Back in the beginning of 2015 the CPUC decided to approve CALSEIA's petition to significantly increase the incentives for solar hot water in California. This was done to bridge the gap to a historically low natural gas price. Consequently CSI-Thermal now offers a cash rebate of up to $4,366 on a single-family solar hot water system.

A single family Heliodyne solar hot water system with two GOBI 406 collectors, 80 gallon storage tank, pump station etc. costs the home owner $4,087 and because of its high output it can qualify for the highest cash rebate. This basically means that homeowners in California can get a Heliodyne solar hot water system for free.

Installation costs (not including equipment) varies with location and with complexity of the install but on average its around $2,500. The out of pocket expense after tax credit and CSI rebates is therefore ($6,587 - $4,366 less 30% tax credit) around $1,555. Amortized over 25 years (10%) its $170 with interest. The Heliodyne system saves up to 200 Therms/year (85% of energy to heat all the households hot water) or around $240/year with current natural gas prices. Paid off in 6.5 years and when financed its cash positive from year one. California's Pace program makes it even more advantageous.

The cost of solar energy from the Heliodyne hot water system in "kWh" terms is $170 divided by the annual energy saved 5,862 kWh (200 Therms) which is 2.9 cents per kWh. Comparably natural gas cost 4 cents and PV around 14 cents per kWh.

Funding for the CSI-Thermal program comes from ratepayers of PG&E, SCE, SoCalGas, and SDG&E. The rebate program is overseen by the California Public Utilities Commission as part of the California Solar Initiative. Detailed information about the program is in the CSI-Thermal Program Handbook.