Wind generation

[rcwilson]

Solar Power

Solar Power

Several power developers are looking at solar thermal power plants in California and Arizona, using fields of parabolic mirrors that focus the sunlight on oil-filled pipes. The hot oil is pumped through a heat exchanger that makes steam to run a turbine to generate about 100-150 MW of power from a square mile of solar collectors. Tanks of salt solutions are used to store heat for evening operation and to increase the thermal cycle efficiency.

This makes sense in the Southwest where electrical load is highest when the sun is shining due to air conditioning. But it is expensive installed cost. I think the cost is less than a similar size solar cell facility.

Example of the size: each collector mirror has two large foundations. A crew pouring one foundation every 20 minutes, 24 hours a day, 7 days a week, can finish the work in 1-1/2 years. Every mirror has an aiming motor that needs to be wired and checked out, which will take about two years round the clock at 1 hour per motor.

 

[e57]

Just from a technical standpoint this sounds absurd.

I saw a program about this some time back which I can not find. But it is more wind power than solar - a solar chiminey.

It works in this animation.... Take note of the size comparisions.:grin:
http://www.youtube.com/watch?v=0tWlP0knKQU
Apparently there are smaller versions that have been built already (a bit more on how it actually works)
http://www.youtube.com/watch?v=XCGVTYtJEFk&feature=related

Not quite what Don was talking about with "compressed air" but apparently works at night due to stored heat - Got a link Don? Wouldn't mind seeing it.

Personally I like this idea of the solar tower - but assume there will audubon type going on about blinding and/or igniting birds mid-flight.
http://news.bbc.co.uk/2/hi/science/nature/6616651.stm

But on the comment that there is nothing to sell down the line - of course there is - the mark up on the labor to run and maintain them.

 

[don_resqcapt19]

e57,
http://www.sciam.com/article.cfm?id=a-solar-grand-plan

 

[peter d]

The problem with these "green" power sources is that they are not very "green" to build - they take lots of resources and fossil fuels in the construction process.

Which is why I say - build more nukes.

 

[Jraef]

The problem with these "green" power sources is that they are not very "green" to build - they take lots of resources and fossil fuels in the construction process.

Which is why I say - build more nukes.

Interesting viewpoint.
Are you implying that Nuke plants are not made with traditional building materials that need fossil fuels to extract and process?

Hmmm... concrete: made of baked limestone, crushed gravel that was mined and transported, processing equipment, mixing equipment, pouring equipment, finishing etc. etc. etc.

Piping, made from mined material, melted metals, alloying equipment, forming equipment, finishing equipment, transportation, welding, fitting, etc.etc.

Waste disposal, now THERE is a "green" part of the process eh? Transporting with extreme equipment for public protection (which means VERY heavy for what it contains). Tunneling, processing of the tailings from tunneling, more concrete, security for 10,000+ years?

Oh and how about all the A/C and lighting for the countless lawyers, lobbyists, protesters and security people is will take just to come up with a place that will accept something so deadly, poisonous and strategically volatile that NOBODY is willing to accept it in their back yard?

Hardly green if you ask me.

 

[peter d]

Interesting viewpoint.
Are you implying that Nuke plants are not made with traditional building materials that need fossil fuels to extract and process?

Of course not. Nor did I mean or imply that nukes are "green" power.

However, they are our only viable non-fossil fuel option to keep up with power demand.

 

[Mr. Bill]

The best energy strategy for the US is to have a diversified source of electricity. If only 1% of our national energy comes from wind right now then yes, I would like to see it as high as 15%. That would also mean I want to see more nuclear.

And once solar becomes more affordable I'd like to see more of these installed on buildings. But solar is not appropriate for all locations. It would take 3 times as many solar panels in Michigan as it would in New Mexico to get the same power output.
http://www.solar4power.com/solar-power-global-maps.html

To complain that "green" power sources are not constructed "green" is a bit unfair and avoids the main argument. But if you must, how long does it take a nuclear power plant to recover it's carbon footprint? If it ever does. I know solar is about 2 years and I suspect that wind power is even less.

 

[petersonra]

Solar central plant generation will probably never make much headway. Solar photovoltaics as distributed generation probably will (IMHO.) If the generation can be kept close to the load, losses in distribution can be reduced. There are a lot of roofs that could have solar panels added. It is not cost-effective, yet.

Solar PV will probably always be a bit of a niche product due to the intermittant nature of the electrical energy produced. Keep in mind that a typical house might have a few hundred square feet at most of suitable roof area. A typical 100W panel takes about about 10 square feet of roof space. You probably won't get more than 5 on a typical house.

