Time for a General Solar Thread?

[madd0ct0r]

Latest salvo:

http://www.theguardian.com/commentisfre ... ?CMP=fb_gu

Last week, for the first time in memory, the wholesale price of electricity in Queensland fell into negative territory – in the middle of the day.

For several days the price, normally around $40-$50 a megawatt hour, hovered in and around zero. Prices were deflated throughout the week, largely because of the influence of one of the newest, biggest power stations in the state – rooftop solar.

“Negative pricing” moves, as they are known, are not uncommon. But they are only supposed to happen at night, when most of the population is mostly asleep, demand is down, and operators of coal fired generators are reluctant to switch off. So they pay others to pick up their output.

That's not supposed to happen at lunchtime. Daytime prices are supposed to reflect higher demand, when people are awake, office building are in use, factories are in production. That's when fossil fuel generators would normally be making most of their money.

The influx of rooftop solar has turned this model on its head. There is 1,100MW of it on more than 350,000 buildings in Queensland alone (3,400MW on 1.2m buildings across the country). It is producing electricity just at the time that coal generators used to make hay (while the sun shines).

The impact has been so profound, and wholesale prices pushed down so low, that few coal generators in Australia made a profit last year. Hardly any are making a profit this year. State-owned generators like Stanwell are specifically blaming rooftop solar.

Tony Abbott, the prime minister, likes to say that Australia is a land of cheap energy and he’s half right. It doesn’t cost much to shovel a tonne of coal into a boiler and generate steam and put that into a turbine to generate electricity.

The problem for Australian consumers (and voters) comes in the cost of delivery of those electrons – through the transmission and distribution networks, and from retail costs and taxes.

This is the cost which is driving households to take up rooftop solar, in such proportions that the level of rooftop solar is forecast by the government’s own modellers, and by private groups such as Bloomberg New Energy Finance, to rise sixfold over the next decade. Households are tipped to spend up to $30bn on rooftop modules.

Last week, the WA Independent market Operator forecast that 75% of detached and semi detached dwellings, and 90% of commercial businesses could have rooftop solar by 2023/24.

[Darth Tanner]

A nonsense article that glosses over the fact coal and gas do all the heavy lifting generating over 91% of total electrical demand.

I'm not familiar with the Australian energy market but a negative energy price is a market failure event in my book, if it happened in the UK (its happened at least twice in the last two years) something would have gone horribly wrong in the planning and gate closure stage. Hardly something to be celebrated.

Australia is a brilliant country for solar, especially with the subsidy system it has, but the article laying into the central grid as being the worst thing since sliced bread is ignorant in the extreme and very short sighted.

The next step, of course, is for those households and businesses to disconnect entirely from the grid.

No answer on where the users are going to get energy at night or under cloud or if they need more than what they can generate in solar panels... or indeed how they would pay for their solar excess without the ability to export unused generation.

By customers generating their own heavily subsidised electricity and not buying it from the central grid the per unit costs associated with the central grid are doomed to increase as their costs are spread across fewer units... however despite this end users still need access to the central system so are forced to pay more per uni on distribution ect. Also the centralised generators will have to increase their prices to stay in business, the article is all well and good saying the coal units are losing money because of the low energy price but what would happen if they shut - they are still providing the foundation of the energy market.

Not that I think anything can be done about this, solar is truly the main growth technology for energy generation in the developed world as its cheap, usually doesn't need planning permission and can be installed in a matter of days/weeks. It also passed the tabloid level of criticism as it doesn't use the word nuclear and isn't as visible as a wind turbine. As a bonus all the damaging by-products can be dumped on China far from sight.

The long term health of these countries electricity networks is severely at risk and I'd image their bills will sky-rocket.

[Borgholio]

Quite the contrary, I think this is a sign of things going the right direction and it's far from nonsense. It points out (correctly) that the highest peak demand should be in the middle of the day. When you have so many solar panels that you actually drive energy costs into the negative for the large power companies, that's a milestone. You are correct in that coal and fossil fuel supply a lion's share of the power at night or on cloudy days, but that was never in dispute. Even the biggest advocates of solar admit that you need something else to provide electricity at night or on cloudy days, and for now that something else is coal. Not ideal, but better than using coal for 100% of your power...and we can fix that later anyways.

