Author Topic: Housewide solar power: Can it be DIY?  (Read 5569 times)

MoneyCat

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Housewide solar power: Can it be DIY?
« on: October 05, 2014, 12:18:17 PM »
I've been using some small solar panels for recharging electronics and my lawn mower and stuff, but I really want a housewide system to use instead.  It looks like hiring a firm to install everything would be really expensive.  Is this a project I could DIY or is it too complicated for someone without a background in electrical engineering?

Rollin

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Re: Housewide solar power: Can it be DIY?
« Reply #1 on: October 05, 2014, 12:47:51 PM »
I've heard of some that have done it.  Check to ensure that your federal tax credits are still available though if you DIY.  Possibly the parts/supplies, but maybe not.

waltworks

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Re: Housewide solar power: Can it be DIY?
« Reply #2 on: October 05, 2014, 02:04:46 PM »
The installation of the panels themselves and figuring out their orientation is pretty easy. The electrical/inverter is also fairly easy but if you f it up, you can wreck a whole lotta silicon and be very sorry. If you're going grid-tied the utility may insist on some/all of the electrical being done by a contractor who is licensed/bonded/insured so I'd check with your local utility company and maybe do some research on what your state's policies and laws are. They vary a LOT.

Also do a very careful analysis of how much you can expect to make back in free power. We did a system about 8 years ago on our former home and in hindsight - no way would I do it again. For a $10k investment (heavily subsidized by the utility - actual cost of the system was more like $25k), we had free power year-round - but at $30/month or so, it takes a LOOONG time to pay for itself. We also had to pay for some extra homeowner's insurance to satisfy the utility company so that ate into the savings a bit. Overall, a huge net loss for us. Doing LED lights and getting efficient appliances would probably be a better use of your money, as would solar hot water, which if done right can pay for itself in a year or two.

-W

sol

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Re: Housewide solar power: Can it be DIY?
« Reply #3 on: October 05, 2014, 02:19:55 PM »
If you're going grid-tied the utility may insist on some/all of the electrical being done by a contractor who is licensed/bonded/insured

This is the kicker.  Building a DIY system is certainly possible as long it's on a stand-alone circuit, which means a battery bank.  The minute you start tying it into your local power grid, though, things get much more complicated from the regulatory perspective (though much simpler from the system operation perspective).

Rollin

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Re: Housewide solar power: Can it be DIY?
« Reply #4 on: October 06, 2014, 02:13:31 PM »
The installation of the panels themselves and figuring out their orientation is pretty easy. The electrical/inverter is also fairly easy but if you f it up, you can wreck a whole lotta silicon and be very sorry. If you're going grid-tied the utility may insist on some/all of the electrical being done by a contractor who is licensed/bonded/insured so I'd check with your local utility company and maybe do some research on what your state's policies and laws are. They vary a LOT.

Also do a very careful analysis of how much you can expect to make back in free power. We did a system about 8 years ago on our former home and in hindsight - no way would I do it again. For a $10k investment (heavily subsidized by the utility - actual cost of the system was more like $25k), we had free power year-round - but at $30/month or so, it takes a LOOONG time to pay for itself. We also had to pay for some extra homeowner's insurance to satisfy the utility company so that ate into the savings a bit. Overall, a huge net loss for us. Doing LED lights and getting efficient appliances would probably be a better use of your money, as would solar hot water, which if done right can pay for itself in a year or two.

-W

Waltworks has a good point that should be emphasized.  That is, solar hot water first.  That is the low hanging fruit - and by that I mean it gets a great return by lowering your power bills, low cost to begin with, and good credits on taxes.  I have two systems and they paid for themselves in about 3 years.  Now I am pocketing the savings (actually investing the savings :)).

MoneyCat

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Re: Housewide solar power: Can it be DIY?
« Reply #5 on: October 06, 2014, 03:47:40 PM »

The installation of the panels themselves and figuring out their orientation is pretty easy. The electrical/inverter is also fairly easy but if you f it up, you can wreck a whole lotta silicon and be very sorry. If you're going grid-tied the utility may insist on some/all of the electrical being done by a contractor who is licensed/bonded/insured so I'd check with your local utility company and maybe do some research on what your state's policies and laws are. They vary a LOT.

Also do a very careful analysis of how much you can expect to make back in free power. We did a system about 8 years ago on our former home and in hindsight - no way would I do it again. For a $10k investment (heavily subsidized by the utility - actual cost of the system was more like $25k), we had free power year-round - but at $30/month or so, it takes a LOOONG time to pay for itself. We also had to pay for some extra homeowner's insurance to satisfy the utility company so that ate into the savings a bit. Overall, a huge net loss for us. Doing LED lights and getting efficient appliances would probably be a better use of your money, as would solar hot water, which if done right can pay for itself in a year or two.

