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Is Solar for real? Or am I missing Something?

 
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bob golding wrote:

r john wrote:The battery problem may be solved with the latest thermal solar CHP



could you elaborate on that please?



Sorry I had posted this in the Alternate Energy section

http://www.vdg.no/index.php?articleid=12

Its similar technology to what I use on a commercial basis
 
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M Foti wrote:I've been wanting to go solar grid tied for years, never had the cash... now, someone gave me 25 commercial panels 230 watts each...



Would you consider selling some of them?
 
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Curious... people that are tying in to the grid and then selling their extra power back to the electric company- - - -   If something happens to the grid does the power company then have any control over your solar system?  wondering what the contract is like, the fine print.
 
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[quote=Justus Walker

(I use about 15 kwh a day. If I were doing a 12v system that had 3 days worth of storage and was scaled for optimum battery longevity, completely off the grid, I would need...



At my current cost of electricity ($0.07) I could buy about 49 kWh electricity per day on just the depreciation of the equipment.

So, do people who put in solar have to be ideologues?

Please tell me I've got something royally screwed up. I want to do alternative energy. So far the only thing looking good is the horse and the gasifier.

And the TOJAN horse in the whole thing is....)

 

There are many ways to amplify the effect of money within the system and the number one target you should look at is ways of getting the same utility as 15kWh/day as you use it now.

What this exercise will do is contrast what power really takes to produce in quantiy and what its really worth.

A nice experiment is to attempt logistics of packing your family car or camper and truck for a long vacation a couple hundred miles away. Now eat a big meal and get the whole family behind and push that bad daddy to ylur destination.

A less ridiculous example would be pedal pumping your water or carying it a couple hundred yards in buckets... for the national average of 100 gallons per person. Now examine your situation and reduce that to say 5-10 gallons per, While getting the same utility. Dont like pedaling or carrying? It is luxury to not have to... it costs money cant do without the hot tub? Get outmore money.

Do not think that the price you pay currently is anywhere near the real price...its not. The amount of work and material in a renewable energy system is nowhere near the amounts involved in manufacturing, maintaining and fueling a utility power station, and all the work people involved have needs, food, homes, consumption akimbo and somehow at the power bill end we get $.07/kWh... even with money thrown in to settle the RE people down (baksheesh) and clean up of ecological devastation (not even) like nuke fuel processing.

Read the O.T.A. report from 1991 "complex cleanup" and get back to me on how cheap that power is! O.T.A. office of technological assesment of the us government has been disbanded... imagine that. 500 million per year for research on toxics leaching from these facilities and the doe cannot tell us how far and how much is contaminating the environmets NEAR them.

Pretty cheap huh.

It is a rigged carney game that i refuse to play.

There is a saying, "if you gotta ask how much it costs, you cant afford it."

The truth is, most all of the people on earth including wealthy europeans and americans cannot actually afford to have electricity natural gas, cars or things like stainless steel pots and pans, not in the real world where the game isnt rigged to make it look cheaper to live by just paying a bill, not if all costs are considered.

So, many systems for renewable energy conversion and storage are designed around a prior evaluation and plan to reduce consumption, organize loads and otherwise improve usage habits starting with selecting proper efficiencies in loads and appliances for good economics.

I will repeat that in many cases utility and convienience can be preserved while consuming less.

We use about 1.2kWh per day or less than 38KWh per month off grid without a generator and its associated costs and environmental impact which costs dearly.
So everyone has different situations.

A guy who owns plantations in india relayed a saying from his home.
"You dont own a car, a car owns you." It is profoundly accurate, even if you enjoy a carefree money situation, you are just letting your car own several other people. I wonder what the real price for a car alternator is...$1000? $5000, i mean a pound of good chocolate or gallon of purified water is how much? Even if the chocolate or water is done onsite with manual labor and primitive tech, it has extreme value. Have you tried building an alternator from rocks? Every alternator sits atop a mountain chain of past expenditures to get to that manufacturing point. Its the same with utility power and their alternators are bigger.

I did a system estimate for a guy i worked for, an actual millionaire, never has to worry about where money is gonna come from again. He said $125,000 was too expensive, would take 25 years to recoup and showed me his cost for power over a year (15 years ago) and i was demoralized too.

But then he said the damnest thing that has stuck with me and i use it with clients all the time.

I said, 'yeah, i didnt imagine it could cost that much to cover your bill'
He says, dryly..." i have more light bulbs than you do"

Ill never forget that addage!

 
frank li
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diana todd wrote:Curious... people that are tying in to the grid and then selling their extra power back to the electric company- - - -   If something happens to the grid does the power company then have any control over your solar system?  wondering what the contract is like, the fine print.



Always read the fine print, it should be downloadable from your utility.

But, no the system is yours. The utility connection is theirs.
if your equipment has storage and something happens to the grid you will still be up and running! With good equipment, you wouldnt even realize when it happened. How cool is that?!
 
