
Rooftop solar power may be flooding the grid - prostoalex
https://www.smh.com.au/business/the-economy/too-much-of-a-good-thing-solar-power-surge-is-flooding-the-grid-20180606-p4zjs7.html
======
gregoriol
Renewable energy is quite predictable: there is sun during the day, and no sun
during the night. Wind is a bit less but could be too.

Why not organise accordingly?

First, there are batteries: solar roofs should come with batteries, than will
power the house during the night. Authorities could enforce that, and could
also build larger energy storages with batteries at a region level (see recent
examples from Tesla).

Then, this is mostly communication: why not make the grid and the roof "talk"
to each other and the roof be turned off from the grid when there is no need
for it? Is it because subsidies or some kind of mandatory buy from the grid
that this could be an issue? otherwise there could be incentive to have this
better integration with the whole system.

Otherwise, use bitcoin miners, during the day!

~~~
probably_wrong
This is the part where someone points out why I'm completely wrong:

> solar roofs should come with batteries

The way I understand it, batteries tend to be bad for the environment if/when
they need to be replaced, because often they are improperly recycled and/or
there are no adequate facilities for that.

If this is correct, do we really want to have more of them around? Wouldn't an
environmentally-friendly(ish) central plant be better in the long run?

~~~
adrianN
Lead acid batteries are pretty easy to recycle. We already do this for car
batteries. Lithium batteries are currently not as easily recycled, but that
seems to be because there is little demand for recycled Lithium and they're
not very toxic in landfills.

~~~
ant6n
Stationary batteries have fewer constraints wrt to energy density, because
they don't move.

------
niftich
This is a tough and awkward problem, because accounting for the externalities
of a "good thing" would curtail progress towards a good thing. Meanwhile, the
externalities of bad things get a free pass. Ouch.

The solutions are either very expensive, very counterproductive, or very
unfair.

The expensive solution is grid energy storage, where the utility installs a
bunch of storage to time-shift some of the generation to better match the
demand. The unfortunate aspect is that this is capital intensive, and most
utilities are already loaded full of debt to pay for capex. This will probably
result in the increase of rates billed to consumers, which is ironic, even if
the grid is now providing a more complex service.

The unfair solution is to legislate that onsite storage must accompany all
residential distributed solar generation. This pushes the costs significantly
higher, and forces homeowners to locally account for the added complexities of
their green energy generation. But full suite of complications around other
energy sources isn't priced into their cost.

One counterproductive solution is to force market pricing on all consumption
and generation. The revenue on residential solar generation would free-fall,
because all of it in a particular area gets generated at a time when it's most
plentiful. It wouldn't be worthwhile for a small player to generate it
anymore.

Another counterproductive, but simple solution, is to dump excess solar at the
inverters at peak time, then run a bunch of natgas peakers in the evening once
solar drops off. This is an environmentalist's nightmare, but takes no effort
to execute.

------
tappaseater
I am in my 5th year of a 9.8MW system. I have generated about 45MW of power
and approximately 1/3 stays in my home and the rest is sold to local power
company.

A couple of years after installation I started to see negative press for solar
and eventually some action by my local power company. "Solar is no use to me",
to quote the manager. Their actions finally killed new solar in our town. They
used arguments like this, but we all suspected they were worried about revenue
protection. There are 7 solar customers, a gnat's cock, so-to-speak, but they
are/were scared. Local newspapers echo sentiments that solar customers have
their hands in the pockets of non-solar and provide no balance.

My goal is to get a 10-15kWh storage (Tesla Powerwall probably) and then keep
most or all of my power and pay the grid like a very low usage customer. I
believed we could do better, but I don't see it happening.

~~~
antisthenes
> I am in my 5th year of a 9.8MW system

Do you run a power plant?

------
nabla9
The same thing is happening in Europe. Energy markets need large
reorganization for the transition and energy grid and storage technology needs
to catch up big time. This takes lots of money.

Wind and solar turn spot prices negative when it's sunny and windy. Existing
nuclear, coal can't be easily turned off for just a part of day. In free spot
energy markets, the price of electricity must jump sky-high during low supply
to pay for the rest of the time.

