Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Railpower Technologies
Table title:
Green Goat Hybrid switchers
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Model designation </th><th colspan=1 rowspan=1 > Wheel arrangement </th><th colspan=1 rowspan=1 > Build year </th><th colspan=1 rowspan=1 > Total produced </th><th colspan=1 rowspan=1 > Power output </th><th colspan=1 rowspan=1 > Image </th></tr>
<tr> <td colspan=1 rowspan=1 > GGS2000D "Emerald" </td><td colspan=1 rowspan=1 > B-B </td><td colspan=1 rowspan=1 > 2001 </td><td colspan=1 rowspan=1 > 1 (prototype) </td><td colspan=1 rowspan=1 > 1,490 kW (2,000 hp) </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > GG20B "Green Goat" </td><td class="highlighted"  colspan=1 rowspan=1 > B-B </td><td colspan=1 rowspan=1 > 2004–current </td><td colspan=1 rowspan=1 > 55 </td><td class="highlighted"  colspan=1 rowspan=1 > 1,490 kW (2,000 hp) </td><td colspan=1 rowspan=1 > - </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > GG10B "Green Goat" </td><td class="highlighted"  colspan=1 rowspan=1 > B-B </td><td colspan=1 rowspan=1 > 2005–current </td><td colspan=1 rowspan=1 > 6 </td><td class="highlighted"  colspan=1 rowspan=1 > 746 kW (1,000 hp) </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > GK10B "Green Kid" </td><td colspan=1 rowspan=1 > B-B </td><td colspan=1 rowspan=1 > 2005–current </td><td colspan=1 rowspan=1 > 4 </td><td colspan=1 rowspan=1 > 746 kW (1,000 hp) </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What is the difference between the GG20B "Green Goat" and GG10B "Green Goat" models?
Answer:
The "10" or "20" in the model designation signifies 1,000 or 2,000 horsepower (746 or 1,490 kW) respectively.