500W that is available only on average 3-4 hours a day, is only 2 kw-hr per day. Most americans use far more than that on a daily basis. Even if you save 20-30 cents a day on electricity, it is only maybe $75-100 a year.

The solar panels and grid tie equipment will cost you in the neighborhood of $3000 installed.

Currently there are a fair number of subsidy programs for solar PV systems that make a big difference in the numbers, but without them, solar PV is mostly a niche product.

By the way, on average, for storing 1 kw-hr of electricity in current lead acid battery technology, it costs 30-50 cents over the life time of the batteries.

 

[don_resqcapt19]

From an e-mailed energy newsletter that I recieved.

Spanish companies have begun to cover the deserts of the southwestern United States with mirrors that convert the area's scorching sun into clean energy to power air conditioners in the casinos of Las Vegas and restaurants of Phoenix.

The Acciona firm inaugurated Friday in Nevada the third biggest solar-energy plant in the world, with 182,000 curved mirrors that tame the sun and put it to work lighting 14,000 homes.
Nevada Solar One can generate 64 megawatts of electricity and is the biggest built anywhere in the world in the last 17 years, according to Acciona.
But it won't keep its title for long, since in 2011 an installation of the Spanish company Abengoa is planned to start up in neighboring Arizona that will dwarf the Nevada facility.
The Arizona installation, to be called Solana, will generate 280 megawatts of power, enough to light 70,000 homes, Abengoa says.
Both projects reflect the enormous interest of European companies in entering the comparatively less-developed market for renewable energy in the United States.
Last week Germany's Schott company announced, for example, that it will build another solar-energy generating plant near Albuquerque, New Mexico.
With state-of-the-art technology tested in Spain, companies in the sector have begun to transplant their experience to the southwestern United States, where the dry air and many cloudless days create one of the best climates in the world for their business, according to Monique Hanis, spokeswoman for the Solar Energy Industries Association.
Spanish investment in the U.S. renewable-energy sector has taken off in recent years, according to Alberto Nadal, economic and trade counselor at Spain's embassy in Washington.
To sound out new business possibilities, last week representatives of Iberdrola, Gamesa, Isofoton, Solaria and other leading Spanish companies of the sector descended on Congress and the White House.
"Spanish companies see a tremendous opportunity in the U.S. market," Nadal said.
In Nevada the directors of Acciona made that clear.
Alberto de Miguel, Acciona's head of corporate development and strategy, told Efe that the company plans to use Nevada Solar One as a shining example to help expand its renewable-energy business.
The array of curved mirrors, which cost almost $270 million, concentrates the sun's rays into tubes that heat a fluid that generates vapor and activates an electric turbine.
Acciona will sell the electricity to two local companies that are particularly interested because in 2013 some 5 percent of the power they supply to their customers must come from the sun, according to new Nevada regulations.
Changes like that in state and federal law are galvanizing the United States market, Hanis said. EFE

 

[mivey]

Here are some hard numbers on electrical plant construction and maintenance for people to review. Better than spreading rumors. These numbers are based on large scale production. 600 mega-W for a coal plant or 50 mega-W for a wind plant.

http://www.eia.doe.gov/oiaf/aeo/assumption/pdf/electricity.pdf#page=3

Wind plant costs $1,206/kW for construction
O&M costs $28.51/kW

Scrubbed Coal plant costs $1,290/kW for construction
O&M costs $25.91/kW + $4.32 mills/kWh

Advanced Nuclear costs $2,081/kW for construction
O&M costs $63.88/kW + $0.47 mills/kWh


Edit:
Is anyone else able to figure out the variable O&M unit cost? $4.32/kWh doesn't make sense because Utilities sell electricity at $0.08/kWh. Maybe it's $4.32/ million kWh. I just thought the fuel cost more. I ended up copying it per the table.

I'm not sure what the original source stated because I could not get the link to work (DOE appears to be having problems) but the variable cost for coal should be near the 3-4 cents/kWh range and the nuclear around 0.4-0.5 cents/kWh. This should be a good idea for the magnitude of costs but I wouldn't bet the farm on these rough numbers as they will vary from plant to plant.

 

[Montanaboy]

I am a former public utility transmission planner. I dealt with wind farm (or as they try to redefine themselves as wind plants) regularly. I support all type of green energy and energy efficiency.

Having said that, I do not support wind farms. Wind farms companies and the utilities that buy/lease their power always show remote, pristine openness, clear skies and a single or a handful of innocent looking wind turbines. They are out of sight ... out of mind.

What they don't show you is that there are miles and miles of large (100 ft +) transmission towers that must be built for the circuits to bring the power from these "remote out of the way areas" to load centers in big cities. Nor do they mention the cost of these circuits which is paid for by the utilities ... oh, never mind, that would be you and I ... when the utilities pass on the cost to us. Estimates for the CREZ (see www.ercot.com for details) transmission infrastructure were in the area of $5B during one presentation I attended. Not a bad gravy train to get on, right?