What is needed is load following power plants and large scale energy storage
(flywheels and lithium ion are only solutions for very short fluctuations). In
the North Europe there is possibility of using Norvegian hydropower to
compensate for wind power as long as the grid capacity keeps up.

~~~
cesis
Just pass those negative prices to customers and they will solve the problem.

~~~
adrianN
That requires "smart" meters everywhere.

~~~
TeeWEE
In the Netherlands smart meters are the default now.

------
CaliforniaKarl
Reading this article, the first thing I wondered was, what does Australia have
in terms of peaking power plants, which can come online—and, just as
important, safely go offline—quickly to stabilize grid voltage?

The second thing I was wondering is, where are the bitcoin miners? Assuming
electricity prices are not being held artificially high, then when they start
to come down, miners will start coming in.

In fact, I could envision a two-tier pricing model, similar to what is used
for EV charging. Combine that with something like Zellweger ripple signaling,
and the grid would have a way to tell miners (et al) “Hey, we have excess,
were reducing the rate so start mining!”

~~~
boyter
Australia is in the unique position of having abundant reserves of gas, coal
and uranium but through what is probably blatant corruption the most expensive
power prices in the world.

The gas is exported at a fixed cost to Japan and other countries where it can
be resold to Australians at a profit.

Other issues are that no power company in Australia is willing to build a new
coal power plant because the current coal subsidies are likely to go away with
a change in government. The current government is very much pro coal. To
illustrate how bad this is the current government Treasurer brought a lump of
coal into sitting parliament and was waving it around showing how non
dangerous it is. The coal lobbies are very strong and are running out of
export options.

Australia is in this position due to a lack of bipartisan support towards any
energy policy. Its also a problem because the power networks have been
privatized and the incentives were set to guarantee returns on building
infrastructure. The network as such is gold plated but the power it carries is
very expensive.

While gas should be the answer to the network shortfalls there was a massive
profit incentive to not do so initially wait for the spot prices to surge and
then jump in and collect massive paychecks.

The result is that people installed solar. Which caused the electricity
companies to raise prices which lead to more solar installs. The companies
here are in a death spiral. They are insanely profitable right now, but the
writing is on the wall.

However companies such as Tesla installed a massive battery to counter some of
the issues and that project after 6 months is almost about to pay for itself.

Its a horrible situation to be honest, and I cannot wait for the power
companies to fail due to their own hubris.

BTW if you think this is bad, do a quick check into the status of the National
Broadband Network NBN in Australia. That's corruption on a whole other level
and you should laugh at us Australians. No matter how bad your internet is I
promise ours is worse, more expensive and despite billions of dollars not
about to get better.

~~~
stephen_g
Australia does not need any more coal stations. Wanting to build new ones has
weirdly become a strange infatuation by the conservatives, but there is
absolutly no need in Australia for more baseline capacity. It's all in the
peaks, which is all gas (which mostly of sets the benchmark price given where
it sits in the AEMO stack).

So most of our price problems are just the price of gas, and the introduced
reservation program has helped with that a little but does not go far enough.
That, and the gold plating of the infrastructure (which alone is like 40% or
something IIRC of the price rises over the last decade).

Most of the 'reliability problems' than the politician are on about are really
just 'fears of possible future reliability problems', stirred up by the
blackouts in SA that were mostly due to transmission lines being blown over in
a massive storm while one of the interconnectors with Victoria was down for
maintenance, and some wind turbines tripping out because of dangerously high
wind speeds. There isn't really that much reliability risk apart from the fact
that our coal stations are all pretty unreliable (the Australia Institute has
taken to tweeting every time a generator trips out, it's pretty crazy how
unreliable our coal stations are).

Perhaps we will need some more gas peaking stations but new pumped hydro and
big batteries will probably take over some of that.

~~~
stephen_g
Sorry, should be ' _baseload_ capacity' in the first bit.

