

Who's afraid of Solar PV? - jdwhit2
http://theconversation.edu.au/whos-afraid-of-solar-pv-8987

======
nl
(I live in South Australia, and I've previously worked on electricity energy
trading systems here)

This is a pretty good article, but misses a little context that maybe helpful
to non-Australian readers.

1) Power bills in Australia have been rising rapidly over the last couple of
years. The reactionary response has been to blame the new Carbon Tax, but the
real causes are much more complex[1].

2) In South Australia at least it gets really, really hot. For example in
February 2009 we had 6 Consecutive days over 40 °C (104 °F) and a maximum of
45.7 °C (114.3 °F)[2], and then in November 2009 we had 6 Consecutive days
over 38 °C (~100 °F)[3]

These peak temperatures occur earlier in the day than the typical power spike
(12pm-4pm instead of 5pm-7pm), and caused huge power spikes (from air
conditioner usage), and this often causes power companies to have to shut off
power (they have a policy of doing rolling blackouts when they don't have
enough capacity).

 _This_ peak demand is much, much higher than the average peak demand shown on
the linked article, and these are the peaks the power companies invest to
meet. If these peaks are reduced by solar panel usage (which they should be,
since the come during the best time for solar production) then it should
reduce the requirements for larger power stations.

[1] [http://www.heraldsun.com.au/opinion/power-play-between-
feder...](http://www.heraldsun.com.au/opinion/power-play-between-federal-and-
state-govenments-is-just-a-costly-farce/story-e6frfhqf-1226454453982)

[2]
[http://en.wikipedia.org/wiki/Early_2009_southeastern_Austral...](http://en.wikipedia.org/wiki/Early_2009_southeastern_Australia_heat_wave#Adelaide.2C_South_Australia)

[3]
[http://en.wikipedia.org/wiki/Late_2009_southeastern_Australi...](http://en.wikipedia.org/wiki/Late_2009_southeastern_Australia_heat_wave#Adelaide.2C_South_Australia)

~~~
greendestiny
As another South Australian I have to say this article makes me a little
concerned about further price rises of mains power to make up for the
shortfall. Although the long term benefits of Solar are amazing the short term
situation for power infrastructure here could be a problem.

*Edit: I can see a flatter usage profile should probably mean cheaper power, but still I think there is some justifiable paranoia in worrying about power prices increasing in South Australia again.

~~~
shirro
Another South Australian. Power is just the next thing to be disrupted by
technology changes.

I think we need smart meters and a more market driven approach to retail
pricing. Peak electricity costs can go through the roof and people will
respond by shifting their usage to alternatives or different times when there
is less demand and prices are lower. Unfortunately there is no market
transparency and we are paying for retail electricity without any real
understanding of the underlying costs. We are paying ridiculously increasing
amounts for electricity so we can build infrastructure to handle peaks that
many would avoid if there were market pressures on consumers. Changes like
rooftop PV and wind farms are only a part of the picture.

~~~
nl
Unfortunately, a _more market driven approach to retail pricing_ is often very
consumer-unfriendly because it means your bills will be very unpredictable.

Power prices vary dramatically during a day, and are often gamed by
generators. Exposing retail customers to those swings directly is dangerous
IMHO.

Having said that, there are many intermediate steps that help. For example,
many power companies do partition prices by time of day, which makes a lot of
sense[1].

In South Australia, ETSA is trialing "Direct load management", where they can
shut off air conditioners for 30 minutes using smart meters when there is high
demand, in return for much lower tariffs[2].

[1]
[http://www.savepower.nsw.gov.au/Portals/0/docs/news/Media071...](http://www.savepower.nsw.gov.au/Portals/0/docs/news/Media07121202.pdf)

[2]
[http://www.etsautilities.com.au/centric/our_network/demand_m...](http://www.etsautilities.com.au/centric/our_network/demand_management.jsp)

------
slapshot
An interesting problem is highlighted on that graph: solar seems to be peaking
around mid-day, but energy demand peaks at 5 - 7 pm when solar is pretty weak.
The curves showing pre- and post-solar have almost identical peaks; solar
hasn't yet successfully reduced peak load. (The California energy system posts
a similar graph, with a similar shape:
<http://www.caiso.com/Pages/TodaysOutlook.aspx> , made worse by the fact that
the California wind farms apparently perform best in the morning and worst in
the afternoon.)

The difficulty is that, unless storage gets dramatically better, we'll still
need a huge conventional electricity base. And it will still burn a huge
amount of fuel: most generators are not "instant-on" -- it can take weeks to
spin up a nuclear plant, days to spin up a coal plant, and hours [1] to spin
up a natural gas plant. Of course, there are some savings, but there is huge
waste if you have to keep the whole conventional energy infrastructure
spinning during the day just to fuel that 6 pm peak load.

Advice to entrepreneurs: finding a cost-effective way to store solar energy
for 4 hours will be worth more than another 2% increase in efficiency. And
inventing instant-on conventional-fuel plants will also make a huge difference
in GHG emissions.

[1] - Page 8 of
[http://www.euec.com/getattachment/euecjournal/Paper_3.pdf.as...](http://www.euec.com/getattachment/euecjournal/Paper_3.pdf.aspx)
gives times between 1.2 hours for a warm start to 6 hours for a cold start.

