Energy Audit and solar energy rebates

I've applied to have an energy audit done through Clean Nova Scotia. The cost is $150 and is a requirement for being eligible for the government rebate programs for improving the energy efficiency of your home.

The province of Nova Scotia through Conserve Nova Scotia of also offers a 15% rebate for solar air heating and solar hot water systems, both to a maximum rebate of $20,000.

That would be roughly $450 towards the purchase and installation of a Cansolair panel or roughly $700 towards the purchase and installation of a solar boiler (net out of pocket investment would be $7,600).

The estimated payback, based on what I've read on the internet would be roughly 6 years.