Creighton Samuels
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I don't know if I mentioned it here, but I'm working on a rather small system, just to run my refrigerator.

http://solar-trap.com/
 
frank li
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https://spinoff.nasa.gov/spinoff2003/er_1.html
 
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6000W of solar PV panels is about $1500 - $2000
15kWh at nominal 12V is 1200Ah not 9000aH so about $3000 (actually 30kWh but you don't take the batts below 50%)
a 3kW mppt controller & inverter is $500 so $1000 for two

$5500 and you can probably start with half of the above then add the rest later if needed when you know more about what you need.

you need some fittings, cabling, fuses etc. the cost of this depends much on your homestead layout and your skills. call it another $1000.

buy small, buy cheap to learn. then spend your budget when you know what you need.

i get 320 days of full sun, it's a no brainer.
whether it's worth it for you depends on your local sun conditions.
 
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Steve Farmer wrote:6000W of solar PV panels is about $1500 - $2000
15kWh at nominal 12V is 1200Ah not 9000aH so about $3000 (actually 30kWh but you don't take the batts below 50%)
a 3kW mppt controller & inverter is $500 so $1000 for two



Thanks for the updated prices, 7 years makes a big difference.  

Where do you find a "3kW mppt controller & inverter" @ $500?  I'm finding $750 each.  Tom
 
Steve Farmer
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Steve Farmer
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The above for €399 is a 3KW inverter but only a 1KW charge controller.

Here is a 3KW inverter with 4KW charger at €599
https://www.leroymerlin.es/productos/energias-renovables/inversores-para-conexion-a-red/inversor-hibrido-omega-umv3-3000w-24v-masterpower-82477655.html
 
pollinator
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It's not just a cost issue either. As these systems are becoming much more mainstream, there are all sorts of other benefits. Longevity of kit, modularity of parts, so that you can rapidly expand your storage if needed just by plugging in more units etc...

We are moving out of the enthusiast driven "early adopter" phase of product development into large scale consumer usage - with all the benefits that come with not being the guinnea pigs finding all the issues.

That and the underlying battery tech is getting cheaper and more reliable as manufacturers streamline their production processes.

Whether it is the right solution for a particular location is always going to need some detailed analysis, but from a global perspective it is becoming a cost effective solution across a wide proportion of the world.
 
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I'm a bit late to the party, but I have to say that Chris is spot on with his suggestion to go to 48V.

This problem is what is known on other solar forums as being "stuck in a 12V box".  The mentality that you somehow must stick with 12V.  It becomes almost as silly as some religious restrictions.

Once you break free of the 12V restrictions, many different solar options are available, and I can say that for my own 48V system, it can produce 15kWh per day without even paying attention.  It's all about selecting the right components for the right scale of doing things.   You wouldn't try to power your 4X4 pickup truck with a lawn-mower engine, would you?  You wouldn't try to put a 300hp V8 engine on your kid's go-cart, would you?  The same sense of scale applies to solar installations.

I have to say though that even 15kWh is a lot, and I myself find myself consuming less than 4kWh per day, and that's with lights, TV, computer, and the frig going 24/7.  For you, with two frigs, I'd say with a bit of conservation, you can live about the same lifestyle with just 5-6kWh.

On solar, 5-6kWh is easy, and maybe you don't even need a 48V system to do that.

The basic concept to start with is the sunhour, and what it is for your area.  A sunhour is NOT the number of daylight hours, but the number of hours of FULL output you can expect.  For most of the continental US I'd say maybe you'd get 2.5 sh in winter, and 5.0 sh in summer.  Maybe in the far North, 1.5/3.5sh.  You can go online and find the sh for your geographical location.

So, saying you need 5.0kWh per day, and you get 2.5sh in December, what you need is 5000Wh/2.5sh = 2000W of panels.  Don't pay retail for panels.  Shipping is baked into the high price.  I've never had to pay 1$/W for locally purchased panels.  Shop on Craigslist, with local cash and carry pickup.  You can find large grid-tie panels for 3-4W/$.  Last summer I bought 260W REC panels for 65$ each.  That works out to be 4W/$.  So, enough solar for ~520$.

A MPPT charge controller acts as a transformer, converting raw high-voltage solar down to battery charging voltage, making extra amps out of the extra volts.  I'm running my solar arrays with four panels in series for 120VDC, which gets transformed down to the 26-28V needed to charge the batteries.  The high voltage solar allows me to position my panels ~130' away from the system, which reduces voltage drop to almost zero.

I'm using Rolls-Serrette flooded lead-acid batteries, with about 600Ah of capacity.  They are performing very well.

I"m using a Schneider SW4024 sine-wave inverter in my workshop for my 24V system.  It makes split-phase 120V/240V AC that gets wired into a standard American main electrical panel.  It also has a generator input circuit, so if really cloudy weather presents itself, I simply plug the generator directly into the inverter to charge the batteries in the absence of solar.  But years go by now before I actually have to run the generator.  I still start the generator a couple of times per year, not because I need it, but to keep it from rusting up.

I've itemized what you need to create a 24V cabin system in another post.  Total cost for a beginner's system was ~2500$.  Total cost of full-scale deluxe system was ~3600$.

BTW, I have a 48V system for the cabin, which is needed primarily to run my 240VAC well-pump.  I find I can make the 2000W needed to run the pump from about 8AM till 4:00PM, with the 4500W of panels I installed.
 
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