I got an estimate for solar panel installation on my roof. Aside from the environmental benefits, what do you think about the financial aspects of this: $34k up front cost $21k cost after refunds and tax credits 14.5y to pay back cost, based on their estimates (average annual energy usage, projected energy production, etc.) House is 18y old, roof 9y old. Plan to stay here for at least 20y more. Would you do it? Has anyone done it? Good/bad experiences?