is not, currently, cheaper than grid power...

Real Time - Dr. Michael Mann on Climate Change

Asmo says...

The inference being that I have a choice..? =) We don't in Aus.

But you're missing the point, X >= 1 feed in tariffs are being subsidised by other users on the grid. You upload your power regardless of demand peaks (so you could be sending power when it really isn't required). Electricity companies are not going to massively drop production of regular power as it takes a considerable amount of time to spool up/down baseload production, and they are still going to switch on high cost gas turbines during peak load just in case a big old cloud blocks out the sun for an hour or so and solar production falls in a heap...

And peak usage times are usually ~8-9am (schools and business start up, switch computers and air con on etc) before solar production really kicks in, and later in the afternoon when it get's hotter, people are getting ready for dinner. If you have significant daylight savings time shifts, then you can certainly get better production when peak demand in the early evening is occurring. If the panels are facing west rather than east or north (because that's where you maximise production and make the most money... =)

As for "the idea that it might take more energy to produce a panel than it will produce itself is ridiculous", I didn't say that it did, just that it's return on that energy invested is comparatively poor. You coal analogy is patently wrong though. Depending on which source you go to, coal is anywhere from 30:1 to 50:1 for EROEI (energy returned on energy invested). It's cheap to obtain, burn and dispose of the waste, despite being toxic/radioactive.

eg. http://bravenewclimate.com/2014/08/22/catch-22-of-energy-storage/

When you talk about solar PV and the energy required to make it, you're not just talking about the production line, you're talking mining the silicon, purifying, the wasted wafers which aren't up to snuff, the cost of the workers and the power that goes in to building, transporting etc, lifetime maintenance, loss of production over time and disposal. The above link puts PV at the low 1.5-3:1 which is well beneath the roughly 7:1 required to sustain our modern society (and does not cover the massive increases in energy demand and consumption from developing countries). And as the author of the article notes, these are unbuffered values. If you add buffering to load shift, the sums get even worse.

"Put simply, if solar PV is such a bad deal, how are they saving me so much money even without any rebates?"

I didn't say solar was a bad deal, I said it's a poor way to reduce carbon pollution. If the electricity company you are connected to is willing to pay high feed in tariffs to you and you save cash, that's great, but that doesn't automagically (intentional typo mean that solar PV is making any sort of serious inroads in to reducing carbon pollution.

If we're going to fix man made climate change, we need to be prepared to pay a far higher cost and worry less about our hip pockets. Nuke might not be economically viable without causing jumps in bills, but in terms of the energy output it provides over it's life time, it is one of the highest returns in energy for the energy invested in building it, paired with very low carbon emissions.

Obviously, the figures on EROEI depend on which article you read, as it's a very complex number to work out (and will always be an approximation), but it's fairly commonly acknowledged by people who do not have a vested interest in solar PV (vs low carbon power sources in general) that PV is a feel good technology that doesn't actually do a hell of a lot in terms of carbon reduction.

Real Time - Dr. Michael Mann on Climate Change

newtboy says...

No, my first paragraph attempts to spell out why solar PV is a dud for people who do it the worst way possible, by selling all the electricity produced at drastically reduced rates to the grid, then buying it back at exorbitant rates, you are wasting well over 75% of what you could be saving. Of course it looks bad when you waste that much.
I have no mechanism needed to make it financially viable, and the idea that it might take more energy to produce a panel than it will produce itself is ridiculous.
I didn't 'make time' for anything, it just so happened that my lifestyle was perfect for solar, since I already did my housework during the daytime.
I have what's called a 'time of use' meter, which means it splits the day into 3 time zones, and keeps track of what I produce vs what I use from the grid. That means I essentially do get 1:1 for my production, which never reaches the point where they owe me money, but does offset almost all the juice I use (during the daytime) At night, we use normal grid power at normal grid rates. Too bad Australia doesn't do it that way.

yes, there are costs to an array, but they are one time costs, and FAR less than what's saved. That part is simple math. My system cost around $34K after rebates, maybe $40 without them, and it saves me around $5K per year in electric costs (based on 2007 rates, which have gone up). That includes production costs, installation cost, shipping cost, permit cost, etc.
Here in the US, daytime IS peak power use time. it's when business are using the most power, and when AC units are on, so the grid uses the power I feed in without problem. Industry uses WAY more power than homes. Solar offsets them using the hydro, gas turbines, and ramping up nuclear plants during the day, when they are used the most.
If my bill is lower, it means I used less fossil fuel generated electricity, so it IS working like a charm. How do you think otherwise? it's not perfect, and doesn't erase all other production, and is not a solution to ALL energy production problems, but it is a good part of the solution, unless it's done in the least productive manner possible.

