Why We Have No Wind or Solar Power

[Big Dave]

MechEngVT has it. It is the intermittent nature of wind and solar that doom them. To back them up you have to run a fossil fuel plant in wasteful "spinning reserve" to cover for when the wind or solar units drop the ball.

We should be working on utility sized energy storage to level out the output of wind/solar. Pumped storage is nice but is highly site dependent and most of the sites have been developed already.

The big Vanadium batteries offer promise but aren't ready for prime time.

Until somebody comes up with a mobile-usage battery, running you car on wind or solar is just out of the question.

[roflwaffle]

Originally Posted by Big Dave

MechEngVT has it. It is the intermittent nature of wind and solar that doom them. To back them up you have to run a fossil fuel plant in wasteful "spinning reserve" to cover for when the wind or solar units drop the ball.

Well, doom renewables for us anyway. Those precise Germans already know how to manage it, but I suppose expecting Americans to do similar isn't realistic, right Big Dave?

http://ca.youtube.com/watch?v=tR8gEMpzos4

[jamesqf]

Originally Posted by Big Dave

MechEngVT has it. It is the intermittent nature of wind and solar that doom them. To back them up you have to run a fossil fuel plant in wasteful "spinning reserve" to cover for when the wind or solar units drop the ball.

Not quite true: you can float some intermittent generation (I've seen numbers up to 30% of total) on the system, basically because you have to have spinning reserve on the grid anyway. Then there's e.g. hydro, where you have a degree of choice about how much water you'll let out at any given time. And of course your system control operators are juggling all the various supplies, trying to get the cheapest electricity while staying within system guidelines... (At one point in my career, I used to maintain the some of the powerflow & stability programs that the utilities used to plan all this.)

There are potentially much better ways of storing energy than pumped storage, hydrogen, or exotic battery chemistry. High-speed flywheels, spinning in a vacuum on magnetic bearings. Very little conversion loss, and little friction loss over periods of a few days. Put a unit like that in every house that has PV panels, add a smart controller, and you could add quite a bit of solar/wind to the grid.

[Concrete]

roflwaffle
good flick - and that is probably the future near term - for going all renewable
You have to get over 10% wind base load for those problems, US is no where near that

we are making progress though
check out the DOE & you will see much of power generation growth is in renewable energy
EIA - Annual Energy Outlook 2008 - Electricity Demand
(at least in the near term - goofs still think 2030 will have less renewable growth )
we are on course - grow the good stuff - let the old wear out and fade away
I am much less worried about the future than I was 10 years ago
we actually have a measurable amount of renewable infrastructure and it is growing

Bird strikes
Bird strikes are an issue with small turbines
they spin so fast they look like a blur and the birds try to fly thru them
new large bladed turbines do not have this issue
ones near here are held to 28.8 RPM - easily visible and avoidable by birds

More data:
compensation for wind turbine on land - 2-10K per year!
http://www.windustry.org/sites/windu...mpPackages.pdf

[NeilBlanchard]

Hi,

The upper midwest of the USA and offshore, the wind blows quite steadily. The southwest has lots and lots of sunshine, and most other areas can certainly produce power from PV much of the time. The ocean tide is always shifting, and there are almost always waves offshore. Geothermal heat is definition of dependable -- drill a deep hole anywhere you choose, and pump water down there, and you'll get steam to run a generator.

With efficient grid distribution, all this power can be "moved" to where it is needed.

[jamesqf]

Originally Posted by NeilBlanchard

Geothermal heat is definition of dependable -- drill a deep hole anywhere you choose, and pump water down there, and you'll get steam to run a generator.

Yes and no. First, in most of the country the hole has to be pretty darned deep, and drilling costs money. Second, you only get so much heat per unit time out of a hole (or an existing geothermal resource such as a hot spring). It comes down to heat flow rates, and rock isn't a good conductor of heat.

[NeilBlanchard]

Hi James,

Recently, and MIT lab developed a way to drill a 7-8 mile deep hole relatively easily; using a gas cutting head rather than a mechanical one. The heat down that deep is pretty darn close to inexhaustible.

[Big Dave]

The German video had a lot of "ifs" and "coulds" and other expressions of uncertainty. Sounds like it has an equal probability of being vaporware.

The plan is built on a number of things not likely in the US.

1. The Germans' plan would require a big increase in T&D lines to wheel power about the country. When was the last time a T&D project of any size was done in the US? Last one I can think of was a 25 mile interconnector link that Schwartzenegger pushed through eminent domain to mitigate the power wheeling problems CA had in the early part of the decade. The German plan would require thousands of miles of either 765 kV or DC transmission lines. It would take decades to force that through the courts.

2. A biogas generating plant is still a generating plant and still subject to New Source Review. for the US we are not talking dinky little 70 Mw peakers. We are talking 400 Mw minimum. Not to mention the emissions from the gasification process itself. Surely nobody things that destructive distillation of cellulose is going to occur without air pollution. It would take at least a decade to get the permit and years more of court challenges.

3. Most of the good pumped storage sites in the US have already been developed. In the West you get into water rights issues. In the Midwest and Middle South you have no delta-y. Once again you are talking more than a decade to get the necessary permits and fight off court challenges.

4. Flywheels, spinning on gas bearing and in a vacuum to eliminate windage, were tried back in the 1970s. Energy storage goes up with the square of the RPM so 100,000 RPM was the starting point. Even with carbon fiber wheel webs they flew apart before they got anywhere near the necessary RPM. Nice idea. Doesn't work.

5. The only idea that is not poisoned is the vanadium redox battery, and it is still at a primitive stage. The technology is at least a decade away from application if some lawyer doesn't find a way to challenge it in court for decades more.

[Concrete]

Originally Posted by jamesqf

Yes and no. First, in most of the country the hole has to be pretty darned deep, and drilling costs money. Second, you only get so much heat per unit time out of a hole (or an existing geothermal resource such as a hot spring). It comes down to heat flow rates, and rock isn't a good conductor of heat.

...now we get to it
the biggest reason we do not have more solar or wind
- it is more expensive than burning carbon
in this part I'm with Dave - these clever energies are harder

wind is close & so is some biomass - the rest can't compete
yet...

[bryn]

there are some promising solar thermal projects out there. insulation is easythe coffee in my stanley thermos can still burn me 12 hours after i put it in there. running a steam turbine twentyfour-seven, should be pretty easy to figure out