[Darth Tanner]

It points out (correctly) that the highest peak demand should be in the middle of the day.

For Australia maybe, the rest of the world largely has their peak in the evening after sun down. I suppose countries with extreme heats and thus wide air con loads this is more suitable.

that's a milestone.

Why is it a milestone, solar forcing a market failure is not a good thing.

Even the biggest advocates of solar admit that you need something else to provide electricity at night or on cloudy days, and for now that something else is coal. Not ideal, but better than using coal for 100% of your power...and we can fix that later anyways.

Yes, when solar is displacing coal - although it is a 'green' solution it is not an efficient solution in terms of minimising the cost of the energy system - those coal plants, by reducing load midday when solar is plentiful must then charge more for their energy for the rest of the day to make up for the losses - they can't really scale down enough to shut down as it takes them too long (not to mention they would still likely be producing the majority of the energy regardless of the solar) so the solar is in effect double producing capacity that is already there at a cheaper level. Obviously with coal that's considered a good thing as it arguably reduces carbon, but you would have the same situation with a largely nuclear fleet.

[madd0ct0r]

Tanner, I think you're getting mixed up between wholesale electricity (sold to large factories and energy supply companies) and domestic electricity, bought at a fixed rate tariff. If coal power companies have had their profits eaten by domestic solar, that's their failure in the market, not a market failure. The least efficient/profitable of them will go bust, and the overall power supply will reduce until it's profitable again.

I mean, really, you shouldn't be using coal plants to cover demand peaks. That's an incredibly inefficient, dare I say stupid, use of resources.

From the domestic user's POV, it doesn't even matter if the cost per grid unit goes up. They're already using less grid units because they put in solar panels, so the net effect on their bill is much less. It just makes it more advantageous to expand the amount of solar panels you have, since the grid price went up, your payback time just went down.
Coal power is digging it's own grave.

[salm]

From the domestic user's POV, it doesn't even matter if the cost per grid unit goes up. They're already using less grid units because they put in solar panels, so the net effect on their bill is much less. It just makes it more advantageous to expand the amount of solar panels you have, since the grid price went up, your payback time just went down.
Coal power is digging it's own grave.

I have no problem with domestic PV but saying that it deosn´t matter if the cost per grid unit goes up is wrong. There are a lot of people who have not way of installing personal PV and to them it matters a lot.

[Darth Tanner]

If coal power companies have had their profits eaten by domestic solar, that's their failure in the market, not a market failure. The least efficient/profitable of them will go bust, and the overall power supply will reduce until it's profitable again.

Exactly... whereby the ability of the energy grid to meet the peak demand is reduced and you risk blackouts. In the UK this is leading to more and more levels of subsidy stacked on top of each other to compensate for non despatchable generation making up a larger share (also because there is no actual financial incentive for a private company to support a grid with excess capacity - as you say it simply leads to lower prices.)

I mean, really, you shouldn't be using coal plants to cover demand peaks. That's an incredibly inefficient, dare I say stupid, use of resources.

Obviously gas is more cost efficient to vary for peak usage but I believe in Australia the vast majority of the installed capacity is coal.

From the domestic user's POV, it doesn't even matter if the cost per grid unit goes up. They're already using less grid units because they put in solar panels, so the net effect on their bill is much less. It just makes it more advantageous to expand the amount of solar panels you have, since the grid price went up, your payback time just went down.

I agree, to either the domestic user or industrial user having a solar panel on their roof is a good situation to be in, they are benefiting disproportionately from having a central grid to draw from whilst receiving subsidised energy themselves. For everyone receiving that subsidy however the price to everyone goes up as they are the ones paying for it, driving up the cost of their energy. Also if you want to keep the lights on your still going to have to pay for the same distribution system and reserve generation capacity regardless of how many solar panels you also pay to install, thus your left paying for the centralised system anyway.

Coal power is digging it's own grave.

Market customers are, their driving up their own energy prices. Obviously coal will be the first victim of this but once the first few die the market price will balance back in their favour. And obviously once the lights are at risk of going out they can rub their hands with glee at being able to set whatever price they like.

There are a lot of people who have not way of installing personal PV and to them it matters a lot.

