What happens when solar power is cheaper than grid power?

[Sylvia Else]

Opinions on this vary, but it appears that sometime in the next ten
years, domestic solar power will have an unsubsidised cost that is below
the daytime domestic grid tarrif.

I need to be clear here what I mean by "unsubsidised". I mean that the
equipment can be bought and installed without a contribution from either
the government or the suppliers(s) of electricity. I'm also assuming
that customers will be able to net off their daytime electricity
consumption by selling their surplus solar power to the utility at the
same price as they'd buy it at that time of day.

There are arguments about whether such a framework is really
unsubsidised, but that's the definition I'm using here.

The subject is "what happens when...?"

At that point, rational consumers will install solar power systems.
Further, for those that cannot raise the capital, I would envisage
business moving in to install and lease the equipment to the consumer,
because it will be possible to let the consumer have electricity for
less than the grid price while providing a profit to the lessor.

So there should be solar panels on every domestic roof that receives
enough sunlight. The grid will only be supplying electrity during the
day when the sky is overcast. This affects the economics of the power
plant. In particular, I would anticipate a move away from combined cycle
(CCGT) natural gas generation to the less capital intensive, and less
energy efficient, generation plant.

That less efficient plant will produce more CO2 per kWh than the plant
that it replaces, but will produce less energy overall (since the solar
panels are producing some). I have to wonder how that pans out. Is the
CO2 purportedly saved by having the solar panels actually simply
tranferred to the outputs of the less efficient generators?

The cost of this less efficiently generated power is higher than that
produced by CCGT. Since that higher cost must be passed on to consumers,
it means that the unit cost of grid power during the day will go up,
thus further pushing the installation of solar panels.

Of course, that's based on unsubsidised solar panels with a simple
net-off of consumption. For some bizarre reason, governments still want
to help create the problem earlier than it would otherwise occur by
subsidising installation, and forcing retailers to pay more for solar
generated power than it's worth to the retailer.

I'm left wondering whether solar power is a mirage. Is it providing any
benefit whatsoever? Or is it a complete and utter waste of money,
regardless of whether CO2 emissions are a problem?

Sylvia.

 

[Sylvia Else]

the only drawback to solar is it takes 20-40 years to install more and
more panels,
they're on 5% of houses in 2010, 10% of houses in 2011, now 15% of
houses have panels.

Er, I think the fact that they don't produce power when the sun isn't
shining is another drawback.

the carbon electricity grid will just be a method to transfer power
from one house
to another - no power plants needed.

And when it's cloudy? What then?

Sylvia.

 

[Sylvia Else]

Your scenario is based on the assumption that electricity can not be
stored economically. Having batteries of such a scale will soon be more
common though, especially with ever more electric cars, the numbers will
make them cheaper. Lithium batteries are increasing in efficiency by
about 7%/year, and with panels getting ever cheaper even the low
efficiency NiFe type could be considered.

Part of the issue there relates to who would pay for them. Consumers
will not install them themselves while they can use the grid as a free
energy store, which is what the net-off amounts to. Disallowing net-off
would change the economics of solar panels such that the large scale
deployment wouldn't occur until the combination of batteries and solar
panels were a cheaper source of electricity than grid power. It's going
to a long while before that's true, the electric car developments not
withstanding.

But I think it would be a brave politician who'd disallow net-off
because most consumers would never understand the rationale, and would
feel (as they're ever willing to) that they were being ripped off.

The grid side of the equation wouldn't install batteries unless forced
to, because there are cheaper ways of supplying electricity -
particularly when one considers that those other ways still have to
exist to handle the not-uncommon situation where the sun doesn't shine
for days on end.

One has to wonder why large power plants based on solar and wind with
battery storage are not in the pipeline yet. Large renewable plants with
battery storage exist already at least in the US, Japan and China.
Example:
http://www.powermag.com/business/4410.html

The answer is that they're hopelessly uneconomic, and only get built
from political motives.

Sylvia.

 

[Sylvia Else]

Wot Rot!

