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Posted (edited)
24 minutes ago, Roger440 said:

However, things go wrong, especially electronics. Yes it "should" cut of the power if it doesnt see "mains power". Should is doing a lot of heavy lifting on a device thats likely sub £200.

 

The big brands offering things like this cost a more than that. If the regs say that to legally sell this product it 'MUST' ensure that the pins are not live unless a mains signal has been seen within the last 20ms then either the product complies and is safe (ie, wont kill anyone even if they touch live pins) or it doesn't comply and is therefore defective.

 

That should be the end of it.

 

24 minutes ago, Roger440 said:

With a plug in panel, if it doesnt detect the mains power has gone, the pins are live. Single point of failure. 

 

Going to a situation of single point of failure is a significant step backwards. The results of which, as ive already said, are forseeable.

 

Really not sure what you are getting at here. The number of things that have to happen to produce mains output from a solar panel these days is huge. The computers involved in generating the waveforms are far far more powerful than desktop computers from the early/mid 2000s.

 

It's not a case that the waveform will be produced unless blocked by a safety system, it's more that the system can't produce a waveform unless a long list of conditions are met.

 

This is technical but heres a reference design from TI for a microinverter. Not suggesting you take anything from it other than it's not a simple system that will just continue working in a fault condition (the document doesn't touch on the safety side unfortunately).

 

https://www.ti.com/lit/ug/tiduf63a/tiduf63a.pdf?ts=1774517354380

 

The MCU (brain) they use to do the control is this :

 

https://www.ti.com/lit/ds/symlink/tms320f280039c.pdf?ts=1774508361987

 

Again not really an accessible document, but you'll note that it supports various functional safety standards. Those are some pretty rigorous standards and if you design a product to meet them then you can make guarantees about the behavior. ie, make it fail safe. Edit: I'm not saying this is currently part of the regs for this, seems a little OTT for the situation, but it's certainly something that could be added to regs if a need is identified.

Edited by -rick-
Posted

Safety never comes with an absolute guarantee and its all managed/regulated on the basis of what is reasonable.

 

Theres 1600 people killed on british roads each year yet were still all free to drive at potentially lethal speeds.

 

Theres 1000s die prematurely each year due to poor urban air quality yet we can still burn oil/gas/diesel/wood in urban areas.

 

Plug in solar, as with anything at dangerous voltage, might injure or even kill the odd person that misuses it or CHOOSES to personally import it and potentially bypass UK/EU safety regulation, but their loss is likely to be outweighed by the benefits

  • Like 1
Posted
10 hours ago, Roger440 said:

With a plug in panel, if it doesnt detect the mains power has gone, the pins are live. Single point of failure. 

 

Going to a situation of single point of failure is a significant step backwards. The results of which, as ive already said, are forseeable.

I'm pretty sure that within compliant inverters there's multiple layers of disconnection so there's unlikely to be a scenario where a single failure within the inverter will keep the power on the plug

Posted
2 hours ago, Dillsue said:

their loss is likely to be outweighed by the benefits

Is this a principle similar to the self-extinction of vaccine deniers?

Posted
1 hour ago, saveasteading said:

Is this a principle similar to the self-extinction of vaccine deniers?

 Similar to importing hazardous kit from un regulated sources.....the majority can probably evaluate the risks and manage accordingly, those that dont have a higher risk of "self extinction"

Posted
9 minutes ago, sgt_woulds said:

The EU is starting make changes to online selling.  We can only hope that our leaders can take note:

 

The excuse before we left the EU was that it was EU rules preventing us from doing anything. Now we've left we could have done whatever, but the government/officials were all too busy dealing with brexit. We'd be further forward with addressing this issue if we'd stayed in the EU.

Posted (edited)

We are seeing a lot of stuff coming out of Europe that is garbage! China is using CE (China export) to run stuff through Europe using the confusion (or ignorance) of the difference between a genuine CE and CE (China export) marking.

IMG_4527.jpeg

Edited by markc
Posted
2 minutes ago, markc said:

We are seeing a lot of stuff coming out of Europe that is garbage! China is using CE (China export) to run stuff through Europe using the confusion (or ignorance) of the difference between a genuine CE and CE (China export) marking.

 

Sure that's been the problem for ages and what is trying to be addressed AFAIK.

  • Like 1
Posted
7 hours ago, -rick- said:

 

Sure that's been the problem for ages and what is trying to be addressed AFAIK.

 

Its unfixable. Whatever process you put in place, they just make it look the same. Of fake the paperwork. Or whatever.

 

You can by rolls of the CE stickers anywhere in China.

Posted
15 minutes ago, Roger440 said:

Its unfixable. Whatever process you put in place, they just make it look the same. Of fake the paperwork. Or whatever.

 

Other countries have made big progress by having customs and/or trading standards equivalent go pick up stuff off the shelves and verify it and then penalise the importers if the right certifications don't exist. You are never going to zero but dodgy imports can be reduced significantly with a bit of enforcement effort.

 

With a lot of electronics (depending on what it is) there are 3rd party testing requirements that have to be done by licensed labs so if those certifications aren't available it's pretty easy to stop. Rules are less strict on other things so it would be harder to stop fake 'CE' imports of toys, etc.

Posted
1 minute ago, -rick- said:

 

Other countries have made big progress by having customs and/or trading standards equivalent go pick up stuff off the shelves and verify it and then penalise the importers if the right certifications don't exist. You are never going to zero but dodgy imports can be reduced significantly with a bit of enforcement effort.

 

With a lot of electronics (depending on what it is) there are 3rd party testing requirements that have to be done by licensed labs so if those certifications aren't available it's pretty easy to stop. Rules are less strict on other things so it would be harder to stop fake 'CE' imports of toys, etc.