------
perilunar
The ABC had a story today on pumped hydro storage:
[http://www.abc.net.au/news/2018-06-07/how-does-pumped-
hydro-...](http://www.abc.net.au/news/2018-06-07/how-does-pumped-hydro-power-
work/9843804)

The Snowy 2.0 scheme looks promising: 2 GW max power, 350 GWh max storage,
A$3.8-4.5 billion. Online ~2024. Just approve the bloody thing already.

For comparison, Tesla's 'world biggest battery' aka the Hornsdale Power
Reserve, is 100 MW max power, 129 MWh storage, and cost ~A$100 million.
(cheaper per Watt, but about 60 times more expensive per Wh) Built in 4
months!

------
baud147258
So solar power is irregular and has a peak production (mid day) far from peak
consumption (start and end of business day)? News at eleven, water is wet and
all that...

edit: I should have said irregular through the day.

~~~
aligibbs
Solar power is not irregular at all, and is entirely predictable with a
weather forecast. Unless Australia has an entirely different usage pattern to
the rest of the developed world- businesses are perfectly aligned to use the
solar power generated during the peak.

~~~
baud147258
From the article: "the growing peak demand that comes at the end of the day,
as the sun sets.". So the solar production of electricity peaks earlier than
the end-of-day consumption peak.

~~~
c12
There is a company in Australia that have improved flow batteries technology
to the point where it can be miniaturised down to the size of a fridge freezer
(previously they were the size of shipping containers) ten shipping containers
full of them are able to store 3.2 megawatt-hours of energy and discharge a
megawatt of power for over three to four hours which is roughly enough to keep
500-600 average homes going for the afternoon during the end of day
consumption peak.

They are perfectly suited to be paired with solar/wind/etc where they can
store up the days usage and discharge at a regular rate throughout the evening
peak when generation is reduced. And as for reliability, unlike lithium-ion,
flow batteries can last for 20+ years with unlimited cycles.

~~~
robkop
I assume you are taking about red-flow?

I head about them several years ago but haven't seen much since. Do they have
the scale/ pricing to sell to the average consumer yet?

~~~
c12
I am indeed. I think they got some press coverage three or four years ago. I
personally discovered them by watching a documentary on YouTube that featured
their technology and discussed its future.

I know that they recently raised some capital to invest in increasing sales.
However I think a large proportion of their target market are grid scale and
remote outposts for telecommunications/industrial applications.

That could be because their residential solution still cant beat something
like the Tesla powerwall on price. However, I believe when investing in
something that you expect to have longevity in the 20-30 years range it's
better to go with something a little more pricey that is proven to last that
long without degrading of performance, so on that point the flow battery wins.

It's like with solar panels, you can pay a premium upfront and get panels that
will be producing the same output in ten years time like my parents did, or
skimp on price and end up with a 30-40% reduction over the same time period
like their neighbour.

------
TangoTrotFox
Interesting. In Australia do people regularly install rooftop solar
installations without also installing battery units? What's the logic there?
Just selling it to the grid?

~~~
stephen_g
Yeah, we had extremely generous feed-in tariffs for a while. It's generally
net-metering too so pretty good value, even as the prices have come down. We
have no shortage of sun most places, so it's pretty easy to almost wipe out
your entire bill (except for the service/distribution fees, which have gone up
a lot over the last few years, I guess to combat that).

~~~
sjwright
A very relevant YouTube video from Dave at EEVBlog, where he goes through the
numbers for his five year old solar installation, to see whether it has paid
for itself. He also does hypothetical modelling of adding a battery, which
proves to not be financially compelling at all.

[https://youtu.be/aQQE8V9NBXw](https://youtu.be/aQQE8V9NBXw)

~~~
John_KZ
This is because those "environmentalist" laws weren't created to satisfying
national energy demand, but only the people's desire to roleplay environment-
savers and get paid for it.

Similar government schemes played out in much of Europe. Install subsidized
solar panels, and the government/electricity companies have to buy your
electricity at unsustainably high prices whenever you produce it, regardless
if they need it/can handle it.

