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      12-03-2013, 01:13 PM   #1
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School me on Solar panels for homes

Recently been thinking about installing solar panels to generate electricity for my home and hopefully become self sustainable. Been researching online but decided to ask you fine gentlemen first.

Here are some figures:

around 62 kWh/day during the hottest summer months
around 21 kWh/day during the coldest winter months
Average around 35 kWh/day year round
Not really shaded by trees or other obstructions
around 6.7 hours of bright sunshine a day during hottest months
around 3 hours of bright sunshine a day during cooler months
Average Total Bright Sunshine of about 5.1 hours a day

To be safe, I would need about 1500kWh per month which comes to around $220usd on my electricity bill.

So here's my Q.

1) How much sq/ft of solar panels will I have to lay to even capture this level of energy (accounted for efficiency of panels)?

2) What would be the ball park cost of purchasing everything required to generate this power? Assuming no rebates.

3) Assuming a $0.155 electricity cost, when will I breakeven?

btw, I know nothing about the technology. Just want to run it through you guys to see if its even feasible.
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      12-03-2013, 02:03 PM   #2
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      12-03-2013, 02:07 PM   #3
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Speaking generally you need a lot of square footage to generate usable electricity. The only house I have ever seen that was completely self-sustainable was about 650 square feet and it had panels covering the entire roof and two large ones in the yard besides.

I have seen people put up a few panels on a "hot spot" on their roof to augment their existing electricity. I'm not sure what is required to make this work but it must be pretty straightforward. Keeps your bill down too!

One other thing to consider is maintenance. Not sure if you would do it yourself or pay someone but they need to be cleaned often or they don't work very well at all.
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      12-03-2013, 02:56 PM   #4
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Houses aren't very efficient because energy is relatively cheap. Going to solar means expensive energy, so it's best to make the house more efficient first so you can get buy with a smaller array.

Heating and cooling the house and hot water is one of the biggest energy loads you have. Beef up the insulation and windows. Try to incorporate solar heating, and use UV films and curtains to minimize heat load in the summer. A large water tank heated with solar tubes can be used to pre-heat running water and to heat the house.

A simple clothes dryer takes a tremendous amount of energy. You'd probably need a $1000 worth of panels to keep that thing fed alone, not to mention installation price, 240V electric, etc. Or, you could use a clothes line, or at least one of those washers with a super powerful spin cycle that gets clothes 90% dry. Lighting, refrigeration and parasitic loads are next. Fridges take a lot of power- get an efficient one. Get LED lights. Get low parasitic load appliances or unplug them when not in use. Your home theatre might take 25 W just sitting there. Your microwave uses most of its energy while it's just sitting there! (It draws about 15W all the time, 1000 when in use. If you use it 15 minutes per day, that's .25 kwh using it, and .36 kwh just sitting there the rest of the day).

Of course, if you have electric heat, the parasitic losses aren't really losses in the winter since they help heat your house.

If the amount of money spent on solar, or even spent SUBSIDIZING solar, was spent on this stuff instead it'd do far more for the environment, and it would make things like solar more feasible eventually. Right now though energy is just too cheap for many of those investments to pay off as quickly as most would like (although lights are a no-brainer with quick payoff)
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      12-03-2013, 03:02 PM   #5

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Originally Posted by upstatedoc View Post
I already posted my comments in the above thread. Long and short, do not believe the sales guy at the solar panel company, he makes money selling you a system they will not tell you the down sides nor may he know what they are.

At this point in time, if your purpose is to feel good about doing your part for the environment then go ahead and do it. If it is about lowering your overall costs, there is more to the calculation than the cost per KW. There is maintenance and up keep on these systems, and most people do not know what those are since most of these systems are new, but what happens in year 10, 15 and 20. If you have a failure you can not call the local power company and have them come out and fix it. This is why they will not disconnect you from the grid.

Just a example, there was a company which started up in my area putting in panels, they probably did well for the first couple of years, but recently they shut down, I am assuming they ran out of new installs so they could not pay their bills and closed the doors since there is a minimal number of house which can or willing to afford the initial costs. I wonder is all their customers in our area know they shut down if they run into a problem. It is not like you can call your local electrician to come out and figure out what is wrong, most are not trained or knowledgeable about these systems.

It would be nice to have a system like this, however, as of today, the costs are high to acquire and install, they have a finite life like most things in your house, you have to be knowledgeable enough to fix your own issues, or be willing to pay high costs to have someone do it for you.

Most of the systems around me are mounted in the back yard if they are big ones and the one on the roof usually are not big enough to eliminated an electric bill which is the best case situation. It looks like you are in Canada and you my be too high to get the best efficiency out of the panels. It also depends on the orientation of your roof. I had a friend put one in, and it so happens the largest part of his roof face in the best possible direction to collect the most sun. They told him very few people are that lucky and do not get the full benefit of the panels because the house is not facing the right way.

Here is another thing to check into. This just became an issue in my area. Local governments as passing laws around panel on roofs. In a couple areas around me the panel can only be on the back of the house as long as panel line of site is not direct at the someone home. Reason being, people have complain that the light reflecting off the panels is directed into other peoples windows and homes. A lot of glare can come off the panel depending on the angle of the roofs and such. So governments are beginning to regulate the use and placement of panels.

Just some things to think about when making your decision.

Last edited by Maestro; 12-05-2013 at 09:49 AM.
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      12-03-2013, 04:09 PM   #6

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Solar panels made for homes have to be replaced every 10 years?
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      12-03-2013, 04:53 PM   #7
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I have to agree with carve in first working to get your home as efficient as possible.

Simply unplugging stuff that isn't used regularly will drop your electric bill drastically. I know it can be a pain to walk around the house and unplug stuff, then plug it back in, only to unplug it again later. But overall, it saves a lot. Computers, entertainment centers, large appliances, all drain power even when they aren't being used. TV's are awful for this too.

I remember when I first moved out on my own and was responsible for my own stuff, I left my computer plugged in all the time. Sometimes I even left it on, just in "hibernation" mode. My power bill was huge. The minute I started unplugging stuff and turning the computer off completely, the prices dropped drastically. I saved a lot of money that way.

Also, not sure how your heating/AC situation is, but you should replace the air filters in the house monthly at the least. Those 90 day filters restrict air so much that they can damage the system, and they also cause your bill to increase (if your heat is electric like mine). I replace my filters every month. I noticed if I were to let it slip for a few months, my bill starts to go up because the house can't be efficiently cooled or heated.
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      12-05-2013, 01:55 AM   #8
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Sorry about the threadjack, but does unplugging stuff include just flipping the switch off on a surge protector? My parents always used to do this for their computers after they shut them down, and it got me into the habit of doing it too.
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