Even though solar, and especially solar PV, has managed to capture the lion's share of public equity investors' attention over the past three years, wind remains far more competitive with with fossil-fired power generation on a cost basis than solar, and thus presents a fundamentally stronger investment case for the time being (and I emphasize for the time being). What's more, wind as an industry is more mature than solar; for solar, the lack of earnings for many companies and the wildly inflated PEs for others make the sector potentially volatile and risky for investors.

While installing a kW of commercial wind in 2007 in the US would have cost you on average $2,200 according to the DOE's EERE (PDF document), installing the same amount of commercial solar PV would have set you back more than twice that amount. In 2007, the cumulative-capacity-weighted-average wind power price (the amount wind farm owners were paid for their electricity on average) was below the nationwide price band for a flat block of wholesale power.