-W

Waltworks has a good point that should be emphasized.  That is, solar hot water first.  That is the low hanging fruit - and by that I mean it gets a great return by lowering your power bills, low cost to begin with, and good credits on taxes.  I have two systems and they paid for themselves in about 3 years.  Now I am pocketing the savings (actually investing the savings :)).

My parents had a solar hot water heater on our house when I was growing up and that reduced their bills considerably.  Maybe I will look into that.  I really like the idea of generating our own electricity, though, especially in the event that we face another Hurricane Sandy situation where the power company was out for the count for two weeks.  I would like to have the ability to actually sell electricity back to the electric company, plus we are planning to live in this house for at least the next thirty years, so I'm sure it would pay for itself.


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waltworks

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Re: Housewide solar power: Can it be DIY?
« Reply #6 on: October 06, 2014, 03:56:01 PM »
If you want power when the grid goes down, you will need a battery system to store power. Your power will not work (even in full sunlight) with a grid-tied system when the grid is out. You need a lot of batteries to run your house for 12 hours, so plan on spending a bundle on those (and periodically replacing them).

Also keep in mind that selling power back to the grid is typically a terrible idea, since in every state I know of, the utility will only buy power from you at wholesale rates (much, much less than you pay). Unless you assume really crazy inflation in power prices, it's a terrible investment from that standpoint. Most grid-tied systems are carefully designed to produce 95-99% of the necessary power over the course of a year so that you end up net-neutral.

There are good reasons to do solar PV (live far from power grid, power only needed intermittently/during daylight hours, freedom from grid dependency, warm fuzzy feeling, etc) but they are generally not financial. The low hanging fruit is using the sun for HEAT, because that's what it already produces for you. Passive solar design, solar hot water, etc, are great ways to do this. For electricity, the easiest way to save power/cut costs is to use less by using efficient devices/lighting. PV is pretty far down the list for return on investment still, though it's always improving.

-W

sol

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Re: Housewide solar power: Can it be DIY?
« Reply #7 on: October 06, 2014, 05:32:59 PM »
Also keep in mind that selling power back to the grid is typically a terrible idea, since in every state I know of, the utility will only buy power from you at wholesale rates (much, much less than you pay).

Allow me to introduce you to Washington State.  I buy power retail for 8.5 cents per kWh.  I sell ALL production (not just surplus power) from my panels back to the utility company for 54 cents per kWh, or almost 700% of the retail rate.

My panels generate roughly 8kWh per year, which means each year the utility company cuts me a check for aproximately $4000.  That's in addition to the reduced power bills I have because I'm not buying power whenever the sun is shining. 

Even without "crazy inflation in power prices" this system will more than pay for itself in about five years.  In a wet and dreary state (that also happens to have a good tax break for residential solar power production).

Quote
PV is pretty far down the list for return on investment still, though it's always improving.

If you had to buy it straight up, I'd agree with you.  But there are significant market distortions right now due to government incentives, and if you happen to live in one of those places you can profit from it.

waltworks

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Re: Housewide solar power: Can it be DIY?
« Reply #8 on: October 06, 2014, 06:09:55 PM »
That, my friend, is *awesome*!!

So I was wrong about every state sucking... but right that you should check what the state laws/regs are where you live. It can be an amazing deal or it can be awful, depends on the incentives available.

-W

dragoncar

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Re: Housewide solar power: Can it be DIY?
« Reply #9 on: October 08, 2014, 09:53:55 PM »
I really want to do solar, but I'm currently in the baseline (aka subsidized) usage tier.  If I wait longer, I'll lose subsidies but hopefully cost/efficiency will get better. 

On the other hand, why advocate home solar in the first place?  Isn't it way more efficient for my utility company to install a bunch of panels out in a sunny field on the edge of town?  Is there a solar REIT that will give me the same basic returns as if I installed my own solar panels?

diymark

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Re: Housewide solar power: Can it be DIY?
« Reply #10 on: October 09, 2014, 08:54:51 AM »
I've had PV for about 6 years now. But I went with a solar lease. So really I'm just renting the equipment. For me this is how I see it:

Good
-No large cash outlays to get started. $0 for install.
-The lease company is responsible for the equipment. Had a transformer go out in year 3. No cost to me...if I owned would be $3K+. And the lease company had to pay my electric bill while it was down.
-Lease company guarantees performance. No risk about installing with improper aspect or right number of panels.
-They get all the permits/paperwork. Here in CA a real challenge is bureaucracy. The utility makes it difficult with regs and hurdles. They don't want to lose a paying customer.
-I'm now saving money over traditional grid connected houses. I save about 25% over my similarly sized neighbors. But it took a few years of electricity price increases.
-Seems like a green thing to do. I like the idea of not burning coal or buying energy from a monopoly utility company that can decide to stick it to the consumer.

