Solar power

[oil pan 4]

Originally Posted by jjackstone

For just the glass and aluminum we are looking at about a year worth of energy.
I could believe a 1 year pay back if it's CdTe cell panels since they take almost no energy to make compared to mono.
But all i can find is abstract not actual numbers.
[4 to 5 energy units of CdTe equal 1 energy unit of mono]

[jjackstone]

Found this paper which appears to be a study of studies of Energy Payback Time for energy used of various PV materials. It's only four years old, so fairly recent.

http://astro1.panet.utoledo.edu/~rel...nergy_revs.pdf

The chart on the fifth page shows the energy cost for the various materials. Later, payback times are shown. Their conclusions are about the same as in my earlier post of about a one to four year payback depending on the material used. Dozens of references are given if anyone would like to dig deeper.

JJ

[sendler]

Originally Posted by jjackstone

Found this paper which appears to be a study of studies of Energy Payback Time for energy used of various PV materials. It's only four years old, so fairly recent.

http://astro1.panet.utoledo.edu/~rel...nergy_revs.pdf

The chart on the fifth page shows the energy cost for the various materials. Later, payback times are shown. Their conclusions are about the same as in my earlier post of about a one to four year payback depending on the material used. Dozens of references are given if anyone would like to dig deeper.

JJ

So it just occurred to me that there are different ways to look at those numbers. On first blush a payback of even the larger number of 4 years seems like a good deal on a solar panel with a 20 year service life. But when viewed in the terms we have always used in assessing fossil fuel extraction, which is ER/EI, a value of 5:1 would be considered economically very marginal.
.
But whatever solar and wind and electrification of all systems that we can get built in the next 30 years will be much better than nothing and will be a big help in extending whatever liquid fuel we have left after that.

[redpoint5]

I agree with sendler's general idea that we need to transition away from dwindling resources prior to "running out", but I foresee a more gradual letdown in resources. After all, we saw what happens when fuel prices are very high; we start cranking out the fracking sources domestically.

So it will go, as scarcity sets in, the more difficult to produce sources of fuel will be tapped. This will cause a gradual rise in prices that will spur further incentive to utilize alternative means of energy. It's not like 40 years of abundance and then the light switch is flipped off.

[oil pan 4]

I would rather have cheap steel, cheap concrete, cheapish aluminum, roads and bridges ect. for the rest of my life then drive a 10mpg pickup around for 10 or 20 more years.

[jjackstone]

Being involved in electronics and engineering for many years now I have become somewhat proficient(lucky) at projecting(guessing) timelines for new or better technology. I was able to guess about when compact disks would come around from working in computer manufacturing. When I started we were still working with 8 inch floppies.
As soon as the television people started talking about hi def digital televisions I knew it wouldn't be long afterwards that they would basically become computers.
From what I see, the break even economic cost of solar is already here as long as you stay connected to the grid. You just have to get the power companies on board. Will they like giving up all the income and control? Almost certainly not. But if they want to stay in business they will have to do just that...or buy more politicians.

And as we have already seen, the energy return has already long surpassed the break even point. Still, that part is based on at least six year old technology. I am going to guess that within ten years even residential solar modules will reach 28 to 30% efficiency using the new technologies that are now being developed. This should give almost every module an EROEI of less than a year. It also should lower the dollar cost per watt even more. Will everyone want to switch over? Of course not. I've actually had friends tell me they wouldn't have solar panels or drive an electric vehicle even if they were given one. Some just don't understand the increased efficiency of an electric vehicle. Some are afraid of newer technologies. Some are the type that won't change because it would require them to admit they were wrong about solar and electric cars.

The thing is that even though both the concepts and physical devices of solar power and electric cars have been around for many decades, they are both still in their infancy on the technological timeline. If either of those two had as much research put into them as ICE vehicles have, there would no longer be ICE vehicles except for specialized uses.

JJ

[redpoint5]

A kid in high school told me he was building a home network, and I said that was dumb and pointless. Then 10 years later everyone had wireless networks.

Internet on phones was a novelty for wealthy folk, I said.

Finally, when SSD storage hit the market, I was done being pessimistic about adoption of technology and experienced firsthand how superior it was. Based on my experience, I figured 2 years and it would become the dominant storage platform. It's been about a decade now and were not quite to the 50% mark yet. It was adopted much slower than I had anticipated.

Location and utility costs have as much to do with solar adoption as the cost of the panels themselves. Half the days in the valley here are overcast or rainy. The sun is never directly overhead even in the summer, and the utility rates are among the lowest in the nation. There's absolutely no reason for me to install PV here. If I wanted to install PV, I'd install it in someone else's house in AZ and have them send me a check for the monthly production.

[Piotrsko]

Raid drives are expensive as all get out when done in silicon. Probably no reason to do them either. 8 or more terabytes done on platter storage is reasonably cheap.

[redpoint5]

I'm just surprised it's still cheaper to build precision mechanical devices that spin at 10,000 RPM to store data than to just print 'em on silicon. I wonder when there will be price parity?

I saw a 8 TB drive for $130 the other day. The cheapest SSD I can find is 1 TB for $94, so still 5x more expensive. My programming teacher in high school said the largest database in the world was owned by Walmart, and it was something like a terabyte in size. He said one day we would have 1 TB drives in our computers. At the time he said this, top of the line computers had 1 GB drives and 100 MHz CPUs.

[jjackstone]

There are also frame less modules out on the market which means essentially no aluminum needed. I'm only going to cite one example and that is the Lumos LSX system.
In its spec sheets the overall weight of a 280 to 290 watt panel is 62 pounds. Glass is on both sides of the panel so I'm going to guess that at least 50 of those pounds are glass. So let's call it 23 kilos.
Using Oilpan's energy usage numbers for flat glass of 5kwh per kilo that gives 115 kwh for a 280 to 290 watt panel not including the energy cost of the cells themselves. So that's an energy cost saving of 300 - 115 kwh or 185 kwh per panel. Seems pretty substantial.
Here's a link to the spec sheet.

https://lumossolar.com/wp-content/up...et-6252018.pdf

Here are a few other thoughts on newer types of panels.

https://news.energysage.com/new-sola...2018/#comments

JJ