Trying to get started on a shoestring.

[Finfan]

Hello.  I live in the desert SW of the USA so I have plenty of sunshine year round.  After reading many articles/websites/posts I understand that I won't be saving any money doing this.  I'm just trying to lessen the impact of my existence.  My basic plan is to install a grid tie system backbone and add panels as I can.  I'll be needing advice and recommendations regarding brand, size, and placement of the inverter. 

I also have what is likely a foolish notion of building my own panels from the factory second cells that are available on ebay and from various vendors.  I am quite good at soldering and small scale fabrication so I don't think the actual assembly would be beyond me but if anybody has some details on frame designs and materials I would appreciate it.  The Arizona sun will destroy just about anything given time so I hesitate to use plywood.

My house is located in town so my available space is mostly on the roof and along a back wall of the property.  These spaces will all get some shade at some part of the day or year but still get many hours of direct light. I'm mentioning this because I've heard that partial shading can be detrimental to panels and I would like to know what I should do to prevent damage.

Finally according to my electric bill my peak usage over the last year was 980 kWh for a 30 day period.  According to the 12 month bar chart on the bill I would estimate that my average usage over the year is about 550 kWh/month. I assume that info will be useful in helping me determine the size system I should be aiming at.  My long term goal would be to match or slightly exceed my consumption.

So hopefully I've provided enough information that you can get me started.  My main hurdle will be getting the inverter and having it installed.  That's going to be expensive. 

[ghurd]

Might consider starting smaller, and without the GTI.

A less costly inverter and battery system can take a circuit or 2 off-grid.
Do you use a laptop?  Add a plug / inverter next to where the laptop is used.  A small step, but it's a step.
Maybe the same with a modern TV.

If you plan to take it fully to the end, get a big GTI now, instead of replacing the existing one with a larger one every 2 years.
G-

[DamonHD]

I started by taking my office desk lighting off-grid evening/night work...

http://www.earth.org.uk/solar-PV-pilot-summer-2007.html

A smallish 12V system with LED lighting could go a long way.  With good LEDs, 5--10W of lighting can be plenty to work by, and you'll get about 1 hour of light for every 1Ah of lead-acid battery without running it down far enough to do any damage.

Rgds

Damon

PS. The best way to reduce your impact is to conserve, so turn off appliances when you're not using them, etc.

[oztules]

"I also have what is likely a foolish notion of building my own panels from the factory second cells that are available on ebay and from various vendors.  I am quite good at soldering and small scale fabrication so I don't think the actual assembly would be beyond me but if anybody has some details on frame designs and materials I would appreciate it.  The Arizona sun will destroy just about anything given time so I hesitate to use plywood."

Foolish? probably...... but here's mine http://fieldlines.com/board/index.php/topic,145004.144.html Now with the second 1000w inverter it seems to do 18kwh/day in spring without any problems if it is not very cloudy (some cloud helps, too much does not).

In your country I would buy factory ones. Also your inverter will need to have galvanic isolation as there is no cert for the panels, so they need to be completely isolated from the grid, and it will still need to be within your local rulings. (once galvanically isolated they could probably  be any power source eg windmill, hydro etc)

I still see evergreen panels in the states from Fred480v now and again for not much more than a dollar per watt. Makes it hard to justify building them at those prices.

Stick to materials the manufacturers use..... no wood, just aluminium (even if it is only angle and  not fancy extrusions). In your area powder coated steel may be good enough, but over here (marine environment) thats just plain silly. Your mounting system will dictate how stiff the frame need to be and how to support them.


.............oztules

[Volvo farmer]

Might check into those Enphase micro inverters if you are only going to grid tie. I have no experience with them, but they seem to be nifty little building blocks that you can have one or a hundred of and not need to buy a huge inverter right away.

Quick, seat of the pants figuring says you might offset your annual consumption with a 3000-4000W array. Nowadays, you might pick up that many panels for six  or seven grand? Looks like the micro inverters are going for $.75/watt or so, so another three grand?

Sunelec has a Phoenix warehouse, you might be able to pick up your panels 3 or 4 at a time in person from them.  That's where I would start anyway.

[rossw]

Finally according to my electric bill my peak usage over the last year was 980 kWh for a 30 day period. 

Thats over 30 kWh/day.
Your biggest investment will be conservation.

I have a fairly large home with 2 home offices, workshop etc. Also have to run water pump for pressure, and bore-pump for water, and all the pumps and air/stiring stuff for the black/grey water treatment system etc, and a bunch of computers that run 24/7, and still use far less than that.

[madlabs]

Finally according to my electric bill my peak usage over the last year was 980 kWh for a 30 day period.

Thats over 30 kWh/day.
Your biggest investment will be conservation.

Ross is right on the money. I learned energy conservation the easy way. Due to the economy I had to give up my rental and move out onto my property, off grid. Since I was broke, I had to start small, a couple of half dead car batteries, a 1000 watt cheapie inverter and 60 watts worth of solar. I quickley hooked a lawnmower to an alternator. Nothing like that setup to learn energy conservation fast. I have a lot more power now but the habits are there and while I was power concious before I went off grid, I use a tiny fraction of the power I used to use.

Now I have a 1200aH battery bank, a real inverter, 660 watts of solar and I pretty much have all the power I need. I am upscaling the power more, but I just use way less than I used to.

Jonathan

[Finfan]

That peak month was with two swamp coolers running 24/7 and me sitting at home unemployed.  I guess keeping the computer and stereo running all day had an effect.  It was the highest electric bill we have ever had.  It is also still far less than than what a lot of our neighbors with AC pay.  Anyway I have already converted all of the lights to CF and I am working on breaking my bad habit of walking away with them on.  Still, our peak summer usage is really not that high for this area. 

I've read oztules threads on panel assembly and I'm looking at that with a bit of trepidation just because it seems a lot more complicated than it probably is.  It also points out some of the problems with other self assembled designs that I didn't know about when I was believing I could build them rather easily.  I'll be reading those threads a few more times before I make a final decision there.

I have decided for now to stay away from battery systems.  Mostly because in order to make room for them I would have to clean out the garage.    I have also known people with off grid solar systems that had essentially traded an electric bill for a battery bill so I want to avoid having both.  I would love to build a household UPS system but it just isn't within my realm of possibility right now.  Perhaps later when my finances aren't so tight.  Thanks for all the help so far!

[David HK]

Fin Fan,

You may not be able to afford what you want at the current time, but there is nothing to stop you from planning what you wish to achieve.

Why not set up a plan to show the juxtaposition of your home in relation to East and West, document the wind conditions that cover your location during the four seasons and so on.

Would you opt for solar or wind power? Whichever, the power has to go into a battery bank ( unless its solar hot water) and if you can reach this goal what would you power first, second, third and so on.

No money does not mean no planning - far from it.

My own concept is remaining on-grid and side by side renewable energy. One does not replace the other but becomes a back up system when you need it.

Keep using this website as a useful reference.

David in Hong Kong