This is a great point, and it may be even better than 50-70% if you account for incentives, tax credits, etc. A 2015 study by Lawrence Berkeley National Laboratories found that if you factor in federal, state, and utility incentives, the increase in home value from install solar panels matches the cost of the panels. https://emp.lbl.gov/sites/default/files/lbnl-6942e-fullreport-factsheet.pdf
In other words, the increase in home value on average recaptures about 100% of the true cost of the system to the homeowner, which is pretty amazing.
Findings from the study include:
"Home buyers consistently have been willing to pay more for a property with PV across a variety of states, housing and PV markets, and home types.
Premiums for PV homes are $1.10/watt larger in California than outside of California, but this difference is not statistically significant, and it seems to reflect the net cost of PV systems in each area (Figure 1). Moreover, the findings should provide greater confidence that PV adds substantial value to non-California homes.
Net cost estimates [of installing PV] —which account for federal, state, and utility incentives—seem to be the best proxy for market premiums."
Premiums for PV homes are $1.10/watt larger in California than outside of California, but this difference is not statistically significant, and it seems to reflect the net cost of PV systems in each area (Figure 1). Moreover, the findings should provide greater confidence that PV adds substantial value to non-California homes.
Net cost estimates [of installing PV] —which account for federal, state, and utility incentives—seem to be the best proxy for market premiums."