~~~
reitzensteinm
We don't need any breakthroughs. Electric cars could handle the entire peak
load with _today's_ technology, the right incentives, and capital flowing in
the right place.

The peak load for South Australia was 1.8 gigawatts. There are 1,275,041 motor
vehicles registered in SA.

If you could get all of them turned into electric cars plugged into the grid,
it would be a 1.4 kW power drain per vehicle, which is less than the power
drain of an ordinary kettle here (240V, 10A, ~2.4 kW).

The cheapest Tesla Model S has a 40kW hour battery meaning it could sustain
that power drain for over 28 hours (a total of 51 GWh). It's got a 10kW
charger standard, which is more than enough.

So if everyone had the cheapest Model S, kept it plugged in with the ability
to send power back into the grid, and didn't mind that their car was sometimes
down to 20% charge, you could power the _entire grid on solar alone_.

That's obviously a set of unrealistic assumptions, but it does indicate that
it is feasible to solve the problem like this.

A more realistic set of assumptions:

    
    
      * 1/10 cars are turned into a Model S base model equivalent
      * Through financial incentives, the owners are willing to keep them plugged in 
        during the day and using up to 20% of the battery to push back into the grid.
      * Cars need to shave 0.2 gigawatts off of peak load for four hours to bring 
        it in line with the rest of the day
    

That's 800 MWh of power to satisfy peak demand, at 200 MW.

We have 127,504 vehicles, can can use up to 8kWh and 20kW each, giving:

1 GWh of capacity and 2.5 GW maximum power draw.

So it's just enough. Alternatively, 5% allowing 40% usage works, etc. The
power draw is insignificant.

Owners can be _heavily_ compensated for pushing energy back into the grid. I
won't run the numbers here for length and time reasons, but knocking out peak
power usage is incredibly profitable. You're literally decomissioning a large
percentage of power plants. It would be feasible to make all the energy your
car uses free; likely the lithium ion battery packs, too.

The question is; would 5% of the driving population buy a $50k car if they no
longer had to pay for fuel or battery packs? Financially that would probably
put it closer to a BMW. I think it's feasible. What about in 10 years when the
cars are $20-30k? Undeniably. In 20 years when you only need 2% of the
population to be in the scheme due to battery increases and the cars cost
$20k? No brainer.

The system would require a smarter grid (so you can plug your car in at work
and have it all taken care of), 10 years of Moore's Law for batteries, etc.

But I think the numbers check out, and it means we could go crazy with solar
(the explosion in solar must continue to charge these vehicles during the
day). What's needed is the will to make it happen.

~~~
brc
>So if everyone had the cheapest Model S, kept it plugged in with the ability
to send power back into the grid, and didn't mind that their car was sometimes
down to 20% charge, you could power the entire grid on solar alone.

The OP said cost effective, not pie-in-the-sky.

Even if you took out the battery packs and sold them separately, the cost
would exceed 10 years worth of electricity supply.

>Owners can be heavily compensated for pushing energy back into the grid.

You're asking people who cannot afford the expensive technology to subsidise
those who can. This is the exact reverse logic of most progressive taxation
regimes.

>The question is; would 5% of the driving population buy a $50k car if they no
longer had to pay for fuel or battery packs? Financially that would probably
put it closer to a BMW.

So you want to subsidise the purchase of expensive cars to the point where it
is financially a good deal. This magic money no doubt comes from other
taxpayers.

And for what end? Just so you can have some type of boutique distributed power
generation system?

>What's needed is the will to make it happen.

No, what's needed it pots of _other peoples money_.

I've spent the best part of 5 years trying to hose down the jetsons fantasies
of people pushing ridiculous schemes like this as not only unworkable, but
inequitable for forcing up a basic cost input of life - energy - for
effectively vanity purposes of a small subset of the population. I usually cop
a pile of flamebait and downvotes each time, but I do so because there seems
to be a mass delusion going on, and this has become one of those things you
can't say.

