Renewable electricity generation

[Prozac the Robert]

How do you get it to be useful in large amounts?

Take a wind turbine. It produces power completely irregularly. How is it helpful? Do you have to pair it with a conventional power plant that's capable of changing its output fairly rapidly, or is thee a decent means of storing the energy?

Some groups (especially greens, obviously) want to make renewables a big part of the energy budget, and I'm wondering if anyone credible has looked at such plans in any detail.

[Edi]

How do you get it to be useful in large amounts?

Take a wind turbine. It produces power completely irregularly. How is it helpful? Do you have to pair it with a conventional power plant that's capable of changing its output fairly rapidly, or is thee a decent means of storing the energy?

Some groups (especially greens, obviously) want to make renewables a big part of the energy budget, and I'm wondering if anyone credible has looked at such plans in any detail.

Depends on what you want to use it for. See for example the lighting stuff I talked about in the other thread. For big industrial stuff, not so good.

[General Zod]

How do you get it to be useful in large amounts?

Take a wind turbine. It produces power completely irregularly. How is it helpful? Do you have to pair it with a conventional power plant that's capable of changing its output fairly rapidly, or is thee a decent means of storing the energy?

Some groups (especially greens, obviously) want to make renewables a big part of the energy budget, and I'm wondering if anyone credible has looked at such plans in any detail.

Hydroelectric is one of the more useful amounts of renewable energy, but obviously if you live away from a major water reservoir it's not very practical. Location is one of the big issues about 'renewable' natural power sources the Green groups are so fond of.

[General Zod]

How do you get it to be useful in large amounts?

Take a wind turbine. It produces power completely irregularly. How is it helpful? Do you have to pair it with a conventional power plant that's capable of changing its output fairly rapidly, or is thee a decent means of storing the energy?

Some groups (especially greens, obviously) want to make renewables a big part of the energy budget, and I'm wondering if anyone credible has looked at such plans in any detail.

Hydroelectric is one of the more useful amounts of renewable energy, but obviously if you live away from a major water reservoir it's not very practical. Location is one of the big issues about 'renewable' natural power sources the Green groups are so fond of.

Ghetto edit: Amounts should read types. Blah.

[Andrew_Fireborn]

What about those "bio-reactors" I've heard of that are basically coal/hydrocarbon plants that divert their emissions into giant algae tanks, and that surplus of algae is then turned into 'synthetic' hydrocarbon fuel?

That seemed a reasonable in between method. (Being basically solar +1.)

[Zixinus]

The only way to scale renewables, with the exception of hydroelectricity, is to build on bigger land mass. For renewables to be competitive with nuclear of even coal, they would require land masses equal to that of some states in the USA.

http://www.nei.org/resourcesandstats/do ... iclanduse/

And there is some stuff here, not checked it myself, so I'm unsure of the BS amount. Seems low though.

http://phe.rockefeller.edu/biblio.php

[Prozac the Robert]

I'm not so much concerned by the amount of renewable sources needed, but in their variation over time. Is there any arrangement of wind, tide, hydro etc. that can produce power to approximately coincide with demand? Or is some sort of mass storage system needed?

[aerius]

How do you get it to be useful in large amounts?

Take a wind turbine. It produces power completely irregularly. How is it helpful? Do you have to pair it with a conventional power plant that's capable of changing its output fairly rapidly, or is thee a decent means of storing the energy?

In theory you could use pumped reservoir storage & generation. During times when the wind turbine is generating surplus electricity, the excess power is used to pump water into a large elevated storage reservoir. When there's not enough wind, you let the water out of the reservoir to run the pumps in reverse which then generates power.

Problem is suitable sites are still a bit hard to come by, plus the generating capacity and ability to smooth power outputs will still be limited. It's not something you can rely on to run a big city, but it should be able to power a small town without too much trouble.

[Civil War Man]

Take a wind turbine. It produces power completely irregularly. How is it helpful? Do you have to pair it with a conventional power plant that's capable of changing its output fairly rapidly, or is thee a decent means of storing the energy?

As an example, there is a single wind turbine not far from where I live. It's small as far as turbines for that purpose go (blades around a couple hundred feet or something like that). It doesn't actually store electricity, but when it is running (which is fairly often, since I live in a windy area), the people that use it draw less power from the grid, and deduct that from their electricity bills.

