6 ms·

I live in San Francisco and just had a solar system installed last week, so I have a few comments about this. 1) It vastly overestimated how big a solar system

by birken 11y ago

I live in San Francisco and just had a solar system installed last week, so I have a few comments about this. 1) It vastly overestimated how big a solar system that could fit on my roof (by about 5x). It didn't care about chimneys or skylights (which are easily visible through Google maps), nor SF fire code which states that you need a 3-foot empty pathway on both sides of the crest of your roof [1]. So for almost every roof with a single ridge, this will cut out a large percentage of the best solar real estate. 2) It didn't include local SF providers in the marketplace which are generally higher rated than national providers and can offer additional SF incentives and cost-savings. So while the estimation of sunlight potential is really cool, the 3d modeling aspect and size of the marketplace leave a little bit to be desired. This site would probably be good at quickly seeing if your roof has any solar potential at all, but if it does, I'd recommend checking Yelp and having a highly-rated solar company come give you a detailed estimate (which would be free). 1: http://www.sf-fire.org/index.aspx?page=1232 http://www.sf-fire.org/index.aspx?page=1232

TTPrograms 11y ago
Is the cost primarily proportional to the size, or do inverters present a major fixed cost? For the former it doesn't really matter how much you can cover, as it's simply an investment with a certain rate of return that has the amount you can invest limited by roof area.
- birken 11y ago
  I think all of the hardware will be very proportional to the size. In my case I had micro-inverters on each panel, so it was directly proportional, but this was actually more expensive than having a single large inverter (though more performant). However, the marginal cost of things like engineering, installation and inspection will certainly go down with the size of the system. How much of that passes to the consumer I don't know, but some of it certainly does. You can imagine the cost of putting 1 solar panel on your roof is not going to be 10x less than putting 10 of them up there. It is hard to get exact numbers from solar sites as they are very sales-oriented, but it seems like the hardware cost is estimated at anywhere from 20-50% of the total cost of the solar system. The rest of it is engineering, installation, inspection, customer acquisition, profit, etc.
mbostleman 11y ago
I always find it a bit dishonest sounding when these things are referred to as producing a "savings". Solar on a residential rooftop is not financially sustainable when you consider the cost of capital and require a market ROI. So I assume that lessors in this case are receiving a non-trivial government subsidy. Which means, in the end, that whatever the lessee is "saving" and then some is being paid in additional taxes that wouldn't be there if there were no subsidy. All of which is fine for those that want to pay more for energy that is cleaner. But people should not be given the impression that they're paying less. If they really were we'd all have solar rooftops over night.
- kuschku 11y ago
  Well, look at the subsidies for the existing energy companies. Nuclear companies get the waste handling for free, if they break regulations, often the government pays the bill... Coal companies never pay for the damages to the environment their huge quarries do... Subsidies for solar are just one part of it. If you take these subsidies that you give the energy companies, and add them as tax to the electricity price, you end up with electricity costs like in Germany – 0.40$ per kWh
  - mbostleman 11y ago
    If what you're saying is correct, if subsidies were removed across the board taxes would go down, energy costs would go up and solar would take off and replace coal because it would be the (real) best deal.
    - kuschku 11y ago
      What do you think why German electricity companies are trying to sell their gas and coal business and focus on renewables as much as possible? In Germany, the effect is even stronger: As we are taxed per kWh, the electricity is quite expensive. On the other hand, this money is then spent on subsidies for solar and wind. Overall making solar and wind so extremely cost effective that anything else becomes stupid. And, at the same time, it leads to people saving really a lot of energy. A family of 4 using 3000kWh per year or less is common.
dhess 11y ago
Which installer did you choose, and would you recommend them?
- birken 11y ago
  I used Luminalt [1] and they did a great job throughout the whole process. The installation job was at the highest degree of quality and professionalism that I've experienced. Though it hasn't been inspected or turned on yet (happens later this week), so I'll see how close their projections were to reality over the coming months as the juice is generated. I did my own projections independently and found that their projections seemed to be on the conservative side, so I'm optimistic. 1: http://www.yelp.com/biz/luminalt-solar-energy-solutions-san-francisco-2 http://www.yelp.com/biz/luminalt-solar-energy-solutions-san-...
pdx6 11y ago
Their vendors also don't include the roofing type. For example, I have a flat tar roof and many vendors, such as Sungevity, won't install on it. Local vendors will, but are not on the list, and require I install a new roof first. There goes the $24k in savings for buying outright!
- cheald 11y ago
  Would that be a sunk cost, or would a new roof increase the value of your home?
newman314 11y ago
Did you choose to lease, loan or buy? Would be interested in knowing the factors driving your decision.