~~~
caf
_So you want to subsidise the purchase of expensive cars to the point where it
is financially a good deal. This magic money no doubt comes from other
taxpayers._

The proposal isn't a subsidy. It's a straight market payment for an economic
benefit - the difference in cost between off-peak and peak electricity is
real, and this means that storing off-peak electricity and releasing it at
peak is an activity that's worth money.

I'm not sure I agree that the economics work out exactly as described, though
- if it would be worth paying for everyone's lithium car battery packs to do
this, then it would be even more profitable to build a giant lithium storage
battery in a central location.

~~~
reitzensteinm
Well, the benefit is that it combines the capital costs of owning a vehicle
and storing energy. Many people will be purchasing a 160+ mile range car, but
day to day use only 20-30 miles of that - an unused capacity large enough to
power an average house for over _24 hours_.

This is in contrast to dedicated lithium ion batteries, which just don't work
out economically. Otherwise you're right - the utilities would do it
themselves at scale.

~~~
caf
I can see how that's true if the car owner's continue to pay the capital costs
of the battery - the part I'm taking issue with is where you say that it would
likely that the car owners would have the capital cost of their battery packs
paid for by taking part.

~~~
reitzensteinm
My back of the envelope calculations elsewhere in the thread were $1571/yr
savings per car (10% overall reduction in grid cost); the Model S battery
replacement insurance is $12k per car, which is a ~7.5 year payback (by which
time, they claim the pack will be at 70% effectiveness).

Elsewhere someone corrected me that the peak grid usage in a year is actually
significantly higher - the figures I was looking at were average daily figures
- which may make grid savings quite a bit higher than 10%.

I don't think it necessarily is a clear financial win now; I'm just saying, if
you squint just right it kind of makes sense now, and with the march of
battery technology and PV, not to mention the inevitable adoption of EVs
whether or not this scheme exists, it's going to look better and better from
here on in.

~~~
caf
No matter how you slice the numbers though, the fact remains that if it's
economical to pay for someone's car-optimised battery pack, then it must be
even _more_ economical to build a giant fixed battery.

