Contributor
One issue with renewable energy that is not always on is that many power generating plants cannot just start up in an instant. A number of power plants have generators that cannot ever be shut down except for overhaul. The armature in the generator is so heavy that it will flat spot if it ever stops spinning.
We do have lots of peaking power plants for high demand days, but they are much more expensive to run.
Contributor
Brian - Just a question for interest - How are those generator armatures installed originally or after an overhaul so as not to create a flat spot? In other words, what's the difference between the original install and a shutdown?Originally Posted by Brian Elfert
Mike
Go into the world and do well. But more importantly, go into the world and do good.
Good point Mike,
If I do this, it will be more or less a demonstration project. I think it would be fun to do but you're right.....not much chance of making a profit.
For now, I'm just fishing to see if costs have come down and if there is a practical way to do this.
Thanks,
Rob
Moderator
Rob,
Do a web search on Homepower magazine. It might help guide you.
Member
Absolutely right. I replaced my home gas furnace with a high efficiency unit. Savings in gass will not cover the cost of the unit for 15 years assuming the cost of nat gas stays on-pace with CPI.... Short term pain, long term benefits.
Open minds are a good thing. Our collective bent towards flash-in-the-pan come-ons and painless, quick solutions encourages the snake oil salesmen. They are going to be out there, and so are the gullible with money to burn. Today's solar technology is yesterday's whale oil.
See my sig.
"I love the smell of sawdust in the morning".
Robert Duval in "Apileachips Now". - almost.
Laserpro Spirit 60W laser, Corel X3
Missionfurnishings, Mitchell Andrus Studios, NC
[quote=Mitchell Today's solar technology is yesterday's whale oil.
See my sig.[/quote]
So do you see any application for solar power?
Like you, I have high efficiency gas furnaces.
Good equipment is not cheap - regardless of the energy source.
Rob
Contributor
Mike
The generators very rarely stop moving, and when they do it is for very short periods of time. It is done though. Ours is offline right now.
A "convential" turbine driven generator will operate at 1800 RPM. When the turbines are taken off line for repairs, PM's and mod's the entire turbine, or just the genrator can be kept rolling at a very slow RPM.
While flats spots are certainley a consideration, the combined length for a multi stage turbine generator is pretty long, and there are 100's of tons of weight involved. Of more consideration is sagging along the shaft which would induce vibration when the turbine is up to speed. 100's of tons of rotational mass at 1800 RPM,any induced vibration can be a very bad thing. 5-7 mills can easily be felt throughout the whole station .
Removing a generator, Armature/Stator, is a very big operation. I've only seen it done twice in my 25 years of working at a nuclear power station.
As to the other point brought up in this thread, not by you, about it taking too long to bring a power plant online. That's a misconception. A gas fired turbine can be brought online very quickly to provide power. There are companies that maintain their gas turbines idle and only bring them online for short periods of time when the cost of electricity is high. Of course they can also delay bringing them online and drive the price higher. Some of these turbines may only be placed online for just a few hours.
Mitchell
I'm going to disagree with some of your position, but I respect the things you have brought up as discussion points.
Electrical generation rates are not going down.They are only going to go up, and now that distribution is seperate from generation in some states. You actually have two seperate bills combined into one, each independent of the other. Either of which can be increased. Creating a situation where solar power can be a viable alternative for powering a residential application.
To go totally off the grid might cost upwards of $35K for me.
With my average electrical bill, here in CT, that system would pay for itself in about 19 years. With the orientation, area, and pitch of my existing roofs,a low profile system could be close to 96% efficient according to the calculators.
Retrofitting an existing home to solar can be very cost prohibitive, but a new construction home, designed from the ground up is a viable option. If I were building a new home. It would be solar/geothermal. Not totally off the grid, but supplemented.
Don't worry about the electric company losing any money on paying residential generation rates for a solar powered system. We're not going to lose money, I promise. The reserve capacity can be sold on the market, and there is always a need for power.
I believe that in a few years we will begin to see more individual solar systems in residential applications. Of course then it will get intersting to see how the feds and states get their share of the pie.
Last edited by Mike Cutler; 04-28-2008 at 6:52 PM.
Member
The model of treating the power company works quite well with respect to solar power because you really can't put up enough panels to come anywhere close to replacing current conventional power sources. But it can be useful to reduce utilities requirements to build new capacity for growth. If solar power supplied 5-10% of overall electrical requirements that would mean fewer new gas or nuclear plants would need to be built. Electrical prices will continue to rise with the price of natural gas, solar panels will come down in price and the payback and economic viability will continue to improve.
Here in BC solar power is still a long way from economic viability as we have cheap (6c/kWHr) hydro power (and not enough sun) but we can't build new powerplants for that price anymore so our rates will slowly rise and eventually it might be viable here.
Greg
Member
ANY??? Yea. Passive heating for non-essentials such as pools and storage-freindly low use systems like showers and dishwashers.
In areas where the sun works best - we need it least. On St Maarten solar works GREAT - but not for heating homes. You don't need to heat homes where the sun shines the hottest. In Upper Saskatchawan heating is needed the most but the sun doesn't shine with enough intensity... Solar is not the solution we hope it is.
