Originally Posted by ssmoot
A 2mē thermal heating
panel will heat about 50 gallons of water in a tropical area. It would take about 10kWh to do the same job.
So it's much much more efficient to heat with thermal panels
I think this common trend has more to do with the fact that houses don't really lack for installation
space, and the cost of extending an existing solar electric
design with another 2 or 3kW of solar electric panels
is lower than the labor cost of plumbing
in a secondary thermal system.
On a boat
, where space is limited, I think the gunwale idea is one of the more clever ones I've ever seen.
A hot water panel is probably multiple times more efficient at transferring solar energy to water versus going the electricity route
. No argument.
And your comments were basically my response also, to my architect as well.
The issue is that you and I were both looking at this from a tiny perspective. Think of this more holistically. You use only a small amount of hot water daily, even in a home. Yet that solar panel up there is sitting there, wasting the sun's energy all day long. Day after day. With an electric-methodology, the electricity is being transferred to the grid, your batteries
, your inverter
loads, etc., day after day after day.
So it is a much more efficient/effective use of space and investment of money
However your comment smoot
about boats being different than a huge house roof is very much noted. Especially on a small sailboat with low electric demands and little room for panels. I like the idea of hanging a long, skinny black collapsible tube vertically by the halyard
. Hoisting it up. Perhaps tied into a water tap on deck - gravity hot water!