Anyone have any ideas on the computer vision techniques used here?
Project Sunroof
191–200 of 233 posts
Re: Project Sunroof
#192Earlier 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.
No access to natural gas? I'm assuming you live too far from the gas lines to make a new gas installation possible?
That said, I had a instructor who's friend bought a house out at the beach 30 years ago. He didn't know what to do about heating.
He decided to put a large diesel tank on his property, and use that fuel to run a boiler. He installed baseboard hydronic tubing. He was very happy with the heating set up. His previous system was electric, and his monthly bill was outragious.(electrical rates really do vary from area to area.)
He also had an old Mercedes diesel automobile. One day he used the heating grade diesel for fuel for his Mercedees. His car ran fine. He was paying someting like 35 cents a gallon for gas. He used that car to commute for years. There are no taxes on the heating fuel, or at that time.
(That 35 cent quote is from a story told to me 20 years ago. I don't know if heating diesel was ever that cheap? I was told this story from a instructor who I don't completely trust. He tended to embellish.)
That said I always thought if I lived in an area where I couldn't use solar, or natural gas; I would definetly use a boiler, with propane, or diesel fuel? They make condensing boilers that are very efficient. I installed one and it wasen't that hard. I don't know if a condensing boiler can use diesel fuel, but I know you can use them with propane.
If you decide to do the work yourself; buy the third edition of Modern Hydronics. It's expensive, but go for it. Hole yourself up in a room for a weekend, and read that book. It's geared for large hydronic installations, but will handle residential installations fine. Hydronic heating is really under utilized, especially on the west coast. It's a great, energy efficient way to heat a home. I bought a fancy condensing boiler and happy with it, but I have a feeling I could heat a house with a water heater if your have enough baseboard, or tubing? And you live in a temperate climate?
Of course, hire a professional if funds are tight. Make sure the professional knows about boilers, and hydronic heating. A good first question for the contractor is what brand of 02 sensor he/she uses to calibrate the boiler. If he doesn't immediately come up with a answer, or looks confused--run. The second question should be "could you write down the what a primary/secondary hydronic piping configuration would look like?" Verify he knows what a primary/secondary system looks like, and why it's important.
Hydronic heating is vastly underutilized in the U.S., at least in California? I don't know why it isn't used in more situations? I guess engineers feel that if you are going to need air conditioning, why bother with it? I have heard incorporating air conditioning with hydronic heating is not that difficult? As to keeping zones at different temperatures, I did not find that to be a problem if you run your zones correctly.
(One other painful lesson I learned by relying on wood burning too long. Don't buy a cord of wood off Craigslist. I guarantee a guy will show up with less than a cord. If you are forced to use the fireplace; put a insert in.)
Re: Project Sunroof
#193I 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…
This was true several years ago, but the cost of solar has come down substantially even without considering tax subsidies, and is continuing to decrease at a healthy rate.
For example, Sunroof estimates that a 5.75kWh system would cost $21,500 before subsidies (about $15k after, but we're ignoring that), and that it will save you (gross) $60,000 over 20 years in utility bill costs. You can either:
a) Invest that capital. At a stable 7%, after 20 years, your balance would be about $86.8k.
b) Purchase a solar system for that $21.5k, and invest the difference on your power bill each month. Assuming a base power bill of $200, and the 2.2% annual rate increase that Sunroof uses, you would invest $2400 the first year, $2452.80 the second year, etc. At the same 7% return, then in 20 years your investment balance would be $122.8k, and your power bills would continue to be $0. Remember, these numbers assume an unsubsidized system.
The gain comes from the fact that after the break-even point (at year 12), you are continuing to invest your power bill equivalent, rather than paying it to the power company, whereas in the non-solar case, the increased power bill will never earn you a return.
The downside is that it (with those numbers) takes 12 years for you to come out ahead, and solar tech is moving so fast that the opportunity cost of committing capital to solar today rather than investing it and then liquidating that investment tomorrow to pay for a cheaper and more efficient system may be substantial, but is arguably specifically unknowable. If you don't offset your full cost, the numbers change a bit, as well (but you can certainly compute what happens at a 50% offset for a smaller upfront capital investment easily enough, as well). There are certainly scenarios in which solar is viable unsubsidized today, though.
Feel free to check my math and assumptions: https://docs.google.com/spreadsheets/d/1JoJxX5t7VmRhV1LDI1UF...
Re: Project Sunroof
#194Earlier quoted context omitted.
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.