Also, rarely are wind farms near to large load centers except along coastal waterways where groups get together to fight them because of the aestetics or slow flying birds (yes, birds somehow run into the blades). The funny part is that they are not protesting the wind farm itself as that is a private transaction between a land owner and the wind farm company. They are protesting the transmission circuit to get the power out because that is the only place they can fight the legal battle.

One of the strong defenses of wind farms is that it will reduce CO2, NOx & SOx emissions; however, since wind farms don't run all the time nor at a controlable rate, natural gas, coal and nuclear facilities must support the transmission grid ALL THE TIME. In addition to the subsidized cost for the transmission grid infrastructure, the wind farms don't replace the base line units.

Also, wind farms (except the coastal) blow at night when there is low load requirements as opposed to the afternoon when load requirements are high.

So, we can build wind farms a long way from where they are needed, spend lots of money to get unreliable power to load centers while not benefiting the environment much ... OR we can invest in other technologies (solar which is where you need it ... panels close to you requiring no transmission, when you need it ... sunny afternoon = hot = air conditioning, geothermal, etc.), new construction methods, materials and maybe change our mindset on the usage of power to begin with.

I'm not a conspiracy theorist; but I do believe that the wind farm political action committees have better PR departments than anyone else. The government supports renewable energy supplies, but provides LARGE incentives for wind farms in particular. Wind farms are a quick fix for a long term problem. They are cheap to the investors and expensive to society.

I'll now stand down from my soap box.:smile:

 

[petersonra]

None of the so called alternative energy schemes are even remotely economical, and would die the death they well deserve if all the various subsidies (both direct and hidden) were cut off.

OTOH, if you have the opportunity to get on the gravy train you might as well do so. If its not you, someone else will benefit from it, so it might as well be you.

 

[jghrist]

Is anyone else able to figure out the variable O&M unit cost? $4.32/kWh doesn't make sense because Utilities sell electricity at $0.08/kWh. Maybe it's $4.32/ million kWh. I just thought the fuel cost more. I ended up copying it per the table.

It's 4.32 mills/kWh, not $4.32/kWh. One mill is $0.001.

 

[Montanaboy]

None of the so called alternative energy schemes are even remotely economical, and would die the death they well deserve if all the various subsidies (both direct and hidden) were cut off.

As of today, you are correct. If the $5B+++ of tranmission costs were invested in R&D for alternative energies, it would bring them down also. All technology gets more economical over time with research and development. As I mentioned, the wind farms are economical because of societal subsidies. Wind farm companies would not be popping up all over the place if they had to pay to upgrade the transmission grid or if they did not have large government subsidies.

 

[crossman]

So let's say we had enough wind farms to generate a majority of the power for the country. We are extracting huge amounts of energy from the velocity of the wind, thereby slowing the wind down. What climatic global catastrophes await us for changing the movement of the winds on a large scale?

 

[Jraef]

From an e-mailed energy newsletter that I recieved.

It's not just Spanish companies. I just finished my part of a pilot project for these guys. They are selling it NOT on subsidies, but on real cost benefits.
http://www.ausra.com/

There is also an upcoming big shift in solar PV systems where architectural glass is being made to generate electricity inexpensively.
http://www.appliedmaterials.com/products/solar_sunfab_3.html?menuID=9_5_3

So now all those big glass towers in LA, Dallas, Houston, Phoenix, Las Vegas and other Southwest cities can supplement their power with their own windows. The old paradigms about solar power are likely to fall as the demand increases.

 

[MJJBEE]

I believe that wind is part of the answer however It can't be counted on. I recently read an article on Wind Power as a dispatchable resource and the basic theory is that while wind is a source of power you need quick moving backup resources to protect the grid from sudden changes in wind speed. This happened to Texas a few months ago and caused load shedding because the wind died near a peak in power usage.


I think the answer to the problem is not one solution but a bunch of items. We need more base loaded plants to deal with load growth this means new Coal or Nuke Plants I would prefer Nukes over coal but that is a choice what type of problems you want to have in the future. We also need more peaking resources this means Huge power storage devices or fast peaking plants such as simple cycle gas turbines or hydro plants.

Solar is also part of the solution however my area is a low sunlight area so solar doesn't make large scale sense. I also wonder about all this hydrogn economy stuff if we are really going that way will it greatly increase our variable loads and what will we do about it? I have may more questions then answers about where th epower industry is going int he next 30 years.

 

[hardworkingstiff]

I believe the problem will go beyond energy. This planet can only support so many people, and one day we may reach that number.