Ha. I am a very unique person to ask, as that I only look at the overall impact of a change to a system and have a cynical outlook on the popular opinion on this matter.
Nowadays we hear so much about the possibilities of solar, wind, and other "naturally good" generation methods. We hear very little about the environmental impacts of the COGS it takes to build these infrastructure.
More importantly, when people ask "Why hasn't the gov bought more solar panels?", they don't understand the blunder of heavily investing in a young tech that is only going to get cheaper and more efficient. It's like when a music firm completely transition to cassettes, only to have the CD replace it. Hence, the job of a good administrator and economist is to look at the growth in price, efficiency, and future trends in alternative energy methods and predict a healthy transition to "green energy", rather than going all-in now.
I'm also a heavy believer in nuclear fusion, as almost every major governments in the world invested in projects like ITER. More people need to talk about that, rather than telling the public that wind turbines will power NYC.
Another thing I read that was fun about wind turbines is Bet'z Law. Essentially wind turbines have an upper bound of efficiency that they cannot exceed (59.3%).
I believe that your project will gear toward home owners that can independently change the consumption habits. For an urban dweller like me, utilities are determined at the state level and city level. I researched a lot on the NYS renewable portfolio, and on a large scale generation (which accounts for 99% of total output) there's a promise of 30% renewable by 2020(?).
Anyways, my point is the actual impact toward urban dweller will be negligible, simply because these strategic moves are made by the government in accordance with consultants in the professional field.
However, in the suburban areas of America, it will have an impact. There are some grey areas though. According to my research in NYS, every solar/wind generation site requires a back-up generation unit (usually coal/natural gas) due to predicted fluctuations of the weather. That ratio, from what I remember, is more than 1:1.
As interesting as an art installation revolving energy efficiency seem, it would be more effective to indicate some sort of metric that is measurable. In your post, you write about linking a call to action to local initiatives. Another words, you're acting as a marketing channel for that initiative, and the featured firm/initiative can measure the number of redirects and possibly compensate your installation accordingly.
I found that this sort of model is already done here in NYC, http://www.greenfestivals.org/nyc, where promotions of technology, local initiatives, and educational installations are constructed.