Interesting example of practical PV usage

Re: Interesting example of practical PV usage

Based on the shadows in the porch, the sun is just about perpendicular to the panels. They literally have tree branches hanging over the PV panels if you look to the middle right

On of my neighbors has a PV system installed when the house was built in 1998 as part of some Fsec grant, they planted palm trees right in from the array that now shades the panels 100% of the day, the owners could care less, they paid nothing for the PV and like the palm trees

Re: Interesting example of practical PV usage

Makes me wonder how much of the renovation cost were considered a business expense in the effort to support of Greenovation.tv . Most I would suspect, All done with pretax dollars would be a big advantage, even if they handled it as a S corp.

Re: Interesting example of practical PV usage

Hmm, this whole article doesn't add up.

They have an 8 kw array that is shaded at least part of the year and their latitude and location isn't great for PV (it's ok, but not great)

They claim to power the whole house, AND charge an EV for 10,000 hours of operation AND sell back $1,400 worth of power per year.

Assuming the EV averages 30 mph and gets about 250 watts per mile, that works out to 75 MW per year just for the EV.

Then again driving an EV for 10,000 hours per year works out to driving it 27.4 hours per day. :roll:

I'm thinking whoever wrote this article didn't pay a lot of attention to the details.

Re: Interesting example of practical PV usage

Oldest net-zero restoration in the country...REALLY?

Because my >100-year-old house is getting solar panels within the next couple of months, and based on my calculations it will be net-zero...heck, I'm in a "historical district", too, for that matter. I doubt that solar panels on older houses are THAT rare. I wonder how much research went into that claim...

As far as the numbers go, I also get only 9.35 MWh/year production for that array (8.1 kW in Detroit, MI, at 34-degree angle). There is a DTE REC program of sorts, but the numbers don't jive with what's in the article.

When I run the numbers, I get a 20-year "income" of $43k. That differs pretty sharply from the $106k that they claim, although my figures don't include inflation, and they may pay a higher rate for electricity.

(Assumptions: the PV-watts production figure is correct, they pay 12 c/kWh for electricity, they consume the exact amount that they produce every year, and DTE pays them $0.11/kWh of production based on their SolarCurrents program.)

We can back-calculate their installation costs as well, based on the federal 30% credit and DTE's $2.40/watt rebate (I'm jealous).

At $19k after incentives, I get $46.5k if the utility incentive is untaxed, and $54.9 if the utility incentive is taxed, for an installed cost of $5.7 or $6.8/watt. Not too bad for a professional installation, especially with those generous rebates floating around.

Payback period after incentives is 8.8 years.

Based on the pictures, it's an enphase installation, so that shading shouldn't matter *too* much.

Re: Interesting example of practical PV usage

It does appear that there is some shading, who knows what the plan is. Maybe that tree is going to be taken down.

Or it's is possible they knew off the shading and decided to go ahead anyway.

Unless I missed something I do not believe sunpower allows the use of any inverter with their panels, then their sunpower rebranded sma inverters.

If they got the real sunpower panels for less than 6 buck Per watt installed I would be shocked.

The math seems a little fuzzy, but I commend them on doing something.

With all of the state and federal incentives, we have gotten to the point where solar can be seen as an investment.

Re: Interesting example of practical PV usage

russ wrote: »

I'm sure they will get invited to all the PC parties by their little green friends with all the fuss they are raising.

That is probably their point.

and they didn't invite any of us.:grr:roll::p

Re: Interesting example of practical PV usage

I'm designed a trailer to be towed behind the Prius for all those panels required to support it.

Unfortunately it causes the consumption to skyrocket therefore the design had to be made larger. Right now it is starting to look like an eighteen wheeler.

Russ

Re: Interesting example of practical PV usage

jagec wrote: »

You guys are too fond of saying things like "Most people tend to overestimate how much power they'll get from solar, and underestimate how much power they use" and "A Honda eu1000 generator can supply reasonable amounts of power for very little fuel, and costs much less than a full off-grid solar system." BORING and DEPRESSING.

Try saying "Solar is the best thing ever, you can eliminate your power bill with panels that you can build yourself for pennies and an ebay grid-tied inverter (don't bother calling the utility first, they'll just deny you because they're GREEDY), and if you add a couple more panels on your Prius you'll never need to buy gas again!"

Then watch the invitations roll in...

sorry, but i'm not always saying that and i do say more realistic things when they apply. i have no doubt solar is a great thing or i wouldn't be here let alone have it. only a fool would look at it as a panacea for every circumstance and a cure-all for all of our energy needs and problems. it is what it is, though.

for the record, i was poking fun at not being invited for an invite from them doesn't all of a sudden make me any different than i already am. also, being in a click doesn't change solar and doesn't make an individual any better.