Solar - need help evaluating importances

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ltlredwagon's picture
ltlredwagon
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Joined: Nov 23 2008
Posts: 87
Solar - need help evaluating importances

Planning for family and others is going pretty well.  Most bases are covered to some extent (but need improvement).  Now looking at renewable energy.  Have a few acres - land, water, in the mountains.  4700 ft.   Winters not too bad, 20s & 30s mostly.  Wood for heating, propane if I get lazy.   Summers great.  Hydro might be possible, but very low head, and government might provide unwanted hassles and barriers.   I’m still looking into that.  But the purpose of this post is to request some advice on solar.

House is shaded, but hill behind has great south-facing location for ground mount solar.    We’re currently on the grid, at the end of the line in a somewhat remote area (handful of nearby neighbors).   When snow, wind, falling trees, downs the power lines, power can be out for a few weeks.  Deciding what to do with limited funds.  We’re looking at a 3.7kw system.   Out-of-pocket is about $19,000 and federal tax credit takes it down under $14,000.  I know that's a lot, but DIY mode is not a current option.  The federal tax credit seems solid for a few more years, maybe even until 2016 as promised.  But in CA the state credit is gradually being eroded (I think it dropped from $1.90 a watt to $1.50 a watt recently in my area) and I suppose could disappear.   

I know no one has a crystal ball, so I’m just looking for some guidelines.  With limited funds, I’ve been hesitating on whether or not to move ahead right now with solar or to hold off - stuck in indecision, feeling a bit stupid.  I sort of want someone to tell me to

1. stop screwing around, get prepared NOW, and this is why....;  or

2.  chill out, you're on the grid baby, things aren't going to just suddenly fall apart, hold off a bit, prices may drop, park your money in some PMs, get a greenhouse, solar isn't something to rush into right now - and this is why...

If I do move ahead immediately, I will probably have a grid-tied system as I have to be grid tied to get the state credit.   But I'm wondering how much urgency I should place on putting a battery bank there ASAP so I can be off the grid if I need to.

Appreciate any comments.

rhare's picture
rhare
Status: Diamond Member (Offline)
Joined: Mar 30 2009
Posts: 1323
Re: Solar - need help evaluating importances
ltlredwagon wrote:

If I do move ahead immediately, I will probably have a grid-tied system as I have to be grid tied to get the state credit.   But I'm wondering how much urgency I should place on putting a battery bank there ASAP so I can be off the grid if I need to.

My thoughts, what are you waiting for?  Do you think the states or federal government will continue to offer incentives when they are bankrupt?  I think any delay means you many not get your incentives so I would say "Stop screwing around".  I suspect we will see governments cut all non-essential programs, including solar incentives, before they start hacking at the union labor force, and California appears to be well down the path. Smile

Also, if we see a dollar collapse, I suspect it will be too late to get solar.  After all, most of the components are imported.  I suspect we will see a dramatic drop in imports and the includes full components or the parts used to build them.  Another reason not to wait.  On the other side you might see a continuing decrease in the cost, but too me that was minor compared to the other possibilities.

As far as batteries.  I took the approach of a small battery bank, just enough to hold up critical loads and night, and allow full use of the array during the day (charging and extra power).  I also went with a AC coupled system, as that provides the most efficient system for grid tie since I suspect we won't completely fall apart but may have some extended outages and large rate increases.  I also selected batteries that are designed to stay at float for very long times  with long lifespans.   They are designed for a 20 year life with only ocassional dischage (ie. not an off grid system), but the trade off was expensive and limitied cycling.  Here are the batteries I chose.

Here is a picture of the system from another forum topic.

docmims's picture
docmims
Status: Platinum Member (Offline)
Joined: Jun 17 2009
Posts: 644
Re: Solar - need help evaluating importances

I have been wrestling with the same question.

I am currently thinking along the lines that you can really go with a small system that runs in parallel with your grid system (ie you don't have to emulate your full up power grid system.

Your solar is just for minimal refrigeration,well pump/water, a few lights, cooking, small tv, radio, small appliance, etc.

Hot water and home heating are more cheaply done without solar panels.

If you want air conditioning you are going to have to design it for one or two rooms max, and even this is very expensive.

 

Damnthematrix's picture
Damnthematrix
Status: Diamond Member (Offline)
Joined: Aug 10 2008
Posts: 3998
Re: Solar - need help evaluating importances
docmims wrote:

Your solar is just for minimal refrigeration,well pump/water, a few lights, cooking, small tv, radio, small appliance, etc

You're cooking off PV electric energy...?

I can't recommend electricity for ANY heating.... has to be the least efficient use of electricity. Use biogas or biomass, but producing kil;owatts of heat with PVs is VERY expensive, and it reduces battery life...

Mike

Juli B's picture
Juli B
Status: Bronze Member (Offline)
Joined: Jan 28 2009
Posts: 87
Re: Solar - need help evaluating importances

Hello  DtM,

Do we have a biogas thread?  I have read some interesting articles on small-scale biogas for cookstoves coming out of SE Asia...I am just curious regarding containment and pressurizing of biogas for stove use in a safe manner?? ('safe" being operative wordTongue out).

Use of biogas for cooking might also reinforce the beauty of having a summer kitchen in locales with a lot of heat. Woodstoves are great in winter or cooler climes but not what you want going when outside temps are sky-high!

Also, what do you think about separate solar hot water systems?? (Sorry if this is covered elsewhere--it just seems like a really good system to install if possible here in the States while some fed rebates are still available...)

juli

Brandon's picture
Brandon
Status: Martenson Brigade Member (Offline)
Joined: Oct 6 2008
Posts: 144
Re: Solar - need help evaluating importances

Not sure if it will help, but if you're looking at batteries, here's some work I did for myself:

http://www.peakprosperity.com/forum/battery-cost-analysis-spreadsheet/40213

(Sorry for creating another thread...only way to attach a file)

-Brandon

Wendy S. Delmater's picture
Wendy S. Delmater
Status: Diamond Member (Offline)
Joined: Dec 13 2009
Posts: 1982
Re: Solar - need help evaluating importances

 My husband is a technician who will have no trouble building our solar system but the batteries and the photovoltaic cells are incredibly expensive.  One person in another thread is using forklift batteries at $3,000 each (forklift not included). We are in the process of  linking Uninteruptable Ppower Supply batteries.

One thing to keep in mind is that battery life is severely affected by heat. We live in the Deep South and will be ganging our batteries together in the crawl space under our house. There's room in the attic, but...no. Even with the solar powered attic fan it's still almost 90 F up there 8 months a year.

If you want quick off-the-grid results and a tax credit, a solar powered attic fans are awesome. Coupled with screen windows it can keep a home much more comfortable in the summer, even in a power failure, and we are saving 1/3 a month on our electric bill. We chose this one because it is made of aircraft-grade aluminum: plastic-covered ones suffer from UV damage and crack, and steel ones rust. Our home is 1,1000 square feet and the 20-watt one drops the temps up there by 20-30 degrees.

http://www.solaratticfan.com/pages/20_watt.html

Brandon's picture
Brandon
Status: Martenson Brigade Member (Offline)
Joined: Oct 6 2008
Posts: 144
Re: Solar - need help evaluating importances

Thanks SR.

Also, some additional helpful intormation on batteries and temperature effects:

http://www.windsun.com/Batteries/Battery_FAQ.htm#Temperature%20Effects%20on%20Batteries

-Brandon

 

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