People who have bought and installed solar panels - what did you look for?

Page 2 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.

kevman

Diamond Member
Apr 20, 2001
3,548
1
81
can solar power be jused to power your home in the event of a power outage? Or is it strictly power that goes back to the grid?
 

Red Squirrel

No Lifer
May 24, 2003
68,334
12,562
126
www.anyf.ca
With a charge controller and a battery bank, you can store the energy. It's ideal if you have lot of equipment on UPS, as that technically acts as a whole house UPS.

I don't know how to set it up, but to me the ideal setup is this:

Solar/Wind => Charge controller => battery bank => Inverter => electrical panel

The hydro would come in to a transfer switch (allowing you to bypass entire system and just feed the panel if needed) and connect to the charge controller. Power would only be drawn from it if there's not enough solar/wind power and the batteries are starting to run low, say, 50% capacity.

When the batteries are fully charged and the hydro is not in demand, extra panel power is diverted to the grid while rest is used by you. Batteries remain topped up until you need more power. So really with a big enough system, you'd save a ton on electricity.

This way you not only have a full blown UPS, but a green one at that, but without worrying about running out of power. Best of both worlds.

I'm not really sure what equipment would be needed to set something like that up though. I'm guessing there must be high end charge controllers that will do it.

As for Chinese solar panels, pretty sure most of them are made there, even if it's a US company, so I don't think it really matters. Best to look at specs/reviews etc on a per panel basis, not just base it on where it's made.

I've been toying with the idea of picking up a small panel, charge controller, battery and inverter to experiment with. Some charge controllers also have the inverter built in. The ones you see at the hardware store are usually very low output, maybe 500w at most. But it would be enough to run a couple lights.
 

Apex

Diamond Member
Oct 11, 1999
6,511
1
71
www.gotapex.com
In a grid-tied system, would it be wise to overbuild and plan on the local utility buying back?
From what I understand they have to buy back power at retail rates vs wholesale rates they used to pay.

No, or at least not for most people.

In general, most residental rates are on a tiered system. For instance, on a 5 tier system, only the 3rd, 4th, and 5th (or sometimes, just the 4th, and 5th) tiers are expensive. Because of this, it only makes sense to get a system big enough to cover the expensive tiers. If you get a system big enough to cover the tiers that you're only paying 10 cents per kwh for, your break even point is probably going to be quite long.
 

Darwin333

Lifer
Dec 11, 2006
19,946
2,329
126
Is there something inherently wrong with cheaper Chinese panels?

The panels themselves? Not any of the ones I have ever used or seen used. Suntech is made in China and they are one of the most used residential panel in the states.

Do they just break earlier? Do they have frequent catastrophic failures? Do they have a more pronounced dip in efficiency as they age? Are they not as durable and crack more easily?

Sure you can find some but most that reputable distributors sell the answer would be no.

Don't a lot of Chinese panels offer 25 year warranties?

Yes.
 

Darwin333

Lifer
Dec 11, 2006
19,946
2,329
126
Well it's nice to have as it also doubles as a UPS for the whole house, sorta. Don't have to put anything on UPS. But yeah, you can skip the batteries, but they are nice to have. Depends on how much you want to spend.

Lol, its nice to have a Ferrari too but its a tad bit impractical for most people.

I have designed a few battery backup systems and the amount they EASILY add 3-4 times the cost to the entire system upfront. Thats not even getting into the battery replacement and maintenance costs associated with it.

Most people don't have a clue how much juice their house actually draws at a given time and the absurd amount of batteries that it takes to run your house for even a relatively shot amount of time.

Before anyone contemplating going "off-grid" even looks at a battery back up system they should spend 5 times the effort and at least half the money on getting their power usage as low as humanly possible. Getting rid of clothes dryers, microwaves, dishwashers, etc... and then purchasing uber efficient necessities like refrigerators and stuff like that. You will never make your money back but its cheaper to do it that way than to add enough batteries to run your house without doing all of that stuff.

Think of a really nice and expensive UPS. How much does it cost, how much does it weigh and how long will it run a single computer for? Now think about the cost, weight, and size of a bank of batteries to run your entire house. We are talking about building on another room to your house big for most suburban people.



Yeah we do, so it probably has to do with that I'm guessing. Though I do recall my coworker saying there was a specific rate per kw based n what is producing it, but may still sorta have to do with time of use. Or maybe he misunderstood. To me it does not make sense. A kw is a kw.

Probably time of use, a kw is not a kw to the power company. During the day when electricity is most in demand a lot of utilities have to purchase excess power from someone else at a premium price, or as an incentive to get you to use less during this time, so they sell it to you at a premium price. This also happens to be the time that solar produces the most electricity so you get that premium price when you sell it to the grid.
 

Darwin333

Lifer
Dec 11, 2006
19,946
2,329
126
can solar power be jused to power your home in the event of a power outage? Or is it strictly power that goes back to the grid?

They have some new products that can used to power very limited stuff in your house during a power outage that I have seen used here in the South where we might have extended power outages due to hurricanes. Typically they are hooked up to the fridge and a few lights, maybe a fan, and thats it.

http://www.xantrex.com/power-products/backup-power/xantrex-powerhub.aspx
 

Tsaico

Platinum Member
Oct 21, 2000
2,669
0
0
As an owner, I have found if you are looking to make money on the investment of solar panels, you won't find it. Yes, you can make some money given some conditions, such as how much sun, counting on the fact your electric utility will go up in cost per unit, and more sunny days than not. I would equate it to buying a more efficient car. You won't "make" money on it, it just won't use as much as the other, and your overall monthly out of pocket is a little lower.

The loan I took to pay for the non-subsidized portion is about the same as my lowest months' worth of electricity, so I am at about even on those months. I would imagine, if I don't change my habits for summertime from pre-panels behavior, the panels will produce much more than I consume, so I might make some money there. My main reason for doing it was to try to take some strain off an aging infrastructure, not so much to make money. From what I hear, many people's habits change and after they install solar, they then leave the AC on much lower or longer than they did before.

There are some residuals that might tilt it more in my favor, such as the electric costs going up (my area just approved another hike in the fees, so it will be 10% more than what it was when I bought my house), and perhaps people will be willing to pay more for my house when it comes time to sell. I doubt it though, as I know if I really liked the house, I really liked it, regardless of the other amenities. I would think it is like a pool in that regard. It costs money to install it, but it won't really affect your selling price that much.

So back to if panels are worth it for you, it will just depend on why you are doing it. If it is to make money, you are probably better off putting into a traditional retirement or investment fund. As for my own reasons, it was really to take some strain off my aging infrastructure in my area, at no real cost or effort on my part.


In regards to batteries, I vote they are not really worth it. They add 10's of thousands to the project, you have to have them replaced twice in the life of your panels, and you lose space to rows of batteries. For having it off the grid like a giant UPS, yes, you can protect a lot of gear from damage since it will protect the whole house from surges, brownouts, or other electric instability. But for 10 grand, what can you not replace in case of these rare situations. In the last decade, I can only think of three times there were black outs, one because of rolling blackouts, once because someone hit a transformer, and the last because a kid fried himself jumping over the barbwire and touching the electrical gear.
I also hear of the nay sayers about the subsidies, and your traditional power plants are government subsidized in order to be built too from both county and state funding sources, so the comparison isn't that effective.
 
Last edited: