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Daniel_Burfoot comments on Stupid Questions May 2015 - Less Wrong
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Why isn't sea-based solar power more of a thing? Say you have a big barge of solar panels, soaking up energy and storing it in batteries. Then once in a while a transport ship takes the full batteries to land to be used, and returns some empty batteries to the barge.
Storing energy in batteries is a net loss. Even at retail prices, the total electricity stored in the battery over its entire lifespan will not pay for the upfront cost of the battery. Even if the electricity were free.
Batteries are a generic technology. If they were useful for grid energy storage, they would be used for it already, not just useful for exotic future energy generation methods. In particular, wind power is terrible because it is erratic (and badly timed where it has trends) and would be the existing technology to most benefit from improved storage.
That hasn't stooped Musk planning to couple batteries with solar power.
The question was about the present, not the future. Maybe Musk will be able to lower the price of batteries in the future, but his current price is pretty much what I said. What he has achieved is to make lithium batteries about as cheap as existing consumer batteries, not even as cheap as the sodium-sulfur batteries that power companies use at the moment, let alone what is necessary for widespread deployment.
Musk is claiming orders of magnitude reduction in cost.
*Orders of magnitude"?? which means at least a hundred times? Methinks you're mistaken.
Meaning more than 1 order of magnitude, which necessitates the plural.
I think Musk speaks of roughly 8% improvement in battery cost per year. At that pace it takes three decades to get them 1 order of magnitude cheaper.
The prices Musk is quoting is a full 10x less than analyst estimates of what those batteries should cost. Tesla would not offer the product unless they felt they could make a sufficient profit, so their costs must be lower still. That is what I was talking about.
Can we see some links? These claims don't make sense to me. Musk didn't achieve any breakthroughs in battery technology.
It's improvements in manufacturing, not underlying technology, that Musk is claiming is responsible for the decreased costs. My analyst source was not online so I can't easily provide a link..
I imagine in most places it'd be cheaper to buy an acre of land on the outskirts of town, or to rent an acre of otherwise unused rooftop from your local big-box store, than to build a barge with equivalent deck area; Wikipedia informs me for example that a Nimitz-class aircraft carrier has a deck area of only about six acres.
Land-based solutions also let you plug directly into the grid rather than futzing with also-expensive battery storage.
Opportunity cost. 15 years later that is suburbia. (And the current suburbia is a slum. Never buy a house unless you are 95% sure this won't happen!)
That should already be priced into the present value of the property. On the other hand, if you can see the land value going up, that'll have an effect on expected property tax rates; but that should be a relatively minor line item. And not all cities are expanding in that way; if you pulled this right now in the States, in fact, there's a good chance that the cheap land you're picking up would once have been intended for a subdivision before the bottom fell out of the housing market.
Meanwhile, the barge full of solar panels will probably have needed hull repairs at least once in those fifteen years, and its batteries (assuming lead-acid, which give the best energy-to-price ratio with current technology, and assuming a cycle per day) will have been replaced two or three times.
If you think that the land will be more valuable in a few decades, that is an argument for wanting to own it. If your solar adventures can pay for just the interest on what you bought the land for, then you have the upside of land speculation without the downside.
Saltwater causes huge amounts of wear and tear, and weather fluctuations can completely destroy your ship. What you're basically doing is paying a ton more money per square foot of solar panel space than you would be on land, because every bit of that space needs to be attached to a ship.
For the usual reason -- it's not cost-efficient, and in this case ridiculously so.
Solar panels don't take that much space. Elon Musk has a nice graphic in yesterday's presentation of his new battery: https://youtu.be/yKORsrlN-2k?t=3m32s The amount of space required for enough solar panels to produce enough energy for the whole world is tiny.
Yep... take a look at this, one of the largest solar PV plants in the world:
https://www.google.com/maps/search/35.383333,-120.066667/@35.383333,-120.066667,12z/data=!3m1!1e3!4m2!2m1!4b1?hl=en&dg=dbrw&newdg=1
It supplies but ~1% of electric power for Los Angeles... However zoom until you can see Los Angeles itself, a little to the southeast.
Batteries? Batteries?
There's the problem.