Thoughts on this SolarCity proposal? **Photos inside**

[J.P.M.]

Point taken. I had forgotten the OP is leasing and not buying his system. leasing throws a big old wrench into what I said.

I think my comment really only applies to purchased systems since you are not paying for what you produce.

Depending on the rate scheme and how much of the annual load is offset, leasing or buying may make little or no difference in the logic. The load time shifting logic is the same for many utility schemes/situations. Not all POCO's have the same net metering/T.O.U policies. As a general statement, most are different. Depending on the situation, a lease w/a planned 100+% offset may or may not make time shifting worthwhile. Same for a purchased system.

[Rdjntx]

Point taken. I had forgotten the OP is leasing and not buying his system. leasing throws a big old wrench into what I said.

I think my comment really only applies to purchased systems since you are not paying for what you produce.

Depending on your rate structure, that can be counterproductive. If a T.O.U. rate structure credits generation at prime time (peak) rates, the trick would be to move as much usage as possible to min. (off peak) rate time, and live like a hermit during the day (peak) time. Some POCO's do that, some don't.

At the extreme this involves a lifestyle shift to doing things like laundry at 3 A.M., etc. Most folks who time shift are not quite that draconian about it, but that's the general idea.

Utilities are responding to this by shifting their peak times to later hours - say from 10 A.M. to 5 P.M., and shifting that to, say, from 11 A. M. to 7 P.M. or such.

Most POCO rate structures have quirks, and general statements and assumptions can cause problems and confusion. As usual, the best way to get accurate info is probably the hardest - dig in and do the homework.

[J.P.M.]

Something else to keep in mind that I rarely, if ever, see mentioned. Once your panels are installed, move all of your optional electrical usage you can to times when you are generating power. Things like your dishwasher, washing machine / dryer anything that you can possibly run during the day.

Depending on your rate structure, that can be counterproductive. If a T.O.U. rate structure credits generation at prime time (peak) rates, the trick would be to move as much usage as possible to min. (off peak) rate time, and live like a hermit during the day (peak) time. Some POCO's do that, some don't.

At the extreme this involves a lifestyle shift to doing things like laundry at 3 A.M., etc. Most folks who time shift are not quite that draconian about it, but that's the general idea.

Utilities are responding to this by shifting their peak times to later hours - say from 10 A.M. to 5 P.M., and shifting that to, say, from 11 A. M. to 7 P.M. or such.

Most POCO rate structures have quirks, and general statements and assumptions can cause problems and confusion. As usual, the best way to get accurate info is probably the hardest - dig in and do the homework.

[Rdjntx]

very good point. The house was built 2 years ago so its very efficient, newest appliances, lighting etc. I'll do an energy audit and see if I can find some parasites before I agree to lock in anything.
Perhaps I could change my exterior timer lights to LED instead of CFL.

Its amazing how they push everything according to current usage, they never speak about what if it goes down.

thank you

Something else to keep in mind that I rarely, if ever, see mentioned. Once your panels are installed, move all of your optional electrical usage you can to times when you are generating power. Things like your dishwasher, washing machine / dryer anything that you can possibly run during the day.

[J.P.M.]

very good point. The house was built 2 years ago so its very efficient, newest appliances, lighting etc. I'll do an energy audit and see if I can find some parasites before I agree to lock in anything.
Perhaps I could change my exterior timer lights to LED instead of CFL.

Its amazing how they push everything according to current usage, they never speak about what if it goes down.

thank you

Or if utility rate increases aren't as high as their ridiculously high projections.

[thejudge]

You can see that they are targeting 95% solar for you which may be more than you need. When I got solar I was targeting 80% replacement. What I found is that output estimates are generally more conservative and I ended up producing about 10% more than estimated, this is based on my first 3 months of usage.

I think it is smart to leave yourself a little wiggle room so that you can reduce your usage and reap the savings. If you size this system too large you are entering into an agreement to buy that much power for 20 years. As kids get older, appliances get replaced and technology improves, I hope to see my power usage go down over time. Only you can estimate your future usage. If you have some old appliances that you know are energy hogs then it might be a good idea to replace them before solar or at least reduce the solar system size to account for the eventual lower usage. When you buy(or lease) solar, you are locking in your consumption for 20 years best to give yourself a little margin for error.

very good point. The house was built 2 years ago so its very efficient, newest appliances, lighting etc. I'll do an energy audit and see if I can find some parasites before I agree to lock in anything.
Perhaps I could change my exterior timer lights to LED instead of CFL.

Its amazing how they push everything according to current usage, they never speak about what if it goes down.

thank you

[prhamilton]

You can see that they are targeting 95% solar for you which may be more than you need. When I got solar I was targeting 80% replacement. What I found is that output estimates are generally more conservative and I ended up producing about 10% more than estimated, this is based on my first 3 months of usage.

