A reader writes:

I saw your post on Sol Focus. I thought you should know that concentrated solar is not a new concept. I retrofitted my pre WWII home for solar, and have been following this industry for years (I wrote an article 4 years ago predicting that Silicon Valley would jump into cleantech as margins on computing products decline).

The main obstacle in small scale solar is the cost of permitting, installation, etc. Existing solar technology works fine, and if it's rolled into a mortgage, costs the same or less than utility electric service. What's needed to make solar popular at the residential and small commercial scale is a modular system in which the solar panel, cabling and DC to AC inverter are "plug and play" (e.g. toss the panels up on your roof, cable them together, hire a local electrician to sign off on the interconnect to the grid). Then you'll be able to go to Home Depot to buy any variety of solar kits. This was the key development in the personal computer industry, the development of easy to use, modular systems that were accessible first to hobbyists and then to the general public.

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