
How cheap does solar power need to get before it takes over the world? - jseliger
http://www.vox.com/2016/4/18/11415510/solar-power-costs-innovation
======
martinald
I think the issue is that OK, say we managed to get to 100% electricity being
solar when the sun is shining.

You'd still have the time the sun is not shining, which would likely be more
expensive than before (a gas powered plant would only be running half the time
- effectively doubling its capital/construction cost per kWh).

So you'd definitely have an improvement on some levels but I'm not sure that
would really help that much.

The real big breakthrough would be somme big improvement on storage. I'm not
convinced this will happen quickly (at least not in anyway similar to the
declining cost of PV panels). The consumer electronics industry has been
paying $$$ for decades for better batteries/battery r&d and has seen pretty
poor gains.

I think Tesla and the electric car manufacturers will definitely rapidly get
the price down by say 30% because of economies of scale but will then hit a
brick wall as more of the cost becomes raw materials, transport, etc which
will set a floor on the cost of batteries.

Happy to be proved wrong though :)

~~~
WaylonKenning
Everyone seems a bit obsessed by batteries as a storage method, when we have
more traditional methods:

\- Pumped-storage hydroelectricity - [https://en.wikipedia.org/wiki/Pumped-
storage_hydroelectricit...](https://en.wikipedia.org/wiki/Pumped-
storage_hydroelectricity). Sure it's not suitable everywhere.

\- There's always Molten Salt as well -
[http://www.solarreserve.com/en/technology/molten-salt-
energy...](http://www.solarreserve.com/en/technology/molten-salt-energy-
storage).

Also, solar isn't the be all and end all of renewable energy generation. Wind,
Solar, Hydro, and Geothermal all have different strengths and weaknesses, and
flexibility of generation is important.

But above all, I think security of supply is probably the number 1 requirement
(unless you're a big fan of load shedding -
[https://en.wikipedia.org/wiki/Rolling_blackout](https://en.wikipedia.org/wiki/Rolling_blackout)),
and therefore, we'll still need energy sources that are reliable.

I predict a move away from coal towards natural gas. Sure it's not perfect,
but it's not the worst either.

~~~
Gustomaximus
Similar to pumped water storage I wonder if we could do a household version
with weight. Something like the gravity light (gravitylight.org) but on larger
scale. I wonder if we could see a resurgence of chimneys on houses except now
instead of letting smoke out they contain a XY ton weights that gets pushed up
by excess solar capacity during the day, and then drops by evening powering
the house.

I have no idea if that's realistic. Does someone know what the weight/distance
to power output would be limited at...

~~~
swombat
A much better and denser option for storing energy mechanically is flywheels.
I haven't researched what happened to this option since but when I was looking
into it 15 years ago it seemed like a good option that needed more R&D into
frictionless axles and vacuum chambers.

~~~
dredmorbius
Excellent rapid response, second only to capacitors. But pretty poor
densities, and hugely significant engineering challenges.

Flywheels that don't become fly-apart wheels is one problem.

Containment of fly-apart wheels another. Buried concrete pipes are usually
what you're looking at. You need _mass_ to contain these things.

The per-kg energy densities just aren't all that high. If you want reactive
load to soak up very short-term demand / supply fluctuations, you can get
that. And you've got crazy charge-discharge cycles.

Bearings are mostly solvable with magnets, as I understand. But you still lose
a given percentage of storage over short time -- ~1% per hour or so, within a
few powers of 2. Enough that long-term storage isn't viable.

And the thing that really screws you over is that the Earth moves. Geometric
precession of your flywheel is something you've got to deal with.

There's a place, but I don't think it's large-scale, long-term grid storage.

------
Animats
Installation has to get much cheaper. Installation is now more than the cost
of the panels for most single family home installations. Home roofs are poor
support surfaces.

