Solar Energy- Should I go for it ?

Factual Questions
1

I met with a guy who builds and installs solar power panels for homes. Bottom line is that to power my home, after state and federal rebates and credits ( real cash back, not a future credit for purchases ) I’d be out about $ 9,000.00 or so.

I pay roughly $ 4,000.00 per year in electric bills. The units are guaranteed for 15 years, the inverter similarly so. Being very conservative, after 3 years and change the entire venture would be paid off ( assuming the world as we know it does not end, we don’t have a nuclear war, etc. etc. ) , and I’d be connected to the grid but not tapping into it at all, month in and month out. Because of tree growth, my sunlight exposure and power generation would be higher in the wintertime than the summertime. That’s nice, because I have an electric home and use electric to generate heat. :wink:

Has anyone done a solar power panel install for their home needs? How did it go? How long ago did you do it? What is the technology like opposed to ten years or so ago, if it has changed significantly?

Does it affect your homeowner’s insurance rates, to have two huge panels sunk into titanic pools of cement in your back yard? I will have them placed away from my house, and very far from any neighbors’ house. Still, it is a large structure. Does it affect the assessable value of your home?

This might be an IMHO, except that I am asking for hard data from other users of solar powered panels for home electric use. Mods, move if you see fit.

Cartooniverse

2

To say it will power your home is pretty vague. Here is a link to a solar electric system that for $9,400 produces a whopping 1140 W at 240 volts. Assuming your inverter is 100% efficient in converting the DC to AC that means you’ll end up with 10.4 amps at 110 V. That’s not the same as powering your house. That’s not even the same as powering a room.

So, how many watts of power will the solar panels you are considering purchases supply?

3

Just to put it into perspective, the average US cost of electricity is 9.86 cents per kilowatt-hour. The 1140 Watt system cited above would, with 12 hours of sunlight, produce $1.12 worth of electricity. If you are average, you, consuming $4,000 worth of electricity per year, use an average of 4,600 Watts per hour, 24 hours a day, 365 days per year.

4

Solar systems do work, but you are not off the grid, you are better off, you can use that grid as a 100% efficient storage battery. You can produce excess power in the day, pump what ever you are not using back to the grid - getting full credit for it. Then buy it back at night, no loss.

People I know who have installed such systems love them, even with payback several years in the future, it’;s a great feeling - usually it averages out to a $0 electric bill. I say go for it - and you are helping out your fellow man too.

5

When compared to grid power, a solar installation based on PV arrays is not cost effective at this time. Lets hope this will change in a few more decades.

6

A buddy of mine installed solar power in his house. He gets a check every month from the electric company that he claims pays for the solar equipment and then some.

7

True but the costs seem to be subsidised in the case of the OP, usual costs are about $30,000

8

If you were to carefully analyze the true lifecycle cost of a PV system, it would become apparent that they are not economically viable at this time (when compared to grid power). Many people who have installed PV systems are simply delusional; they don’t want to admit - or perhaps they don’t realize - what a poor economic choice they’ve made.

Now having said that, whole-house PV systems still have their place in certain situations. If you live in BFE, for example, such a system might make sense. There is also a psychological component to it… there is a sense of satisfaction of not be “dependent” on “the grid,” which apparently imporntant to some people. Finally, some people make a hobby of it.

9

This guy is sellingSolar Systems.
You do not say where in the US you live. This has a big bearing on the applicability of any solar system. I would get an energy audit by a recogonized energy consultant before plunking down $9,000 on a salesman’s say so.

Why the concrete? Is he a concrete salesman?

Has the earmarks of a scam!

10

Before I say anything, I’ll give the caveat that I don’t have a system, have never installed a system, and my knowledge is pretty academic, based on classes I’ve taken, books I’ve read, and discussions I’ve had with a friend who has a system and is running a renewable energy business.

The size of your system is very important, and it is something you didn’t mention at all. The size should be in kilowatts (kW). Based on the estimated cost of your potential system, I would say that it’s about 1 kW worth of Solar Panels. I’ll use 1 kW for ease of computing.

Having 1 kW worth of solar panels means that at 1 peak sun (1 kW/m^2, this is power from the sun per area. It is a standard of measure) the output of your panels will be 1 kW. By the time this power goes through your wires and your inverter and reaches your home and the grid, it will be between 70-80% of that, or about 700 - 800 Watts.

