
Rooftop solar is now cheaper than the grid in 42 American cities - diafygi
http://www.utilitydive.com/news/rooftop-solar-is-now-cheaper-than-the-grid-in-42-american-cities/352799/
======
chrisBob
Solar is cheaper because of you suckers that don't have panels. There is a
good government subsidy up front which people know about but the real secret
is green energy credits. The green energy credits that the power companies are
required to buy from home owners are worth at least as much as the
electricity. If it wernt for these incentives then more efficient things like
solar hot water would win out, but instead I put a PV array on my roof. When I
got my panels the anticipated payback period was just 5 years in
Massachusetts.

~~~
brc
I'd like someone here to mount a moral case for why driving up the price for
regular users of power to subsidise solar panels is acceptable?

Would anyone accept that increasing gas taxes to give Tesla owners a cash
payment is an ethical proposition?

The people most affected by increased electricity prices are the poor. These
are the people most unlikely to have solar panels.

I'm all for allowing people to put their money into whatever they want. I am
against subsidies for solar or any other energy, when those subsidies are paid
for by the other users. It is very unfair on low income households.

~~~
crdoconnor
>The people most affected by increased electricity prices are the poor.

If you want to see where solar panels have _really_ taken off, you should pay
a visit to the third world where the US government isn't subsidizing them.

~~~
bsilvereagle
Demand for solar panels may be higher in some of the third world communities
since it is one of the few sources of electricity; there aren't too many grids
to connect to.

~~~
crdoconnor
Point being that it's one of the few power sources that ARE available to poor
people, especially poor people who are not on the grid.

It's pretty much just that and diesel generator, in fact.

------
sterlingross
It is interesting that Hawaii isn't at all mentioned, considering that
electricity is 30 to 45 cents per kWh and the electric company limits the
number of grid-tied solar installations per neighborhood.

No where in the US is solar more cost effective than here, and the electric
company is restricting homes from installing solar. The alternative is to go
fully off-grid with battery arrays, but that is more than most people can
handle.

~~~
reustle
Not that they have to go fully off the grid all the time, just when they want
to use solar.

------
ctdonath
Packaged right, this could give electric cars a big push. A Nissan Leaf sports
a 26kW/h battery; a rough guess puts the cost of a home solar charging system
dedicated to the car at about half the price of that car. For context:
charging it from 110v is like running a moderate hairdryer for the charging
period (up to 21 hours for a full charge, which is unlikely needed).

Packaged right, this could get a big push for dedicated A/C operation. Home
cooling being most needed when sunlight is strongest, solar could
significantly reduce or outright replace the considerable power needed for
cooling - and do it with a minimum, if any, battery buffer.

~~~
lotharbot
One of the most important attributes of solar power is that it produces peak
power during peak usage times -- the middle of the day, when people are
running the air conditioning, businesses are open, computers are on, and so
on. With a grid designed to provide continuous power at off-peak levels and
solar filling in for some of the shortfall at peak levels, that allows a
reduced number of peak-only reactors.

~~~
floatrock
An earlier post linked to a California operator's report:
[http://www.caiso.com/documents/flexibleresourceshelprenewabl...](http://www.caiso.com/documents/flexibleresourceshelprenewables_fastfacts.pdf)

...that shows peak load is actually 6pm-9pm.

~~~
lotharbot
From the report, just before the graph -- _" The net load is calculated by
taking the forecasted load and subtracting the forecasted electricity
production from variable generation resources, wind and solar"_

In other words, _after_ projected solar generation is accounted for, the peak
remaining power need for the specific grid in question is at 6-9 pm. (Other
parts of the paper describe the "belly of the duck" being caused by "supply
from solar generation resources" \-- reducing the need for the rest of the
grid to supply daytime power.) The paper in question may also be describing a
residential-only grid.

Residential peak usage is from 6-9 pm, but when commercial/industrial power
usage is accounted for, the peak is more like 2-6 pm. See the chart at around
the 2/3 point of
[http://www.mpoweruk.com/electricity_demand.htm](http://www.mpoweruk.com/electricity_demand.htm)
. Also note that residential demand may peak earlier on super hot / high sun
days, as shown at [http://blog.opower.com/2012/09/hot-and-heavy-energy-usage-
ho...](http://blog.opower.com/2012/09/hot-and-heavy-energy-usage-how-the-
demand-and-price-for-electricity-skyrocketed-on-a-100-day/) , and tends to
peak later in the winter due to electric heaters kicking on in the evenings
([https://www.gov.uk/government/uploads/system/uploads/attachm...](https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/295225/Seasonal_variations_in_electricity_demand.pdf)
).

