Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Sustainable Energy

Let (Some) Sun Shine In

Imagine darkening a window with the turn of a knob. Such technology exists, but has been costly to install. The National Renewable Energy Laboratory (NREL) in Golden, Colo., is trying to erase this barrier by combining two technologies: electrochromic materials that darken in response to electrical input, and photovoltaic (PV) devices that produce electric current from light. A transparent PV coating on the window provides the juice to activate the window’s change from clear to nearly opaque, eliminating the expense of wiring the windows into the building’s power. The PV coating would double as a light sensor, so windows could darken as the sun shone brighter. The PV and electrochromic films could both be deposited on a polymer sheet that is then glued to an existing windowpane, says NREL’s David Benson.

More from Sustainable Energy

Can we sustainably provide food, water, and energy to a growing population during a climate crisis?

Want more award-winning journalism? Subscribe to Insider Plus.
  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus the digital magazine, extensive archive, ad-free web experience, and discounts to partner offerings and MIT Technology Review events.

    See details+

    Print + Digital Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

    Technology Review PDF magazine archive, including articles, images, and covers dating back to 1899

    10% Discount to MIT Technology Review events and MIT Press

    Ad-free website experience

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.