Averages Daily Insolation (Incident Solar Radiation) is measured in (hours of peak sun)/day. Averages can be found for a year, a season, or a specific month for your region. (http://rredc.nrel.gov/solar/pubs/redbook/) These averages vary based on the angle of tilt of your panels, and your location. For instance the average daily solar insolation on a panel tilted at an angle equal to its latitude in Miami, FL is 5.2 hours of peak sun/day. For Seattle, WA it’s 3.7 hours of peak sun/day (It’s pretty cloudy there). But around 5 hr/day is a good rough estimate.

Assuming an 80% system efficiency, and 5 hr/day of peak sun, you system will provide:

1 kW x 0.80 x 5 hrs = 4 kWh of energy/day.
4 kWh/day x 365 day/year = 1,460 kWh/year

If you pay $0.10/kWh, this will save you $146/year. Not much when compared to $4,000 electric bill, or the installation of a $9,000 system. In addition if your system is only 1 kW, it will definitely not supply all of your power. You will still be paying the electric utility.

Initially, this seems like a poor investment, but there are other factors to consider. If the system is sized correctly, it will allow for expansion, addition of panels and power, at a reduced cost. It will probably add equity to your home rather than lower it. If the system is paid for by a home equity loan, interest payments can be written of. As the cost of electricity increases, so will the amount of money, you’re saving.

And most important is the value of the system to the environment, a price of no monetary value.

11

My next door neighbor has just installed such a system, which is the extent of my knowledge about it. One thing that he told me which I found surprising, was that when the grid power went out, his system could not provide any power to the house. The way I understand it (and I could be wrong) is that the system is always pumping energy back into the grid while your house is always being powered from the grid. When the grid goes down, your system stops (you don’t want to be pumping electricity back into lines where someone might be working) and you are in the same fix as your neighbor. It might be possible that some systems could reroute some power back into circuits used by the house, but that strikes me as a much more complex system, especially considering the variable nature of the power you are generating.

So, while you may be contibuting to the grid, you are still very much on the grid.

12

Last I heard, not all electric companies will pay you for power you put back into the grid. This may be changing now, in an effort to promote alternative technologies, but make sure you check with your electric company before deciding.

Perhaps, but it’s strongly correlated to the economic value. Much of the cost of a photovoltaic system is the cost of the energy needed to make it. So if your solar panels are not able to pay for themselves, in dollars, over their expected lifespan, then they also won’t pay for themselves in energy production. That is to say, you would be burning as much or more coal to produce the panels, as you would by just powering your house directly. This varies, of course, with the technology you use, the conditions you use it in, and just plain luck, but it’s possible for solar panels to have a net negative environmental impact.

One other factor that might figure into your decision, also, is driving the technology. Even if your system is not economical, it’s putting more money into the hands of the folks who are researching how to make it more economical. Effectively, you’re subsidizing the future solar panels, which will be more efficient. Of course, you have to decide for yourself how much this is worth to you.

13

From what I’ve read you don’t want to use a solar electric setup for heating. Its not very efficient and hard on the batteries and inverter, I would think.

You’r best bet is to go to a thermal mass system for heating. A system that heats water or rock during the day that can be released at night.

I’ve read materials from solar suppliers and they even said that solar electricity isn’t cost effective if you’re already on the grid. In my mind the only reason to do it is if you live out in no man’s land and can’t get on the grid or if the cost to run a line is too costly.

Otherwise, it seems like you’d be throwing money away and probably not really helping the environment much considering the cost of recycling the batteries and the energy to produce all of that stuff.

14

Actually, most of the cost ($) of making solar panels is in the relatively expensive silicon that they are made out of. Solar panel manufacturer are competing with the computer chip industry for materials.

That’s not true. Solar panels are mass produced, so the cost of energy required to make a panel is far less than they would produce over their life time it was used properly.

So, 1,500 kWh/yr x 15 to 25 yr life span = 22,500 to 37,500 kWh/life span.

Most panels are guaranteed for 25 year now. This is much more energy than it would take to produce a panel.

If your panel sat in your garage until it rotted, then yea, it would have a negative environmental impact, but otherwise these things are helping.

15

I wonder how much it costs to recycle the huge battery banks that these things require? How often do they have to be changed out?

I think that most people forget about the huge amount of energy needed to power a house. If you just want to power the lights and a radio then that’s doable, but running the frig, stove, hot water heater, air conditioning, heater, etc… will take a really big system. For optimum efficiency you’ll need a sun tracking system which isn’t cheap either.

I could see using solar to power the lights and electronics, providing you have a good inverter. Then look at using natural gas to power the heater, stove and hot water.

Also, they make wood fired hot water heaters, and natural gas powered refrigerators.

I don’t know what you’d do about the AC. If you had a solar powered AC in my part of the world, I don’t think you’d last very long.