 

You "can" do checks. Indeed ive pointed this out already up there ^^^^

 

Sadly however, we wont do any checks. This is the UK. Nothing works anymore.

 

Paperwork checks are pointless anyway, as said certificates will just be forged.

 

Only a proper physical check will achieve anything.

Posted
4 minutes ago, Roger440 said:

Sadly however, we wont do any checks. This is the UK. Nothing works anymore.

 

And this is the thing to fix. As said earlier, you fix the root cause, don't apply regulations on top based on the assumption that you are too weak to fix the cause.

 

4 minutes ago, Roger440 said:

Paperwork checks are pointless anyway, as said certificates will just be forged.

Only a proper physical check will achieve anything.

 

Not sure what you mean by physical check. You won't be able to tell much by physically looking at products. (product depending, egregious things more obvious but lots of subtlties no)

 

By checking the certificates what I mean is communicating with the labs who supposedly issued them to check they are geniune and confirm they relate to the product in front of you. Historically most of the China Export stuff hasn't even bothered to go to the stage of faking these certificates. They just put some general (not product specific) certificates up and call it a day.

 

Amazon should be checking this stuff on things on their store. They don't and offload the responsibility to the seller (not sure that legally holds up in the first place but if it doesn't the law can be changed). Going after Amazon (and aliexpress, etc) would stop a lot of the crap stuff getting in. High street retaillers, etc, are already pretty good.

  • Like 1
  • 1 month later...
Posted

are there any reliable and sensibly priced wind turbines that are worth looking at

I have solar but that don,t work in winter ,but i do get lots of wind  as I am in exposed position about 350ft above the estuary 

 Is it worth t considering something at 5-10kw  

any working examples would be good 

 

Posted
1 hour ago, scottishjohn said:

wind turbines that are worth looking at

I'm out of touch so accept the word of @SteamyTea, of course.

But I recall  a time when lots were being pitched at the new sustainability market. 

Planners were expecting to see that sort of thing too.

They were being sold as gimmicks or to please planners,  and in totally unsuitable locations. Then suddenly about 15 years ago there were none being touted.

 

Since then, solar technology has improved dramatically but not, I think,  turbines.

 

We've discussed this on here before, and I think the moral was that tiny ones work on yachts, out in the ocean,  but still won't boil a kettle.

 

Thinking further, I once had journalists visiting as we had won an award for sustainable design, and they didn't understand that there was nothing to photograph. They wanted a wind turbine. I think that this may still be an impression, and being seen with one would be the only perceived  benefit.... unless you are on top of a hill but always in shadow, , don't mind the noise and there is no alternative.

 

Shorter answer: no.

Posted

I am on the top of a hill and get lots of wind 

there is a 125kw big turbine on the farm just behind me  

so it is the right place

was looking for any real world experience if anybody has any 

 

this winter  i spent alot of time in cloud --so solar had no chance

 the original house was not built with a front door of any sort as it faces south west 

and the courtyard at the back had walls and doors to keep wind out

 

Posted
17 minutes ago, saveasteading said:

Since then, solar technology has improved dramatically but not, I think,  turbines.

Turbines, even small one, are mature technology, with the majority of the price being the tower, blades and inverter.  The actural generator is the cheap bit.

PV, while when understood technology 25 years ago, was a minor player, but as it initially rode on the back of the semi-conductor industry, and could use silicone billets that were not good enough for higher end computer 'stuff', there were opportunities to cheaply get all the rest of the components (glass, frame, backing and a little wiring) in place, before extra expense of silicone was needed.

The engineers with vision, soon realised that PV produces more energy per unit land area than wind power, even with the technology for the early 2000s.  This may seem counter intuitive, but you cannot cluster wind turbines too close together, and with all things 'energy', the larger the better.

The other big difference is that it is a global market, so the USA, Canada and Germany soon outsourced the PV technology to China.  China wanted to increase its domestic energy production, were willing to subsides the industry, and more importantly, take a 30 year view on it.

The rest is history.

 

Just had a look at the price of a Britwind 5kW

"Please consider a budget of between £35,000 and £40,000 + vat for a fully installed H5 wind turbine, depending on tower type (there is currently 0% vat on new domestic installations)"

So prices have doubled since I was involved with making them, which when I think about it, was 19 years ago.

26 minutes ago, scottishjohn said:

I am on the top of a hill and get lots of wind 

It is probably not that windy in real terms, and not a 'clean wind'.

Height is the key.

https://www.mdpi.com/jmse/jmse-11-00134/article_deploy/html/images/jmse-11-00134-g007.png

 

Then there is the distribution, which is not linear, it follows a Weibull distribution pretty well.

Basically the higher the mean wind speed, the more often you get even higher wind speeds, and as power from a turbine is proportional to the cube of the wind speed, you need to start with a high mean.

77578fc4-18bd-4e9a-9ad1-19dd69db19b0-768

A quick look at my local satellite data shown that over Land's End, at the moment. with wind speed is 6.7 m.s-1 at the surface.

Now when studying weather, especially wind speed, it is more normal to use air pressure than altitude.  It is currently 1003 hPa.

Going upwards a little to where the air pressure is 1000 hPa, the wind speed is 7.4 m.s-1 , a lot higher to where is is 850 hPa, the WS is 9.3 m.s-1 (that is about 1500 m high).

 

So to get a good yield out of a small turbine, you need to put it at the top of Ben Nevis, on a 300 m tower.

Small turbines have dreadful efficiency, probably no more than 30% (efficiency is based on the maximum energy that could be extracted, Betz Law).  Larger turbines are around 50 to 55%.

 

Don't get me wrong, I like turbines, but you would be better off spending the money on a diesel generator.

 

 

 

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