$20,000-30,000 for a family of 5 with a swamp cooler, no A/C. Power consumption is directly corelated to the cost, so A/C would have raised the cost. The actual cost/ out of pocket cost was about $10,000 less than that with tax credits. Not sure how much in tax credits are available now. We did not buy battery backup/ did not go off grid. Including the tax credits it will take us about 9 years to 100% recoup the costs with savings in electric costs. We have already recouped half the cost.