Go the Lehman’s website and you can see some alternative appliances.

Solar power is doable (if you want to do without AC and heat), but its not near as convenient as using the grid and startup costs are prohibitive. Being energy independent sounds cool, but its a pain in the butt for an individual to do. I’ve looked into hydroelectric power, windmills and solar. Its pretty neat to think about, but unless you have lots of time and money its not very practical for an individual.

It just doesn’t make sense to go solar unless you live out in the boonies and can’t get electric any other way.

As far as helping the environment, I could see solar farms out in the desert helping. But everything has its drawbacks. They say that those windmills kill quite a few birds, for example. .

You’re better off moving your thermostat up/down a few degrees, driving a little slower, using energy effiecient appliances and cars if you want to help the environment…(my opinion)

16

Most of that cost is energy that is used when purifying the silicon.

17

Batteries are expensive. They have a finite life span that roughly correlates to how much they are used. Lead Acid batteries when used efficiently cost about 17 cents a KWh. If you live near the power grid it is best to put power onto the grid when the sun is shinning and take power from the grid when it is not.

18

I don’t have the answer as to my house’s use per year or per month. BUT I WILL !!

As for the battery issue, it doesn’t use them. ( Or, I didnt’ see any. )

It uses an Inverter to change the d.c. created by the solar panels into a.c., on an ongoing basis. While this concerns me to a degree ( what do I do when the sun goes down… ), it doesn’t concern me greatly. I will still be tied to the grid. The idea, like many other conservation ideas, is to minimize the use of the coal and gas firing grid and use other resources.

Running my home off of batteries is lunacy, there are excellent reasons why Edison lost in the a.c. v.s. d.c. wars. I see this as a chance to generate a.c. through the inverter, and shave down my electric costs per month so seriously as to pay for the gear in a few years. The gear will last me what- 10 to 15 years longer than the payoff period, and that is gravy every time the sun rises.

19

Cartooniverse: I have a 6700 watt system on top of my house. The total installation cost to me was around $15,000 with the state paying 70% of the real cost.
This investment is paying off at around $1200 per year currently an is strictly a social investment. In the long run I would have been better off investing $15,000 in Mutual funds. However phase II will be to add $4000 worth of batteries that are guaranteed for 15 years and will be sufficient to power my Refrigerator and plenty of Compact florescent lighting and a few low drain items.
The Panels have work out quite well so far and most estimates are that future electrical cost is likely to rise quicker than it has in the past. This means the payback might be as little as 10 years.
There is no track record of Solar Panels adding value to a house yet, so I cannot speculate on the value in resale.
What I amtrying to say, is do not buy a Solar Panel system to save money, buy it because you can afford, it will pay for itself and you believe it will help encourage the industry to grow and improve.

If you want details you can Email me with your Phone number and I will happily call you and break out my folder on how the plan all works. I have a lot of information filed away and I could detail the entire porcess for you, that I went through.

One more payback that is not just in electric savings. I sold my energy credit last year for $650 dollers to BP. I do not know what the yearly amount will be but if it is $650 per year, this will pay for my phase 2 of batteries in about 6 years.

Some Questions:

  1. Do you have a suitable roof with Southern exposure.
  2. Do you have large trees that will need removal.
  3. Does your neighbor have large trees that could reduce your sun exposure.

Jim

20

Don’t forget to factor in the cost of money - $9,000 could be put in 5% interest-bearing investments today and generate $450 per year compounded.

Also consider that you’ll have to clean the things and maintain them.

As for the lack of batteries, I assume the grid is your battery. It’s actually a pretty smart way to go if you’re already on the grid - the grid provides a known load to the solar system, you don’t need batteries (and therefore no charging losses or maintenance or environmental disposal issues), and you don’t have to worry about sizing your system for peak loads.

That said, you won’t make your money back from this unless the state is giving you whopping tax credits. And I’m not that sure you’re doing the environment a lot of favors - a lot of electric companies that will ‘buy back’ power had to be forced to do so at gunpoint by the state, which means they don’t really want it. I don’t know enough about how efficient the energy flow back into the grid is, but it wouldn’t surprise me to find out that it makes essentially no difference to the amount of energy the electric company has to use to provide electricity. It could be all smoke and mirrors. A good example of that is forced recycling programs that did nothing more than require more garbage trucks and temporary storage facilities for all the ‘recyclable’ good that no one wanted anyway, and then another trip to haul the stuff to a landfill in the end anyhow. A net negative for the environment. (Not all recycling programs are like this, but when government gets involved and mandates these things for political purposes, it can happen).