Panels which _are_ the roof have potential. The "solar shingle" vendors are
making progress.[1]

[1]
[http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_0944/...](http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_0944/0901b80380944dfa.pdf)

~~~
Gravityloss
I'm amazed that they aren't integrated much more. Roof materials already have
a cost. For example, one could create big roof tiles that are mostly solar
panel. Edges have to overlap so it's a good idea to not have the panel extend
there. One could lay them like other traditional flat panels, in an
overlapping fashion. Since the actual panel is so cheap, that shouldn't bring
up the cost of the roof panel much.

The wiring can be on the underside and can be then connected after
construction. (By some other team than roof constructors). After 30 years,
they can be swapped. There might be some new technology then.

Another alternative would be roll-out plastic panels on ordinary roof
materials. External wiring.

Everything should be laughably easy if you don't need to deal with snow and
ice. They are a whole new design problem. To best limit CO2 emissions, the
manufactured panels should be installed in places with best production
ability, so freezing tends not to be among the first problems.

------
paulsutter
Storage is the /only/ way for solar to provide baseload power. Pumped water
storage is vastly cheaper than batteries, and a better example of grid scale
storage today. I should add that battery prices are coming down as volume
increases (manufacturing learning curve), but not as fast as photovoltaic
cells.

Elon Musk's goal with tesla is to boost battery production volume
significantly to reduce the cost of batteries.

This is a really low quality article.

~~~
eru
Pumped water storage is awesome where you have the geography to support it.

Alas, that's not everywhere.

~~~
ISL
Furthermore, mountains, canyons, and valleys are beautiful and valuable as
they are.

~~~
tonyedgecombe
That hasn't stopped us digging them up for coal though.

------
coredog64
There's another large effect that is left out of this story. As solar gets
cheaper, and as we get more of it, it reduces the marginal pressure on fossil
fuel production. That, in turn, makes fossil fuels cheaper and forces solar to
get cheaper still to compete.

~~~
dredmorbius
Solar doesn't much compete with petroleum. Its main effect is to reduce prices
for coal. You'd expect that this might start to affect the profitability of
coal companies eventualy....

For solar to affect _petroleum_ , whose primary use is _transport_ , we'll
need to solve the storage problem. _Tesla notwithstanding that has not
happened._ Electric vehicle sales were 0.66% of _unit_ auto sales in 2015, and
actually represented a sharp numeric _decrease_ from 2014.

(The _dollar_ volume is higher given the higher price of electrics, but it's
unit sales you want to watch.)

~~~
pdonis
_> For solar to affect petroleum, whose primary use is transport, we'll need
to solve the storage problem._

The obvious solution here is solar-generated biofuel, such as the algae
projects now being investigated.

~~~
ThrustVectoring
That's not necessarily the correct solution - there's competing chemical
processes like Fischer-Tropsch.

~~~
dredmorbius
Once you've got electricity, FT appears to win. Though again, there's the ages
of investigation without large-scale application, on a power-to-fuels basis.

Sasol, the South African energy company, did run commercial coal-to-liquids
via Fischer-Tropsch, since the 1950s, and I believe may still do so. The US
tried but ran into technical issues.

------
omginternets
My biggest concern with solar power (which, by the way, may be based on
outdated information) is that the production of photovoltaic cells produce
more greenhouse gasses than will be spared in the cell's operational lifetime.

To ask an actual question: is this still the case? (Was it ever?)

~~~
api
This is directly tied to EROEI. If the EROEI of a cell is greater than 1X, it
will produce more energy that it took to manufacture it. In that case it's
net-negative -- over time it replaces fossil fuels in a net sense.

Lately I've read EROEI numbers for solar PV from 10-15X.

So no, this is not true, and likely has not been true for a long time. It
might have been true back when PV was kind of a lab curiosity and niche item.

~~~
Gibbon1
The interesting thing is the EROEI (energy returned on energy invested) for
oil and gas has been falling for a century. I remember reading somewhere a
claim that historical EROEI for crude oil.

    
    
        Year   EROEI
        1920     125
        1970      30 
        2010      15
    

Things like tar sands are less than 10.

~~~
Retric
Some tar sands are below 1 once you include refining and transportation.

~~~
Gibbon1
Everything I've read about tar sands leads me to propose, 'yeah lets just not
do that'

------
jimrandomh
There's an economics caveat to interpreting solar prices, which I think may
have put a lot of people on the wrong track.

Suppose solar panels were priced such that, after accounting for installation
costs and subsidies and everything else, solar was much cheaper than grid
power and paid off quickly. Then pretty much everyone would want one, and the
manufacturer would have a huge backorder. So the manufacturers wouldn't do
that; instead, they'd price the panels a little higher, sell everything they
could produce but not have the backorder, and invest the extra money into
expanding their production capacity.

