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Project Sunroof

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Re: Project Sunroof

#51

Post by lotharbot »

vblord wrote: post #17

Wow. I can't believe how expensive solar panels are. This really is a great tool to give you an idea how much solar panels would cost. What about wind... does anyone know of any affordable residential wind turbine solutions?

under Solar City's finance model (and possibly others) payments on solar panels are less than buying the same amount of electricity off the grid. That includes maintenance on the panels for 30 years.

This is assuming you get adequate sunlight, which we do here in Denver.

Re: Project Sunroof

#52

Post by larrys »

They use 20 years and in the past I have heard that the average time for home ownership is typically 7 years. I don't know the true figure today (wasn't able to find it when I just searched) but for most people a 20 year payback is way to long and I would imagine this certainly contributed to lack of adoption of solar in addition to other factors obviously.

Edit: Note this: https://www.google.com/get/sunroof/faq/#financial-considerat...

Re: Project Sunroof

#54

Post by thrownaway2424 »

wereHamster wrote: post #27
jpollock wrote: post #20

Earlier quoted context omitted.

Residential wind has some issues: 1) Performance - best performance is when the wind blows in a straight line, houses and other features will deflect it making it turbulent. 2) Noise - turbines are noisy, you're not likely to have neighbors appreciate it. 3) Mounting - Mounting one requires either a pole, or it can be mounted to the roof. However, roof mountings tend to cause issues (read damage) due to vibrations tr…

Aren't there turbines with a vertical shaft, which don't need a large tower? I saw one a few months ago, built especially for city rooftops where you don't have that much space and generally need something not that expensive. You'd still have the problem of turbulences though (i.e. non-optimal performance generation)

Yes but vertical axis windmills take more ground space and make even more noise than their horizontal-axis counterparts.

Re: Project Sunroof

#56

Post by willyk »

ljk wrote: post #26

This seems pretty cool, so any downsides I'm not seeing?

Agreed, this made my day. IMO only downside is that we don't have more of this sort of innovation happening at a smaller scale (akin to PG's recent tweet about the maturity of self driving cars relative to early versions of Google.

Re: Project Sunroof

#57

Post by Shebanator »

davidw wrote: post #34
melling wrote: post #28

Want to see what it does, try City Hall: https://www.google.com/get/sunroof#a=2600%20Fresno%20St%2C%2...

Interesting: "1,960 hours of usable sunlight per year" I wonder how they arrive at that number, and how accurate it is? Anyone in SF want to try a few addresses in Outer Sunset vs the Mission? I'd be interested in seeing that number alone mapped out over the US on a zoomable map.

FWIW, at least in my case, the numbers here seem optimistic. I had SolarCity come out and do a proposal for my house in San Jose about four years ago. Because my single story house is surrounded by big trees and two story houses, they said I only had a small area where they could install panels with sufficient efficiency, for a 3kW system. Sunspot says I could install an 8kW system covering 1475 sq ft, compared to about 800 sq ft for the Solar City system.

Re: Project Sunroof

#59

Post by joesmo »

netfire wrote: post #47
joesmo wrote: post #32

Earlier quoted context omitted.

So City Hall would actually save less money (12k vs 13k/14k) than the two regular homes I tried in San Francisco. If the numbers are correct, we're looking at $650-700 a year in savings. Not bad, but not that great either, especially considering heating alone in both buildings I looked at ran $150-300 / month (including summer which is hardly warmer at night in SF). Can solar panels be installed at such a price on a…

I'm guessing you left the average monthly electric bill slider at the $125/month position. You'd have to adjust the to what it actually is for City Hall, which I'd think is a lot more than $125/month.

There's no such slider on my page, only a text box. Tried disabling privacy plugins, but they're not the culprit.

Re: Project Sunroof

#60

Post by birken »

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

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