Chart works when added in body field, but not in node-page.tpl.php file

I've setup a chart here: http://www.concordconserves.org/carbon/chart-test by placing the php code into the page's body field, but when I try and use that exact same code in a node-mycontentype.tpl.php file, I just get a blank white area where the chart should be. I think it is throwing some kind of error which I can't see.

Any idea why it doesn't work in the tpl.php file?

Here's the code for the chart:

<?php

$homeeff=500;
$food=200;
$travel=85;


$example = array(
  '#type'     => 'pie3D', // Display a 3D pie chart
  '#color'    => 'f0f0f0', // Background color, in RRGGBB format
  '#height'   => 290, // in pixels
  '#width'    => 590, // in pixels
  '#title'    => t('Carbon Footprint Breakdown'), // Chart title
  array(
  array('#value' => $homeeff, '#label' => t('Home and Utilities')),
    array('#value' => $travel, '#label' => t('Food and Diet')),
    array('#value' => $food, '#label' => t('Travel')),
   
  ),
);
return charts_chart($example);
?>