I don't know if you want a 3D modeling program, but Sketchup is free and incredibly powerful. There is a Pro version also available with more advanced tools. It's about as simple as 3D could be. You could do 2D with it also.<div>

<br></div><div>I just got back from Sketchup 3D Basecamp, and saw some amazing things architects are doing with it.</div><div><br><div id="WISESTAMP_SIG_798"><div style="font-size:13px;font-family:Verdana,Arial,Helvetica,sans-serif">

<div style="margin:0 0 8px 0"><p style="margin:0"><span style="color:#808080"><strong>Jason Szumlanski</strong></span></p><p style="margin:0"><span style="color:#808080"><em>Fafco Solar</em></span></p></div></div></div><br>

<div class="gmail_quote">On Thu, Oct 18, 2012 at 3:04 PM, Jonathan Hill <span dir="ltr"><<a href="mailto:solarjon@gmail.com" target="_blank">solarjon@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

<div style="word-wrap:break-word">Dear fellow wrenches-<div>I'm looking for a good, simple drawing program for mac. I need it for pv system layouts. Free if possible. Any suggestions?</div><div><br><div>
<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:12px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<div><font size="4"><span style="font-size:14px">Jonathan Hill, senior system engineer and founder</span></font></div><div><font size="4"><span style="font-size:14px"><div><b>Sierra Solar Systems</b></div><div><br></div>
</span></font></div>
</div></span></div></span></div></span></div></span></div></span></div></span></div></span></div></span></span></span></span></span></span></span></span></span></span></span><div><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;text-align:-webkit-auto;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="font-size:14px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:14px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:12px;white-space:normal;font-family:Helvetica;word-spacing:0px"><div style="word-wrap:break-word">

<div><div><font size="4"><span style="font-size:14px"><div><div><div><div><div><div><div><div>
</div></div></div></div></div></div></div></div></span></font></div></div></div></span></div></span></div></span></div></span></div></span></div></span></div></span></div></span></span></span></span></span></span></span></span></span></span></span></div>

</span></span></span></span></span></span></span></span></span></span></div><br><div><div><br></div></div></div></div></blockquote></div></div>