What are you talking about, 2-3X the energy input? If you actually only count the costs, not the profit made at each stage in selling/installing panels, they probably come in more like 5-10 times the energy input, with little or no carbon footprint (many factories make the panels using power produced by other panels...as in pure solar factories).
My calculations (verified by my bills) put it at <1/2 the cost of buying (mostly coal produced) electricity from the grid at 2007 prices (even without any rebates), so how do you figure coal power production is cheaper, even ignoring all the other costs/problems? Coal may give a 30 to 1 return if you ignore ALL the other costs involved in using coal. If you count them, it's more like 1 to 2, because the effects of coal are so incredibly expensive, as is the cost of digging it up, transporting it, storing it, burning it, and disposing/storing the toxic waste products.

The cost of restoring a river is far more than the value of 100% of the power generated by a dam during it's lifetime.

Put simply, if solar PV is such a bad deal, how are they saving me so much money even without any rebates?

Asmo said:

And your first paragraph pretty much spells out why solar PV is a dud investment for small plant/home plant if it were completely unsupported by a plethora of mechanisms designed to make it viable financially (and that's before even considering whether the energy cost is significantly offset by the energy produced), not to mention trying to make time to do things when your PV production is high so that you're not wasting it.

I try to load shift as much as possible, even went so far as to have most of the array facing the west where we'll scrape out some extra power when we're actually going to use it (eg. in the afternoon, particularly for running air conditioners in summer), but without feed in tariffs that are 1:1 with energy purchase prices and government subsidies on the installation of the system, the sums (at least in Australia) just do not ever come close to making sense.

But as I said in the first paragraph, that is all financial dickering, it has nothing to do with actual energy used vs energy generated. There is no free energy, you have to spend energy to make energy. You have to buil a PV array, pay for the wages of the people who install it, transport costs etc etc. They all drain energy out of the system. And most people in places where feed in tariffs are either on parity with the cost of purchasing energy when your PV isn't producing align their solar arrays with the ideal direction for greatest generation of energy that they can get the best profit for, not for generation of energy when energy demands spike.

The consequences of this are that at midday, energy is coursing in to the grid and unless your electricity provider has some capacity for extended storage and load shifting (eg. pumped hydro, large scale battery arrays), it's underutilised. Come peak time in the afternoon when people get home, switch on cooling/heating, start cooking etc when PV's production is very low, the electricity company still has to cycle up gas turbines to provide the extra power to get over that peak demand, and solar does little to offset that.

So carbon still get's pissed away every day, but as long as PV owners get a cheaper bill, it's all seen to be working like a charm... ; )

The energy current efficiency panels return is only on an order of 2-3x the energy input, which is barely enough energy returned to support a subsistence agrarian lifestyle (forget education, art, industrialisation). There's a reason that far better utilisation of coal and oil via steam heralded the massive breakthrough of industrialisation, it's because coal has close to a 30 to 1 return on energy invested. Same with petrochemicals, incredibly high return on energy.

The biggest advances in human civilisation came with the ability to harness energy more effectively, or finding new energy sources which gave high amounts of energy in return for the effort of obtaining them and utilising them. Fire, water (eg. mills etc), carbon sources, nuclear and so on. Even if you manage to get 95% efficiency on the panels for 100% of their lifetime (currently incredibly unlikely), you're only turning that number in to 8-12x the energy invested compared to 25-30x for coal/petro, 50x+ for hydro and 75-100+x for gen IV nuke reactors.

Real Time - Dr. Michael Mann on Climate Change

Asmo says...

And your first paragraph pretty much spells out why solar PV is a dud investment for small plant/home plant if it were completely unsupported by a plethora of mechanisms designed to make it viable financially (and that's before even considering whether the energy cost is significantly offset by the energy produced), not to mention trying to make time to do things when your PV production is high so that you're not wasting it.

I try to load shift as much as possible, even went so far as to have most of the array facing the west where we'll scrape out some extra power when we're actually going to use it (eg. in the afternoon, particularly for running air conditioners in summer), but without feed in tariffs that are 1:1 with energy purchase prices and government subsidies on the installation of the system, the sums (at least in Australia) just do not ever come close to making sense.