It also doesn't matter how much PV you install, you will always be paying for the now higher rates over night and for any power your pv cant generate.

[salm]

It also doesn't matter how much PV you install, you will always be paying for the now higher rates over night and for any power your pv cant generate.

Well, obviously, but people who have PV can compensate (probably overcompensate) for the higher price.
People with PV will all in all pay less, whereas people without one will pay more.
This crates an incentive to install PV which is good but one shouldn´t forget that poor people can not install PV because of the initial cost, so poor people will actaully pay rich people´s bill if you don´t watch out and do something to counter act this.

[Darth Tanner]

linky

Also I found the above data on Australia energy demand profile... I had no idea their transmission system was not joined with 5 separate regions seemingly operating independently... I would hate to work for their grid balancing organisation!

Their peak demand periods however are all 18:00-19:00... not the period when solar would be outputting at maximum although I'm guessing the embedded nature of solar is not capturing solar generation except as demand reduction - the differences are not large enough to shift the peak however considering there's only 3.2GW installed nationally.

so poor people will actaully pay rich people´s bill if you don´t watch out and do something to counter act this.

It was a running joke in the UK that the solar subsidy was a subsidy to the rich... if your renting you can't install it and if you have a mortgage your better off paying that off early - only people who have paid off their mortgage and have cash sat around really benefit from a solar install financially. We did have a craze of companies offering free solar in exchange for keeping the subsidies which many people took up, leasing off their roof. I'm sure they appreciate making their house practically unsellable.

[madd0ct0r]

COMPARE
SA
http://www.aemo.com.au/Electricity/Data ... d-Graph-to queensland (where the article is set):
http://www.aemo.com.au/Electricity/Data ... -Graph-QLD

Lessee, domestic solar would appear on the Queensland graph as a depression in average demand compared to the South Australia one (and even that one has solar in there too). SA graph is largely flat between getting up at 5am and getting home at 6pm. Queensland shows a MASSIVE drop in the same period that tracks the sunlight perfectly.

And with that sort of volatility they use coal to cover the peak? I'm not surprised the power generating companies are struggling to make a profit. Either they go bust and something else takes their place, or Australia gets into the Aluminium refining business pronto.

Also laughing a bit at Darth Tanner's logic. 'It's more cost efficient to pay off a mortgage then buy solar, but when I see a house with the solar rights already owned by someone else for 10 years, I'm not going to buy it (with a mortgage)".

@Salm, you are 100% correct those unable to get solar get shafted under the current system. The article argues that by allowing the remotest parts of the grid to go off-grid, costs of maintaining the overall grid will vastly reduce (20% of customers is 80% of the cost, the last mile problem and all that). Going off grid, especially on solar alone, is not a trivial problem, but there's profit to be made in it: http://www.gizmodo.com.au/2014/05/austr ... -sunpower/

[Darth Tanner]

SA graph is largely flat between getting up at 5am and getting home at 6pm. Queensland shows a MASSIVE drop in the same period that tracks the sunlight perfectly.

True, that is a massive drop in demand over those hours. You seem quite optimistic over the consequences of the coal generators going bust though, I don't know how close Australia is to their capacity safety levels but I'm sure with such a broken up transmission system they can't allow a large chunk of despatchable generation to disappear, especially when it is needed to hit the peak demand when solar is mostly shut down for the night.

Also laughing a bit at Darth Tanner's logic. 'It's more cost efficient to pay off a mortgage then buy solar, but when I see a house with the solar rights already owned by someone else for 10 years, I'm not going to buy it (with a mortgage)".

Free solar offers negligible benefit to the house owner (although since its free money its difficult to argue against), you would be able to buy the energy generated by the panels at reduced rate compared to grid energy from the solar company but the actual saving would be almost unnoticeable on an annual basis.

Also you simply would not be able to buy a house with a mortgage from most providers when the roof has been leased to someone else. Well I imagine you could but you would have to go through significantly more legal hoops to get additional paperwork regarding that and letters of authorisation from the solar company, which likely would put off most buyers as well as finding a bank that would accept such a deal which is not that many in the UK.

