At last : Some intelligent engineering to mitigate a climate problem

[Michael GilliganParticipant @michaelgilligan61133]

Reading this has brightened my day: **LINK**

https://theconversation.com/first-solar-canal-project-is-a-win-for-water-energy-air-and-climate-in-california-177433

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

[Tony Pratt 1Participant @tonypratt1]

Looks good, in light of the current energy & food situation which has been flagged for the last 20 odd years exactly why are we covering over arable land with warehousing, housing & 'solar farms'?

Tony

[Brian WoodParticipant @brianwood45127]

An excellent idea, well spotted Michael.

Something we could exploit here in the UK is to install solar arrays on the roofs of industrial buildings rather than continue to cover productive land with solar farms. There must be square miles of those surfaces simply crying out for such use.

And for the Government to put some real money into developing the recently unveiled flexible solar sheeting to cover other surfaces. It may not be as efficient as rigid panels, but it should be cheap to produce and treat like a form of carpet once manufacture is geared up for it.

Brian

Edited By Brian Wood on 02/03/2022 10:33:43

[J HancockParticipant @jhancock95746]

4000miles of canal , equals say 200sq miles max of solar panel , equals say 15 x15 sq miles of desert

equivalent installation. Now compare installation costs and see why it hasn't been done.

[HopperParticipant @hopper]

Posted by Brian Wood on 02/03/2022 10:29:10:

An excellent idea, well spotted Michael.

Something we could exploit here in the UK is to install solar arrays on the roofs of industrial buildings rather than continue to cover productive land with solar farms. There must be square miles of those surfaces simply crying out for such use.

….

Edited By Brian Wood on 02/03/2022 10:33:43

Don't forget domestic house roofs. They are doing that here in Australia. Some new housing estates all have panels on the roof that feed into the grid, regardless of where the occupants choose to buy their power from. All run by a power company that co-ordinates it. These days in Australia, there are dwindling numbers of industrial buildings and growing numbers of houses. The roof of a house fully covered in solar panels will produce more power than one household typically uses. Gian batteries are used to iron out the day/night supply/load issues. It's to the stage already that power companies are planning to shut down coal fired powerstations 10 years before the planned end of their life because they are not going to be economical in the face of solar for much longer. Despite a federal government that has fought against it tooth and nail, the cost factor means the private sector is running with solar.

[HopperParticipant @hopper]

Posted by J Hancock on 02/03/2022 11:51:47:

4000miles of canal , equals say 200sq miles max of solar panel , equals say 15 x15 sq miles of desert

equivalent installation. Now compare installation costs and see why it hasn't been done.

The big issue in California though is the water, and evaporation there of. Water is like gold there. Huge population, hot dry climate and no local water supply. So it comes in open canals across miles and miles of dry windy desert. The savings from reduced evaporation would have to be entered into the cost equation.

As far as multiple small installations vs huge solar "farms" goes though, Australia is full of 5 to 10kW house rooftop arrays and as said in above post, it's running the coal burners out of business. A real game changer. Of course it's a smaller market and sunnier climate than UK but shows what can be done rather easily to a level higher than anyone really expected if the economics are right. Cheap is cheap. Power distribution companies love it, all that cheap rooftop power being fed into the grid. HOme owners love it, all those lower or non-existent power bills. Win-win.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by J Hancock on 02/03/2022 11:51:47:

4000miles of canal , equals say 200sq miles max of solar panel , equals say 15 x15 sq miles of desert

equivalent installation. Now compare installation costs and see why it hasn't been done.

.

Did you read the whole story ?

MichaelG.

[Ex contributorParticipant @mgnbuk]

Australia is full of 5 to 10kW house rooftop arrays

Must have bigger roofs in Australia than UK houses !

My* installation is around 3.5kW & it fills the south facing side of the roof. Seems that we are limited to around 3.8kW single phase without getting express approval from the supply authority.

* on my roof, but not owned by me – yet. I get to use all the electricity the panels generate, with any excess I can't / don't use going into the grid. The company that owns the panels gets the feed-in tariffs which, IIRC, were 42p per kWH generated at the time of installation – the system has it's own mobile phone connection & sends generation reports back automatically for them to claim the feed-in tariff. Last I heard our installation generates around 4250kWH a year.

The company installed the kit & maintains it. At the end of the 25 year agreement, they guarantee that the installation will be at least 80% of the original installed capacity, replacing any degraded panels to achieve that, then it becomes mine. Cost at the time to install was around £18K IIRC (more than I could have afforded then ) – installation costs have fallen substantially since, as have the FITs. The "rented roofs" model must only have worked out for them when the FITs were high, as they no longer install systems under the arrangement I have.

Germany is way ahead of the UK for putting solar PV on building roofs – must have paid out a lot in subsidies to get the kind of uptake they have. Probably why they have amongst the highest electricity tariffs in Europe.

Nigel B.

