Splintered off from the Nuc thread. There wasn't a huge demand, but there was a request.

I've been involved in Solar Power for about 5 years, including 3 1/2 as the owner of a company that installs photovoltaic solar systems in California. I'm a licensed general and electrical contractor. I've installed somewhere between 100 and 150 systems.

Why is solar power so expensive?

Any technological breakthroughs in the works?

How long until we have a solar panel that can power a 60-watt bulb for 24 hours?

You frame that question as if you know how much it costs, so I'll assume you do.

Costs are where they are now because of supply and demand. I expect supply to keep growing fast as more factories are build and they are more automated and for prices to keep falling.

thread is not off to a good start

There are lots of technological breakthroughs in the works. Most of them involve thin film, but some in concentrated solar.

I don't think these breakthroughs are going to be what really drives the industry. I think the main thing will just be prices dropping (they have already dropped a lot). So, the tech breakthroughs that are most important might be in the manufacturing more than in the modules themselves.

Strange question - if you mean power the bulb after the sun sets, then you need energy storage. There are some solar panels large enough that on a sunny day they could provide 24 hours worth of power for a 60 watt bulb, but you'd need storage if you want 24 hours in a row (or put it in space or on a jet that stays in the sunlight or something).

What kind of maintenance is needed for a home system and what are the costs like for that?

how much would it cost to power my house year-round, if that's possible? does anyone do this, and if so, what do you need to take into account about location?

thoughts on wind power?

What is the future of solar? Panels on everyone's roof providing localised generation or massive solar plants in really good areas? Or both to varying degrees i guess?

Ive read about eco houses that are electric neutral in Britain of all places by selling their extra solar generated electric in the summer to the power companies to offset the cost of buying it back in the winter, yet i think ive seen less than a dozen houses in my entire life which has had panels on the roof.

Do you think solar power use will continue to increase, or is it not feasible alternative long-term? It doesn't seem effective enough to me.

Not really, but it's picking up now, don't you think?

The modules themselves should not need any service other than cleaning. In most cases, dirt will cause about 5-10% decrease in power and most people just live with the modules being dirty. Modules are generally warrantied for 80% of rated power in 25 years.

The inverter, which converts the DC power to AC and connects to the grid (in a grid tied system - which is the vast majority going in now) will probably have a 10 year warranty, maybe 15 for some. Usually no maintenance there either, but replacement at some time.

We've replaced a few inverters under warranty. A few modules have had some burning on the cells, they still worked fine, but the manufacturer replaced them. A cable pulled out of one other modules. One job got replaced as part of a recall, but that system worked fine.

Inverter replacement cost? Well that could be from $1500 and up depending on the inverter, but by the time the warranty is out I really expect the inverter prices to be no more than 1/2 what they are now.

Cleaning cost? $100+ depending on who is doing it, what kind of roof, etc.

Most installations are grid-tied, so you get credit for power generated when you produce more than you use and you can still draw whatever power you need from the utility. This means you don't have to store power and you also size the system to provide your average use, not your highest use.

A stand-alone off grid system has to provide enough power for you on the darkest winter days and if that system produces more than you need during the rest of the year, you probably won't have anything to do with that extra power.

The cost of your system will vary a ton based on how much power you use and where you are located. In the sunniest part of the US there's about twice as much sunlight as the least sunny part (continental US, not counting the arctic), so it would take twice as big a system to produce the same energy. If you give me more details, I can give you a ballpark, and yes, lots of people generate as much electrical energy as they use.

Wind power is cool, but I'm in an urban area and it's not really viable. I have heard mixed things about big wind farms though. I installed a PV (photovoltaic) system on a guys house who buys power for a public utility. He said they buy power from some big wind farms in Texas and they can go a month or so with almost no power because of lack of wind. I'd love to install a wind system though, but it'd have to be out in the desert where small wind systems are somewhat common I reckon.

That's what i was asking, yes.

If I'm looking for a solar panel that can power a single 60-watt bulb that I leave on all day I'll need 60Wh x24hr = 1440 Wh/day

Assuming perfect storage or that I can sell power to the power company or something, how much will a rig that can generate 1440 Wh/day cost me?

If:
1) I live in Las Vegas (dream)
2) I live in Southern Canada (closer to reality)

This info is super hard to find on the net.

Also, does hail mess these things up?
I suppose I'd have to somehow clean the snow off of them every day?

Both for sure. I'm biased, but I definitely prefer local roof mounted systems. Of course not every roof (maybe 1/2 at most) are really good for solar because of shading. I'm always wary of utilities biasing laws/regulations for utility scale solar because they want to do it all themselves.