I think it is smart to leave yourself a little wiggle room so that you can reduce your usage and reap the savings. If you size this system too large you are entering into an agreement to buy that much power for 20 years. As kids get older, appliances get replaced and technology improves, I hope to see my power usage go down over time. Only you can estimate your future usage. If you have some old appliances that you know are energy hogs then it might be a good idea to replace them before solar or at least reduce the solar system size to account for the eventual lower usage. When you buy(or lease) solar, you are locking in your consumption for 20 years best to give yourself a little margin for error.

[J.P.M.]

here is another attachment of the "simple" breakdown

[ATTACH=CONFIG]4527[/ATTACH]

For starters, I'd question the utility rates used given a 2.9%/yr. lease payment increase. Also, the future of rates is not written yet but the 4.8% annual increase the vendor is using is historically inaccurate and logically unjustifiable. finally, those costs /kWhr. seem to have little to do with the LCOE (Levelized Cost Of Electricity). Your money - your choice.

[russ]

here is another attachment of the "simple" breakdown

[ATTACH=CONFIG]4527[/ATTACH]

Maybe yes and maybe no - all assumptions and no basis given.

[thejudge]

here is another attachment of the "simple" breakdown

solar7.JPG

[Tyler]

Thanks guys,

can someone please explain the premise of "overproduction" for me

I was under the impression that if the system makes too much power then its fed back into the grid and I get a credit.

how can I be screwed by the sytem overproducing?



thank you guys so much for the responses!

Our electric company buys it back from us once a year at .04 (last years rate) and I am paying .07 for solar produced. Not in my best interest to sell back a lot to the electric company. My system is sized to produce enough to cover all of my electric needs for 7 months a year and 5 months a year I will have a small bill. Our electric company trues up in April so over producing in the other months doesn't benefit me. If they trued up in December or January producing more in the winter would benefit me as I could push the extra over my higher months.

[Rdjntx]

Over production is when you produce more during the day than you use. How that is handled will depend on your agreement with your utility.

1. Net metering - The electric company pays you for your over production at the same rate you buy it from them when your system is not producing.

2. Simple buy back - the electric company pays you for your over production but at a wholesale rate which is much less than what you pay them when your system is not producing

3. None of the above - i.e. you over produce, they get the benefit and pay you nothing

Which method used will depend on which POCO you have and what is or is not mandated by state law.

The electric company I currently use combines both method 1 and 2. They pay me the same as I pay for the first 900kw per month after that they pay me 50% of that rate. I usually wind up with either a zero bill or a credit. jun, jul, and aug will be the months I have a small elec bill if any.

I think I have those correct. I am sure others will come in and correct where I have it wrong

Thanks guys,

can someone please explain the premise of "overproduction" for me

I was under the impression that if the system makes too much power then its fed back into the grid and I get a credit.

how can I be screwed by the sytem overproducing?



thank you guys so much for the responses!

[prhamilton]

Your 'monthly payment' is a function of production. If the system overproduces your monthly payment goes up. You have to buy everything that comes off the array but net metering lets you get a credit but only for a calender year(at least that is how it works in California). That works fine to level out over production in June so long as it matches a decrease in December.

The place where you can get screwed is if they size the system to 95% of annual usage but it turns out the system makes 120% of usage. Now you are paying for power you aren't using. In California excess power during a full calender year(called true up period) is credited back at $0.04/kWh and you bought it from Solar City at $0.107/kWh.

You might look into the net metering laws in Mass. Maybe their excess reimbursement rate is higher and you can't really get screwed.

[thejudge]

Thanks guys,

can someone please explain the premise of "overproduction" for me

I was under the impression that if the system makes too much power then its fed back into the grid and I get a credit.

how can I be screwed by the sytem overproducing?



thank you guys so much for the responses!

[Tyler]

You can spend a couple minutes and get a couple of other quotes. If your committed to doing this PPA style lease at least get a couple of quotes and maybe save $60 per month. Your first quote isn't usually your best quote. Solar City might sweeten the deal if you get a better quote from someone else.

I started with Solar City then followed up with several other quotes. For the exact same size KW output Solar City was promising I was able to get a lease with Sun Topps for $60 less a month. I would highly recommend taking your time and getting a few more quotes. I asked the Solar City rep if I was able to get a lower price per month should I give her a call and let her have a chance to beat it. She said they do not price match and this was the best she could do. Others might have other experiences though. I look at it like going to buy a car and only going into one dealership and buying it at MSRP vs. shopping around and saving yourself some money.