If you can pay your power bill 3 years in advance you can go to Solar
and never pay a bill again!

You put a sheet of cardboard on your roof and get 100W for every 1m2!

Oh no! the clouds! the clouds!

What have you got your mums head in a cryogenic freezer in the
basement?

Herc

Graham, there are two entirely different situations.

The first, which is the one you're talking about, is where the
government subsidises your solar panels, and lets you treat the grid as
a free battery, and possibly pays you more for the electricity you
generate than it's actually worth.

The other is the real world, unmodified by politicians who think you can
legislate that one chicken be counted as two, where all of the costs of
acquiring power have to be paid by someone, not just some of them.

Sylvia.

 

[terryc]

Opinions on this vary, but it appears that sometime in the next ten
years, domestic solar power will have an unsubsidised cost that is below
the daytime domestic grid tarrif.

What is the basis of that claim?
Grid power equals very large economy of scale.
Solar power equals expensive, high maintenance storage device.

 

[terryc]

Your scenario is based on the assumption that electricity can not be
stored economically. Having batteries of such a scale will soon be more
common though, especially with ever more electric cars, the numbers will
make them cheaper. Lithium batteries are increasing in efficiency by
about 7%/year, and with panels getting ever cheaper even the low
efficiency NiFe type could be considered.

Way to shoot yorself in the foot. If there is one battery that would
illustrate your point, it is the basic lead acid battery as in the
standard car battery, or even derivative, aka the deep discharge lead
acid battery as used in power systems. cost of them is still a major
sticking point.

 

[terryc]

Apart from the solar issue, I reckon they should start a national grid
system followed by an international one. That would go a long way
towards solving the shortages in one area and taking the surplus from
the active areas. Costly I know but the longer it's left the more costly
it will become. The same goes for water.

Transmissin losses in both cases. You can shift electrical AC power
around and minimises the losses by bumping the transmission voltage. SFA
you can do with water, except pay monstrous power bills for pumping.

 

[Sylvia Else]

It's the REPLACEMENT COST of the batteries.

http://jaycar.com.au/productView.asp?ID=SB1695&form=CAT2&SUBCATID=997#12

12V 100Ah Deep Cycle Gel Battery
$305

This will deliver 1200W for 1 hour.

But if you fully charge and fully discharge every day..

3 month = 91%
6 months = 82%
12 months = 64%

so it loses 9% every 90 days.

But if you don't run AIRCON and ELECTRIC OVENS

you can effectively trickle charge them.

i.e. have way more batteries than panels.

you can supply a good SURGE POWER - i.e. microwaves, pressure
cleaners..
and keep the batteries charged for 1-2 weeks of cloud cover,
but your total power usage must be kept down.

then you get triple benefit
by batteries only charging / discharging 10% capacity each day

1 long battery life in decades
2 batteries always topped up over 2 weeks cloud cover
3 high surge power when needed

Herc

The cost of capital gets you then. All that money tied up in batteries
that could be earning interest in a bank account or and capital gains
and dividends invested in shares.

Sylvial

 

[Sylvia Else]

What is the basis of that claim?
Grid power equals very large economy of scale.
Solar power equals expensive, high maintenance storage device.

I haven't looked at the details. Prices of panels have been dropping,
and the price of grid power (particularly in NSW) have been rising.
There's going to be a crossover point.

I've assumed in the discussion that no storage devices are involved. The
point of the posting was not to argue that solar is cheap, or cost
effective, but just to look at what will happen at some point in the
future given the way things have been going, and to raise a question
about whether solar panels are actually achieving anything other than to
line the pockets of some manufacturers.

Sylvia.

 

[terryc]

It's the REPLACEMENT COST of the batteries.

Why are they magically cheaper when you replace them?

http://jaycar.com.au/productView.asp?ID=SB1695&form=CAT2&SUBCATID=997#12

12V 100Ah Deep Cycle Gel Battery
$305 Very expensive.

This will deliver 1200W for 1 hour.

Definitely not unless you want to explode the battery. That rating is at
best 60watts for five hours. Any more or longer and the life cycles head
south.

