Solar Energy Prices: This Is What A Disruptive Technology Looks Like

The paper from that article is pay-walled, but there is an author talk here:

http://energyseminar.stanford.edu/node/431

It isn't about the energy returns of panels finally hitting 1 (he actually puts it at about 10 for end to end systems). It is about comparing the growth of the solar panel manufacturing industry and the installed base and doing some analysis of that. One of the conclusions is that installed panels are currently providing more energy than is being used to manufacture new ones. The 2020 number is when all the energy ever used to make solar panels will have been paid back (the talk (and I imagine the paper) makes that claim too, not just PopSci).

Except you missed the point, which is that solar PV systems have been posting compounding gains in terms of power output per $ for 35 years. No other energy source I am aware of is becoming ~15% cheaper per year. I'll assume that most of the people here are familiar with compounding interest and its implications.

The point isn't that solar energy is disruptive today, it's that it will be in the not distant future. It's sort of like cellphone technology. It started out as a niche technology that hardly anybody used (even in San Francisco circa 2000, I know eons ago, people outside the tech industry didn't use them, now everyone has a smartphone).

I put my money where my mouth is on this, and retrofitted my pre-WWII home with solar some eight years ago. Even then, the amortized cost of the solar array was 50% less than what I paid to PGE for grid power, and I basically have a net zero electric bill.

Maintenance? A couple times a year I go up on the roof and hose the panels down to wash the dust and pollen off (no moving parts, etc). That and I make a point to double check that a meter reader hasn't flipped the safety cutoff switch. Other than that, I don't do a goddamn thing and my house generates about 75-80% of its power.

Gigawatts per gigawatt is a poor measure of energy efficiency because all forms of energy are not equal. Gasoline is a highly compact easily portable power source that also happens to fit into a lot of existing capital equipment, a gigawatt of "gasoline" power costs more than than same amount energy in the form of natural gas becausee it has a lower energy density and isn't not as easily portable. A process that used two gigawatts of coal or natural gas to displace one gigawatt of gasoline would be inefficent under your measure but make perfect economic sense.

We live in an economic world. Rational people are going to make choices about what type of energy they use based upon price. If one choice uses more gigawatts than another but is still cheaper people are going to chose it and it will be disruptive.

I used annual averages from the EIA. This smooths out short term variations (I am looking at a 30-40 year trend). Also be sure whatever price history you're using is adjusted for inflation.

That said, even with short term price fluctuations, the decrease in solar energy costs (100:1) trumps the variation in conventional energy commodities (5:1). The point of the article is the long-term "moore's law" trend and how that will play out over the next 10-20 years.

The data I got from the EIA is inflation adjusted using the consumer price index.