I am building a solar water heater, and thought I would add a Fresnel lense to speed things up.

My question is, If I have a hot water tank, in an insulated box, covered with a piece of glass , ( Storm door glass)
And I shoot a beam of light through that glass with a Fresnel lense, Will it pass right through the glass and be absorbed into the black water filled tank, , or will it shatter the glass lid?

Any suggestions would be appreciated...I would hate to sacrifice that fine piece of glass. ;>

Thanks,

Rick