I think this is where we're currently at; solar power is in fact cheaper than
grid power, it's just priced to support investment into expanding the
manufacturing/installation capacity to properly take over.

~~~
losvedir
> _Suppose solar panels were priced such that, after accounting for
> installation costs and subsidies and everything else, solar was much cheaper
> than grid power and paid off quickly. Then pretty much everyone would want
> one, and the manufacturer would have a huge backorder. So the manufacturers
> wouldn 't do that; instead, they'd price the panels a little higher, sell
> everything they could produce but not have the backorder, and invest the
> extra money into expanding their production capacity._

That's what finance is for. I assume if this were actually the case, wouldn't
the manufacturers _take_ the backorders and separately raise money for
expanding their production capacity? I don't buy it.

~~~
eru
Manufacturers will sell as expensive as they can get away with. Of course,
there's decent competition in this market to counteract that.

jimrandomh's scheme would require a significant amount of collusion between
all major producers.

~~~
jimrandomh
No, it's just that building a solar-panel factory is really expensive and has
a longer lead time than customers will wait.

~~~
eru
Isn't that the same with almost any kind of factory? If I was in the market
for a car or computer, I wouldn't want to wait for a new factory to be build,
either.

Is that anything special about the solar-panel industry?

------
ZeroGravitas
It says a lot about the progress of solar if the big worry is that it won't
provide 100% of all energy by itself.

Even cheaper solar would be nice but I'm not sure why it would be better than
a radical battery breakthrough or some cheap and cheerful fusion thing or some
mix of different solutions.

~~~
Gibbon1
If you run the numbers pumped heat storage can likely do the job of time
shifting electric power from daylight hours to night time.

The pricing structure will flip though, electricity at night costing probably
2-3 times peek daytime rates. One would expect industrial users would adjust
and avoid using power at night[1]. That would reduce demand.

[1] Think of a mini-mill (steel) that currently runs its electric furnaces at
night when rates are cheap. If rates are cheaper in the day they'll switch to
daytime operation.

