Reclaim Energy CO2 Heat Pump Hot Water System – Excellent choice when coupled with a solar roof top array. Minimal grid import costs estimated over the last nine months at about 350 to 500 watts per day. Quite frankly I don't even believe it is that much as I run a spreadsheet recording daily PV and grid import data and there is hardly any difference between last year and this year. I'm glad our old gas storage hot water system failed as we are saving over $300 per gas billing period. I estimate the new system will pay for itself in around four years.