Bad
-It is a commitment. For me 15 year lease. If I sell my property I have to get new owner to take over remainder or pay lease to term.
-What happens at the end of the term is TBD. My contract says if I choose not to renew they have to return the house to original state. My hope is with panels getting cheaper might be less money for them to leave the system rather than repair my roof. Which would mean free system...albeit nearing useful life of panels.
-They get the benefits supplied by state/fed for install.
-my homeowners insurance went up. I had to increase to cover the cost of the panels for theft/fire.
-equation for saving money does not work for all situations. Electricity is expense here in CA so I reached positive ROI fairly quickly but your rates may make much farther off. Keep in mind many areas are seeing 7+ percent increases in rates which will effect the calculation. 

megaschnauzer

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Re: Housewide solar power: Can it be DIY?
« Reply #11 on: October 09, 2014, 09:59:26 AM »
i wonder if there's a benefit to having a small pv system with batteries to maybe run lights and your wifi and such. that way you will feel good about being partially off the grid and still having a backup in case of power outages. it might not pay for itself in quite a while but the cost might not be that much either.

enigmaT120

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Re: Housewide solar power: Can it be DIY?
« Reply #12 on: October 09, 2014, 11:17:21 AM »
- My hope is with panels getting cheaper might be less money for them to leave the system rather than repair my roof. Which would mean free system...albeit nearing useful life of panels.

I think most solar panels will keep working for a long time, after they get down to 80% of their new rating. 

http://energyinformative.org/lifespan-solar-panels/

A company named Real Goods used to sell used solar panels.  I don't know if they still do.  You just buy a few more than you think you'll need.

MillenialMustache

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Re: Housewide solar power: Can it be DIY?
« Reply #13 on: October 09, 2014, 11:45:00 AM »
My husband did a DIY solar hot water heater. I highly recommend that. I think we save $20 a month or so and he only paid $400 for the materials. It does not work "as good" as a commercial one, but we often do not turn on our regular water heater for hot showers! Also, we saw a lower reduction than many people because we already had a hot water heater timer that only turned it on for like 5 hours per day, and we already had it at a pretty low temperature, and we already had something where FPL (Florida) was giving us a bill reduction for having the ability to turn off our hot water heater during high power usage times. Therefore, most people would save more than we did.

My husband has considered doing a DIY PV system, but decided the payback probably wasn't worth it and he simply didn't want to do it. He did find out that an electrician would have to inspect the system, but otherwise he could do it himself in Florida.

Also, my husband is an electronics technician, so he does have a background in stuff like this. He watched a lot of YouTube videos though, so I bet a lot of handy people could do it.

gimp

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Re: Housewide solar power: Can it be DIY?
« Reply #14 on: October 09, 2014, 03:55:38 PM »
EE here... I'll echo what other people are saying. Setting up an isolated PV installation isn't too difficult - it's like an expensive lego with a lot of instruction manuals. Even easier for hot water. But the moment you start tying things into the grid, it gets very complicated, both from the tech side and the management side (grids need proper load balancing, distribution, proper phase, low ripple / variation, etc).

DarinC

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Re: Housewide solar power: Can it be DIY?
« Reply #15 on: October 10, 2014, 06:01:02 PM »
It's not too complicated even from the POV of the grid. There are regulations, like you can't exceed 80% of what your breaker box is rated for unless you get a line-side tap, but even in CA, most of what you need to do is just heavily regulated.

For example I need to get an EE or electrical contractor to sign off on wet plans for my system design, and if I have a ground mount or roof mount that's above some lb/ft^2 threshold I also need plans signed off from a civil engineer. If I run a line-side tap I need a PE to sign off on it. The regional building inspector also needs to sign off on it.

All these things are irritatingly expensive, but not too bad if you shop around and you can still do all the labor yourself and save a lot there.

i wonder if there's a benefit to having a small pv system with batteries to maybe run lights and your wifi and such. that way you will feel good about being partially off the grid and still having a backup in case of power outages. it might not pay for itself in quite a while but the cost might not be that much either.
You can even have power in the day time w/o a battery pack.

http://www.teslamotorsclub.com/showthread.php/36058-AC-coupling-using-grid-tie-array-during-utility-failure

dragoncar

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Re: Housewide solar power: Can it be DIY?
« Reply #16 on: October 10, 2014, 06:33:54 PM »
I'm less worried about the electrical and more the putting hooked in my roof.  Cause everyone always tells me you never want to do that.

Are you guys doing your own design too?  I have a semi complicated roof, and not sure how close to put the PV to the chimney (morning shade) etc.