RIP PiP?

None of it is theoretical. There are unknowns (and projections over time).

This is NOT a whole town thing, rather it is 9 or 10 households (that is in fact the limit for this, given the current regulations). This is slightly more expensive than using your own roof, so TIME UNTIL FREE will be less for a house sized system. It is aimed at houses without sufficient solar exposure or for people who rent or may need to move in the near future.

Fortunately, our electric company puts the information on the monthly bill; however, they only pay up to the amount you use, which is why we need this arrangement at all.

 

I did not include ANY tax rebates, look up what you can get in state and federal credits, and take those off the base cost.

If you can INSTALL a 50kW solar farm for less than $3.40 per Peak Watt, you should go into the business!

Exposure time and weather are included in that 1.55 kWh/year per Peak Watt conversion factor. (YMMV of course)

As I said, these are ACTUAL numbers for an ACTUAL project. YMMV was implied.

People in California with 50% more sun and twice the electric cost are crazy not to have already done it.

 

Thank you -- excellent post.
Does the minimum payment to the utility include the base charge ?

By the way, the math is considerably simpler than your detailed analysis:

1. Interest on the PV is less or equal to the increases from the utility, so one can ignore financing costs and be conservative in PV benefits.
2. kWh per watt per year * avoided cost per kWh = money saved per year from each installed watt
3. So years until free is (1) / (2), meaning cost per watt installed divided by avoided annual kWh cost

3.4 / (1.55*0.158) = 13.9 years

 

From what instrument does one read the avoided KWHr cost ? Interesting formula tho.

 

TY for your post. Here in CA we only get reimbursed for the amount that is distributed back to the Grid, exactly how the utility differentiates between PV power used and PV power distributed back to the grid. II think it's a guess factor based on ones PV plan. We have smart meters which aid the meter reader, but I they are not that smart . Code 12 gives me the total output in KWHrs produced on that day and accumulates to my PV installation birthday. At that point I'll get a refund check after they do there math and also refund my overpayment, ( if there is one ) Altho the retail price is about .10/KWHr. The reimbursement is only .05. Our legislators and Utility think that's FAIR. Anyway at the end of the year I will be able to have better information ( Oct 2015 )

 

The PiP isn't designed to be only an EV. It has EV capabilities, but not at the expense of the other suite of advantages that no other car-maker has been able to successfully put into one package. Nothing comes close to the Prius for it's fuel economy, interior space, ride comfort, affordability and mechanical reliability.

• The Volt has more EV range, but it has much less interior space and the actual fuel economy doesn't come close.
• The Tesla has great EV range and no backup gasoline option, and it's not affordable to many people.
• The Leaf is EV only, but it has few other advantages.
• The BMW i8 is great but also unaffordable.
• Most of the others are "mild hybrids" which also offer "mild benefits" and don't really compete in this class.

That leaves us with the Prius, which is still the best combination of all of the above.

 

Agreed, all the way around.

 

Not sure, what does a base charge represent?

The minimum payment represents a the delivery charge on 50 kWh at %0.213 per kWh. I pay this even if my usage was 0 kWh. If my usage was actually 50 kWh, I would pay $14.43 ($10.65 delivery charge + $3.78 ($0.75603 / kWh) supply charge). Does that answer your question?

 

Avoided kWh * cost per kWh. Around here one merely reads avoided kWh off one's second meter. Others may need to find a different way.

 

Now I'm confused

What is the marginal kWh cost ? If you pay by tier, I'm interested in the lowest. Thanks!

 

My Winter rate is.0955 / KWHr. We have a system infrastructure fixed charge of $14.00 ( this used to be $5.00) that charge may be equivalent to your $14.43 charge.

 

I do not have that second meter. I see now, so the meter right off the solar array reads the total then the house meter reading is subtracted from the total. However only some is avoided ( that which is being used by the residence). But, usage is still a mixture of solar and grid. ??

 

Uh, you still ignored the FEDERAL tax credit of $2,500, no?

 

Not sure how solar power "doesn't make economic sense..." if you live in a reasonably sunny part of California. And you need to factor in that solar power puts you into the lower tiers, even if it doesn't make your meter run backwards, making that $.30/kWh even less.

 

I agree. (Sorry, I'm catching up on the threads after being on my honeymoon the past couple of weeks.) If you don't plan on staying in your home for at least 10 years, solar may not make sense. In our case, we are just doing a straight purchase. The panels and their advantage to power bills will accrue to the new owners when we sell, and will be factored into the price. The leases - yep, they can be a pain in sales transactions.

 

It's marginally economic at best. The time required to recover your investment makes it very hard to justify your investment.