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How do we think they are doing now?

whjohnson
So, in a provocative curious mood on the eve of Easter w/end I began to wonder about PV panels.

There must be many by now which have been in service for 10 years or more.

How do we think they are doing in comparison to when they were new?

How does, or rather, what is a typical rate in efficiency fall-off over time?

My guess is that many, especially those installed on dwellings with difficult accessible roofs will not have been looked at nor cleaned for at least a decade if they have been in service for that long.


What do we reckon? Would a figure of say 50% or less be an unreasonable estimate of today's efficiency level for a decade old installation?

I wonder if Greta does a PV cleaning round in the same way window cleaners do?

Happy Easter.
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    whjohnson:

    On the subject of renewebles, I read today that there is talk of going for 'Green Steelmaking' by running electric arc furnaces from windmill output!

    These so-called 'Scientific Journalists' really have no idea do they?


    All currently used bulk steel making proceses use coke as both the heat source AND as the chemical feedstock that reduces iron oxide to liquid iron, and then adds carbon to molten iron to make steel..

    An electric arc could be used instead of burning coke for the heat, I am not aware of this being done to make "new" steel, though it is widely used for steel recycling.

    Carbon would still be needed to reduce iron oxide to liquid iron, and then form steel which contains a mixture of iron and carbon. The amount needed would be very much smaller than when it is burnt as the fuel supply. Biochar made from waste wood would be suitable.


    Another way to reduce iron oxide to metallic iron is to produce hydrogen and oxygen by electrolysis of water. Burn these gases in a furnace, with hydrogen being present in excess of that required for perfect combustion. This will produce a reducing atmosphere and turn iron oxide into iron. No carbon needed at this stage. Carbon would still needed to add to the iron to make steel, but the small amount needed could be from biochar as above.


    Either process needs a great deal of electricity, but there is no reason why this can not be produced from wind turbines.


    Neither process is used on a significant scale at present, therefore I reluctantly support the proposed coal mine for coking coal.


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  • 0
    whjohnson:

    On the subject of renewebles, I read today that there is talk of going for 'Green Steelmaking' by running electric arc furnaces from windmill output!

    These so-called 'Scientific Journalists' really have no idea do they?


    All currently used bulk steel making proceses use coke as both the heat source AND as the chemical feedstock that reduces iron oxide to liquid iron, and then adds carbon to molten iron to make steel..

    An electric arc could be used instead of burning coke for the heat, I am not aware of this being done to make "new" steel, though it is widely used for steel recycling.

    Carbon would still be needed to reduce iron oxide to liquid iron, and then form steel which contains a mixture of iron and carbon. The amount needed would be very much smaller than when it is burnt as the fuel supply. Biochar made from waste wood would be suitable.


    Another way to reduce iron oxide to metallic iron is to produce hydrogen and oxygen by electrolysis of water. Burn these gases in a furnace, with hydrogen being present in excess of that required for perfect combustion. This will produce a reducing atmosphere and turn iron oxide into iron. No carbon needed at this stage. Carbon would still needed to add to the iron to make steel, but the small amount needed could be from biochar as above.


    Either process needs a great deal of electricity, but there is no reason why this can not be produced from wind turbines.


    Neither process is used on a significant scale at present, therefore I reluctantly support the proposed coal mine for coking coal.


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