Solar Panels and a Tractor

Matteo92065 · Jun 27, 2005

Well after reading all the 'project' posts for the last 2 months, I thought I should contribute...

I'm putting a 5kW solar system on my new house. Unfortunately I'm doing it all by my self. One of the hardest tasks is to get all 30 panels up onto the roof. They are about 40x50 inches, weigh 45lbs (awkward), and very expensive.
So I built some forks for my new BX-23 and can now safely raise the panels up to the roof.

Matteo92065 · Jun 27, 2005

another angle...

hudr · Jun 27, 2005

I have thought about a similar project on my "house" here in East Texas. But everything I have looked at has been, as you stated, pretty expensive. Where did you come up w/ the specs for how many panels, wattage and the such? And do have any kind of payout time versus hooking to the grid.? One of my goals in life is to get pretty much "off the grid".
Given my "druther"s I would come to town twice a year for sugar and copper tubing. /forums/images/graemlins/wink.gif

RalphVa · Jun 27, 2005

I've been thinking about putting some panels on the south roof of my carriage house. They do make panels that can replace and look like asphalt shingles. Think this is the site for them: http://www.solarcentury.com/

In your case, looks like you're doing roof tile. So, the regular panels are probably the way to go.

Think the payout time is quite long unless you face the alternative of having to pay for lines and all a long distance into your house.

Ralph

Tom_H · Jun 27, 2005

When I first saw the title of your thread, I thought you were going to tell us that you'd outfitted your tractor with solar panels because you'd discovered that was now cheaper than buying diesel fuel. That day may come sooner than we'd all like.

have_blue · Jun 27, 2005

( Where did you come up w/ the specs for how many panels, wattage and the such? And do have any kind of payout time versus hooking to the grid.? )

There are calculators all over the web for figuring the panels and system you need.

Typically, when you make the switch to solar, you also make some lifestyle changes to match the lower power available.

Payback is typically 30 years at purchase time. Payback time is so long partly because expensive battery banks go bad and must be replaced every 5 years or so. On the positive side, every time your utility rates ratchet up, payback time is reduced. That 30 year payback time could shrink drastically unless the USA adopts a coherent energy strategy.

Solar PV is almost like a catch 22. Older people can afford it, but may never get the payback. Younger people will live to see the payback, but often can't afford the massive initial cost.

SPIKER · Jun 27, 2005

also check into getting some government grants: many states and feds have grant $ foir people installing and maintaining solar systems and can even PAY you if you are hoked to the grid and put power into the grid. Federally elec companies are now required to buy it even if it is at a reduced rate. usually it will simply make you're monthly bill much lower.

Ohio has a grant program for o cost energy systems, (solar wind & water generations.) they have a 50% payback of the materials cost to install once it up nad running & proven to work... even if it only makes enough to lessen you're own dept., biggest problem is the upfront costs usually 20 grand or more from my research.. /forums/images/graemlins/frown.gif I even got soem of the peperwork sent out for the grant which here was that you had to have it up & running for 2 yrs prior to getting the grant $ back. and was primarly targeting big buisness who have large flat roofs.. store houses ect. /forums/images/graemlins/frown.gif /forums/images/graemlins/mad.gif

Anyhow nice looking mar land scape, (sorry had to mention that post form the other forum /forums/images/graemlins/wink.gif )
Markm

justforme · Jun 27, 2005

( I have thought about a similar project on my "house" here in East Texas. But everything I have looked at has been, as you stated, pretty expensive. Where did you come up w/ the specs for how many panels, wattage and the such? And do have any kind of payout time versus hooking to the grid.? One of my goals in life is to get pretty much "off the grid".
Given my "druther"s I would come to town twice a year for sugar and copper tubing. /forums/images/graemlins/wink.gif )

here's a site with a bunch of info

http://www.wind-sun.com/forum/

Dk45_Jeff · Jun 28, 2005

Matteo92065,

Is the 5KW a back up power source? If so that is a very clever approach for extended power outages. No generator maintenance issues, and no worry about running out of propane. If its the sole source of electricity you’re a tougher man than I. 5KW would handle my AC but would not leave much room for anything else.

Solar power has its place, especially in remote areas with only modest power requirements are expected. I have a system at my off-grid cabin powering the lights, and in the winter keeping the insulated battery box above 50f.

Anyone looking at the economics of solar power should be aware of a couple of important issues sometimes over looked when calculating payback time. First the cell loose efficiency as they age. A typical cell may produce 97% rated power in ten years, 85% at twenty and 60% at 30 years. The actual rate of deterioration various with the type of cell being used, but panels commercially available today will be doing well if they are still producing 40% power in 35 years.

The other issue is heat, the hotter the cell becomes the less power it produces. Designing the arrays to stay cool why sitting in intense sun light is a real challenge. With air temperatures reaching 100 the cells loose 5% or more efficiency; that is above any loss due to aging. The cells also age more rapidly when used in a hot environment, but I don't know the rate of change. When these factors are taken into consideration its hard to justify solar electric systems on a cost basis.

Matteo92065 · Jun 28, 2005

Actually for me the solar panels should work out quite nicely. The way I sized them is this,
I looked at my electric utility bills for a couple of months and then sized the system so that it would supply 100% of my electric needs (4bedroom, 3bath, spa, AC, etc. i.e.;standard house). For me that is about 650kW/month. There are charts that will tell you how much solar radiation you can expect for where you live. Between the available sun power and my electric needs I needed a 5kW system.
As for paying for it,
The system I bought is actually a preconfigured for 2.5kW. So I bought two of them. They cost about $125000 per kit. The kits are complete with racks, panels, switches, inverters and wires. I drove out to pick them up in another state (AZ), so no shipping and no sales tax. Now I'm into it for $25000 plus some extra for misc wire and tools (who can't use extra tools?) . I'm also installing it myself so there is no labor costs. I'm not rich (right now) so I'm financing 80% of it. But after I finish the installation, the state of California will pay me $2.38/Watt or about $10710 (after efficiency losses). So now I'm financing $11440 for 30 years at fixed 6%. That comes out to be about $69/month. Right now I'm paying about $.09/kWh from the utility and use about 650kwh/month that is $58.5/month. BUT, BUT, BUT If utility rates go up that gap is closed very quickly. I'm betting that utility rates will increase and once it gets to $.11/kWh, I'm saving money.
So the bottom line is my system is costing me about $2860 upfront, plus $10/month. But I get a tax write off on the $11440 loan, and as rates go up my monthly goes down.

The system is not a battery back up system. Its called a grid-tie system. It feeds back through the main panel and will spin the meter backwards all day long, then at night it will turn around and spin forward again. At the end of the year my utility will look at the meter and If I use more than I generate, I will own them the difference, If I generate more than I make then they take it for free.
For us batteries are too much up keep, too many efficiency losses, and too much up front costs. Generators are the perfect solution for short term blackouts.

I hope I've answered the questions. Its probably not the best thing to do financially, but I'm not an accountant, I'm an engineer who likes to do things a little differently.