Solar is not that widespread everywhere. There's a lot in Germany, Spain, Japan and the US. Of course it's most viable and should be adopted first where power is expensive and sunlight is plentiful. So, where I am, Southern California, is a pretty prime location.


It will definitely increase. The costs before any government incentives are already lower than they were after government incentives just a few years ago and the market was growing then. Prices will continue to drop, while energy prices increase.

There are still a few variables, so I'll just give you some info:

A sun-hour is the unit people use to measure a given locations average amount of sunlight energy available. 1 sun-hour is the equivalent of 1000 watts/square meter for one hour.

SoCal is about 5.5 sun-hours. LV is maybe a little over 6. (that's for a fixed system - no tracker - with good orientation to the sun and little or no shade)

Solar modules (panels) are rated in Watts under what they call Standard Test Conditions (STC) which entails, among other things, being exposed to 1000 watts/square meter of light.

Real life is not at good as STC and you're probably talking about an AC bulb and not a DC bulb. So, you'll get about 77% of the rated power.

[1440 wh/day / 5.5 sun hours (SoCal) ] / .77 efficiency = 340 Watts

[There aren't many modules this big, but there are some.]

I get good modules for less than $2/Watt, but retail is more like $3.

If all you are going to do is light one lightbulb, you can get a hobby battery, a small step-wave inverter, and charge controller for $75 total or something. I don't know of any grid tied inverters that small.

Snow would have to be cleaned off, but if you have the panels tilted pretty steeply (roofs are steep where it snows a lot), I think they might not always accumulate snow. Not something I worry about much here in SoCal though.

[my efficiency numbers were too high for a small inverter, battery, charge controller set up - they were grid tied numbers. If you are really going to do this off grid it'd probably be more like 400 watts of solar.]

Jayteemee,

Also, if the system isn't grid-tied and is under 1 kilowatt, you won't get a utility rebate in Cali - don't know about NV. I think for the 30% federal income tax credit the system will have to be attached to the house, but maybe that's it.

My home has a 5KW connection, assuming I have to power my home solely based on solar energy in LV, how much would it cost including batteries etc?. How much area would it take to install panels that can produce this much electricity?.

I read somewhere that Solar panels were so expensive because they contained silicone.

Need to know how many kilowatt-hours you use. That's energy, rather than power. It's what you are billed for, so it shows up on your bill. Why do you want batteries as opposed to grid tied?

They contain Silicon, which is cheap and abundant as a raw material, but it does require processing to get it pure enough.

Do you think a law will ever be passed making it mandatory for any new residential, commercial or industrial building to be outfitted with solar panels? If the answer is no, do you personally feel such a law would be a good or bad thing?

I'm also curious what is the profit margin on setting up a typical 2K square foot home? I know it is prohibitively expensive without a government rebate.

In summers we use about 900 KWh a month. I don't live in America anymore, just inquiring about the cost there to get an idea..

How far north can you install a set of solar panels on a house and have it be break even? How long would it take to break even and see gains on a set. 10 years? Longer?

I read somewhere about solar glass for your windows, where they put transperant solar fiber between two glasses.

Is that technology efficient at all?. What's the cost of that compared to a normal setup on the roof?

Wow solid answer. thank you

I was told at a meeting the other day that California is going to require net-zero energy homes for new construction starting in 2020. Brief googling tells me that a bill may have passed requiring this, but allows for the date to be pushed back.

I definitely don't think a law should specifically require solar as opposed to being open for any technology.

Whether it's a good thing or the right thing is slightly different. I think more renewables is good. I generally want to limit government intervention, but the environment needs to be protected by the government - tragedy of the commons and all. Requiring net-zero homes might not be the best way to help renewables, and I don't think it's fair if no one can ever build a home in a shady, non-windy spot.

It's not the way I'd go about it, but it will sure be good for business if it happens.

There's no way California survives until 2020 so it's a moot point.

In LV, that's about a 6.2 KW system. That would cost about $38k, but as with all contracting, that price will vary substantially. I'm not really familiar with Nevada rebates, but it looks like about a $12k utility rebate and then about an $8k federal tax credit after that. Final cost around $18k, assuming good sun and orientation at the house. This system will take up about 430 square feet on your roof.

This depends on how much your power costs and on local rebates. That varies a huge amount. Solar is fairly big now in New Jersey because of good rebates and expensive power. Germany and Japan have lots of solar and they are pretty far north.

In many cases there are better ways to look at it than simple payback, like Internal Rate of Return. Anyway, the best simple paybacks I see are 4 or 5 years and in many places with cheap power and/or little sun and/or no incentives, payback could be decades or possibly never - until things change anyway.

There are such panels on some buildings, but they are much less efficient and more expensive. But, they are architectural elements in addition to solar modules and that has to count for something.