Cleaning Solar Panels

The $40K is actually after the 1/1/09 Fed 30% solar tax credits, as well as the appx $15K state solar initiative that goes directly to the contractor, so the 4KW guess was off by almost 200%. The panels are rated at 225 watts AC, and there are 36 of them, with room for 4 more. Aren't various state solar initiative amounts based off readings taken with the sun/angle/thingie guage?

I know there is a premium on 'summer-after-noon' power, especially in hot areas, because both business & home AC draws are at their highest. With that in mind, it seems to me (maybe especially using 'time-of-use' metering) our south-west facing panels would actually benefit by sloping 13˚-14˚ towards the south-west setting sun. If all the panels were all laid flat, they immediately capture less & less light, once the sun passes its most perpindicular point in the sky. But the 13˚ southwest slope means that optimum capture time coincides better with usage. Right?

And yes, feel free to post the picture. It's just what I pulled off a web satelite shot. Certainly if you can suggest a more ideal layout, given our roof, yet conforms to us wanting to meet our neighbor's 'non-hideous' expectations. We'd love to hear what you feel might work better. As we mentioned earlier, our hope is to encourage neighbors to go solar, based in part because it can be done without looking like poo. Anyway, the power expectation is supposed to be a monthly average of 7.8kw. I guess by februarey we'll have the 1st bill & then we'll know. BTW, I DO thank you for, and appreciate the feedback.

 

Hill,

As I said, I am involved in the Pv business, and partake on a very good solar forum, populated by some very smart and practical folks, many who have forgotten more about PV than I will ever no.

I have posted your information on the forum and will let you know when someone responds with a useful reply.

Icarus
Help with orientation?? - Solar Electric Discussion Forum

 

awesome icarus... have spent waay more time than i actually have right now browsing thru the forum

 

Hill et al,

There are several responses to my question. It seems like you will harvest something on the order of 85% of an ideal array layout. As I stated on the other site, my northern Bias shows up. Sorry if I caused any undue anxiety. If more posts show up that show any new info. We do have one other concern however, and that is shading of your panels due to the parapets of the neighbors houses as well as from the vent pipes shown in the pictures.

What many people don't know is that even tiny little bits of shading on one part of one panel can have a huge effect on the performance of the entire string,,,depending on how it is wired. Most panels are wired into series/parallel arrays to get proper voltages. In any series array any shading, on any part of any panel will drop the output of that entire string to nearly ZERO! This is because individual cells in a panel go high resistance while shaded, forming and effective block to the entire string. This can be overcome to a limited extent by use of diodes but not completely. As a test, if you have a series string, partially shade one portion of one panel and watch your output meter drop like a stone.

Tree branches, even a utility wire, or the shadow of a gas vent pipe can have this effect. My guess is that the array in question (Hill's) has series/parallel arrays to get to a running voltage of ~200 volts or better. (I confess that my expertise is with off grid applications more than grid tie.) That means that at least several panels are series together on each side of the roof.

In any case, it looks like your installation was pretty good, given what you have to work with.

Help with orientation?? - Solar Electric Discussion Forum

Icarus

 

I appreciate the diagnostic review ~ maybe after a few seasons of productivity pass ... and all the neighbors are less histrionic about our roof ... who knows ... we may go on the roof & tilt our northeast panels a skosh more favorable (late at night, when nobody is looking )

 

Question is, can your neighbors even see your roof from the ground? Shoot me a pm after you get up an running. I am curious to see how the real world works compared to the calcs. on a daily, weekly basis.

Icarus

 

Hill: as any pioneer, your journey must be on a path you help create. it will be an easier path for any that follow you. i think as time progresses. solar will be much more accepted and as is true with all types of home design, it will become more accepted in all forms and configurations.

if its feasible, maybe after a few years, you will be able to adjust the layout without repercussions.

your situation reminds of of satellite dishes back in the mid 90's. i can remember when nearly every housing association was against them even after they went to the smaller 16-18" dishes. now, there is little opposition to them anymore.

 

Hill,

Now you should consider putting a hot water collector on the south facing side, around the dormers. Hot water is cheap to install, simple to operate and pays off fast! While it is not as "sexy" as PV solar, it generally is suggested first, as it saves more BTU/KWH for far less money.

My little home made system in NW Washington give use 40% of our hot water in December and 100% from March through September.

Icarus

 

Home Power had an excellent article a few years ago where a guy showed how "non crictical" panel orientation can be.

