Solar for dummies

[cody]

The minimum monthly charge is 45 whether you turn a light bulb on or not, then after all the service charges fees and taxes, the minimum you can pay is 62 dollars a month, after that you have the usage to deal with. 

[Lin]

Sean,

I know that I have seen 200 watt panels with 25 years warranties in the area of $600. each.  Since your 400 watts would then cost you $1200, your payback would be 5-7 years.  That, of course, is based on rates staying the same.  If rates were to increase, which is quite possible, the payback would be faster.  Another thing to look into is whether the particular state has some sort of rebate program.  CA was paying about 1/3 of the cost on approved grid-tie systems.  I do not know if they still have the program.  Anyway, this would be based on the very high rate that Cody quoted.  I do not think most people pay even close to that.  We probably averaged about .13 last month.  At that rate, payback is not part of the concept.

People also sometimes move and sell their existing systems.  Although state subsidies would be unlikely, they could be good enough deals to make a system viable.

[belfert]

Lin, a total system for a house is a lot more than just the solar panels.  You need an inverter unless everything is DC powered.

Now, if you're adding solar panels to an RV that already has batteries and inverter then you're correct that you only need the panels.

[belfert]

You can.  But it will still take decades to pay back.  You are much better off reducing your bill by changing your consumption.  Replacing incandescents with fluorescents, or fluorescents with LEDs, will have a much more immediate payback (years instead of decades).  Same goes for replacing CRTs with LCDs, resistive heaters with heat pumps, single-pane windows with thermal glass, etc. etc.

Where does one find an LED light bulb that can rival an incandescant bulb in light output?  All of the LED bulbs I have seen are 1/3 to 1/2 the lumens of a regular bulb.  If I want to save money by having less light why don't I just install 25 watt incandescant bulbs at a far lower cost than LEDs?

I do use CFL bulbs and don't mind them.  My only problem is the CFL bulbs I use in my ceiling fan burn out constantly.  I currently have 9 burned out CFLs.  I haven't used the fan in six months and I'm still burning out CFLs.

[Sean]

... I know that I have seen 200 watt panels with 25 years warranties in the area of $600. each.  ...

I'm sure lots of people would like to know where you can get individual panels for that price, if you would care to share your source.

Photovoltaic panels are a rapidly fluctuating commodity item.  Prices have swung up and down between $2 per watt and $8 per watt in the last few years.  Right now, they are running on the high side.

The per-watt price also follows something of a bell curve, with very small and very large panels being on the higher side, and 150-200 watt panels on the lower side.  So, yes, at this moment, 200-watt panels are cheaper per watt than 400-watt ones (or 30-watt ones).  I used the 400-watt panel as an example simply because that's the one that Cody mentioned.

Remember also that advertised prices on photovoltaic panels are often by the box, case, or pallet.  So for example right now I see 25-year panels from BP at $618 for 140-watts ($2.60 per watt), but that's only by the pallet-load (20 panels), for over $12k.

Even at Cody's electric rates, I don't think he can get a payback on any type of solar in less than a decade -- remember he's in Michigan, so less than half the solar energy of a place like Arizona, the epicenter of solar power in the US.

Speaking of which, the best deals on solar panels are also usually in Arizona, for the same reason, and so Cody would need to add freight to any of those killer prices, or figure a different way to get them.

-Sean
http://OurOdyssey.BlogSpot.com

[Sean]

Where does one find an LED light bulb that can rival an incandescant bulb in light output?  All of the LED bulbs I have seen are 1/3 to 1/2 the lumens of a regular bulb.  If I want to save money by having less light why don't I just install 25 watt incandescant bulbs at a far lower cost than LEDs?

High-intensity LED lights are now widely available.  However, they are better suited to task lighting than general lighting, because LEDs are highly directed.

Installing lower-wattage incandescents will not save nearly the energy that can be saved with other technologies.  Yes, you'll save money up front, but you will pay more in the long run.

If you simply prefer the light output of incadescents, that's a highly subjective matter and simply says you are willing to pay the price to have it.  All of the lighting in our bus is incandescent (high-efficiency xenon-filled) for exactly this reason, with the exception of low-level (floor) lighting for moving around at night, which is LED.  That said, the color temperature of LEDs is improving constantly, and lamps are being made now with spread patterns that mimic many types of incandescents; for example the many MR-11s we have throughout our coach.  If I were building the bus today instead of seven years ago, I might well have chosen more LED fixtures.

-Sean
http://OurOdyssey.BlogSpot.com

[Lin]

Brian,

I did mean to say that you only need panels.  I was just using that as an example of possible payback.  I had a system with 12 200 watt panels and a grid-tie inverter that I got on a trade.  I decided that it did not make sense for me to use it, so I sold it for about $7k.  The system had been used for only 1 year and was still covered by warranty.  The retail on the inverter was about $3k.  The buyer had a problem with it and the manufacturer just sent him a new one.  I think that if I were paying .47/kwh, I would have used them.  

Sean,

Just a quick google:

http://www.solareffects.com/viewitem.php/solareffects/pd1921901/Evergreen_Solar_Panel_ES-A-Series_200_Watt_B_Module_

http://www.siliconsolar.com/gridmaxx-200-watt-solar-panel-p-501564.html

I do not know if it would work for Cody in his situation, but $3/watt makes it much more of a prospect than $8/watt.  Actually, I am told that wind gives more watts for the buck than solar if you've got the wind.