(Since we know that the latter isn't economical, then that also indicates a
problem with your numbers - I suspect that for one thing, insurance couldn't
be economically provided at $12k/pack if all of those packs were being used
for daily peaking storage).

~~~
reitzensteinm
I suspect you're right, and it may well mean it doesn't make outright
financial sense today.

The key is probably that the $12k replacement program is an investment in
Tesla; they're cash starved, and are willing to sell the batteries at a loss
in return for the cash advance. Also, they're betting on the batteries being
~half price in 10 years.

From further reading, they'd be $30k - 2.5 times the price - to buy upfront
today.

But that doesn't mean that the subsidy doesn't exist - if 1% of consumers
would buy a Model S due to its other advantages, maybe 2-3% would if that
purchase returned $1500 a year back to them.

So while you're right that it's not outright going to pay for itself in 2012,
it probably halves the gap between a Model S and a BMW in the same class, and
it's only going to get better as battery/PV technology improves.

------
ChuckMcM
TL:DR; version: Utilities make most of their profit during 'peak' times (noon
to 5pm) and SolarPV systems are reducing the requirement during those times,
putting price pressure on electricity.

Here in California we had a similar challenge but with Watar. We periodically
go through drought cycles and during the last big incentives were put in place
to get people to use less water, rebates for toilets, reduced cost if you were
20% below your non-drought average, no watering during the day, drip
irrigation, etc etc. Then the utility needs a rate increase because they
aren't getting as much water usage. It is a hard sell though to tell people
"You have to use 20% less but we're going to charge you the same amount"

So electricity, like water, is a blended cost where the scarcity unit is
priced to cover the physical plant costs of delivering the unit. We wholesale
adoption of Solar PV it will require power utilities to come up with a
different formula to recover their costs. The end result is that it will shift
the cost from business (who pay the biggest power bills during the day) to
non-businesses.

[1] [http://sanfrancisco.cbslocal.com/2011/04/19/east-bay-
custome...](http://sanfrancisco.cbslocal.com/2011/04/19/east-bay-customers-
could-face-water-rate-hike/)

------
yessql
The article doesn't focus much on spot pricing, which is really important in
what is going to happen in the future. They showed a big drop in utility
revenue during peak hours. This revenue used to be caused by high usage
multiplied by really high prices. Now its high demand multiplied by moderate
prices.

If solar adoption continues along the path described (which is inevitable at
this point, considering steadily dropping solar PV equipment prices) then the
midday spot price will continue to drop as well.

We'll find out some answers to the question, what do you do when the spot
price of electricity approaches 0? Water desalination. Pump water uphill.
Charge electric car batteries. Electrolysis to convert water to hydrogen, for
later use in fuel cells or combustion engines.

We will certainly see some innovation in short term energy storage, since the
price of electricity just before the late afternoon peak will be much lower.

------
spenrose
Related:

[http://reneweconomy.com.au/2012/why-generators-are-
terrified...](http://reneweconomy.com.au/2012/why-generators-are-terrified-of-
solar-44279)

[http://grist.org/article/2011-11-23-the-problem-with-the-
ren...](http://grist.org/article/2011-11-23-the-problem-with-the-renewables-
are-reaching-cost-parity-meme/)

[http://www.recycled-energy.com/newsroom/publication/the-
batt...](http://www.recycled-energy.com/newsroom/publication/the-battle-over-
centralization/)

<http://www.ilsr.org/solar-grid-parity-101/>

[http://www.greentechmedia.com/articles/read/how-will-the-
cal...](http://www.greentechmedia.com/articles/read/how-will-the-california-
system-operator-cope-with-33-renewables/)

------
jorgem
>> The unspoken fear of all utility managers is the “Death Spiral Scenario”.

>> In this nightmare, a utility commits to build new equipment.

>> However, when electric rates are raised to pay for the new plant, the rate
shock moves customers to cut their kWh use.

We have a "death spiral" in water prices in my local (southern California)
water district.

There was a drought. People were asked to conserve. People conserved too much.
Drought ended. Water use did not return. Water companies then need to raise
prices to meet their distribution costs. Which lowers demand further.

It can only end ugly.

~~~
kiba
It only end ugly for the water companies. On the contrary, it ends beautifully
for the customer.

~~~
jorgem
Not really. The water company is raising prices on everyone because we're not
using as much, but they still have same overhead. If the whole community
hadn't conserved, we'd have gotten more water for the same or lower cost.

~~~
pbhjpbhj
> _The water company is raising prices on everyone because we're not using as
> much_ //

If they're like the UK water companies then they'll be moaning they're
suffering but still be making vast profits.

It's like "we can't fix the pipe network without increasing water bills and we
already put them up 10% this year; oh and we made 20% more profit this year so
we must be serving our customers well ....".

------
politician
A shift in energy production is good news, so now we can use our coal
generation capacity to desalinate water. We get new sunlight every day, but
the fresh water that we have is all we have.

~~~
danmaz74
"We get new sunlight every day, but the fresh water that we have is all we
have." Actually, we get new fresh water every other day - it's called rain.

~~~
politician
If we actually got new water every day it'd be arriving on meteorites.

Of the water present on the planet, 97% is salt water which is unusable for
drinking or agriculture. Of the 3% freshwater, 68.7% is locked in glaciers.
So, 1% of the water on the planet is liquid and most of that is underground.
We don't really have a lot and things like fertilizers damage what we have.

It turns out that the amount of fresh water is relatively constant. If we want
more in places that have less then we have to manufacture it from seawater,
steal it from our neighbors by cloud-seeding, or rely on the weather cycle
convert seawater into fresh water and then distribute it.

If you live in Dubai, you aren't waiting for it to rain. You're building
desalination plants and processing seawater.

~~~
nl
In South Australia we are building a wind and solar powered desalination plant
too: <http://en.wikipedia.org/wiki/Port_Stanvac_Desalination_Plant>

------
evolve2k
Sounds like technology driven disruption to me.