Going off grid, especially on solar alone, is not a trivial problem

A challenge indeed, the cost of providing battery storage to keep the average house running over a long cold winter night from the solar produced during a cloudy winter day under snow and rain would be immense. If the cost of the transmission system keeps on rising however its going to look more and more attractive especially as the general trend on storage prices is downwards.

[salm]

It was a running joke in the UK that the solar subsidy was a subsidy to the rich... if your renting you can't install it and if you have a mortgage

That´s actually something I don´t understand. Why don´t the legislator simply make it possible for renters to install PV on the roof?

As for fearing that people will disconnect from the gird: This doesn´t seem to be problem in a lot of countries because the law simply says that you´re not allowed to disconnect.

[madd0ct0r]

SA graph is largely flat between getting up at 5am and getting home at 6pm. Queensland shows a MASSIVE drop in the same period that tracks the sunlight perfectly.

True, that is a massive drop in demand over those hours. You seem quite optimistic over the consequences of the coal generators going bust though, I don't know how close Australia is to their capacity safety levels but I'm sure with such a broken up transmission system they can't allow a large chunk of despatchable generation to disappear, especially when it is needed to hit the peak demand when solar is mostly shut down for the night.

Also laughing a bit at Darth Tanner's logic. 'It's more cost efficient to pay off a mortgage then buy solar, but when I see a house with the solar rights already owned by someone else for 10 years, I'm not going to buy it (with a mortgage)".

Free solar offers negligible benefit to the house owner (although since its free money its difficult to argue against), you would be able to buy the energy generated by the panels at reduced rate compared to grid energy from the solar company but the actual saving would be almost unnoticeable on an annual basis.

Also you simply would not be able to buy a house with a mortgage from most providers when the roof has been leased to someone else. Well I imagine you could but you would have to go through significantly more legal hoops to get additional paperwork regarding that and letters of authorisation from the solar company, which likely would put off most buyers as well as finding a bank that would accept such a deal which is not that many in the UK.

Going off grid, especially on solar alone, is not a trivial problem

A challenge indeed, the cost of providing battery storage to keep the average house running over a long cold winter night from the solar produced during a cloudy winter day under snow and rain would be immense. If the cost of the transmission system keeps on rising however its going to look more and more attractive especially as the general trend on storage prices is downwards.

On the first, yeah, I'm optimistic. Bigger companies have moved faster when their existence is threatened. The Uk uses oil stations running 6% of the time to cover peaks. To put it the other way, I don't particularity see why the status quo of dirty coal overproducing electricity should be protected. Dropping half the plants and running a couple of coal gasifiers instead actually linking up the grids so that other states can benefit from Queensland's glut; or just building short term storage-generation plants would all be profitable in the long run, and almost certainly will be pursued.

As for the mortgage issues: an admittedly biased source: http://ashadegreener.co.uk/faqs/

Some people say it won’t be possible to get a mortgage or re-mortgage on properties that have your panels.
This myth is born of selective reporting by some journalists. The leases of some ‘Rent a Roof’ schemes do not comply with the Council of Mortgage Lenders Guidelines, and these could cause future problems for their customers. Our Lease does comply with the Guidelines and our in-house solicitor and Legal Director, Anne Emmerson, was actually consulted by the CML when they were compiling the Guidelines. Many of our customers’ homes have already been sold with our free systems in place without any problem whatsoever. We have the agreement of every major mortgage provider that they will give their consent to our installations. We have also had confirmation from these mortgage providers that having our system installed would not stop a homeowner from raising a mortgage on a property or for re-mortgaging purposes. In fact, some of our customers who have had remortgages since having our system installed found the process much quicker than normal because we put them in touch with our established contacts within the legal departments of the relevant mortgage providers. Our legal department will assist with this type of thing.

Finally - snow? in Asutrailia?
Off grid in the Uk is a different beast, but fortunetly we mostly need heating, not electricity to drive an AC. I've got the calcs somewhere for a solar thermal system pumping heat into a GSHP over the summer to be used in the winter. Sadly, though, I'm renting and will be for some time to come

[Simon_Jester]

I think something's being missed in the posts debating against Tanner.

The catch with household solar is that peaks in demand will rarely coincide with peak solar power production.

Therefore, you still need a national electric grid capable of producing however many megawatts the nation needs at peak demand, and the household solar isn't reducing the number of giant power plants you need to build.

