When outside, the instructor will provide the solar flux meter for you to record the solar

intensity. Record your measurement here:

$943\mathrm{.}6$

$\frac{W}{m^2}$

Perform the calculations outlined below to determine how long solar energy must be collected

to match the energy required for your $10-$minute shower.

Theory

Solar energy is diffuse, that is$,$ it is spread out over area at an intensity that changes due to the elevation

of the sun in the sky$.$ The sun's energy is measured as a flux: power per unit area or $\frac{W}{m^2}.$ Solar

thermal collectors absorb this energy and transfer it to circulating water or a water$/$antifreeze mixture.

This lab estimates how long it will take to collect enough solar thermal energy for your shower

measured in lab #$1.$ Some assumptions are required:

i$.$ The collector has an area of $1\mathrm{.}0m^2.$

ii$.$ The collector has an efficiency of $50\%.$ Half of the solar energy incident on the

collector surface is transferred to the circulating water.

The rate at which energy is collected is given by$,$

$Q_{\text{c}\text{o}\text{l}\text{l}\text{e}\text{c}\text{t}\text{e}\text{d}}^{}=q^{\text{'}\text{'}}*A*$

Where,

$Q=943\mathrm{.}6*1\mathrm{.}0m^2*\mathrm{.}50\%$

$q^{\text{'}\text{'}}$ is the solar intensity as measured outdoors in $\frac{W}{m^2}$

$A$ is the collector surface area given as $1\mathrm{.}0m^2$

$$ is the collector efficiency given as $50\%.$

You previously calculated the amount of energy required for the $10-$minute shower $(Q_{\text{s}\text{h}\text{o}\text{w}\text{e}\text{r}}).$ Now,

determine how long $(t)$ solar energy must be collected to provide the energy for the shower.

$Q_{\text{s}\text{h}\text{o}\text{w}\text{e}\text{r}}=Q_{\text{c}\text{o}\text{l}\text{l}\text{e}\text{c}\text{t}\text{e}\text{d}}^{}*t,or,t=\frac{Q_{\text{s}\text{h}\text{o}\text{w}\text{e}\text{r}}}{Q_{\text{c}\text{o}\text{l}\text{l}\text{e}\text{c}\text{t}\text{e}\text{d}}^{}}$

Be careful with your units. Note: $1$ Btu $=1054J$