Of course, I'm glossing over a lot of complexity here. Each region is going to
be different depending on a lot of factors. But in general, having a decent
amount of solar power generation can help meet demand at the peak of
commercial/industrial demand.

~~~
floatrock
ah, thanks for explaining the details!

------
jksmith
This is Nick Carr's "The Big Switch" in reverse as I predicted years ago. It
used to be the case that centralized distribution was cheaper, than, as
described in the book, every factory having its own water wheel power plant.
The technology is getting good enough now though that each endpoint can be
self-sustaining, and even provide services - just as the internet should be -
every endpoint providing and consuming. This trend will be massively
disruptive, and expect centralized services to do just about anything they
have to, to protect their dinosaur business model.

------
ChuckMcM
Having had solar panels on my roof for nearly 15 years now I can tell you that
the 25 year warranty is optimistic at best. Our panel maker, Sharp, cannot
replace panels under warranty (180W) because they no longer make them and have
no replacement stock. We discovered this when we tried to exercise the
warranty on a panel that failed.

~~~
djrogers
As with any warrantied product there are likely provisions for that in the
warranty - you should either get cash value compensation from them or an
equivalent modern panel.

Just because your first attempt resulted in a 'no' doesn't mean you are
without recourse...

~~~
jms
You have to be careful to match the panels though - slightly different specs
can cause problems for your setup. The same goes for batteries - mixing new
and old will degrade your new batteries. (Lead acid batteries at least)

~~~
reustle
Sure, but in the long run it is far better to take the new panels and tweak
your system.

------
willholloway
I believe this is the development that will let us avoid run away catastrophic
warming.

In order to avoid catastrophic warming we have to reduce emissions by
something like 80% by 2050. That seemed a pipe dream before cheap solar
panels, now it feels inevitable to me.

70% of the power generated by a coal plant is wasted in the transmission line
before it reaches your home, distributed generation has this huge efficiency
benefit going for it.

The Chinese solar industry has gotten the price down below .50 per watt this
year, in a few years it won't make sense to add carbon-sourced marginal
capacity. Almost all of new demand can be satisfied with solar pv. We will
have to solve the energy storage problem, and I think we will. Superconducting
magnetic energy storage gives me hope.

[https://en.wikipedia.org/wiki/Superconducting_magnetic_energ...](https://en.wikipedia.org/wiki/Superconducting_magnetic_energy_storage)

~~~
dragontamer
Solar is only a piece of the puzzle.

The main issue is that in the US, we use up twice the amount of electricity in
the day than we do at night. Spinning up and spinning down the turbines /
generators causes enormous amounts of waste.

Green energy can't "spin up" and "spin down" like coal, oil, or nuclear.

[http://www.forbes.com/sites/quora/2013/10/07/what-is-the-
hol...](http://www.forbes.com/sites/quora/2013/10/07/what-is-the-holding-
capacity-of-the-us-power-grid/)

Some large percentage of our grid (in particular, the "dynamic" portion) will
have to be Coal, Oil, Gas, or Nuclear. The Gigawatts of energy differential
between day-usage and night-usage foregoes any hope of storing that energy.

~~~
jgamman
here in NZ (no subsidies in our electricity market) we are about 70% renewable
via hydro and geothermal. we run a parallel 'reserves' market (everyone does,
it's there to take up the slack of a plant tripping out). typically a hydro
plant will run 'tail depressed' which means it's not as efficient as it could
be but can scale up within 7 seconds (there's another 7 minute reserve
market). prices adjust, people get paid to conserve fuel (water) but it's
availalbe when needed. fast start gas turbines are also common but these tend
to be at the 10-15 min mark (which is still blistering!). tl;dr 'green' energy
_systems_ spin up and spin down just like the regular kind...

~~~
dragontamer
Hydro is one of the best "green" energy sources, and we definitely need more
of it.

The downside is that rivers of the size that can power a Hydro-dam are
relatively rare, and ecological issues (flood zones, and whatnot) need to be
taken into account.

So I'll amend my original post with Coal, Oil, Nuclear or Hydro.

Solar and Wind are absolutely terrible at "spin up" and "spin down". So other
sources are needed to cover the differential.

------
JamesBarney
The report estimates an inflation rate of 2.7% but the core inflation rate is
currently much closer to 1.7%. They therefor underestimated the cost of the
loan which will make solar panels more expensive.