[belfert]

I don't have anything against LED builbs other than the amount of light outputted sucks.  A 75 watt incandescant bulb produces 800 lumens of lights.  I've looked at the LED bulbs at major retailers and I haven't seen any of them anywhere close to 800 lumens.  There probably are LED bulbs that can produce 800 lumens, but not at a price the average person would consider affordable.

I don't have any special love for incandescant bulbs.  All of my high usage light fixtures have CFLs in them.  It doesn't make sense to put CFLs in fixtures that might get used a few times a month at most for a few minutes at a time.  At least not until the existing bulbs burn out years from now.

I am planning to put LEDs in my bus.  I bought the LEDs last year, but didn't install them yet.  I like the fact they are dimmable compared to the overly bright flourescents I have now.

[philiptompkjns]

I am planning to put LEDs in my bus.  I bought the LEDs last year, but didn't install them yet.  I like the fact they are dimmable compared to the overly bright flourescents I have now.

belfert, what sort of LED's did you get for your bus?  I'm going to use LED's as well but haven't bought any yet, I'm looking though.

[Sean]

Just a quick google:

http://www.solareffects.com/viewitem.php/solareffects/pd1921901/Evergreen_Solar_Panel_ES-A-Series_200_Watt_B_Module_

http://www.siliconsolar.com/gridmaxx-200-watt-solar-panel-p-501564.html

I do not know if it would work for Cody in his situation, but $3/watt makes it much more of a prospect than $8/watt.

I actually came across both of those in my search earlier.  However, they are the exception rather than the rule, and the price does not include shipping or tax.  I agree that $3 is more reasonable than the $7.50 today for the 400-watt panels; again, I used that for my example only because that is the size that Cody mentioned.

Actually, I am told that wind gives more watts for the buck than solar if you've got the wind.

True; however wind has several drawbacks.  It's noisy, and maintenance is much higher than photovoltaic.  Wind also virtually mandates batteries, whereas many solar systems get by without them.

I don't have anything against LED builbs other than the amount of light outputted sucks.  A 75 watt incandescant bulb produces 800 lumens of lights.  I've looked at the LED bulbs at major retailers and I haven't seen any of them anywhere close to 800 lumens.  There probably are LED bulbs that can produce 800 lumens, but not at a price the average person would consider affordable.

Well, Lumens is not really an effective measure of usable light, because it does not account for the light that goes in an unwanted direction.  You're really looking for Lux, or maybe even candlepower at the target.  Again, LEDs are highly directional, which means that for certain types of task lighting, they are ideal, as all the generated light ends up in a usable direction, whereas incandescents and fluorescents require sophisticated reflectors to maximize the usable light.  "Lumens" in this case is virtually a meaningless number.

Unless you are an experienced lighting designer, you really can't buy lighting based only on published specs -- you really need to try the products in the intended locations.  I include myself in this category.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[oldmansax]

Cody,,,
You need to move, my friend!

I thought the communist state of Maryland was bad until I started reading about yours. They charge us $15 a month here, whether or not you use any electricity. Besides, it's warmer here & you will use less!



TOM

[cody]

The 400 watt number I listed is what a wind turbine (like nick has) was rated at but it could work with a person connecting 60 or 80 watt solar panels too, I have no urge to look at a payback, tho it would be nice, Jamie and I just got back from the skanee house we went out to do some puttering and the meter is gone with a note on the door that if I continue with my attempts at illegal power generation they will see me in prison, on the door, nice huh?  MY mission is clear now, I've got to do whatever I can to generate as much power as I can, I'd like to see them try to get me arrested for it, I'd even invite then to the party when I throw the switch and light up the house, I just can't believe their attitude.

[belfert]

I am planning to put LEDs in my bus.  I bought the LEDs last year, but didn't install them yet.  I like the fact they are dimmable compared to the overly bright flourescents I have now.

belfert, what sort of LED's did you get for your bus?  I'm going to use LED's as well but haven't bought any yet, I'm looking though.

I bought a 5 meter strip of LEDs that are warm white.  They are sold by many sellers on Ebay.  See http://cgi.ebay.com/ebaymotors/5m-Warm-White-SMD-3528-Waterproof-Flexible-LED-Strip_W0QQcmdZViewItemQQhashZitem5ad6957464QQitemZ390147175524QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories for an example.  The usually ship from Hong Kong.  Some ship from the USA, but they usually cost more.  I bought the dimmer seperate.

Someone here recommended this type of LEDs.

[philiptompkjns]

Why is your power generation illegal Cody? What is their reasoning?

[NeoplanAN440]

Living in New Mexico,one of the few perfect places to use Solar,still has shown me that even the State here has Problems to understand or accept it.After buying my Property outside of the city limits,i had the challenge to get Power out here.I got tired of begging to get power or how could i even ask for 3 phase to set up my Lathe!!
so i started to build my own offgrid Power system.we are living now on Solar ,Wind and WVO powered backup generator and heater for over 4 years and enjoy every day of it.

from what we learned,is that its still cheaper to go on the grid,if its available.solar power is still to expensive,and most installers dont know what they do (my opinion).also you have to be ready to change your lifestyle and work and learn with your system.there will be up s and downs,as with most bus conversions (at least mine).

as for the bus.i used almost the same system.large battery bank,xantrex inverter,kubota engine running as dc charger.solar panels on the roof will help keep the batteries up,but you will never have enough space to live on it.ok maybe i saw one bus with a enclosed trailer that had also panels on the trailer.but that very rare i guess.

just my cents to it