With one layer the case is simple. There is a certain light energy at which the conversion of light to current occurs called gap energy. If the light energy is lower than that no conversion can happen and if the light energy is higher the extra energy is converted to heat and only gap energy remains.

Filtering UV would be a loss but a small one.

I would be grateful if you could include the country this applies to in the title.

For everybody else: it’s the US. Who would have thought.

I never understood BRICS. Sure, they are the second line of industrial powers (China?) but especially India Russia and China hate each other to the bone. They are partners only on paper. If someone can explain it to me please go on .

Gas has a conversion efficiency of 100% but not all of it every the kettle. That leads to efficiencies lower than the electric ones. With good induction it is also faster than every other method so that would be my choice if I had an induction cooker. Until then I use the next best and cheapest solution which is electric with a wall plug.

Keep in mind that the us - as usual- historically made strange political choices so their kettles are limited to half the speed as everywhere else.