~~~
cma
But core inflation excludes energy costs..

~~~
dragontamer
Energy costs are much lower today. Have you noticed the $2.00 gas signs?

~~~
toomuchtodo
You should not confuse a temporary turf war between tight oil drillers and the
Sauds with long-term energy cost inflation.

$2/gal isn't sustainable for anyone except consumers, and it won't last more
than a few months.

~~~
tdaltonc
Oil futures for 2020 are trading at $67/barrel. If you think that's low, maybe
you should buy some. If you think that's right, maybe this will last more then
a few months.

~~~
toomuchtodo
I stick to equities and food commodities for trading. Trading oil at my scale
(<$10MM/year volume) is like walking into a Mos Eisley cantina inebriated and
with cash hanging out of your wallet. I'll make you a Long Bet [1] though if
you're interested (a beer of your choice if you're right).

[1] [http://longbets.org/](http://longbets.org/)

------
jacquesm
Does this factor in the huge tariffs on panels made in Asia?:

[http://www.nytimes.com/2014/12/17/business/energy-
environmen...](http://www.nytimes.com/2014/12/17/business/energy-
environment/-us-imposes-steep-tariffs-on-chinese-solar-panels.html)

If it doesn't then the picture won't be as nice, but if it does then imagine
what the situation _could_ be like.

~~~
floatrock
> but if it does then imagine what the situation could be like.

Depends on how much of the "asian manufacturers are artificially deflating
costs through government subsidies in order to buy up global market share,
therefore we need tariffs to level the playing field for domestic
manufacturers" argument you buy.

~~~
jacquesm
Actually, none. If they can provide solar panels for free for the rest of the
world let them. That's a subsidy of other governments with as ultimate
beneficiary local citizens.

~~~
floatrock
> with as ultimate beneficiary local citizens.

Yep. See the Thiel essay about how the point of business is to acquire a
monopoly, at which point you kick back and let the cash flow come in because
there's no competition: [http://www.wsj.com/articles/peter-thiel-competition-
is-for-l...](http://www.wsj.com/articles/peter-thiel-competition-is-for-
losers-1410535536)

One theoretical use of tariffs is to sacrifice economic efficiency in the
short run to maintain healthy competition in the long run. Don't get me wrong
-- tariffs also serve many more interests (protectionism, regulatory capture,
etc.), but the there still is a short-term/long-term difference I think you're
discounting.

------
thyrsus
I've got a mix of evergreen and deciduous 30+ meter trees on my lot that
produce (eyeballed) about 25% roof shade in winter and about 50% roof shade in
summer. For aesthetic reasons, the trees are non-negotiable: they stay (and
neighbors' trees provide morning and evening shade; equally non-negotiable).
It appears that kills the deal; the linked PDF says my region could expect
about $60 worth of power a month without the trees, but with them I'm guessing
it would be at best $40 a month, which isn't going to cover a 5% interest
cost.

------
frankosaurus
Solar panels would be fantastic at my townhouse in San Jose, where the sun
shines 300 days a year.

Unfortunately, my HOA bans rooftop solar panels.

~~~
3am
You may have already done so, but you may want to see if that restriction is
in conflict with CA law: [http://solar-
rights.com/files/THE_CALIFORNIA_SOLAR_RIGHTS_AC...](http://solar-
rights.com/files/THE_CALIFORNIA_SOLAR_RIGHTS_ACT2.pdf)

~~~
djrogers
The roof of a condo is often considered common area, which is excluded from
the linked law.

OTOH, parent can (and should) work with the HOA to get those CC&Rs changed. In
the uber-green region that is the valley, it should be pretty easy to get a
group of like-minded owners together to approach the board, or even get a
member or two elected.

------
cubano
Interesting stuff, but there are financial assumptions being made here that
should be examined.

1\. The 25-year ROI is tied to the projected price of electricity moving
forward. It is simple market issue that if and when more and more people start
using these systems, the utility-based kW price will (must) come down and
therefore, the ROI will change, perhaps dramatically.

2\. What about the opportunity costs of such a significant financial
commitment? Have they been examined in any way?

------
phkahler
Sunshine. They talk about a 5kW system, but do they use some theoretical cost
or do they consider the amount of sunshine in each location. When I see
Detroit at #25 I'm suspicious because we have a lot of grey days.

------
daxfohl
Impressive given how cheap gas is now. Solar has gone down even faster?