Obviously, as far as I know, this didn't last very long, especially in the
countries with more limited budgets. Eventually the sale prices dropped close
to normal wholesale electricity prices and the subsidies were dropped. Those
who installed the panels late in the bubble probably got out with a loss.

It was just a terrible idea all around. The grid isn't made for distributed
production, energy storage isn't solved, and solar electricity is just not
sustainable as rooftop photovoltaics.

------
John_KZ
Why don't Australians use Solar water heaters? It's the best ROI you can get
from solar, Mediterranean countries and the sunny parts of China have
absolutely massive capacities installed. It's direct thermal, so it's not a
cool high-tech gadget, but if you're worried about the environment, it's
"better" than solar panels when applicable. It also essentially includes on-
site thermal storage, so no grid instabilities.

~~~
stephen_g
Lots of them around (especially in my state, Queensland, which has hot summers
and mostly fairly warm days in winter), but you need to use a gas or electric
booster to have hot water all the time. So in a lot of places it actually
turns out to be fairly similar energy use to put in a high-efficiency heat-
pump hot water heater.

I've just evaluated this because I want to replace the hot water system at my
house, and I was initially thinking of solar because my parents have had one
for years and it generally works well but the heat pump will be cheaper and
I'll eventually get some PV anyway. So all in all it should be a bit cheaper
and more efficient per square metre of roof space.

~~~
John_KZ
Solar panels mix well with heat pumps in hot and dry climates indeed, because
of the happy coincidence that peak solar radiation=peak demand for cooling. In
that case it's not a bad combo, especially if you have mild winters without
temps deep in the freezing (which ruins the COP for heat pumps, assuming you
use them for heating too).

------
D_Alex
Please note that there are powerful lobby groups in Australia that have
interests in fossil fuel businesses and promote journalism that exaggerates
problems with renewable energy. Eg see this:

[http://artsonline.monash.edu.au/climate-change-
communication...](http://artsonline.monash.edu.au/climate-change-
communication/files/2013/09/Newspaper-reporting-of-South-Australian-mid-
latitude-cyclone-2016.pdf)

~~~
ThomPete
Just as there are powerful interest in solar and wind.

Edit: To the downvoters. What are you disagreeing with? Are you claiming that
the wind and solar industry doesn't have special interest and that they aren't
powerful especially when you look at the support it has politically?

~~~
pjc50
People are generally familiar with the self-interest of the fossil industry,
but you seem to be saying that everyone who supports renewables is _also_ in
it for the money? Without evidence?

~~~
ThomPete
What do you want evidence for? Are you saying that those who invest in solar
or wind do not have a self-interest in what they invested in. That seems to be
a much bigger claim that the very obvious that any investment you make you
have a self interest in.

Climate gate should have made it quite obvious that no one is excempt from
bias. Thomas Kuhn wrote a whole book about it.

------
WalterBright
Much stabilization could be done by varying the price of electricity on a
minute-by-minute basis according to the supply.

Then, electricity users can correspondingly adjust their usage for things like
electric car battery charging and heating the hot water.

------
Angostura
An interesting alternative to battery storage opened in the UK this week -
liquified air energy storage. I wonder if this may be helpful.

[https://www.theguardian.com/business/2018/jun/05/pioneering-...](https://www.theguardian.com/business/2018/jun/05/pioneering-
liquid-air-project-can-help-store-excess-electricity)

~~~
D_Alex
>liquified air energy storage. I wonder if this may be helpful.

Let me answer this: No, it would not be helpful, because on pretty much all
metrics (capital and operating costs, efficiency, flexibility, size etc) this
technology is way worse than battery storage.

Unfortunately - today - a lot of money which could be sensibly used deploying
cost effective technology such as solar and wind power (and to a lesser extent
battery storage) is wasted pursuing fundamentally flawed concepts (such as
compressed air energy storage, and now this liquified air), which have no
chance of being competitive .

~~~
dsign
Horse stables were in their day a cost-effective solution to transportation,
and those steam engines had no chance of ever moving a couple of meters on the
rails...