When lower class people living in the rust belt states start paying $2K, $3K, $4K for heating costs in an average sized home - look out. The solution for these homeowners isn't going to be a $30,000 solar system that only supplies 50% of their heat.
Are you willing to take down a few 60 foot trees on your property so your neighbor's panels catch the sun? Me neither. Tell your neighbor his trees are casting too much shade on your proposed solar feild and see what happens. Medium scale solar isn't the solution and the faster we realise this, the faster we'll move towards a real-world solution.
"I love the smell of sawdust in the morning".
Robert Duval in "Apileachips Now". - almost.
Laserpro Spirit 60W laser, Corel X3
Missionfurnishings, Mitchell Andrus Studios, NC
Speaking of change, you can pump the water with a windmill and be completely green!I'm heating my pool using the sun...still need 'lectricity to run the pumps, however.
Change is always in the air....
Lee Schierer
USNA '71
Go Navy!
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Tell your next door neighbor to take down his trees because they cast too much shade on your proposed panel location.... Let me know how this goes.
People who can affort to install systems, can affort to buy power at market rates and then the proposal is moot. There isn't enough insentive for the average homeowner - who, by the way, ask thier kids to set up their ipods.
I think we'll be on widespread nuclear/electric decades before we see even moderate use of individual solar systems.
"I love the smell of sawdust in the morning".
Robert Duval in "Apileachips Now". - almost.
Laserpro Spirit 60W laser, Corel X3
Missionfurnishings, Mitchell Andrus Studios, NC
Contributor
I previously provided a link to an article that proposes a plan large-scale solar power generation for the US. The obstacles for solar power are economic, not technical (like fusion reactors). Experimentation in solar power generation is on-going. There are generating plants in the southwest that have been running for years. As the cost of fossil fuels and emission controls rises, and solar cell conversion efficiencies get better and manufacturing costs fall, solar power is already becoming economically viable.
Solar is not the only choice for new large-scale power generation, nuclear and geothermal are additional possibilities. Just as today, the power grid in the future will include a mix of technologies. And there is "inertia" in the system - for example, the cost per KW-hr of hydropower from existing dams is really cheap, partly because the infrastructure is already built. But that doesn't mean building lots of new hydro is a good idea - construction costs are high, and suitable locations are scarce. But this example of a power source that doesn't burn a fuel is a good example for development of future electrical generation facilities.
Last edited by Jeff Bratt; 04-28-2008 at 5:59 PM.
Member
We just (last November) installed a 4.2 Kw array. In California you can 'sell' back power to PG&E. During the summer peak hours (noon-6pm) we get 3x normal rate for excess but pay 3x for what we use. Shifting use (dishwasher, dryer, aquarium lights) to off peak and paying 1x for off peak means we are net producers. We pay electric bill once per year. So far we owe about $220. This will come down as we are just getting into the real production time. It's mostly cloudy Nov. to March here and few clouds and no rain April thru Oct.
Our BPV (before photovoltaic,) use was about $250/month. System cost about $25K. At current rates for power we will break even in 10 years - less if (!) rates go up.
One place I see the utility making money is not actually paying for power we generate but giving us credits. If there is an overproduction on our part they get it for free. We have jokingly considered running extension cords to the neighbors so they can tap off our 'extra'.
Is it the solution? No. If it was possible to actually sell back to the grid then it would be possible for investors to buy into PV for profit. I believe this is what happens in Germany.
Last edited by John Hemenway; 04-28-2008 at 5:59 PM.
Contributor
Mitchell
I love your insight. That sentence is absolutely perfect.
I still think that you will see a growing shift to solar power in some form. Will everybody be able to do it? Unfortunately no. To be truly efficient requires some pretty ideal conditions, and the neighbors trees are certainly part of it.
It's starting in the southwest and the southern states, where the condition are more ideal, but even here in the Northeast it can be done.
I'm not sure that it's simply a question of affording solar, versus buying at market rates. I would expect that a viable, professionally designed system would also return some of the investment at the sale of the house. It's a numbers game though, no doubts there.
Lest it sound as if I'm some nostalgic hippie, with stacks of High Times magazine and the Whole Earth Mother News laying around. Believe me, I'm not. I'm just a guy trying to figure out why it is that here we are, in the most technologically advanced country in history, and the most economical solution to heat a house is to burn wood like a cave man.
The price of electricity is going to go up significantly in the next decade or so. The demand is only going to increase,and the supply is not increasing at the same rate. The cost benefit of alternative sources of energy will change.
By the way. I like your position on Nuclear Power. I'd like to see more plants built also. We, as a country, do need to address the long term waste issues associated with nuclear power to move forward though.
Oh yeah. Tennessee would be perfect for solar.
Member
Honestly, I think nuclear is where it's at. Solar, wind and hydro power are all "piddle power". Even together they can't come close to providing a significant amount of the energy this country uses. All of them are limited in where they can be successfully deployed. That said, I think they have their place. While I don't have a PV panel, I do have a solar hot-air box on my roof that does help in the winter--on a sunny day in the winter it can keep the furnace from running for about 6 hours. I'm looking into building another of my own design at some point, perhaps even adding a PV panel to power a DC fan for the system (but that's the expensive part).
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