Sizing Solar System for the home @ 80% ?

[DanKegel]

Constantly touting any and all sources that support only one position...

? I don't do that. In this thread, you said
"I'd not be surprised to see sentiment come around to viewing existing solar as a less desirable feature as time goes on".
In other words -- and I know you dispute this, but it's the clear implication -- your hypothesis is that solar decreases the value of a house. I simply went out and found some data on that question.

When testing hypotheses, I do not go looking for data that agrees with my position; I look for data that tests the hypothesis.

[silversaver]

Solar is like an appliance. You like it, keep it.... vice versa. If you own it, you are okay. If you lease it with unpaid balance, then prepare to spend some $$$ when you selling your house and don't count on the luck.

Lots new home were pre-loaded with solar panels for reasons from builders.

Back to the topic. IMO 80% coverage is a good starting point if you want every penny counts. I went with 100% coverage and that's max the POCO allowed. I know I will be using more electricity in long run. I read/study/plan my system so I know what I'm looking for. Nothing wrong with 100% coverage, it is only a few thousand more for 20 yrs. They are people spend thousands of dollar switching to LEDs or more efficiency appliances just to save the electricity bill. make your own decision base on your living standard.

[SunEagle]

Solar is like an appliance. You like it, keep it.... vice versa. If you own it, you are okay. If you lease it with unpaid balance, then prepare to spend some $$$ when you selling your house and don't count on the luck.

Lots new home were pre-loaded with solar panels for reasons from builders.

Back to the topic. IMO 80% coverage is a good starting point if you want every penny counts. I went with 100% coverage and that's max the POCO allowed. I know I will be using more electricity in long run. I read/study/plan my system so I know what I'm looking for. Nothing wrong with 100% coverage, it is only a few thousand more for 20 yrs. They are people spend thousands of dollar switching to LEDs or more efficiency appliances just to save the electricity bill. make your own decision base on your living standard.

I understand wanting to cover as close to 100% of your usage as possible but in reality people should be finding ways to REDUCE their consumption.

Why do people think that it is ok to burn more electrons because now they have solar to offset the high cost of their POCO rates?

It would be a lot simpler (and less costly) to reduce you electrical foot print which would allow you to also reduce the solar pv system.

[silversaver]

I understand wanting to cover as close to 100% of your usage as possible but in reality people should be finding ways to REDUCE their consumption.

Why do people think that it is ok to burn more electrons because now they have solar to offset the high cost of their POCO rates?

It would be a lot simpler (and less costly) to reduce you electrical foot print which would allow you to also reduce the solar pv system.

I totally agree; but in reality, people use more electricity after solar installed...... at least for the people around me including myself.....

[SunEagle]

I totally agree; but in reality, people use more electricity after solar installed...... at least for the people around me including myself.....

I hear ya. I just don't understand why. Especially if they want to reduce their electric bill wouldn't you try to use less?

[J.P.M.]

I hear ya. I just don't understand why. Especially if they want to reduce their electric bill wouldn't you try to use less?

I bet part of what's going on is if something is perceived as less expensive, the common tendency is to use more of it. I suspect the common perception is not so much on the total life cycle cost of solar + POCO power, but the immediate 1X/month bill that may be substantially less as a result of adding solar.

In the end, we may find that bills of solar owners will tend to creep up to something that might approach the pre solar levels over time, depending on the discomfort level induced by the bills.

[SunEagle]

I bet part of what's going on is if something is perceived as less expensive, the common tendency is to use more of it. I suspect the common perception is not so much on the total life cycle cost of solar + POCO power, but the immediate 1X/month bill that may be substantially less as a result of adding solar.

In the end, we may find that bills of solar owners will tend to creep up to something that might approach the pre solar levels over time, depending on the discomfort level induced by the bills.

I believe you are right in that people will tend to use more power because they will overall be paying less.

That is my biggest fear for areas that go too far with relying on RE to provide power 24/7. If they found ways to reduce the overall peak & night usage they may have a chance to meet that 50% RE goal. IMO more electrical usage just pushes the reality of higher % of RE farther away.

[J.P.M.]

I believe you are right in that people will tend to use more power because they will overall be paying less.

They'll have a lower bill, but they won't be paying less unless they got the PV system for a song.

That is my biggest fear for areas that go too far with relying on RE to provide power 24/7. If they found ways to reduce the overall peak & night usage they may have a chance to meet that 50% RE goal. IMO more electrical usage just pushes the reality of higher % of RE farther away.

In some ways of looking at it, if PV users draw from the POCO ramps up, at some point POCO supplied energy could equal or exceed pre PV demand. I suppose one answer would be to add more PV to a roof. At some point you wind up chasing your tail with PV supplying all or some of the growing demand that the perception of free energy might create.

[MikeInRialto]

Hello, I am new to the forum, but have been reading and learning on this site.

My average usage over the past 12 months is 635, or annual usage is 7615.
I am located in San Jose, CA and have also looked at the PV Watts Calculator for my area.

I see comments that typically you get the best bang for your buck, if you size the solar system at 80%-90%. Is there some analysis that explains why we should go with 80%-90% vs 100%.
The only additional usage I may have would be a new A/C...

Thanks,

Back to the original thread... Who knows what the electric companies will do in the future as far as TOU rates goes, but one thing is certain. If you are producing/offsetting 100% of the power you normally consume, you have a darn good idea of where you'll be for the next 20 years. I'm sure we all know someone who bought a new car and then shortly after had to trade-in because of a new addition to the family or the kids get bigger. You can try and figure out where 80-90% might be, and if you find you want to go bigger because you underestimated and are well below the 80% (especially after panels degrade) - it's going to COST you A LOT later.

As posted in this thread - many people tend to use more after installing solar: In my case, i was very conservative because i didn't want to pay SCE tier 3 & 4 rates. I would liked to have used the backyard lights more, the AC more, and a few other things more - but tier 3 & 4 tend to get a little expensive. Having shot for 100-110%, if i fall short - I'm still in tier one =)

I think I might have been able to get by with one panel less, savings of $646 (after 30% tax credit) - but to add that one panel later would probably cost me closer $2000. Permit, new plans, panel, wiring, and labor.

Not to mention... any excess power you produce helps offset someone else's carbon footprint =)