~~~
spacecowboy_lon
I thought blast furnaces ran 24/7 and if they shut down you need to
effectively rebuild parts of them.

~~~
Gibbon1
You are correct integrated mills use blast furnaces and thus can't stop.
However Mini mills are secondary producers. They process scrap into finished
steel. Since they use electric furnaces they can start and stop production.

------
jwingy
A significant impediment is handling peak usage power. Maybe solar can provide
most of our energy needs, but for those times where peak power is needed, it's
probably more sensible to take a more balanced/mixed approach.

*edit looks like the article has a convenient link to another article talking about this exact problem:

[http://www.vox.com/2016/2/12/10970858/flattening-duck-
curve-...](http://www.vox.com/2016/2/12/10970858/flattening-duck-curve-
renewable-energy)

------
InclinedPlane
People are comparing the wrong things when it comes to solar, and that leads
to solar not showing how expensive it truly is.

For one, there is nowhere where solar is the baseload power, because it can't
be, so it gets a bit of a "free rider" advantage. For another, solar plants
depreciate like any other, but those costs aren't really factored in to a lot
of solar power costs yet.

We'd need to build out a significant amount of energy storage capacity and
change a lot of the grid as well in order to fully adopt solar as a baseload
power source. And that would increase its cost by non-trivial factors. Would
it still be worthwhile? Maybe?

------
Osiris30
This is a poorly researched article with many inaccuracies.

(1) Utility Scale Solar is already less <$1/W installed in India, and heading
for sub $1.5/W in US.

(2) The price of Solar PV panels is already at $0.40/W. US-based $FSLR is has
a roadmap to get to $0.25/W by _2019_. In addition PV efficiency is increasing
by 10% yoy. This is just from purely riding the 'industrial learning curve'.
See [1].

(3) "Value deflation" is a policy issue that has a simple policy solution. As
a tech that produces an intermittent product, but has high fixed-costs but
zero-marginal costs - solar (like wind) should be financed (and paid for) via
a fixed tariff (feed-in tariff or FiT). See [2]. This is how Solar is financed
in the rest of the world outside the US. If 'value deflation actually became
an issue - then my guess is that regulators in the US would step in (but one
can never say with US regulators who tend to get captured by various lobby
groups).

(4) Solar will account for 30% of all new capacity power additions going
forward globally. This is happening - now. There is over 100,000MW installed
globally already.

In addition - every time solar or wind comes up for discussion on HN or
elsewhere, the same misconceptions and confusions about baseload,
intermittency and costs arise.

To summarise the counter-points again:

(1) Renewables does not need to be base-load or compared to 'base-load'.
'Base-load' is spectrum not a point. See [3]

(2) There is a difference between intermittent and 'unplanned'. Planned vs
unplanned is the main issue. Even nuclear has unplanned shut-downs - no tech
has a 100% 'capacity factory' running 24/7 365 days. see [4]

(3) Renewables can get to 60-80% penetration via:

(a) increasing efficiencies (happening now)

(b) increasing energy storage efficiencies with declining prices (happening
now)

(c) geographical grid-integration (happening slowly)

(d) more flexible software-led demand-side and supply-side management
(happening). See [5]

[1] [http://www.bloomberg.com/news/articles/2016-04-14/first-
sola...](http://www.bloomberg.com/news/articles/2016-04-14/first-solar-making-
panels-more-cheaply-than-china-s-top-supplier)

[2] [http://www.greentechmedia.com/articles/read/3-ways-
renewable...](http://www.greentechmedia.com/articles/read/3-ways-renewable-
energy-can-grow-in-a-21st-century-grid)

[3] [http://cleantechnica.com/2016/03/02/base-load-power-is-a-
myt...](http://cleantechnica.com/2016/03/02/base-load-power-is-a-myth-used-
for-defending-the-fossil-fuel-industry/)

and [http://cleantechnica.com/2014/08/08/rmi-blows-lid-
baseload-p...](http://cleantechnica.com/2014/08/08/rmi-blows-lid-baseload-
power-myth-video/) [short video in article]

[4] [http://www.energypost.eu/dispelling-nuclear-baseload-myth-
no...](http://www.energypost.eu/dispelling-nuclear-baseload-myth-nothing-
renewables-cant-better/)

[5] Links on renewable energy penetration potential

\- NREL Analysis of how to achieve high-penetration renewables in US
[http://www.nrel.gov/analysis/re_futures/](http://www.nrel.gov/analysis/re_futures/)

\- Ramez Naam [http://rameznaam.com/2016/01/31/how-far-can-renewables-go-
pr...](http://rameznaam.com/2016/01/31/how-far-can-renewables-go-pretty-darn-
far/)

\- California [http://ww2.kqed.org/science/2016/04/04/what-will-
california-...](http://ww2.kqed.org/science/2016/04/04/what-will-california-
do-with-too-much-solar/)

------
alexc05
I think the biggest impediment to widescale solar adoption is legeslative.

If you follow hackernews, you'll regularly see articles about places like
Florida (and possibly Nevada if memory serves) where solar could easily power
homes, but disingenuous legislative instruments and manipulativly worded
ballot initiatives are housed to effectively block solar adoption.

This is an example of the top result in Google news
[http://www.miamiherald.com/news/local/news-columns-
blogs/fre...](http://www.miamiherald.com/news/local/news-columns-blogs/fred-
grimm/article69905142.html)

Not the greatest example I've seen, but again, if you follow HN you've seen
variations on this story dozens of times.

Lobbyists protect big utilities instead of facilitate solar.

It's tragic to think how much further along we could be.

~~~
kitsunesoba
Another example of what you mentioned:
[http://arstechnica.com/science/2015/12/north-carolina-
citize...](http://arstechnica.com/science/2015/12/north-carolina-citizenry-
defeat-pernicious-big-solar-plan-to-suck-up-the-sun/)

~~~
alexc05
That reads like satire.

------
Spooky23
A: It needs to get efficient enough and paired with storage to survive the
regulatory kickback.

Power companies and non-solar ratepayers will get increasingly unhappy with
net metering customers. That joyride will end.

~~~
mgnacl
Next up: taxes on solar cells?

~~~
Qwertious
Hopefully not before taxes on greenhouse gas emissions.

------
alok-g
>> 25 cents per watt by 2050 — down from around $3 per watt today

Can I trust a report that does not even have the units right?! Price should be
proportional to energy (i.e., Joules or Watt-seconds) not power (Watts).

~~~
smac8
Huh? What's wrong with measuring in price/watt? Price/watt is actually the
standard for comparing electricity generation due to not having to create
arbitrary units of time to compare with