But as I said in the first paragraph, that is all financial dickering, it has nothing to do with actual energy used vs energy generated. There is no free energy, you have to spend energy to make energy. You have to buil a PV array, pay for the wages of the people who install it, transport costs etc etc. They all drain energy out of the system. And most people in places where feed in tariffs are either on parity with the cost of purchasing energy when your PV isn't producing align their solar arrays with the ideal direction for greatest generation of energy that they can get the best profit for, not for generation of energy when energy demands spike.

The consequences of this are that at midday, energy is coursing in to the grid and unless your electricity provider has some capacity for extended storage and load shifting (eg. pumped hydro, large scale battery arrays), it's underutilised. Come peak time in the afternoon when people get home, switch on cooling/heating, start cooking etc when PV's production is very low, the electricity company still has to cycle up gas turbines to provide the extra power to get over that peak demand, and solar does little to offset that.

So carbon still get's pissed away every day, but as long as PV owners get a cheaper bill, it's all seen to be working like a charm... ; )

The energy current efficiency panels return is only on an order of 2-3x the energy input, which is barely enough energy returned to support a subsistence agrarian lifestyle (forget education, art, industrialisation). There's a reason that far better utilisation of coal and oil via steam heralded the massive breakthrough of industrialisation, it's because coal has close to a 30 to 1 return on energy invested. Same with petrochemicals, incredibly high return on energy.

The biggest advances in human civilisation came with the ability to harness energy more effectively, or finding new energy sources which gave high amounts of energy in return for the effort of obtaining them and utilising them. Fire, water (eg. mills etc), carbon sources, nuclear and so on. Even if you manage to get 95% efficiency on the panels for 100% of their lifetime (currently incredibly unlikely), you're only turning that number in to 8-12x the energy invested compared to 25-30x for coal/petro, 50x+ for hydro and 75-100+x for gen IV nuke reactors.

newtboy said:

Well, it seems the big problem there is that you buy electricity at 4.5 times the price of what you sell it for, and you seem to sell off almost all of what you make. That means you're wasting over 75% of what you generate, no wonder it seems like a bad deal. If you could find a way to use the power you generate instead of selling it and buying it back for 4.5 times as much, things would change I think. That could be as simple as starting your laundry and dishwasher as you leave in the morning rather than at night. Since I'm home all day, it wasn't a change for me to use most of our power during the day, which made it totally economical for me, even when I do my calculations based on power costs from 9 years ago, if I added in the rise in power rates here, my savings would seem even larger.

True enough about the batteries, but I only use them for backup power in outages, so they'll last a while as long as I keep them full of acid. By the time I need new ones, perhaps I can use a flywheel for storage instead. They're great, but expensive right now.

It depends on your point of view, hydro decimates river systems for about 15 years of power. Totally a worse deal than coal's significant part in global warming/climate change, in my eyes, and coal is terrible. A dam can kill a river in one season, coal takes quite a while to do it's damage. That said, coal does it's damage over a much larger area. Hard math to try to figure out, comparing the two. Here in the US, we're removing dams to try to save the last few fish species in many rivers.
Wave generation seems like it could be a promising method of power generation, you don't damage anything by capturing some wave energy. Too bad it's not seeing much advancement (that I know of).

Elon Musk introduces the TESLA ENERGY POWERWALL

radx says...

I'm intrigued by the different strategies they seem to have taken with regards to different markets.

The US market has been covered here already. Living off the grid, buffer for power outages, etc.

But they appear to market the Powerwall as a decentralized buffer system for our regional/national grid, as a means to shave off the spikes in power usage at times when both wind and solar fail to meet expectations. Seems like a virtual power plant of Powerwalls would be an alternative to gas turbine plants. Add some pumped-storage hydroelectricity in Norway and the Alps, and the need for standby power plants would be vastly reduced.

Additionally, they are probably aiming at the time when diminishing feed-in tariffs for PV panels make it more attractive to charge batteries instead of feeding into the grid.

However, even if they manage to sell only a handful of Powerwalls, it'll force all the other players to get off their fat asses for once. Politics managed to kill the local solar industry and the big players came up with fuck all in terms of meaningful innovation over the last years.
Yes, I'm looking at you, Siemens!

Elon Musk introduces the TESLA ENERGY POWERWALL

newtboy says...

I use slightly less than that myself on average, but we have solar water heating (supplemented with gas), so that's a good savings (especially since it also heats the hot tub), and we replaced all our light bulbs with led bulbs when they became feasible last year. Now, we usually read between 400 and 1000 watts during the day (depending on how many lights I have on, and if the refrigerator is cycled on or not.) That's running a big screen TV, computer, and often ps4 almost all day, every day. We also have electric stove and oven...and I weld, adding somewhat to our total.

