Who's afraid of Solar PV?

http://theconversation.edu.au/whos-afraid-of-solar-pv-8987

by jdwhit2 • 14 years ago

52 58 14 years ago

theconversation.edu.au

spenrose• 14 years ago

http://reneweconomy.com.au/2012/why-generators-are-terrified...

http://grist.org/article/2011-11-23-the-problem-with-the-ren...

http://www.recycled-energy.com/newsroom/publication/the-batt...

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

http://www.greentechmedia.com/articles/read/how-will-the-cal...

slapshot• 14 years ago

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... gives times between 1.2 hours for a warm start to 6 hours for a cold start.

reitzensteinm8• 14 years ago

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.

SoftwareMaven• 14 years ago

Until fast-charge batteries are a reality (such as the carbon-laced Li-ion discussed previously here), people very much will mind their car being at 20% charge. That means they don't get to drive until the next day, except 5-7pm is key commuting time, when they need to drive now.

brc3• 14 years ago

>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.

rdl• 14 years ago

I think cycle counts for expensive low mass batteries are going to be a lot more of an issue than you think; it would be cheaper to put thermal, flywheel, or gravitational batteries as retrofits into substations and transformers instead, I think, or at least to put them at fixed locations like businesses which draw a lot of power. Even better, it's a free backup power supply for when the grid is down, too.

We agree on some form of distributed storage and maybe generation, though, combined with a smarter grid. It's all current or 5 years out technology.

uvdiv• 14 years ago

The peak load for South Australia was 1.8 gigawatts.

No, that's the average load at a particular time of day. (Averaged over all days over two years). The peak is about twice that:

South Australia experienced a mild summer with only a few days exceeding 40°C. A relatively short heat wave occurred in late January 2011.

The maximum demand for the year was 3,433 MW, and occurred 4:30 PM (Australian Eastern Standard Time) Monday 31 January 2011 (at a temperature of 42.9°C). A higher maximum might have been expected if the same conditions had occurred later in the week, after an extended hot weather period.

http://www.aemo.com.au/~/media/Files/Other/planning/0400-003...

prawn• 14 years ago

FWIW, I forwarded the article and these comments to my friend who works in the energy sector in South Australia. His comment:

"The comments talk about electric cars effectively being used as batteries to help supply the grid during peak times which is a concept I haven’t heard of. Electric cars being plugged in overnight to increase the night-time demand would certainly help as you would significantly increase the base-load demand, thereby improving the load factor of the network. This then distributes the fixed infrastructure costs over a higher number of kWh lowering the per/unit cost of energy."

comicjk• 14 years ago

Or just install twice the solar panels, if they're getting cheap enough. Or put them 4 time zones East (they will have to float in some cases) and send the electricity West.

grecy2• 14 years ago

Better yet, go crazy with daylight savings, moving everything by 5 hours.

The sun will be high in the sky at 5-7pm, generating power when we need it most.

nl5• 14 years ago

Or put them 4 time zones East (they will have to float in some cases) and send the electricity West.

This is a good idea, except electricity transmission costs are significant over long distances like that.

Andys• 14 years ago

I propose a new type of grid with electronic signaling of spot prices.

For heavy duty appliances (eg. air conditioning, water heating) the consumer pre-programs it with a desired average cost and a maximum price per kWh.

Then as demand and supply rises and falls on the grid, the spot price changes, and the devices receive signals and turn themselves on and off as needed. (There would be a certain minimum of fixed-price energy per month to make sure financially strained families never have to go without any)

brc3• 14 years ago

You still need the conventional energy base. You cannot have a grid reliant on solar, because sometimes the sun doesn't shine for days on end.

Solar can top up the grid, and correlates well with air-conditioning driven demand on hot days. But it doesn't coincide with peak load - especially in winter - and will always be a diffuse power source.

You would not only need a cost effective storage solution (and none is in the foreseeable solution) you also need a lot of available space. Even if the panels were virtually free - there still remains large problems with solar power as a baseload energy source. If you solved the storage problem - cheaply - you'd still need 4 - 5 times the collecting capacity to get close to being able to reliably produce power over even a 48 hour period.

It's a great boutique energy solution, particularly for remote usage. But large scale electricity generation will remain the dominant energy source well into the foreseeable future.

nl5• 14 years ago

This is a solved problem. It's called pump storage[1], and is in use world wide. The US has some existing pump storage power plants (eg [2]), but typically they are used to smooth out demand on non-renewable generators (Coal, Nuclear etc).

[1] http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

[2] http://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Stat...

gvb• 14 years ago

[2a] http://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_...

MikeCapone3• 14 years ago

One potential solution is grid-scale liquid metal batteries:

http://lmbcorporation.com/

http://www.ted.com/talks/donald_sadoway_the_missing_link_to_...

Daniel_Newby• 14 years ago

> The difficulty is that, unless storage gets dramatically better, ...

Refrigeration! Put all the air conditioners and refrigerators on timers. Run them hard during peak solar hours. Then turn them off during the evening peak. If that would make the buildings too cool, make ice and melt it later to chill the air. (Some event venues already do this to handle air conditioning ten thousand people during midday.)

pippy• 14 years ago

Capturing energy should only come till after solar PV's generates surplus electricity. If solar panels continue to become cheaper and more efficient it's likely no revolutionary capturing technology needs to be developed. There are plenty of simple, cost effective energy capturing technologies currently in use today (see: http://en.wikipedia.org/wiki/TV_pickup)

ChuckMcM• 14 years ago

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...

politician3• 14 years ago

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.

danmaz742• 14 years ago

"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.

grecy2• 14 years ago

I can tell you've never been to Australia.

EDIT: http://www-das.uwyo.edu/~geerts/cwx/notes/chap10/continents.... (Sorry for the horrible background, the data is there)

politician3• 14 years ago

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.

mikeash• 14 years ago

You do realize that a significant portion of that new sunlight we get every day ends up producing new fresh water?

politician3• 14 years ago

Meanwhile, rivers run into oceans.

evolve2k• 14 years ago

Sounds like technology driven disruption to me.

jorgem4• 14 years ago

>> 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• 14 years ago

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

jorgem4• 14 years ago

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.

maxerickson2• 14 years ago

I doubt it gets that ugly. The per gallon charge for municipal water in the East Bay is ~$0.005. People like flushing their toilets and taking showers, so conservation only eliminates so much.

jorgem4• 14 years ago

I dunno. My water bills average $200/mo, for a single home (no pool, mostly drought resistent yard, etc). We're in an area with low density (out in the country).

I pay about $120 in fees. Then the water is the rest of it.

In winter, when we use less water, my bill goes down to about $130. $10 worth of water per month.

caf4• 14 years ago

If the water utilities are smart they'll increase the fixed "connection charge" component of their bills to cover more of the fixed infrastructure costs.

jorgem4• 14 years ago

Yes. That is why the water part of my bill is sometimes only $10, but the connection charge is $120. It's a worst case scenario in the few months where I hardly use water.

nl5• 14 years ago

(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...

[2] http://en.wikipedia.org/wiki/Early_2009_southeastern_Austral...

[3] http://en.wikipedia.org/wiki/Late_2009_southeastern_Australi...

greendestiny• 14 years ago

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• 14 years ago

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.

yessql• 14 years ago

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.

Who's afraid of Solar PV?

Related Stories