It pretty much sums up this thread. 15% isn't worth the effort, hassle and expense of an "optimum" mount.

For anyone interested in solar energy go to Home Power Magazine: Solar | Wind | Water | Design | Build and buy their DVD compendium of their entire Magazine. You will save the $99 easily if you ever go down the road of renewable energy.

 

Unfortunately HOA's lack of opposition had nothing to do with them "loosening up".

Back in the 90's DirecTV and DishNetwork lobbied the FCC for a federal preemption of HOA regulations and CC&Rs. They won...

Installing Consumer-Owned Antennas and Satellite Dishes

 

Agreed! For the ~15%, go buy a couple more panels and mount them as the rest,,,.

As for HOA's. As Groucho Marx once said,,,any club that would have me as a member, I wouldn't wish to join!


Icarus

 

My favorite Groucho saying: Alimony is like buying hay for a dead horse.

I'll post the results when we get our first bill in February. Thanks again.

 

Icarus, defo inter-tie. I'd lose $1.50/W in rebates if Xcel couldn't use my excess power and frankly, off grid makes no sense in the middle of suburbia.

 

Tripp,

I don't quite understand what you are saying. Please explain,

Icarus

 

ya i remember partying over that decision, but hmmm... the trickle down effect of that legislation was dry as bone by the time it reached us.

 

I'm just saying that there are some considerable disincentives to going off-grid in my situation. I wouldn't qualify for some rebates and having to buy expensive batteries, when I'm already connected to the grid, makes absolutely no sense at all.

 

I would never encourage one to ever go off grid, if the grid is available! The grid is a very valuable resource that brings us power at VERY cheap prices. It also acts as the worlds largest storage battery, by allowing grid tied PV solar to sell back to the grid, thereby decreasing demand on other generating sources.

An off grid PV system is, in rough numbers, twice as expensive per KW or KWH as a grid tied system, primarily due to the battery life cycle cost. We live off grid for a large part of the year because the nearest grid power is ~150km away!.

Perhaps I wrote something poorly that could be misread to be advocating going off the grid. Sorry for any confusion.

Icarus

 

No worries, mate. Some friend of mine were in a position where they were thinking about going off grid because to tie into the grid was gonna cost $40K! It ended up being cheaper to pay the $40K and grid-tie because of the rebates they would have lost out on.

 

This is an interesting thread. Hill, I too live in Southern California, Northern O.C. The image you show is certainly HD, what satellite source did you get it from? I have looked at the Google Earth image from the Lat and Long coordinates you gave, but your image is 180 degrees reversed i.e. South is at the top in your depiction, but the shadows almost convince me that the top of the photo shows North. I know it is not from the Google Earth image. I have to say though that the 8kW nominal system you describe is on the high side for the average residence

I have had my solar panels in place for just over a year now. Last 12 months since the panels were installed, my total electricity bill was $162.13, less than a tenth of what it used to be. I am connected to the Southern Cal Edison grid, and have been feeding them power during the summer months, (which I don't get paid for) but draw from them during the winter. Our house is quite small (1700 sq. ft.). I did a tremendous amount of research, for which the web was invaluable, and many computer based design layouts using Turbocad on my iMac, finally settling on a 19 panel arrangement using 200 Watt (ND-200U1F) Sharp panels; 12 on the South facing roof with a 34 degree slope and 7 on the West roof of the garage, same slope. The contractor I used was Energy Efficiency Solar from Pomona and I recommend them highly.

I must agree with the other posters that it is very important to survey all your existing appliances, lighting fixtures and other sources of electrical energy consumption. I was utterly amazed at the savings obtained by replacing incandescents with CFL bulbs, especially outside lights burning at night. Doing this and noting the reduced consumption helped me greatly in finally sizing the required solar panel count.

One final thought on value. I have read that many real estate professionals consider a well designed solar system will recoup its cost in increased value for the home at resale. I am personally convinced that is true, and anecdotal evidence is accumulating which verifies that claim.

 

Yep, Google maps ain't got squat, compared to microsoft local.live maps. They allow you to flip your search to look from all 4 compass directions. And yes, the near 8K ystem may sound big, but we run a lot of juice from our home office. Plus, meeting customers out of the home requires that they be nice & cool on those 90 degree summer days. Our average electric bill from Edison over the last 2 years is $217. ... and that's with low e windows, lots of insullation, high efficiency appliances, ad nausium.
More important, we actually did over build, because we're planning on the surpluss charging at least one EV.