Coal power

[sendler]

Net metering (meter runs backwards) is a big loss for the Utilities in my state where they are forced to provide this since they are in practice paying the homeowner back for the electricity AND the line fees and taxes. The home owner is selling the electricity for $0.12/ kWh even though the utility buys from it's normal suppliers for $0.04. The only fair way to do it would be with smart meters and 15 minute spot pricing.

[redpoint5]

Originally Posted by JSH

We have found an alternative- steel roofs. Last time I replaced my roof it added 10% to the cost but was expected to last twice as long as asphalt.

I do want a roof on a roof. Solar panels with an air gap shade the roof and reduce A/C use in the summer.

Quick math double-check...

Sendler said NY is 13.7% of nameplate output. PNW should be similar.

A 5,000 watt system would cost $10k if the cost is $2/W

5,000 watts * 0.137 efficiency = 16.44 kWh per day = $1.32 at 8 cent per kWh rate

That's $480 per year in electricity savings, or 20 years to recover the cost of the system, not including lost opportunity cost to invest the $10k, and not including maintenance, degradation, etc.

Even if the system could reach 20% of nameplate, that is a 14 year payback, not including opportunity cost of lost investment money. Solar may never pay back if you include lost investment opportunity.

My utility bill averages less than $40/mo, and that includes the $12 fixed cost.

Where did my math go wrong that I conclude a never payback period, when you figured a 10 year payback?

[JSH]

Originally Posted by sendler

Net metering (meter runs backwards) is a big loss for the Utilities in my state where they are forced to provide this since they are in practice paying the homeowner back for the electricity AND the line fees and taxes. The home owner is selling the electricity for $0.12/ kWh even though the utility buys from it's normal suppliers for $0.04. The only fair way to do it would be with smart meters and 15 minute spot pricing.

I don't know how variable pricing works in NY but my utility charges 19.978 cents per kWh for on-peak power and 4.209 cents for off-peak power. If the utility is loosing money on that swap they are ripping off their customers.

[redpoint5]

Originally Posted by JSH

We have found an alternative- steel roofs. Last time I replaced my roof it added 10% to the cost but was expected to last twice as long as asphalt.

I do want a roof on a roof. Solar panels with an air gap shade the roof and reduce A/C use in the summer.

PGE?

I've got them at the apartment and the rate is a flat $0.11/kWh, no TOU pricing. My dinky apt utility bill is about $60/mo, which is larger than my 4 bedroom 2100 sq/ft house utility bill at $40/mo.

Stupid 2/bed apt costs more per month than my house too.

[JSH]

Originally Posted by redpoint5

Quick math double-check...
Where did my math go wrong that I conclude a never payback period, when you figured a 10 year payback?

1. You aren't using enough electricity. If you are only using $40 a month you don’t have an all electric house. If you have your own powerplant on your roof you would want to use it.
2. I pay more than 8 cents per kWh – more like 11 cents per kWh after generation, transmission, and distribution charges.

The numbers from my quote (I got 3 they were all very close)

4.97 kWh system
Cost of system: $9489.73 (Using Oregon manufactured panels - cheaper with Chinese panels)
Yearly Production: 5769 kWh (That is 13.25% of nameplate)
Annual Usage: 5840 kWh
My annual bill: $1020

Say I save $1000 a year that is a simple payback of 9.5 years. That doesn’t take into account opportunity cost for investing that money but it also doesn’t take into account electrical rate hikes over the next 30 years the system is warrantied. Add in my $10 per month usage charge and I save $900 a year for a 10.5 year payback.

[JSH]

Originally Posted by redpoint5

PGE?

I've got them at the apartment and the rate is a flat $0.11/kWh, no TOU pricing. My dinky apt utility bill is about $60/mo, which is larger than my 4 bedroom 2100 sq/ft house utility bill at $40/mo.

Stupid 2/bed apt costs more per month than my house too.

Yes, Portland General Electric. They give you the choice of flat rate or time of use.

Where is the house located that it is so much less expensive?

[redpoint5]

Originally Posted by JSH

1. You aren't using enough electricity. If you are only using $40 a month you don’t have an all electric house. If you have your own powerplant on your roof you would want to use it.
2. I pay more than 8 cents per kWh – more like 11 cents per kWh after generation, transmission, and distribution charges.

