Those green power science people have a youtube channel where they cook on a cast iron pan with fresnel and also parabolic lenses. They're pretty damn powerful. On one of their videos they mention that boiling 5 gallons of water requires something like 25 times more energy to boil than 1 gallon so depending on his needs it may or may not be cost effective for BOL86 to use the fresnel lenses.
A fresnel lens is what use to be found in light houses. There's an interesting history to them. Anyway, you're correct in stating water takes a lot of energy to heat. Water holds its heat better than any natural substance there is. It's slow to heat and its slow to cool. This is what provides us seasons and climates.
I've seen these fresnal lens ovens being sold on the internet. I don't know how effective they are. To me, a very pointed heat source like that of a fresnal lens is ineffective compared to a distributed heat source from say a propane burner or a wood fire.
Yeah the main issue with using them to cook with is that you need the focal point in front of the pan so the heating area is large enough to not cause a hotspot. This reduces it's heating capability. They work good on cast iron cookware though.
Those green power science people have a youtube channel where they cook on a cast iron pan with fresnel and also parabolic lenses. They're pretty damn powerful. On one of their videos they mention that boiling 5 gallons of water requires something like 25 times more energy to boil than 1 gallon so depending on his needs it may or may not be cost effective for BOL86 to use the fresnel lenses.
A fresnel lens is what use to be found in light houses. There's an interesting history to them. Anyway, you're correct in stating water takes a lot of energy to heat. Water holds its heat better than any natural substance there is. It's slow to heat and its slow to cool. This is what provides us seasons and climates.
I've seen these fresnal lens ovens being sold on the internet. I don't know how effective they are. To me, a very pointed heat source like that of a fresnal lens is ineffective compared to a distributed heat source from say a propane burner or a wood fire.
Nice info on the light houses.
Yeah the main issue with using them to cook with is that you need the focal point in front of the pan so the heating area is large enough to not cause a hotspot. This reduces it's heating capability. They work good on cast iron cookware though.