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Project Sunroof

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Re: Project Sunroof

#151

Post by mikeash »

JshWright wrote: post #141
mikeash wrote: post #111

Earlier quoted context omitted.

I assume part of the training is how to locate the right stuff to cut to shut off the high-voltage connection? Have you ever had to do that in practice, and if so how hard is it on a car that's been mangled?

Tesla actually does a really nice job of providing training materials to first responders: http://www.teslamotors.com/firstresponders You can watch a Tesla get cut up in this video: https://www.youtube.com/watch?v=ntK3rvVl2Qw

Very nice. I was somewhat aware of the materials they provide, but I didn't know that video existed. I'm kind of impressed they sacrificed a car for it (although I suppose many of the valuable spare parts remained untouched).

Re: Project Sunroof

#152

Post by URSpider94 »

mbostleman wrote: post #145
URSpider94 wrote: post #144

Earlier quoted context omitted.

The common definition of "savings" is a reduction of cash outlay for the purchaser. The fact that there are government subsidies (or surcharges) involved is not relevant for that calculation. The Google site is extremely thorough -- for the case where the consumer is buying the panels, they calculate the time to break even, but also a net present value given a 4% cost of capital. Same thing for the lease cases -- for…

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 could avoid or sit out the next land war in the Middle East ...

Additionally, even without a tax subsidy, installing solar on my roof in CA would generate a positive NPV over 20 years. Here in CA, it's just plain cheaper than the utilities, even without the (nice to have) tax subsidies.

Re: Project Sunroof

#153

Post by nimitkalra »

Risks to getting solar power (according to Project Sunroof) are something to consider.

> As with any investment, there are some risks, though a well-installed system will make most risks extremely rare. Risks include PV systems catching fire, installations leading to roof leaks, theft, obsolescence, and hail damage and/or wind damage to the solar system itself.

> Fast-growing trees can shade solar installations, reducing production over time. Utilities can change how much they charge their customers for electricity, changing the savings from solar.

Re: Project Sunroof

#154

Post by coldtea »

freehunter wrote: post #142
dafrankenstein2 wrote: post #140

Earlier quoted context omitted.

Mind your comment and wait and see what will happen after 20 years

20 years doesn't change their price today.

No, only make the world better for our kids, with a small premium to pay today instead of loaning from the future...

Re: Project Sunroof

#155

Post by thrownaway2424 »

JshWright wrote: post #121
dreamcompiler wrote: post #109

Earlier quoted context omitted.

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))

How can heating your house with electricity be less than 100% efficient?

Re: Project Sunroof

#156

Post by [deleted] »

mbostleman wrote: post #145
URSpider94 wrote: post #144

Earlier quoted context omitted.

The common definition of "savings" is a reduction of cash outlay for the purchaser. The fact that there are government subsidies (or surcharges) involved is not relevant for that calculation. The Google site is extremely thorough -- for the case where the consumer is buying the panels, they calculate the time to break even, but also a net present value given a 4% cost of capital. Same thing for the lease cases -- for…

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.

[deleted]

Re: Project Sunroof

#157

Post by mbostleman »

URSpider94 wrote: post #152
mbostleman wrote: post #145

Earlier 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…

"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 be a pretty big milestone. Not doubting you, but I'd love to see it on paper.

Re: Project Sunroof

#158

Post by JoeAltmaier »

thrownaway2424 wrote: post #155
JshWright wrote: post #121

Earlier quoted context omitted.

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))

How can heating your house with electricity be less than 100% efficient?

Turning electricity into heat isn't all the work you can get out of the energy. Heat pumps get even more, by using the energy to move heat from one place to another (e.g from ambient outside air to the volume to be heated), and the heat from this process also heats the volume.

Re: Project Sunroof

#159

Post by Daishiman »

mbostleman wrote: post #139
tstactplsignore wrote: post #134

Earlier 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 ignore externalities, sure. But that's not how the realities of climate change and pollution work.

Re: Project Sunroof

#160

Post by thrownaway2424 »

JoeAltmaier wrote: post #158
thrownaway2424 wrote: post #155

Earlier quoted context omitted.

How can heating your house with electricity be less than 100% efficient?

Turning electricity into heat isn't all the work you can get out of the energy. Heat pumps get even more, by using the energy to move heat from one place to another (e.g from ambient outside air to the volume to be heated), and the heat from this process also heats the volume.

If the air outside my house is warmer than the air inside my house, I'll just open the windows. Generally when one needs a heater it is because the system surrounding the house is colder, sometimes much colder, than the house itself.
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