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Project Sunroof

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Re: Project Sunroof

#121

Post by JshWright »

dreamcompiler wrote: post #109
VLM wrote: post #92

Earlier quoted context omitted.

Something I worry about with solar is once power is psychologically "free" I'll be tempted to set the thermostat down to 65F or whatever, and end up paying full rate when clouds blow by. I think it would be difficult not to increase power use once its free. I'm not talking about explicitly leaving stuff on for fun, but more like "well, power is free, so I guess I can afford a tropical reef tank instead of a plain fis…

Heating your house with electricity is extremely inefficient. 5KW of "excess" electricity won't go very far in heating your house when it's cold outside, and any excess you might have will be less in the winter because of your latitude. I'm not saying you can't do it, but even with today's cheap solar panels it's not likely to be a good value proposition.

Heating your house _directly_ with electricity is inefficient. Using that electricity to run a heat pump can be very efficient (assuming you have a large enough heat reservoir (e.g. a few hundred feet of pipe buried underground))

Re: Project Sunroof

#122

Post by [deleted] »

andyl wrote: post #21

Fusion of maps, 3d modeling, electricity & lease rates, solar intensity, installers. Easy to use. This feels like something new and powerful. For society: I wonder if it is safe for so much power to be concentrated in one organization. As a technical accomplishment: I'm impressed.

[deleted]

Re: Project Sunroof

#123

Post by [deleted] »

andyl wrote: post #21

Fusion of maps, 3d modeling, electricity & lease rates, solar intensity, installers. Easy to use. This feels like something new and powerful. For society: I wonder if it is safe for so much power to be concentrated in one organization. As a technical accomplishment: I'm impressed.

[deleted]

Re: Project Sunroof

#124

Post by wmeredith »

andyl wrote: post #21

Fusion of maps, 3d modeling, electricity & lease rates, solar intensity, installers. Easy to use. This feels like something new and powerful. For society: I wonder if it is safe for so much power to be concentrated in one organization. As a technical accomplishment: I'm impressed.

I had a similar thought. I'd bet an "enter your address and Google will tell you your household political orientation" could probably be pretty accurate.

Re: Project Sunroof

#125

Post by ZeroGravitas »

_delirium wrote: post #98
jsprogrammer wrote: post #78

Earlier quoted context omitted.

Is there no real solar power market then? If your local utility is a monopoly then you basically have to accept whatever the utility wants to pay you (even far below 'market' rate). You have no power to negotiate, only capitulate or try to get the local regulator to enforce fair trade.

I suspect you'd fare pretty badly in a market, even if a better one existed. In Texas's deregulated electric marketplace, the market price for large-scale solar installations selling into the grid has fallen to around $0.05/kWh. Power from a single small-scale residential installation with less reliable delivery is probably worth less than that.

Depends on how much "better" the market is e.g. if it priced in the greenhouse gas externalities, the avoidance of transmission losses and grid upgrades etc then solar may be worth triple the residential rate. I believe a couple of states have calculated "value of solar" to use as part of their grid regulation, though specific factors like mix of gas and coal production and projected grid expansion factor into this.

Re: Project Sunroof

#126

Post by mbostleman »

birken wrote: post #60

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 ev…

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.

Re: Project Sunroof

#128

Post by mikepurvis »

protomyth wrote: post #79
ChuckMcM wrote: post #71

Earlier quoted context omitted.

Perhaps it should link to a solar installer, and a lumber jack :-) More seriously though, I installed solar about 13 years ago now on my roof, California has some case law about trees blocking solar, post install, which was decided in the favor of the solar panel owner. The city tree across the street had gotten large enough in the last 10 years to start shadowing some of my panels. So when the arborists were in our…

> Perhaps it should link to a solar installer, and a lumber jack :-) Let's not be cutting down the carbon dioxide remover when we're trying to go eco-friendly. :)

Any gains from PV would be washed away by increased air conditioner usage. If you have a house in shade, be very happy.

Re: Project Sunroof

#129

Post by kuschku »

mbostleman wrote: post #126
birken wrote: post #60

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 ev…

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 ta…

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

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