But if you fully charge and fully discharge every day..

Then you are definitely fscking it.

 

[Peter]

I haven't looked at the details. Prices of panels have been dropping, and
the price of grid power (particularly in NSW) have been rising. There's
going to be a crossover point.

I've assumed in the discussion that no storage devices are involved. The
point of the posting was not to argue that solar is cheap, or cost
effective, but just to look at what will happen at some point in the
future given the way things have been going, and to raise a question
about whether solar panels are actually achieving anything other than to
line the pockets of some manufacturers.

Sylvia.

Why do they install a roof just to cover it with solar panels?
I would imagine solar panel roofing material (tiles/paint) could save in
building costs and alter the math.

 

[Trevor Wilson]

Opinions on this vary, but it appears that sometime in the next ten
years, domestic solar power will have an unsubsidised cost that is below
the daytime domestic grid tarrif.

I need to be clear here what I mean by "unsubsidised". I mean that the
equipment can be bought and installed without a contribution from either
the government or the suppliers(s) of electricity. I'm also assuming
that customers will be able to net off their daytime electricity
consumption by selling their surplus solar power to the utility at the
same price as they'd buy it at that time of day.

There are arguments about whether such a framework is really
unsubsidised, but that's the definition I'm using here.

The subject is "what happens when...?"

At that point, rational consumers will install solar power systems.
Further, for those that cannot raise the capital, I would envisage
business moving in to install and lease the equipment to the consumer,
because it will be possible to let the consumer have electricity for
less than the grid price while providing a profit to the lessor.

So there should be solar panels on every domestic roof that receives
enough sunlight. The grid will only be supplying electrity during the
day when the sky is overcast. This affects the economics of the power
plant. In particular, I would anticipate a move away from combined cycle
(CCGT) natural gas generation to the less capital intensive, and less
energy efficient, generation plant.

That less efficient plant will produce more CO2 per kWh than the plant
that it replaces, but will produce less energy overall (since the solar
panels are producing some). I have to wonder how that pans out. Is the
CO2 purportedly saved by having the solar panels actually simply
tranferred to the outputs of the less efficient generators?

The cost of this less efficiently generated power is higher than that
produced by CCGT. Since that higher cost must be passed on to consumers,
it means that the unit cost of grid power during the day will go up,
thus further pushing the installation of solar panels.

Of course, that's based on unsubsidised solar panels with a simple
net-off of consumption. For some bizarre reason, governments still want
to help create the problem earlier than it would otherwise occur by
subsidising installation, and forcing retailers to pay more for solar
generated power than it's worth to the retailer.

I'm left wondering whether solar power is a mirage. Is it providing any
benefit whatsoever? Or is it a complete and utter waste of money,
regardless of whether CO2 emissions are a problem?

Sylvia.

**I did the sums about 4 years ago. For about a week's energy needs, I'd
need to plonk down around $4k for high quality, lead/acid batteries.
With careful use of energy, that 7 days could be stretched further,
particularly given the lower energy requirements of many appliances now
(inverter air cons, LED/LCD TV sets, LED lighting, etc). $4k is less
than I spend every two years on coal generated power right now. As for
PV cells, don't forget that amorphous type cells are better at supplying
power in low/dappled light conditions. Price falls with these types of
cells are expected to be nothing short of spectacular over the next few
years. $10.00/sq Metre installed is not unreasonable, since the cells
could be incorportated into roofing materials at extremely low cost.

 

[Clocky]

Er, I think the fact that they don't produce power when the sun isn't
shining is another drawback.


And when it's cloudy? What then?

Sylvia.

Herc's brainfart theories based on a blend of naivity, stupidity and
ignorance fall in a stinking heap, as always.

 

[Clocky]

Can you stop being an idiot?
If you stalk me in aus.electronics its the last aus group I'm posting
to.

I'm not stalking you aywhere, you crosspost everywhere and I respond
depending where I'm reading it. You make it public, I can respond. That's
not stalking.