Yes, my battery bank is only useful for power outages. It's enough to keep the lights on and the fridge from thawing, but not much else. We get about 3-4 hours out of it if I don't notice the power went out, but can make it all night if we conserve. Our system is grid tied, and first powers the home, then tops off the batteries, then sells any excess to PG&E. To date, I've never drawn the batteries down to zero...but we do have a small generator to supplement it when the power's out for days. The average home would certainly need more, but a 10kwh battery should be plenty to make it through an average night without AC (we don't have AC here).

My current system could not produce that much, but close. I live in N California, one of the foggiest areas in the US. Because we have a renter, an electric hot tub, dishwasher, and electric washer and drier, we use slightly more than we generate at this point, but my system is upgradeable to 6500 watts of generation (I have less than 1/3 of that now) when panels get cheaper...and when I can find space for more.

My system is not flat to my roof, and I have 2 strings of 8 panels. With the solar water tubes, it takes up most of the south 1/2 of my roof (1200 sq ft home). I could maybe fit 4 more panels up there and still be able to walk around them to clean them, but any more and I'll need some mounting structure. I really want to add a small wind turbine to generate at night or when there's a storm...solar doesn't work in the dark.

In America, we still have some rebates for people adding solar to their homes, but they are drying up fast. 15-20 years ago, you could almost do it for free if you got every rebate available.

We used to have about 1-2 weeks of power outage where I live per year, and that was part of why we did they system. We hated having no power and losing food every year, and also hated paying the ever rising cost of electricity. Before adding our system, we had $4-500 a month electric bills, now we have <$100 in winter and sometimes a negative bill in summer...we pay our bill once a year now, lump sum at the end of 12 months.
On to your second post....
I often think...electric cars were popular and the norm in cities before Ford came along. It's still astonishing to me that it was basically dropped for a century as a technology (with minor exceptions). I'm glad someone had finally gone back to it and is trying to fix it's issues. If I could afford a Tesla, I would have one.

I also agree, people won't adopt the technology as long as they have to sacrifice lifestyle for it. I said the same thing, but I found that I don't change my lifestyle at all with my solar system, I just pay lower bills. I determined that buying a system would pay for itself in under 10 years, with the lifespan of a system being about 20 years, that's 10 years of free electricity! That all assumes electric rates didn't go up, and they certainly have gone up...but not for me. You just need to be sure you install enough panels to supply all your power, and you're there.

The battery thing is really mostly for non-grid tied systems, or emergencies. Most people don't use batteries at night, it's simpler and cheaper to just sell power to the grid during the day and buy it back at night if you can, using them as your battery. Perhaps this battery will change that, but with lead acid, it's hard to make them worth the cost.

Panels aren't that expensive, really. In many areas, with rebates, they can be near free. (some companies will even give them to you and split the power generated off your roof). It's a myth that solar is expensive...when compared to non-solar. Mine are paid for by bill savings already (8 years + in) so I'm saving money with them now, and my lifestyle has not suffered in the least. I have lights on if its dark, I watch TV all day, and use the computer all day, have tons of electric devices I use, and soon will power a pond, etc. I often think that my life is a much better example of how you can be 'green' without much change than Gore's. He really doesn't seem to walk the walk, but he can sure talk the talk.

So, some smartass went and reinvented the wheel ...

newtboy says...

Great! But how does it do with large side forces, like cornering at high speed? If they do well, perhaps this is a way to eliminate suspension in electric vehicles, reducing weight but keeping a smooth ride. That would be a big leap forward!
I've seen something similar with maybe 20 curved 'spokes' (looking like a turbine from the side) that was tunable, made harder or softer by adding/removing 'spokes'. The issue with them was the spokes created lots of resistance...like turning a turbine.

RMS Titanic: Fascinating Engineering Facts

Ickster says...

Me either. I ended up doing some Wikipedia reading, and it turns out that there was a sort of transitional phase where the combination of reciprocating engines with a cruising turbine wasn't entirely uncommon. I'd always thought it one or the other exclusively.

I also hadn't realized how many ships used turbine-electric setups instead of direct drive. Wiki page.

One quibble with the video--I didn't get all of the ships shown when he was talking about coal dust as the reason for black hulls, but at least a couple were late enough that I'm pretty sure they'd been build as oil-burners (SS Normandie for example).

radx said:

I had no idea they used a Parsons turbine to drive the center propeller. Fascinating.

*promote



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