But yeah, as many have pointed out, most renewable energy sources have low density, so an increase in power generated can only really be done by increasing the size of the generator. Hydroelectric is probably the exception, but has only been real widely applied in Washington State and the Tennessee Valley, where they have a lot of rivers.

[Sea Skimmer]

How do you get it to be useful in large amounts?

Take a wind turbine. It produces power completely irregularly. How is it helpful? Do you have to pair it with a conventional power plant that's capable of changing its output fairly rapidly, or is thee a decent means of storing the energy?

Most wind turbines are situated in areas which always have enough wind to keep the turbines spinning, so they’ll always be making some amount of power. Large wind farms are indeed paired with conventional power plants that switch on to handle any drop in power production. That makes installing the wind farms expensive for the peak power output they can provide, but they are worthwhile investments. They just aren’t any kind of magic bullet, but then nothing is.

The only way to store commercially meaningful amounts of electricity is pumped storage hydropower. You build a reservoir up on a hillside that has no natural source of water, and then fill it up using huge turbine generators which can also be reversed to work as pumps. You take electricity off the grid to run the pumps to fill it up when demand is low, like at night, using surplus power from other sources (nuclear plants are ideal since they like to run constantly at full power) and then drain it out to make power when demand is high. Overall efficiency is about 97%.

The major sources of reliable renewable energy are hydropower, tidal/wave power and wind power. Solar power and geothermal power are big contenders as well, but they suffer from the biggest limitations on were the plants can be installed. If we tapped all the possibul power from these sources, we'd have many times the output of all power generation in the world today.

Biomass, be burning wood, corn or grass or dead whales is also a major source, except that the world already has problems making enough food with sustainable farming methods. We’ll have to wait and see if those algae to hydrocarbon conversion proposals work out on an industrial scale.

[Zixinus]

I also recall something regarding how biofuels are actually more polluting then non-organic fuels. Is this true?

[CaptainChewbacca]

In the past year there has been great strides made in drawing energy from the oceans. Ocean Power Technologies has designed several power-generating buoys, and by 2010 hopes to produce a single buoy capable of generating 500 killowatts. A field of 40, anchored 2 miles off the coast of a town, could have very exciting possibilities.

[Count Dooku]

In the past year there has been great strides made in drawing energy from the oceans. Ocean Power Technologies has designed several power-generating buoys, and by 2010 hopes to produce a single buoy capable of generating 500 killowatts. A field of 40, anchored 2 miles off the coast of a town, could have very exciting possibilities.

500 kilowatts is respectable for a single unit. A community college around me (Diable Valley College, in California) is about a year away from completing a 1 Megawatta solar panel system. It's largly funded by Chevron. If it wasn't, I'm not sure how it could be built.

Another community college in my county is also getting the same solar system, but it's about two years away from completion. The cool thing about these systems is that they'll cover the parking lots (which are completely uncovered), and in the summer where we have 3 straight weeks of a temperature of 110 F or more. There are always a huge variety of events (related to, and not related to the school), and everyone I've talked to will be glad once the project is complete.

[Illuminatus Primus]

How do you get it to be useful in large amounts?

Take a wind turbine. It produces power completely irregularly. How is it helpful? Do you have to pair it with a conventional power plant that's capable of changing its output fairly rapidly, or is thee a decent means of storing the energy?

Most wind turbines are situated in areas which always have enough wind to keep the turbines spinning, so they’ll always be making some amount of power. Large wind farms are indeed paired with conventional power plants that switch on to handle any drop in power production. That makes installing the wind farms expensive for the peak power output they can provide, but they are worthwhile investments. They just aren’t any kind of magic bullet, but then nothing is.

The only way to store commercially meaningful amounts of electricity is pumped storage hydropower. You build a reservoir up on a hillside that has no natural source of water, and then fill it up using huge turbine generators which can also be reversed to work as pumps. You take electricity off the grid to run the pumps to fill it up when demand is low, like at night, using surplus power from other sources (nuclear plants are ideal since they like to run constantly at full power) and then drain it out to make power when demand is high. Overall efficiency is about 97%.

