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The price of solar power just fell 50% in 16 months

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Re: The price of solar power just fell 50% in 16 months

#421

Post by ChuckMcM »

thinkcontext wrote: post #182
ChuckMcM wrote: post #103

The aggressiveness of the price drops on solar is pretty amazing. I just lost one of the inverters on my grid-tie system after it had run trouble free for 13 years. So we're looking at the first "major" repair to the system I installed in 2003. And in 2003 my 5.2kW of panels on my roof cost $38,000 before subsidies and $19,000 after. 28 panels, two 2.5kW inverters, net about 4.2kW of generation. I priced out replacin…

Why not replace your current panels with new ones? If you can generate nearly 3 times as much electricity with the same roof footprint and be able to reuse your racks and electrical installation, you should be able to be in the black in no time.

Sort of, and sort of not.

I am already "in the black" as it were since the system has already provided more value than it cost to install and maintain. So no worries there. But 325W panels are physically larger than 185W panels (not twice as large but still) so replacing the 28 panels on the roof with them would get my raw input up to 9.1kW but I'd need roughly 33% more surface area. That would add another strut on the mounting system and the top row of panels would extend beyond the peak of the roof (now disallowed by the building code). However, it would be "easy" get get 16 in there, which would be an equivalent raw foot print (5,200 watts)

Re: The price of solar power just fell 50% in 16 months

#422

Post by mikestew »

MichaelBurge wrote: post #61
mikestew wrote: post #42

Earlier quoted context omitted.

Care to explain? Because unless you're arguing along the lines of something something farm subsidies, I'm pretty sure you're wrong.

Usually farmland is zoned only for farmland use. You need an inspector to approve any building, and it must be related to farm use. In Oregon, here's the list of allowed uses of farmland: http://www.oregonlaws.org/ors/215.213 You could probably install solar panels for the purpose of powering your house and farm equipment, but you couldn't install solar panels everywhere and sell the electricity to the public: "Utili…

Thanks. It's been so long since I've lived in farm land that I forgot about "let's not turn farm land into subdivisions" zoning.

Re: The price of solar power just fell 50% in 16 months

#423

Post by usrusr »

usrusr wrote: post #393
bigger_cheese wrote: post #373

Earlier quoted context omitted.

I recall reading a while ago about using molten salt storage at large solar concentrators. Did this ever take off? The theory was you generate excess power during the day and you can use this excess to heat the salt solution which then release thermal energy during the night. Does anyone know more about this? Is this able to meet baseload demand?

Thermodispatchable solar, even if the word does not exist, has been a recurring theme. But installations seem to be one-offs that are rarely followed by a direct successor project with the ever dropping price of photovoltaic. In areas with cold weather, one of the most interesting (and underrated, due to only making fossil use more adaptable) developments is the installation of huge, insulated hot water tanks, to mak…

Sorry for the late correction: in the last sentence I meant cogeneration plants, not combined cycle. (which would typically not be combined cycle, because the heat not captured for electricity is not wasted in cogeneration)

Re: The price of solar power just fell 50% in 16 months

#424

Post by toomuchtodo »

harryh wrote: post #417
toomuchtodo wrote: post #366

Earlier quoted context omitted.

Just because the S&P has seen such returns over the last 40 years, doesn't mean you'll see those returns over the next 40 years. The US economy is aging out, has stagnant wages, etc.

Also we saw a huge drop in interest rates that won't happen again over the next 40 years.

Going to disagree with you here. I think it'll be impossible to raise interest rates much further without causing economic damage. See negative interest rate policies in Japan and Europe, and close to zero rates still in the US.

Re: The price of solar power just fell 50% in 16 months

#426

Post by yourapostasy »

lisivka wrote: post #303
dragontamer wrote: post #138

Earlier quoted context omitted.

Unlikely. Solar Panels don't replace all of your electricity costs. Naturally, you'll still run your refrigerator at night, right? And during the day, when you have peak-solar energy, you'll be at work and won't be taking advantage of it. You'll recoup some of the costs through net-metering, but you usually buy back at wholesale prices and not at retail prices. Finally, I'd expect utility companies to change their pr…

If you have space and money, you can create huge "gravity lamp" to store energy: lift up something massive using solar energy and electric motor, then it will slowly generate electricity at night using same motor as generator. Or you can use "molecular spring", which is very compact, for same purpose.