No access to natural gas? I'm assuming you live too far from the gas lines to make a new gas installation possible? That said, I had a instructor who's friend bought a house out at the beach 30 years ago. He didn't know what to do about heating. He decided to put a large diesel tank on his property, and use that fuel to run a boiler. He installed baseboard hydronic tubing. He was very happy with the heating set up. H…
Hydronic heating is great, but I don't think it's well suited for retrofits.
I'm not very far from the gas lines, just on the wrong side of the street, and digging up the street is expensive.
Oil burning is more expensive than using a modern-day electric water heater, by the way. Oil has gone up in price and electric heaters have gotten much more efficient.
Re: Project Sunroof
#195Earlier quoted context omitted.
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.
This is the direction I'm most likely to go. The other option is a fireplace insert. Cheap, but not as environmentally friendly.
Re: Project Sunroof
#196Earlier quoted context omitted.
I don't accept your conclusion. If we all had solar on our roofs, there are many possible factors that could reduce power rates (including tax burden, by your definition): -- fossil fuel prices would drop, since demand would fall -- we would spend less tax money on grants and subsidies for oil and gas marine terminals -- fewer emergency responses, disaster clean ups, etc. for fuel transportation mishaps -- maybe we c…
"Additionally, even without a tax subsidy, installing solar on my roof in CA would generate a positive NPV over 20 years." I would like to see this analysis. I know that there are certain (mostly remote and very sunny) areas of the U.S. that have demonstrated unsubsidized market viability. But even then only with utility scale installations. I would think rooftop surpassing grid parity with conventional energy would…
Go pick an address in Silicon Valley (take for example 2 College Ave, Los Gatos). Set the monthly electric bill to $125. The calculator recommends a 4.25 kW installation, which has a 20 year NPV of $12,056, if you click into the detailed analysis and check the last line.
Subtract out the $5028 Federal tax benefit, and you are still left with a $7000 20-year NPV (assuming 4% cost of capital).
Still a positive ROI over and above inflation, even without a rebate.
Re: Project Sunroof
#197For those with 404 errors, it works if you add "?hl=en" at the end of the URL. https://www.google.com/get/sunroof?hl=en
Re: Project Sunroof
#198Earlier quoted context omitted.
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 ab…
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…
Actually in California a solar panel owner already does have solar rights.
http://www.leginfo.ca.gov/cgi-bin/displaycode?section=prc&gr...
"25982. After the installation of a solar collector, a person owning or in control of another property shall not allow a tree or shrub to be placed or, if placed, to grow on that property so as to cast a shadow greater than 10 percent of the collector absorption area upon that solar collector surface at any one time between the hours of 10 a.m. and 2 p.m., local standard time."
There are a number of exceptions later in the act, including a notification requirement.
However, once a solar system is installed - a neighbor can't cause the system to be shaded with impunity.
Re: Project Sunroof
#199Earlier quoted context omitted.
This is an argument detached from two realities: (1) that fossil fuels receive enormous subsidies in the US and worldwide, and (2) that there is an enormous impact of CO2 on global climate, health, and ecosystems (not to mention the local environmental and health impacts of coal mining and fracking). When accounting for these costs, it becomes increasingly dishonest to claim that fossil fuels are cheaper than renewab…
That may or may not be the case, but the claims that these systems are "cheaper" prey on economic ignorance.
If you don't know if this is the case, how can you say that you know that this systems are not cheaper?
Re: Project Sunroof
#200Earlier quoted context omitted.
You are correct - the impact on your personal tax is negligible. Solar accounts for something well under 2% of total energy generation and residential rooftop far less. So almost all of your subsidy is paid by others. That doesn't make the over all analysis any more sound. What if we all had solar on our rooftop? Energy would cost more. The savings would be negative.
I don't accept your conclusion. If we all had solar on our roofs, there are many possible factors that could reduce power rates (including tax burden, by your definition): -- fossil fuel prices would drop, since demand would fall -- we would spend less tax money on grants and subsidies for oil and gas marine terminals -- fewer emergency responses, disaster clean ups, etc. for fuel transportation mishaps -- maybe we c…
I don't understand how people connect oil and gas imports to electricity generation. Go read this article
http://www.washingtonpost.com/graphics/national/power-plants...
Now how much electricity is generated from oil in the US? A whopping 1%.
Now while it is true that we import a lot of natural gas... "Natural gas imports to the United States, 98% of which arrive via pipeline from Canada, have decreased almost every year since 2007, and in 2014 reached the lowest level (2,636 Bcf) since January 1995." According to http://www.eia.gov/naturalgas/importsexports/annual/.
So if you think putting solar on your roof, or wind, is going to make any OPEC countries upset please think again.