~~~
aidenn0
petroleum is not a significant fraction of energy on the power grid.

[http://www.epa.gov/cleanenergy/energy-and-
you/](http://www.epa.gov/cleanenergy/energy-and-you/)

~~~
joshuaheard
It looks like about 1/3 to me. I would say that is significant. I wonder if
the study would have the same conclusion now that oil costs about 1/2 of what
it did several months ago.

~~~
pixl97
Natural Gas != Oil. These products might come out of the same well but do not
track prices.

All oil based products are less than 1%. Nat Gas is 27%, Coal 39%.

------
tsemple
Will new solar panels last 25 years? Most of stuff on the outside on my house
doesn't have a lifespan that long. You could end up paying off the loan after
the panels have stopped working.

~~~
3am
Most are warranteed at a particular percentage of nameplate capacity (95%+) at
delivery and then in a straight-line decay after a certain point out to a
certain level (75-80%) at 25 years.

[http://us.sunpower.com/sites/sunpower/files/media-
library/wa...](http://us.sunpower.com/sites/sunpower/files/media-
library/warranties/wr-sunpower-limited-product-and-power-warranty-pv-
modules.pdf) [edit: better link], for example. that is 95% through year 5,
then .4% linearly through year 25, or 87% of nameplate at year 25. They are a
premium vendor, but the warantee structure is fairly standard across
legitimate vendors.

edit:
[http://www.yinglisolar.com/assets/uploads/warranty/downloads...](http://www.yinglisolar.com/assets/uploads/warranty/downloads/PANDA_standard_110928.pdf)
\- 98% at install, 92% at 10 years, and 82% at 25 years.

edit:
[http://www.trinasolar.com/downloads/us/products/EN_Trina_War...](http://www.trinasolar.com/downloads/us/products/EN_Trina_Warranty_Jan_2013.pdf)
2.5/3.5% in year 1, 0.7/0.68% through year 25 (80.7/80.18 % at end) for
poly/mono- crystalline products, respectively ... and so on.

~~~
cagenut
an upvote is not enough, thank you for a response with hard numbers and
multiple linked sources.

------
kelukelugames
Seattle is on the list! I'm pleasantly surprised.

~~~
bluthru
Seattle actually gets a decent amount of insolation compared to Germany:
[http://www.greenrhinoenergy.com/solar/radiation/images/World...](http://www.greenrhinoenergy.com/solar/radiation/images/World%20Insolation%20Direct.jpg)

As we know, Germany isn't shy about its solar investment.

------
Spooky23
Like most things, making a capital investment results in a cheaper cost than
consuming a service.

The problem is, you need to invest $30k to save $50.

------
pstrateman
Subsidized rooftop solar is now cheaper than artificially expensive
electricity in 42 American cities.

Electricity from natural gas costs $0.03-0.05/kWh to produce and deliver.

Anything beyond that is mark up; either profit or regulatory.

[http://www.wolframalpha.com/input/?i=%28natural+gas+price+to...](http://www.wolframalpha.com/input/?i=%28natural+gas+price+to+usd%2FkWh%29+%2F+0.30)

~~~
jakswa
Any more references here? It looks like you just mean the price for natural
gas futures is $0.03/kWh. I am hesitant to believe that includes production
and transport. In addition, are you including the efficiency at which natural
gas is converted to electricity?

~~~
pstrateman
I'm dividing by 0.3 to account for the efficiency of natural gas turbines. (In
reality they're higher at around 35-45%)

If you assume a 100% efficient natural gas plant the cost is $0.00983/kWh
(100% efficiency is of course nonsense though).

At 30% efficiency the marginal cost is $0.0327/kWh, distribution usually costs
around $0.01-0.02/kWh.

This leads to a grand total margin cost of $0.0427-0.0527/kWh.

DoE estimates from 2012 show $0.0189/kWh in fixed costs.

So a combined grand total of $0.06-0.07/kWh.

~~~
refurb
What about capital costs?

~~~
pstrateman
"DoE estimates from 2012 show $0.0189/kWh in fixed costs."

That includes capital costs.

~~~
refurb
Fixed costs =/= capital costs.

Fixed costs are the reoccurring costs that arise regardless of production. You
can build a plant with free money, but you still have fixed costs.

~~~
pstrateman
Sorry I meant to say that the metric I called fixed costs is actually fixed
and capital costs.

Fixed costs alone are ~$0.002/kWh...

------
api
... not counting storage, but it's progress.

