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Post by GTCGreg on Nov 26, 2012 21:27:53 GMT
Here's one place I got my figures. greenecon.net/understanding-the-cost-of-solar-energy/energy_economics.htmlAnd 35 years on a solar panel is really pushing it. Most companies claim their panels will last 25 years but almost all only offer 5 year warranties. And even those 5 year warranties come with a lot of limitations. Again, it's almost impossible for you to generate electricity cheaper than you can buy it from the power company. Out of all the sefl-generation systems, solarvoltaic is by far the worst. The best is hydro. That is if you have a stream on your property with enough elevation drop and flow. Next would be wind. Provided, of course, you are in the right location and have enough property to support a wind turbine. |
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Post by rmc on Nov 26, 2012 22:22:30 GMT
A friend of mine now lives on a small 'ranch' out in the high deserts of California. Their system charges batteries all day and then they use those batteries for their evening work. They are not at all on the grid.
But, as GTCGreg has pointed out, there are problems not being on the 'grid'. The big problem they are currently fielding is the expense of getting new batteries.
They'd like to go more in the direction of wind energy, but the current expenses up-keeping the solar equipment have them pretty well strapped -- and more strapped then they were initially, if you get my meaning.
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Post by the light works on Nov 27, 2012 1:52:55 GMT
In case you haven't noticed, those rolling blackouts only occur in California. The reason? On every turn, the environuts blocked the construction of new transmission lines and power plants, including alternative power. They want their energy but they block every means to make and distribute it. You can't have it both ways. And THAT'S why you have your blackouts. and I never heard my uncle complain about them even though he lived in the heart of hot country. of course, his PV system probably had an effect on that. |
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Post by GTCGreg on Nov 27, 2012 2:23:18 GMT
of course, his PV system probably had an effect on that. Maybe you should ask him. It would be interesting to hear what he has to say. |
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Post by silverdragon on Nov 27, 2012 5:39:09 GMT
No, not that way....
Your meter runs backwards when you are generating but not using any power...
Otherwise, it "Slows down".
You are still buying electricity, but, not as much.
Say you buy 100kwh, but during the time you use that, you generate say 30 kwh, you effectively have 130 kwh to use?....
You dont effectively sell anything, because say over a week, you will use more than you sell, as in the meter will run forward more than it runs back, but the fact it has run back some of the time, makes the weekly bill less as you have bought less.
Is I making any sense of this or just confusing it more?...
You are billed on what you use at the end of the month, or when the meter has been read, say every three months, or in my case, once a year.
As I have used more than I generated, I will always be paying.
Whet I send back to the grid when I am not using power at home goes back at the same price I pay for any I buy.
In the current economic climate, "Green" electricity is worth more than dirty fossil duel as the Govt is hell bent on getting away from fossils...
Which surprises me, cos there is a lot of old fossils on the Govts Back benches?....
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Post by GTCGreg on Nov 27, 2012 13:59:47 GMT
I can understand the "save the earth" mentality. I can understand Lightworks reliability argument, but I still don't understand the idea that it's saving you money.
If you can buy power at a lower rate, but offset doing so by substituting more expensive power, then you will never save by using the more expensive source. And all PV solar is much more expensive than grid power when you take initial cost plus maintenance into account.
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Post by the light works on Nov 27, 2012 16:11:55 GMT
of course, his PV system probably had an effect on that. Maybe you should ask him. It would be interesting to hear what he has to say. know any good mediums? |
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Post by GTCGreg on Nov 27, 2012 16:14:15 GMT
I don't even know any good mins or max's, let alone mediums.
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Post by the light works on Nov 27, 2012 16:19:40 GMT
I can understand the "save the earth" mentality. I can understand Lightworks reliability argument, but I still don't understand the idea that it's saving you money. If you can buy power at a lower rate, but offset doing so by substituting more expensive power, then you will never save by using the more expensive source. And all PV solar is much more expensive than grid power when you take initial cost plus maintenance into account. it is the same as the decision between upgrading your old computer and buying a new computer. there are some circumstances where it makes sense to upgrade your old computer (power grid) and some where it makes sense to buy a whole new computer (power grid) add in the fact that right now, building a whole new power grid is not going to happen; and you get some idea of the situation. right now, when I have a power outage, I use a gasoline generator - at best I am paying $.20 per KWH for it, and it is much more likely I am paying closer to $1.00 per KWH. sure makes those solar panels look cheap, doesn't it? |
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Post by GTCGreg on Nov 27, 2012 16:47:28 GMT
Well, you can buy a 5kW gasoline genset for around $500. It will burn through about 1 gallon an hour of fuel at full load. At $3.50 per gallon, that's 70 cents per kWh.