[garyParticipant @gary44937]

anyone thinking about getting solar panels fitted please make sure you get a firm that has a good reputation. i am a self employed slater and have seen some terrible bodges, brackets simply screwed through the slates without a sealing washer, on tiled roofs some brackets are screwed on to the rafter and the tile laid on top which leaves a gap for wind and rain to get in, then there is the rattling noise when windy and the mess of birds using the ideal place for there nests. i refuse all repair work where solar panels are fitted because the leaks are often under the panel and you cant use a roof ladder for access.

[Phil H1Participant @philh196021]

A bit alternative and completely crazy idea – or is it? As I flicked the button on my central heating to warm up a bit, I decided to look at my boiler information. It kicks out 10s of kW to keep all the rooms in the house warm and with other females in the house (not being sexist – just a fact), they tend to like it warmer than me.

Then I had a crazy thought. Why aren't we all walking round in temperature controlled suits that would be rated at about 100W rather than 10s of kW? The building would be controlled to say +10 degrees C at a fraction of the energy and we would be very comfortable walking round in our individually controlled 'space suits'.

I know some might just say well put a jumper or two on but you then have difficulty with the layer thicknesses and the on and off business as you overheat at certain times.

[MikeKParticipant @mikek40713]

I'm skeptical of all such magical solutions. Magical as in, "Let's just put solar panels over the canal!". Financial and environmental costs are often naively understated. How will it change the environment? What happens to birds and other animals that use that water? Does having a shade over the canal produce some other unanticipated/undesired consequences? Will it rust easily by being over water?

I'd rather humans stop living in the DESERT and drastically reshaping it to suit them. All of that water used to empty out into Mexico's Sea of Cortez with environmental consequences of its own.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by MikeK on 02/03/2022 13:58:42:

I'm skeptical of all such magical solutions. […]

.

I suppose that’s why they are doing a ‘proof of concept’ installation first.

MichaelG.

[J HancockParticipant @jhancock95746]

Yes MG, I did read the article.

The 'PoC is, rightly ,just one mile of the 4000.

My guess , we'll have fusion before the other 3999 miles get covered.

[clogsParticipant @clogs]

I used to live there nearly 50 years ago (Calif) and they were compaining about water evap losses then…..

just how many millions of gallons of precious water has been lost…..Regardless of cost it needs to be done…..

theres a lot of unemployment there so plenty of labour….

no prob for wildlife just raise it off the wall a foot….

besides other than scorpions n snakes there aint much wild life and the Hippy's have grown old n left…hahaha….

Solar panels should be copulsory thoughout the western style world where houses should face south where poss…..

lastly…..

when I lived in sunny SW France the quote for materials only for a 200ltr hot water array was over €4000 almost 20 years ago….extra lab €1500 min subjected to a survey….

mine came complete from Israel for a grand…..

the same thing in Greece……is a little over €1200 for the same thing……90% of houses have them fitted…..

At that kinda money even in the UK with it's rubbish weather it wont take long to get ur money bake….Promise…

[Dave HalfordParticipant @davehalford22513]

In the UK with only one desert the solar farms have grass grow beneath the panels, the answer to this is sheep.

[duncan webster 1Participant @duncanwebster1]

Posted by Brian Wood on 02/03/2022 10:29:10:

………

Something we could exploit here in the UK is to install solar arrays on the roofs of industrial buildings rather than continue to cover productive land with solar farms. There must be square miles of those surfaces simply crying out for such use.

………..

This really is a no-brainer, but our government has no brain. They should amend the building regs so every industrial building has to have solar panels from new, then change the business rates regime so if you haven't got them on existing buildings you pay more. I do accept that some old buildings it won't be practical, but this could be allowed for

[HopperParticipant @hopper]

Posted by mgnbuk on 02/03/2022 13:29:32:

Australia is full of 5 to 10kW house rooftop arrays

Must have bigger roofs in Australia than UK houses !

My* installation is around 3.5kW & it fills the south facing side of the roof. Seems that we are limited to around 3.8kW single phase without getting express approval from the supply authority.

etc…

Yes I think that is the case. We don't do semi-detached or those row houses that are common in the UK. Everyone has to have their own "McMansion" which I think is what you call bungalow style. As kids don't play outside these days and dads don't work on cars in the backyard etc, the houses have grown to full the whole block to the point that their eaves almost touch the eaves of the house next door. So lots of large roofs and the most common base model solar array now is about 6kW.

Sounds like a good scheme that you have for where you live though.

[HopperParticipant @hopper]

Here is another piece of brilliant engineering in use to mitigate the results of global warming. A flood barrier in the coastal town of Maryborough, Queensland, made from hundreds of special aluminium trestles and long tarpaulins plus presumably sandbags. It is erected when a flood is imminent and taken down after the waters recede. Brilliant. Currrently in use holding back floodwaters about 3 feet deep from the local high street. (Which obvoiusly is not high enough!), following record summer rainfall and rivers bursting their banks linked to higher temperatures than normal.