Stalking is what you did when you were convinced you were the son of God and
you thought you found your "Eve".

Here is my 4 battery stack that runs a lot of things, flouro lights
all night
even though the solar panel angle is wrong for winter.

http://camaffiliate.com/4-20AH-GelCells.jpg

Doing a 100 page print job!

See the $80 regulator 20AMP.

With solar you just have to budget your usage.

If you used the same budgeting for grid power it would cost you less than
the money you have tied up in that setup. The ongoing costs (batteries don't
last all that long)would mean it would probably be no more cost effective to
use solar over the grid supply.

The money spent on the solar setup could earn you more interest over a year
than a fluoro and your low wattage short usage items would consume in $ off
the grid.

Most appliances are 50W - 200W

It's only HEATING and COOLING that taxes the full 2KW installed in
houses.

Mind you I'll be upgrading to a $4K Amorphous System to run a
Microwave and 400W heater soon.

4K buys a lot of power off the grid, especially if you economise it in the
same manner as you will have to using solar.

I'm considering using something similar for my workshop, but since I can get
a lot of bits and pieces for cheap or even free it's more economical to do
so as a fun hobby project.

 

[Sylvia Else]

Why do they install a roof just to cover it with solar panels?
I would imagine solar panel roofing material (tiles/paint) could save in
building costs and alter the math.

A conventional house roof is very heavy. This means it tends not to get
blown away in high winds (despite being a less than ideal shape). The
way the tiles overlap means it's very easy to make a roof that doesn't leak.

If you get rid of the tiles, you need to address the structural and
waterproofing issues.

Sylvia.

 

[Sylvia Else]

**I did the sums about 4 years ago. For about a week's energy needs, I'd
need to plonk down around $4k for high quality, lead/acid batteries.
With careful use of energy, that 7 days could be stretched further,
particularly given the lower energy requirements of many appliances now
(inverter air cons, LED/LCD TV sets, LED lighting, etc). $4k is less
than I spend every two years on coal generated power right now. As for
PV cells, don't forget that amorphous type cells are better at supplying
power in low/dappled light conditions. Price falls with these types of
cells are expected to be nothing short of spectacular over the next few
years. $10.00/sq Metre installed is not unreasonable, since the cells
could be incorportated into roofing materials at extremely low cost.

Let's be clear that I'm looking at the total cost and total benefit, on
the assumption that neither consumers nor suppliers will install
batteries because the government will not require them to. If amorphous
cells fall in price soon, it just brings forward the point where the
economics of the grid generation as presently configured are undermined.

I'd still like to see an analysis of the long term effects on the choice
of generation plant (I don't have access to the required input data),
and the consequential net benefit, if any, in CO2 reduction.

If installation of solar cells doesn't in fact reduce CO2 emissions, and
doesn't reduce the true cost of electricity, then the money being spent
on them is just money that's being wasted.

Sylvia

 

[terryc]

that's only 5AMP! wouldn't even get warm!




you still have 64% capacity after 1 year, that's with full 365 charge/
discharge cycles.

Not if you ever fully discharge them or discharge Gel at a rate >
C(amphour capacity)/20.

 

[terryc]

Why do they install a roof just to cover it with solar panels?
I would imagine solar panel roofing material (tiles/paint) could save in
building costs and alter the math.

solar panels are not manufactured to funtion as roofing.
Caveat, Canon made some PV roof tiles about 2000. I think the major
problem was wiring the blighters up.

 

[terryc]

Sure of course there are losses in transmission but if you are wasting a
surplus

hint, the riverbed doesn't think so.

that might help a bit to compensate. There are some very
efficient electric transmission lines about and pumping is not the only
way to move water

I've got the chair and popcorn. Post away with the information on other,
economically feasible methods of moving water.

although the most used I guess.

You any relation to Tony Abbot ?

Thank diety,I an not related to any current politician.

 

[Sylvia Else]

An ice age, perhaps. They died out long long before the most recent one,
which is the one usually referred to as "the" ice age.

Sylvia.