As part of the federal stimulus package, there are several attractive tax credits available right now.

Check this great site from Energy Star for complete information: http://www.energystar.gov/index.cfm?c=tax_credits.tx_index

Among the highlights are a 30% tax credit for the installation of a geothermal heating and cooling system.  The key here is, though, that there is NO LIMIT to the amount of this rebate.   Most of the other energy efficiency rebates are maxed out at $1,500.

With that much of a rebate, and no limit, the upfront cost of the geothermal system is very close to that of a high-efficiency gas system, but with a huge decrease in operating costs.

Check it out!!