How 'Green' are solar panels?

I think the vocabulary is an age thing - condensors and valves are terms from an era of electronics that is passing or maybe past- To be fair it was passing when I was a kid (1970s), but I started quite young and learnt a lot from my father and also his text books, which in some cases were pre-war, and in other cases when he was training in the 1950s. I suspect no-one measures the  electrical capacity of condensors in jars any more, (they are about 1nF) but the 1930s Admiralty handbook of Wireless Telegraphy certainly did.

Agree its a side track - but the threads support branching. I do not like it, but as it is there, to use it.

Mike.

mapj1 said:

Slightly counter intuitively, this is sometimes called a a "synchronous condenser" at least not intuitive to me, for whom the word condenser implies capacitance.

I can see the reasoning, it is storing energy in a similar manner to a capacitor in a dc circuit. I've always thought an "ac capacitor" would be useful, e.g. (to take trivial case) put across a lamp so that it dims gently on power off, in the same way that a dc lamp with a capacitor across it would. Which from your description (I hadn't come across these before) is what this does.

Apologies, a bit off a quite important topic!

The thing that is problematic with the lack of spinning reserve, means that the traditional canary in the coal mine of an overload, which is the frequency falling, may not occur as the timing of inverters are derived from the electronics.
It is possible to emulate this better with some effort, and is being, also the inverters can be switched out of phase with the mains to not invert as such but to load the mains at one part of the 50Hz cycle to fill the internal resevoir capacitor and then to push that charge out at another point in the cycle- in effect  providing a first order phase change power-factor correction that is programmable from cycle to cycle, and on 3 phase systems with further tweaking to load one phase to prop up another.

As far as I know this can be done quite reliably, and is being rolled out with newer kit at large sites but is not yet common.

The other more traditional thing that achieves a similar end and can be done of course is to have a large spinning motor/flywheel that motors or generates to smooth things over. Slightly counter intuitively, this is sometimes called a a "synchronous condenser" at least not intuitive to me, for whom the word condenser implies capacitance.
Mike

Thank you for sharing.

I think its pros at the moment outweigh the cons.

In the energy transition, solar becoming cheap, and its installation boosted by governments has definitely helped.

However, the heavy metals used in panel manufacturing are unrecyclable and an impending fiasco that would add to our pollution problems. 

A way to combat this would be to regulate technological innovations and companies to invest heavily in closing the manufacturing loop with sustainable solutions. 

Suppose it's also worth pointing out, there's an option not being considered here. 

reuse. 

Refurbish the panel and reuse it elsewhere, or use an aging panel in an area that doesn't need the full capacity that the panel had when new. 

There are large parts of each panel which can be recycled though - Solar Panel Recycling | US EPA

You are aware solar panels work in varying conditions? 

According to the national grid "The current peak solar electricity generation record seen by our Electricity National Control Centre in the UK is 9680MW on 20 April 2020 – enough to boil five million kettles!"

I did find this though which seemed interesting:

"National Grid ESO is preparing Britain’s electricity system to be able to run on purely zero-carbon electricity by 2025 – ready to accommodate whatever quantity of renewable electricity, including solar power, is being generated.

In order to bring ever increasing amounts of renewable energy onto the grid, and keep costs down for customers, they’re working to overcome two intertwined challenges: ensuring that demand for power is balanced by electricity generated and updating the foundations of the electricity system. Electricity has historically relied on fossil fuels, so they’re designing new approaches and incorporating new technologies.

In a recent successful test, as part of the Power Potential project, the inverters at a solar plant were upgraded so that, on top of providing power during the sunshine of the day, the plant could also provide a use at night time, smoothing fluctuations in voltage and keep the grid stable.

Solar power also plays a role in providing frequency response, one of the balancing tools that the ESO uses to keep the electricity system in balance.

A recent trial saw a contract made up entirely of domestic users, allowing them to get paid to export their excess energy to the grid and help to balance supply and demand with cleaner, decentralised power at the same time."

Link to that is here: Power Potential | National Grid ESO

And isn't that a failing of regulatory bodies? Consider the Walleys Quarry constantly on the UK news for being the most complained about landfill site in the UK, if the prices to dump there were much higher, people would be spending more time and effort in separating waste and recycling more. 

for reference here's the link to the scheme 

www.dell.com/.../index.htm

Agreed, isn't this why the likes of Dell are introducing their own recycling scheme (it's already on their website) where they will literally pay for the postage for you to send old tech into them as it's getting to the point of being more viable them having a recycling loop than to continue material extraction from the ground. 

Great discussion, and timely.

We use gas for heating (typical for Germany), reckoned on an annual basis, with a monthly payment and an annual adjustment in July. My heating bill has just gone up 33% for the next year. Gas prices are forecast to treble, and maybe even to sextuple, and I can't pay that kind of price if it is passed along. (Politically, I have never supported the increasing German dependence on Russian gas supply. Chickens-home-roost-IToldYouSo .... but that doesn't reduce my prospective bills.)

I just got a formal proposal from my heating engineer for an upgrade to install an air heat pump as support (I can't heat my building on air heat pump output alone, because it is not insulated to the required extent, and we have many days of temperatures below those at which the heat pump can operate). €43K. The price of air heat pumps seems to have gone up 50% since I talking to him a month ago, and the price of the warm-water accumulator 400%. 

I have known for many years what it would cost for "standard" insulation to allow a heat-pump-only solution. 5 years ago, it was €140K. That is 50% of what I paid for the house in the first place. I would get back some of that in subsidy, but there is no way that cost would amortise over my expected lifetime.

There are German government subsidies for energy-efficient building mods. But only some. Insulation installed on the outside of the building - yes. Internal insulation - no. Heat exchange devices to existing radiators - yes. PV panels to a circuit supplying on-demand Dyson-type warm-air-stream heaters in each room - no. This last is what I think would be part of a cost-effective solution. But I am the only person I know who thinks along such lines.

I agree with the comments that PV panels just shouldn't end up in landfill. But, having lived in California, I am not surprised at the throw-away behaviour pattern. Half the state picks up needle and thread when there's a hole in a shirt; the other half throws the shirt out of the car window in some city other than where they live. 

There appears to be some serious research at most of the car manufacturers being put into how to recycle batteries, and, equally importantly, how to design them for effective recycling.