The major sources of reliable renewable energy are hydropower, tidal/wave power and wind power. Solar power and geothermal power are big contenders as well, but they suffer from the biggest limitations on were the plants can be installed. If we tapped all the possibul power from these sources, we'd have many times the output of all power generation in the world today.

Biomass, be burning wood, corn or grass or dead whales is also a major source, except that the world already has problems making enough food with sustainable farming methods. We’ll have to wait and see if those algae to hydrocarbon conversion proposals work out on an industrial scale.

So I take it you have optimism about the technology factor, which is what you think will overcome the future energy issues?

My biggest hurtles are not theoretical alternatives, but eventually constraining growth - which seems unthinkable from modern attitudes but it necessary, the fact that tractors and whatnot probably can never run off anything but hydrocarbons in the foreseeable future, and whether heavy industry and sustainable high-yield agriculture can be operated off an electric, higher-cost, post-hydrocarbon world. Otherwise, I think your grasp on energy alternatives is better than most. Do you think we're going to see a nuclear resurgence? I always wince reading that nearly 100 reactors were canceled from 1973 to 1985.

[Sea Skimmer]

So I take it you have optimism about the technology factor, which is what you think will overcome the future energy issues?

My biggest hurtles are not theoretical alternatives, but eventually constraining growth - which seems unthinkable from modern attitudes but it necessary, the fact that tractors and whatnot probably can never run off anything but hydrocarbons in the foreseeable future, and whether heavy industry and sustainable high-yield agriculture can be operated off an electric, higher-cost, post-hydrocarbon world. Otherwise, I think your grasp on energy alternatives is better than most. Do you think we're going to see a nuclear resurgence? I always wince reading that nearly 100 reactors were canceled from 1973 to 1985.

I’m confident that existing and very near future developments of technology could solve existing world energy problems, given proper long term planning for construction. I’m not confident that the proper action will actually be taken in time but it’s quite possible. It’s not at all impossible for the US to spend 1 trillion dollars on new construction of power infrastructure over a period of only a few years, and it would be no larger then the existing defense budget.

I suppose it might take a bit of lead time, to build more construction equipment ect.. but it can all be done. We aren’t about to just implode into the dark ages worse then the Great Depression because we ran out of crude oil early one morning.

If we don’t see a resurgence of nuclear power, and the reprocessing of nuclear fuel (that can wait, but not forever) then we’ve got a problem. Interestingly, the US is currently reopening several uranium mines which closed down because of reduced demand and cheap foreign ore. Now that prices are rising, a very large number of former US mines could be profitable again. That would in turn force prices way back down again, but a blance can be found and any actual increase in demand met.


If we keep growing to 10-15 billion people, then that is another question entirely.

[Illuminatus Primus]

Well this stuff has to be graduated, of course. Some people want to hear feel good shit like people won't die, everyone will live in a suburb with a hydrogen cell SUV, and stuff like that. For example, I think we all agree that the dysfunctional Arab world will never do anything until its too late and they're going to die-back to shitty camel nomadism. Ditto for almost all of Africa. China is probably going to hit a wall with growth and their environmental degradation and resource depletion. North America remains the best long-term prospect for advanced and progressive civilization in the world.

[Zixinus]

What about Europe and other areas of Asia besides China?

[Illuminatus Primus]

Europe is all over the place. France has a robust rail and canal infrastructure which permits electrification, and already supplies upwards of 70% of its electricity from nuclear power with a large portion of the remainder coming from hydroelectric. Its building a new set of nuclear plants. Its agriculture retains decentralization and isn't as mechanized as the U.S. Contrastingly, the UK let their rail languish during the Thatcherite period - which was due to cheap oil from the North Sea, not due to neoliberalism - and couldn't feed itself a hundred years ago. Not being food or energy self-sufficient is a big no-no. Depending on how bad it goes, the UK could be in various graduations of big trouble, from bad to worse. Basically, your risk factors are population growth, resource depletion, environmental damage, energy non-self-sufficiency, food non-self-sufficiency, and political risk in the form of unstable domestic situations or neighbors with unstable political situations. Asia pretty much sucks, all over the map. They are all liable to have to deal with Chinese or Indian resource grabs or caught in the middle in future wars. I could definitely see a nuclear exchange in south Asia in the next century. There is no room for over 2.5 billion on that continent on any long-term time span.