~~~
blkhawk
I think there a physics problem there. The efficiency is way worse than
charging almost any type of battery. So unless material for any type of
battery becomes completely unavailable (including say Iron and sulfur or
lead), the power free and you manage to build your Air Liquifier with less
resources than batteries it will always be a stupid way to spend resources.

~~~
Angostura
They are claiming efficiencies of 60-70% compared with batteries of nearly 90%

~~~
D_Alex
OK, I have thought about this a bit (I have worked on gas liquefaction plant
design), and I do not believe this claim.

70% is about the maximum thermodynamic efficiency of any heat engine operating
between -190 degrees and ambient. And the best efficiency you can expect in
liquefaction, in a very complex and large plant, is circa 50% (1). Combined
with storage losses, I think the overall cycle efficiency cannot be more than
25% or so.

Happy to review and comment on any back-up to their claim.

(1) see eg here:
[https://search.informit.com.au/documentSummary;dn=8933572137...](https://search.informit.com.au/documentSummary;dn=893357213721903;res=IELENG)

~~~
Angostura
Thank you for that thoughtful and informative reply.

------
StreamBright
People finally starting to realise that energy systems and grids are more
complex than just put a solar cell to your roof. There is minimum level of
service has to be provided (even over night) and the balance of production and
consumption has to be kept in balance otherwise very bad things happen.

~~~
terminatax
It’s called battery storage of excess energy

------
quicon
Ten Years of Analyzing the Duck Chart
[https://www.nrel.gov/news/program/2018/10-years-duck-
curve.h...](https://www.nrel.gov/news/program/2018/10-years-duck-curve.html)

------
jlebrech
home appliances should be aware of the home's solar panels somehow.

you could fill a washing machine and have it wait a few days and turn on if
the solar panels are at full usage.

other things could operate at peak hours (dishwasher)

you could also pump water into a silo when it's bright outside.

~~~
t0liman
>home appliances should be aware

You mean IoT installed into wallplugs and whitegoods appliances, pool pumps,
heaters, washers, heat pumps/air conditioners, hot water systems, etc.

Yeah. If there was only an IoT standard that worked to allow for usage to be
monitored and devices to be switched on/off in a standard way ... sure.

There are "appliances" like HomeAssistant.io and OpenHAB and Domoticz out
there to micro-manage these peripheral home devices and monitor
consumption/excess/PV generation, and rulesets that can trigger responses and
excess/egress of energy,

but it's too complex for the Inverter/Solar managers to take care of usually.

~~~
jlebrech
it's better to spend the energy directly than to sell it cheap now and buy it
expensive later.

------
Double_a_92
Couldn't the problem be solved my publicly registering your solar panels
(location and power output)?

The utilities could access that data and actual weather data and predict the
demand curve in a better way.

~~~
pjc50
Those on feed-in tariffs will be registered in order to pay them. Mine
certainly are in the UK.

------
ianai
If you’re going to replace something and keep uptime then you’re going to have
situations where you have more than you need.

------
decentralised
Good opportunity to mine cryptocurrencies.

edit: [https://cointelegraph.com/news/even-with-energy-surplus-
cana...](https://cointelegraph.com/news/even-with-energy-surplus-canada-
unable-to-meet-electricity-demands-of-bitcoin-miners)

------
pixelpoet
Use the power for crypto mining (while it's still based on hashing), use
returns for energy storage infrastructure.

~~~
stephen_g
Better just to use it for aluminium smelting or some other productive purpose
instead...

------
carreau
"Monitor electricity 3600 times a second" in the video seem wrong, as AC is
usually 50 to 60 HZ that would be measuring the consumption 60 to 72 times per
period which does not really make sens. It's likely 3600/hour or 1/seconds.
Immediately make me doubt the quality of the research.

Edit: DC -> AC. was tired.

~~~
rabidrat
*AC is 50 to 60Hz (DC does not alternate). Also I can see how it's possible that electrical fluctuations could happen at a higher rate than the utility frequency. 3600 Hz does seem like a lot though.

~~~
carreau
Oops. Fixed AC/DC. I know better. 3600Hz seem also quite a weird number while
3600 time an hour ends up being exactly once a second.