by birken 11y ago

TTPrograms 11y ago

Is the cost primarily proportional to the size, or do inverters present a major fixed cost? For the former it doesn't really matter how much you can cover, as it's simply an investment with a certain rate of return that has the amount you can invest limited by roof area.

birken 11y ago
I think all of the hardware will be very proportional to the size. In my case I had micro-inverters on each panel, so it was directly proportional, but this was actually more expensive than having a single large inverter (though more performant). However, the marginal cost of things like engineering, installation and inspection will certainly go down with the size of the system. How much of that passes to the consumer I don't know, but some of it certainly does. You can imagine the cost of putting 1 solar panel on your roof is not going to be 10x less than putting 10 of them up there. It is hard to get exact numbers from solar sites as they are very sales-oriented, but it seems like the hardware cost is estimated at anywhere from 20-50% of the total cost of the solar system. The rest of it is engineering, installation, inspection, customer acquisition, profit, etc.

mbostleman 11y ago

I always find it a bit dishonest sounding when these things are referred to as producing a "savings". Solar on a residential rooftop is not financially sustainable when you consider the cost of capital and require a market ROI. So I assume that lessors in this case are receiving a non-trivial government subsidy. Which means, in the end, that whatever the lessee is "saving" and then some is being paid in additional taxes that wouldn't be there if there were no subsidy. All of which is fine for those that want to pay more for energy that is cleaner. But people should not be given the impression that they're paying less. If they really were we'd all have solar rooftops over night.

kuschku 11y ago
Well, look at the subsidies for the existing energy companies. Nuclear companies get the waste handling for free, if they break regulations, often the government pays the bill... Coal companies never pay for the damages to the environment their huge quarries do... Subsidies for solar are just one part of it. If you take these subsidies that you give the energy companies, and add them as tax to the electricity price, you end up with electricity costs like in Germany – 0.40$ per kWh
- mbostleman 11y ago
  If what you're saying is correct, if subsidies were removed across the board taxes would go down, energy costs would go up and solar would take off and replace coal because it would be the (real) best deal.
  - kuschku 11y ago
    What do you think why German electricity companies are trying to sell their gas and coal business and focus on renewables as much as possible? In Germany, the effect is even stronger: As we are taxed per kWh, the electricity is quite expensive. On the other hand, this money is then spent on subsidies for solar and wind. Overall making solar and wind so extremely cost effective that anything else becomes stupid. And, at the same time, it leads to people saving really a lot of energy. A family of 4 using 3000kWh per year or less is common.

dhess 11y ago

Which installer did you choose, and would you recommend them?

birken 11y ago
I used Luminalt [1] and they did a great job throughout the whole process. The installation job was at the highest degree of quality and professionalism that I've experienced. Though it hasn't been inspected or turned on yet (happens later this week), so I'll see how close their projections were to reality over the coming months as the juice is generated. I did my own projections independently and found that their projections seemed to be on the conservative side, so I'm optimistic. 1: http://www.yelp.com/biz/luminalt-solar-energy-solutions-san-francisco-2 http://www.yelp.com/biz/luminalt-solar-energy-solutions-san-...

pdx6 11y ago

Their vendors also don't include the roofing type. For example, I have a flat tar roof and many vendors, such as Sungevity, won't install on it. Local vendors will, but are not on the list, and require I install a new roof first. There goes the $24k in savings for buying outright!

cheald 11y ago
Would that be a sunk cost, or would a new roof increase the value of your home?

newman314 11y ago

Did you choose to lease, loan or buy? Would be interested in knowing the factors driving your decision.