So as a consequence, there is still a need for an expensive national electric grid... except that running this grid is now less profitable because the individual power plants sell fewer kilowatt-hours than they used to. So energy costs to buy power from the grid go up... which is bad for everyone who doesn't already have solar cells installed.

[salm]

I think something's being missed in the posts debating against Tanner.

The catch with household solar is that peaks in demand will rarely coincide with peak solar power production.

Therefore, you still need a national electric grid capable of producing however many megawatts the nation needs at peak demand, and the household solar isn't reducing the number of giant power plants you need to build.

So as a consequence, there is still a need for an expensive national electric grid... except that running this grid is now less profitable because the individual power plants sell fewer kilowatt-hours than they used to. So energy costs to buy power from the grid go up... which is bad for everyone who doesn't already have solar cells installed.

That´s one of the reason why the poor who can´t buy PV subsidize the rich who can if you don´t implement this correctly.

[Darth Tanner]

Finally - snow? in Asutrailia?

Australia has snow too!!! I think Admittedly its rare but if you don't want the lights to go off when it does snow you have to plan for that worst case scenario.

That´s one of the reason why the poor who can´t buy PV subsidize the rich who can if you don´t implement this correctly.

How would you implement this so that the poor benefit? The only means would be to dump the solar subsidy on the tax payer rather than electricity consumer. This would still equate to the rich getting in effect a tax rebate whilst the poor are left with their tax revenue going to the rich instead of wherever else it could be spent.

[madd0ct0r]

another newish one:

http://sciencealert.com.au/news/20140807-25843.html

India is building a massive, floating solar power plant
BECKY CREW
TUESDAY, 08 JULY 2014
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India will install a 50 megawatt solar power plant on a 1.27 million square metre floating platform by the end of the year.
solar
Having already started on their plan to install 10 megawatt (MW) solar plants on top of several canals, India has taken the creative use of space one step further and is planning on floating a power station on one of the large stretches of water in Kerala, a state in south-western India.

This floating solar power technology was developed by India's Renewable Energy College and the plant is being built by Indian energy company, the National Hydro Power Corporation (NHPC). The first plant is scheduled to be commissioned in October this year.
"NHPC had contacted us for offering technical know-how and installation assistance for their proposed 50-mw plant,” said SP Gon Choudhury, chairman of the Renewable Energy College, to Andrew Tarantola at Gizmodo. “Each station would require around 3000 square feet [914 square metres] of space to generate 20 kilowatt of power. There are many water bodies that could be used for this."
And it looks like there’ll be little environmental impact from the project, as Choudhury explains:

“The ecology of the water body is not likely to be affected much and it will also reduce evaporation, thus helping preserve water levels during extreme summer. Solar panels installed on land face reduction of yield as the ground heats up. When such panels are installed on a floating platform, the heating problem is solved to a great extent. This isn’t an ideal solution, it’s not as though we can go and cover the world’s oceans with photovoltaic cells, but it’s certainly a solid intermediary step until we get those space-based solar farms up and running.”

The project is similar to Japan’s largest offshore solar power plant, which was launched late last year. The 70MW Kagoshima Nanatsujima Mega Solar Power Plant was designed as part of a move towards clean energy following the 2011 Fukushima disaster, and is located in Japan’s Kagoshima Prefecture of islands.

I'm not so sure about his 'little ecological impact' but if you go to the site the image shows the plant barely covers a quarter of the lake. and most of the lake life happens in the shallows anyway. I really don't understand where the journalist got the 1.27 million square meters platform idea from, the 914 square meters mentioned below is much more sensible.

[salm]

How would you implement this so that the poor benefit? The only means would be to dump the solar subsidy on the tax payer rather than electricity consumer. This would still equate to the rich getting in effect a tax rebate whilst the poor are left with their tax revenue going to the rich instead of wherever else it could be spent.

I don´t know. I have not concerned myself enough with this topic enough to give a qualified anwer to this question. It just occurs to me that this is problem that has to be either tackled or accepted.

One important part of it is creating an easy way (concerning the legal as well as the practical part) to install PV on rented property, as well as creating a legal and technical framework for setting up cheap and safe balcony PV which you can simply plug into your wall socket. Also there needs to be some kind of way to setup PV which is halfways mobile, so when I move I can take it with me.