**LINK**

 

Edited By Hopper on 03/03/2022 03:45:01

Edited By Hopper on 03/03/2022 03:46:42

[Michael GilliganParticipant @michaelgilligan61133]

That looks excellent, Hopper

Closely spaced to nicely distribute the load.

MichaelG.

.

Smug edit: __ I thought the frames looked more like steel than aluminium

… Reading your link seems to corroborate that.

… but please correct me if you know for sure.

Edited By Michael Gilligan on 03/03/2022 07:27:02

[Frances IoMParticipant @francesiom58905]

similar schemes are, I think, in use in UK – there was a very similar system erected when the Wey threatened to overflow in Guildford a couple of years ago.

[pgk pgkParticipant @pgkpgk17461]

Posted by Frances IoM on 03/03/2022 08:41:16:
similar schemes are, I think, in use in UK – there was a very similar system erected when the Wey threatened to overflow in Guildford a couple of years ago.

Indeed – shrewsbury

[noel shelleyParticipant @noelshelley55608]

Hoppers flood defences ! Check out PORTADAM. I saw it used to repair the bridge piers at Sturminster Newton in dorset. What a brilliant idea. It was it's simplicity that was so clever ! The output from solar panels can be considerably increased by auto tracking the sun, why is it not done ? cost or complexity ? Noel

[Brian WoodParticipant @brianwood45127]

More flood barriers in use along the Severn at Ironbridge only recently.

Tracking the sun for PV systems means moving large support frames, simply impractical on rooftop installations

Edited By Brian Wood on 03/03/2022 10:59:22

[Nigel Graham 2Participant @nigelgraham2]

The title alone highlights a major aspect of the entire climate-change problem:

– Far too few campaigners, politicians, journalists etc really understand the nature of science and engineering. They have little idea of what Engineering is or what Engineers do, their lay knowledge of anything technical is woefully inadequate; and many seem unable to think beyond pressing "Enter" on a keyboard to make it all happen.

It and some of the contributions together show another major difficulty –

– That the whole matter hinges on electricity. Look at this way:

Which of these is not a "fossil fuel" : coal, peat, petroleum, lignite, natural gas, "bio-gas" ?

We know, but do they know, that the peat might be considered one, sort of; but petroleum is not. It is a source of fuels, but also of so many other materials for products so universal we take them for granted. I wonder if those campaigners, politicians etc. have really considered the implications of its non-availability. Such as, with what would we make wind-turbines?

+++++

That photograph of Shrewsbury shows a terrace built probably in the 19C. I wonder how they coped with the river overflowing then? Old riverine towns used to be either built up the valley-sides or on local eminences where possible, but over the years crept down to the banks. In the last several decades of course, remote building companies and planning-authorities have allowed the most crassly-located developments, then their inhabitants want everyone else to save their homes from the floods that always been known to occur there.

' ' ' ' '

A somewhat different problem, but one that will become especially pertinent if the seas do rise by more than a foot or so:

The lowest part of Chiswell, at the foot of Portland, used to suffer from flooding when South-Westerly gales combined with high Spring Tides to drive sea-water through the Chesil Beach shingle bank. The water used to have an easy outlet through an area called The Mere, into Portland Harbour; and the 19C houses built in the lowest part (an area called Victoria Square) had raised ground-floors and were largely self-draining.

Over the 20C MoD developments covered The Mere, raising the land surface and blocking the natural outlet. The joint LSWR/GWR railway had been built with culverts.

Eventually the various authorities realised Something Had To Be Done. In the 1960s a massive sea-wall was built to protect a very vulnerable section of coast from heavy erosion. In the 1990s (I think it was) an interceptor drain was constructed within the Beach, opening into a new channel and culvert taking the water into Portland Harbour.

A point about those 19C and earlier properties in areas prone to flooding is that although floods would have been as distressing for householders then as they are now, no-one had the sort of very fragile furnishings, fittings and possessions most of use have now. They knew floods could and did happen so must have been fairly well prepared for it.

' ' ' '

Aurto-tracking for solar panels is not technically difficult and not even new engineering (think of astronomical observatories). My brother built his own tracking version, using an array perhaps 3 X 2ft, on his shed roof. The problem with applying it to a big commercial installation is that it could increase the ground area for the array area, and certainly add significant construction and maintenance costs. The gain might not be sufficient for the effort and cost.

…… …… ……

I am impressed by those 'Portadams'; but ending on a lighter note, they make me think them only a more adaptable version of how one of my caving-clubs deals with Fell Beck for our annual Gaping Gill Winch Meet, a public caving 'experience' (even shopping has to be called an 'experience' these days…).

To divert the stream down a subsidiary entrance we plant heavy steel stakes in holes drilled in the bed-rock, fasten big plywood boards to them, propped further by heavy rocks; then cover the boards with plastic sheet weighed down with stones. Heavy rain can still make the stream over-top the dam, about two feet high.

At the end of the Meet the whole lot is dismantled and taken away, leaving the stream to do what comes naturally in a setting where it harms no-one.

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