The numbers from my quote (I got 3 they were all very close)

4.97 kWh system
Cost of system: $9489.73 (Using Oregon manufactured panels - cheaper with Chinese panels)
Yearly Production: 5769 kWh (That is 13.25% of nameplate)
Annual Usage: 5840 kWh
My annual bill: $1020

Say I save $1000 a year that is a simple payback of 9.5 years. That doesn’t take into account opportunity cost for investing that money but it also doesn’t take into account electrical rate hikes over the next 30 years the system is warrantied. Add in my $10 per month usage charge and I save $900 a year for a 10.5 year payback.

My bill shows a fixed cost of $11/mo, and assume it's the same for you ($10 is close enough too). Subtract that out of your yearly cost, and divide it by 5840 kWh consumed, and you end up with $0.15/kWh, which is quite a bit higher than 11 cents.

Anyhow, assuming your 11 cent per kWh and an annual electrical production of 5769 kWh, that is $635, not $900. 15 year payback.

If your actual rate is $0.15/kWh, that is $877/yr. Almost 11 year payback.

So my assumptions weren't way off from what you're saying.

Taking the average rate of return of the stock market of 7%, the money invested rather than put into solar would have doubled in 11 years. Due to compounding interest, there is no catching up with the savings from solar unless electricity prices skyrocket for some reason.

I like solar, but the PNW isn't a great place for it. If I lived in HI and paid $0.33/kWh, I'd have gone solar long ago. Heck, if I lived in Phoenix, I'd probably go for it.

[oil pan 4]

Originally Posted by redpoint5

If solar could provide 60+ years of weatherproof service, I'd rather spend extra to install it than crappy asphalt, which itself costs a fortune. I'm open to the idea, but I don't want a roof on top of a roof. That just doesn't make sense.

100 years later, why haven't we found an alternative to asphalt for roofing?

The only place i have seen use asphalt shingles is the US.

[JSH]

Originally Posted by redpoint5

My bill shows a fixed cost of $11/mo, and assume it's the same for you ($10 is close enough too). Subtract that out of your yearly cost, and divide it by 5840 kWh consumed, and you end up with $0.15/kWh, which is quite a bit higher than 11 cents.

Anyhow, assuming your 11 cent per kWh and an annual electrical production of 5769 kWh, that is $635, not $900. 15 year payback.

If your actual rate is $0.15/kWh, that is $877/yr. Almost 11 year payback.

So my assumptions weren't way off from what you're saying.

My rounding does move the numbers a bit. It was more of a back-of-the-napkin calculation.

10 or 15 year payback - at that point the projections are based on things we can't know today. What we do know is that today solar easily pays back the cost within the life of the system. So long term there is a savings and it is a hedge against future rate inflation.

Originally Posted by redpoint5

Taking the average rate of return of the stock market of 7%, the money invested rather than put into solar would have doubled in 11 years. Due to compounding interest, there is no catching up with the savings from solar unless electricity prices skyrocket for some reason.

The average rate of return on the stock market is 7%
The average annual increase in electricity rates is 4%

So now we are down to 3%. The stock market returns are taxed at a capital gains rate of 15-20%. Money saved on electricity is tax fee. So that is another 1 to 1.5%. At that point the question is do you want to lock in a fixed rate of return or roll the dice to get another 1 - 1.5 percent?

I get what you are saying about opportunity cost. That is why we didn't do the install this year. We decided we wanted to pick up a rental house so we are saving the down payment this year. Solar is only getting cheaper and we want to have cash in hand - ready to buy - when the next recession hits.

Originally Posted by redpoint5

I like solar, but the PNW isn't a great place for it. If I lived in HI and paid $0.33/kWh, I'd have gone solar long ago. Heck, if I lived in Phoenix, I'd probably go for it.

I agree, the PNW isn't a great place for solar. It is only a good place for it.

[jamesqf]

Originally Posted by JSH

You aren't using enough electricity. If you are only using $40 a month you don’t have an all electric house. If you have your own powerplant on your roof you would want to use it.

So you buy an electric car. Or a plug-in hybrid. That should take care of the not using enough electricity problem :-)