[Darth Tanner]

I'm guessing the National Hydro Power Corporation owns the lake anyway so doesn't have to pay for any land to put the panels on, a significant saving compared to renting some fields.

I'd imagine if there happens to be a pumping/treatment station using the lake they can plum the panels straight into it and save significantly on losses.

I really don't understand where the journalist got the 1.27 million square meters platform idea from, the 914 square meters mentioned below is much more sensible.

I think he just did the maths to scale up from 914 square meters proving 20KW - which gives a 21W per square meter which seems pretty terrible to me, that many panels would be at least 110KW but I guess they could be using cheap panels? Or the article has the sizes confused by the fact the picture is definitely not a 50MW site. A 1.27 million square meter array should be round 150MW as well!

[Darth Tanner]

PV which you can simply plug into your wall socket. Also there needs to be some kind of way to setup PV which is halfways mobile, so when I move I can take it with me.

I'm not an electrician but I don't think that's possible because of the AC/DC issues. Mobile would be doable but as its has to be roof mounted to be worthwhile it would be rather difficult to keep it secure without some sort of permanent fittings. Its its just on top of your garage or other flat roof then maybe?

[madd0ct0r]

I'm really confused now.
If 20 kilowatts is 914 square meters, 50 Megawatts is 1000* 2.5 *914 square meters = 2,285,000 square meters, literally double what the article predicts (and with an astonishingly lousy wattage). Using my figures for Bangladesh, at 20% efficient panels 50 MW needs ~ 72,700 square meters of panel, with probably 10% again for framing

( , are thousand markers, not decimals)

I give the fuck up. let's see what gets built.

[salm]

PV which you can simply plug into your wall socket. Also there needs to be some kind of way to setup PV which is halfways mobile, so when I move I can take it with me.

I'm not an electrician but I don't think that's possible because of the AC/DC issues. Mobile would be doable but as its has to be roof mounted to be worthwhile it would be rather difficult to keep it secure without some sort of permanent fittings. Its its just on top of your garage or other flat roof then maybe?

Oh no, it´s definetaly possible. You can actually buy them and they´re pretty cheap as well. The problem with them is that on the one hand they can cause problems such as starting a fire because they´re plugged in after the circuit breaker of your appartement and (I guess, because of that) they´re in a legal gray area.
But, if you could tackle these problems (which seems pretty possible), they´d be a great way for adding some free kw/h to your appartement if you have no access to decent PV space otherwise.

I don´t think there is an AC/DC issue at all. You just put an inverter into you circuit and you should be fine.

[Darth Tanner]

Oh no, it´s definetaly possible. You can actually buy them and they´re pretty cheap as well.

Interesting - I didn't know people were actively selling these. I would stress however they are apparently illegal as they are not only fire risks but could electrocute anyone working on your power grid during an outage as they tend to lack proper island prevention circuits.

I don´t think there is an AC/DC issue at all. You just put an inverter into you circuit and you should be fine.

The inverter is the solution to the problem, a proper inverter is a large and expensive piece of kit though requiring an electrician.

I'd love it if they were safe though - I'd definitely buy one.

[Me2005]

I'd love it if they were safe though - I'd definitely buy one.

Here is an example of such a device. Looks like they sell kits up to 5 kW.

The kit meets the federal standards for grid interconnectivity, and the inverter is UL-1741 approved.

I guess UL approval means 'is safe to be operated by morons,' so that answers that. I'm wondering if you'd pop breakers (either on your house or on the panel itself) though - most 120 outlets aren't going to be dedicated or on big enough breakers/wires to take much more than 1 kW. Many of their bigger systems use 240 outlets, which would probably be dedicated (as you'd either have an electrician install one or plug in where your oven/drier used to be) and that'd solve that problem.

[His Divine Shadow]

One of my future projects is going to be building my own solar collector using beer cans. It'll be a simple air heating device with a fan that I'll use to supplement heating in my garage. Someone already did it and got good results so I'll be following his plans, in swedish though, but google translate the page, super simple in chrome:

http://www.brunzell.com/projekt/solfangare/