Now what would a 5kW solar array cost you. And if the power should go out after sunset, you'll also need at least a 70kWh bank of batteries and inverters. Of course, if the power's not on the next morning, you can't recharge the batteries since you'll need the full output of the PV panels to power your house. The next night, you'll be in the dark.
So we can spend $500 on a 5kW generator, or $35,000 on a 5 kW solar system.
As for me, I'll take the generator, which in 25 years, I've only needed to use twice.
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Post by the light works on Nov 27, 2012 17:10:17 GMT
but I ONLY use the genset during power outages, because it burns a minimum of $40.00 in fuel per day. with a PV system, your fuel cost is zero - which means you can run it continuously for no additional cost.
in fact, assuming the 5 year warranty is mean time before failure, you get (assuming 50% efficiency) 109.5 MEGAwatt hours out of that system in its lifespan for your money - about 31 cents per KWH.
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Post by GTCGreg on Nov 27, 2012 17:20:36 GMT
I still fail to follow the logic. 31 cents per kWh or 10 cents per kWh, and you'll opt for the 31.
No wonder California is going bankrupt.
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Post by unavailable on Nov 27, 2012 17:27:53 GMT
... So we can spend $500 on a 5kW generator, or $35,000 on a 5 kW solar system. As for me, I'll take the generator, which in 25 years, I've only needed to use twice. One problem with a backup gasoline generator is finding a gas station with power for the pumps during a long term wide area blackout. I know from personal experience this can can be pretty difficult. |
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Post by GTCGreg on Nov 27, 2012 18:22:38 GMT
Yes, as many people on the east coast can tell you, that can be a problem.
Wonder how well solar panels on the roof hold up to a hurricane.
Of course, there's no reason for that either. You could run all the pumps at a typical gas station off a portable generator.
The failure on the east coast was a governmental response one, not because of lack of technology.
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Post by chriso on Nov 28, 2012 2:05:18 GMT
Where the heck were they suppose to get that many generators? Seems like a tall order, when those resources could probably be used better elsewhere... like getting the grid back in order.
Anyhow, adding another angle to this discussion, their are a few places that solar works very well, and it has nothing to do with electricity. Electric heating can be as much as %80 of a household electric build, and so using the sun for heating can work far better.
Solar heating, both water and the entire home, is well established and can save large amounts of cash as well as being, more importantly, cheap. Although solar heating in a house usually requires considerations during construction of the home, making retrofitting a system difficult if not impossible, it can, when set up right, largely negate a need for electric or gas heating, saving a lot over the course of the house's life. Roughly, it comes down to setting it up so in winter months the sun shines into the home, onto a heat-storing medium of some kind (giant slab of granite, for example) while during the summer months an awning keeps the sun, now high in the sky, from shining in. These systems are totally passive, and last as long as the house does.
Solar water heating is very easy to setup on any house. Composed of black panels that absorb the suns rays, and through which water is pumped, it can save on your heating bill by preventing the need to turn on the backup electric or gas heater on you hot water tank. The heated water is pumped into the water tank to await use. Although the pump uses some power, it is far less than would of been used heating the water using electricity.
The catch, of course, is the places where it works best, where AC is not really needed, are the places that receive less sun.
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Post by the light works on Nov 28, 2012 2:16:33 GMT
I still fail to follow the logic. 31 cents per kWh or 10 cents per kWh, and you'll opt for the 31. No wonder California is going bankrupt. keep in mind: .31/KWH is only if the panels fail 5 years, to the day, after you bought them. if they last 15 years, you've dropped it to .103/KWH, and if they last 20 years, you're paying .08 per KWH. |
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Post by GTCGreg on Nov 28, 2012 5:02:02 GMT
If you can get solar panels that produce electricity for .08 per kWh, then I'd say go for it.
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Post by chriso on Nov 28, 2012 5:45:37 GMT
I still fail to follow the logic. 31 cents per kWh or 10 cents per kWh, and you'll opt for the 31. No wonder California is going bankrupt. keep in mind: .31/KWH is only if the panels fail 5 years, to the day, after you bought them. if they last 15 years, you've dropped it to .103/KWH, and if they last 20 years, you're paying .08 per KWH. Where are you getting the kilowatt statistics for 5 years? The one greg linked to specified .38 as the return for 20 years already. |
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Post by silverdragon on Nov 28, 2012 8:41:51 GMT
Better than your actual roof....
The Panel is one unit, and better than conventional tile, and its bolted down securely to the rafters/cross members/whatever Solid they can find up there.....
Of course, one GOOD hurricane, your whole roof is away with the faeries, but I guess you would have bigger fish to fry anyway?....
Thats why you have home insurance.
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Post by ironhold on Nov 29, 2012 0:43:37 GMT
She's come to understand that the system she proposed won't work, but now has a follow-up question:
Thanks.
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