How close are we to actually manufacturing molecular springs? My understanding is our materials science and engineering is not up for making macroscopic molecular springs yet, and what I can Google up seems to indicate we nowhere near macroscopic scale springs.

Re: The price of solar power just fell 50% in 16 months

#427

Post by harryh »

toomuchtodo wrote: post #424
harryh wrote: post #417

Earlier quoted context omitted.

Also we saw a huge drop in interest rates that won't happen again over the next 40 years.

Going to disagree with you here. I think it'll be impossible to raise interest rates much further without causing economic damage. See negative interest rate policies in Japan and Europe, and close to zero rates still in the US.

I 100% agree with you about the difficulty of raising rates. But I don't think they'll continue to drop like they have over the past 30 years.

I have a hard time imagining a world of -5% to -10% rates!

Re: The price of solar power just fell 50% in 16 months

#428

Post by yourapostasy »

peppaz wrote: post #102
jmcgough wrote: post #80

Earlier quoted context omitted.

My gf is an electromechanical engineer at a solar power startup (and obviously supportive of solar power initiatives). Just asked her about this, and she said that: 1) the electrical grid wasn't designed for transferring power this way, and it can damage the grid 2) because solar power isn't a constant power source (say, a cloud blocks the sun for a minute), power companies need to keep power available for someone wh…

Good thing Tesla is making huge battery packs for our homes so we can ditch the grid entirely.

I wish more engineering work would be performed on different chemistries in redox flow batteries. I'd rather spend the capital up front for a much longer-lasting redox flow battery (they are way, way bigger than other batteries, but that's not a concern when you are working with building sites and are willing to put the battery bank underground) than a lithium battery.

Re: The price of solar power just fell 50% in 16 months

#429

Post by yourapostasy »

efields wrote: post #149

Curious… does it ever get low enough that electric heat becomes desirable? We moved into a place that had electric heat on the ground floor, ran it the first cold month, saw the bill, then made it a purely "on demand" heating solution. The rest of the apartment was gas forced hot air, which was on a normal schedule. To heat a whole home in a Boston winter seems like it might cost $1000 or so. Is it reasonable to expe…

In places that cold, the gist I get from reading about heating/cooling is you are better off bringing down your air changes per hour [1] (a function of how airtight your residence is), then insulating (including nearly eliminating all thermal bridges), then passive heating, then active heating, in that order.

I've read field reports of people with measured air changes per hour that meet the PassivHaus standard, with 60+ R-value insulation (again, PassivHaus standard), isolated the foundation with insulation, consolidated all possible thermal bridges into a single, small conduit, and heat input from passive solar concentrator, enjoying NE US winters with only double-digit gas/electric bills for active heating in the worst months. With a rocket stove, most could avoid even that nominal amount and take care of burning their brush pile at the same time.

The insulation will cost you upfront, though. Corning FOAMGLAS is my favorite at the moment because it doesn't involve greenhouse gases during its manufacture, but it and its installation can easily add 15% to your overall build cost. Use EPS (looks like giant styrofoam blocks roughly the size of 3 feet thick doorways, wish all the styrofoam we throw away into landfills could somehow be recycled into these) instead, and you still are looking at around a 10% upcharge. Granted, you're hovering around 70'ish R-value with that much, and thermal changes take a much longer time compared to conventional residences.

[1] https://en.wikipedia.org/wiki/Air_changes_per_hour

Re: The price of solar power just fell 50% in 16 months

#430

Post by toomuchtodo »

harryh wrote: post #427
toomuchtodo wrote: post #424

Earlier quoted context omitted.

Going to disagree with you here. I think it'll be impossible to raise interest rates much further without causing economic damage. See negative interest rate policies in Japan and Europe, and close to zero rates still in the US.

I 100% agree with you about the difficulty of raising rates. But I don't think they'll continue to drop like they have over the past 30 years. I have a hard time imagining a world of -5% to -10% rates!

> I have a hard time imagining a world of -5% to -10% rates!

A year ago I would've agreed with you, but with the ECB at -.04 and Japan at -0.02, I believe it more likely than previously.

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