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Project Sunroof

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Re: Project Sunroof

#181

Post by andor436 »

aidenn0 wrote: post #175
mikepurvis wrote: post #128

Earlier quoted context omitted.

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

Energy wise, I wish my lot were less shady. I spend 0kWh per year on AC (days over 90 are rare), but heating is another matter. Which reminds me. If anyone knows a good way to retrofit an house with no ducting and no natural gas for any form of efficient heating, let me know.

Heat pump! You can get wall mounted units that work just like an A/C (but in reverse of course.) Efficiencies have gotten pretty good in the last decade. Check out units made by Daiken, Hitachi, Mitsubishi for example. I know they make multi-room versions. You'll need to run the refrigerant lines, but that's usually a much smaller task than adding ducting.

Re: Project Sunroof

#182

Post by toephu2 »

MRSallee wrote: post #112

Can anyone with more knowledge of solar technology speak to this? I know nothing about solar technology developments. I am interested in adding solar to my house some day, but concerned about spending a lot of money today for solar panels that will either (a) be much cheaper in 5-10 years, or (b) be replaced by much more effective panels in 5-10 years. Assuming that the economics of it are the only motivation for goi…

If you do go for solar just make sure you install it before December 31, 2016 as that's when the 30% Federal tax credit expires (note: this is if you buy, not lease the panels. Leasing does not earn you the 30% credit).

Re: Project Sunroof

#186

Post by anigbrowl »

aidenn0 wrote: post #175
mikepurvis wrote: post #128

Earlier quoted context omitted.

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

Energy wise, I wish my lot were less shady. I spend 0kWh per year on AC (days over 90 are rare), but heating is another matter. Which reminds me. If anyone knows a good way to retrofit an house with no ducting and no natural gas for any form of efficient heating, let me know.

If you have a crawl space or basement, you can install electrical under-floor heating at fairly affordable costs. Basically the heating element comes in a roll which you then tack the the underside of your floor.

I have lived with such a system before for a year and it was both easy to use and did a good job of heating the space. I don't remember the electricity costs so I can't comment on the economic efficiency, but AFAIK it's moderately good. I wish I had it in this house instead of the noisy, draughty, and inefficient gas-powered duct heating which I avoid switching on whenever possible.

Re: Project Sunroof

#187

Post by jseliger »

listic wrote: post #178

Why are so many people in the USA live in individual houses rather than condominiums (apartments)? The latter is just so much more economical.

Because zoning codes mandate it: see The Rent is Too Damn High (http://www.amazon.com/Rent-Too-Damn-High-Matters-ebook/dp/B0...) and The Triumph of the City (http://www.amazon.com/Triumph-City-Greatest-Invention-Health...) for more.

The short version is this: Property owners now have shocking amounts of control over what their neighbors do with property. Owners, especially of single-family houses, elect officials who restrict development through zoning and similar means. Height limits and parking requirements effectively mandate single, detached housing in most of the U.S.

This only really got started in the 70s (see http://jakeseliger.com/2013/07/03/jane-jacobs-is-everywhere-...), and it didn't get really bad until the 2000s, when the shift back to cities ran into insane urban zoning rules to produce huge affordability crises. By now, most developers who dare to build condos or apartments have to build luxury apartments: http://www.wsj.com/articles/rents-rise-faster-for-midtier-ap... because that's the only way to make the economics work.

In the meantime, much of the population growth has shifted to Sun Belt cities in Texas, Arizona, Georgia, and Florida where development is easier and/or simply sprawls more.

Re: Project Sunroof

#188

Post by drited »

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…

Actually by the standards of rates of change in the energy industry, we are going to all have solar panels powering our homes 'overnight' (see the rapid growth of solar forecast in slide 33 of the doc linked below). In many areas, due to rapid price declines and relatively low prevailing interest rates, solar is cost competitive without subsidy now so the ROI is real. As cumulative solar installations continue to grow, we will continue down the cost curve shown on slide 13 and that will be true for more and more people. Which means that subsidies today can actually lead to long term lower energy costs as prices continue to drop. On that topic, we should all be thanking Germany for being farsighted enough to invest in subsidies to keep the industry going for long enough to get us down to where we are on the cost curve today.

Bloomberg new energy finance talk slide deck: http://about.bnef.com/content/uploads/sites/4/2015/04/BNEF_2...

Re: Project Sunroof

#189

Post by cheald »

pdx6 wrote: post #149
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…

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!

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

Re: Project Sunroof

#190

Post by DirtyAndy »

Another take on this sort of thing: http://app.dumpark.com/sunlight/

The guys behind this apparently wanted to know the best place to go for a beer at any time of the day. They use the zenith of the sun, the surrounding landscape and the surrounding buildings and have it modeled throughout the year. I think they then realised there may be more useful ways to use this data.

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