Solar PV

Stats before I forget all these numbers.   I had a speaker from SolarCity talk to my class early this week.  Their standard module is 3'x5' (15 sq feet) with a current of 252 watts and weight of 44 pounds. So 4 modules=1 kW and covers 60 square feet.  They install only on roofs that have shingles or raised seam metal.  With raised seam metal they install the panels w/out roof penetration by attaching to the raised seam.

This site can give you really good estimates for your particular location.  It will even let you place a rectangle around your roof and it will back-calculate about how many kW of solar modules will fit  (not corrected for roof slope). http://pvwatts.nrel.gov/index.php

The northeast is not the greatest for solar PV but it's all relative. A professor from Germany told me once that Germany wasn't great for solar PV and he was right.  Compared to Germany the northeast US has a lot of potential (google insolation maps for Germany and the United States).

Total costs for materials/installation of solar PV (around $5/watt) are down about 50% from when I last looked about 10 years ago. SolarCity's model (apparently) is to install with no money down by using NYSERDA/federal grants.  Although many others are not a fan of govt. subsidies, I'm okay with it.  Solar PV panels on roofs have so many environmental benefits compared to every other energy source.  All fossil fuels-too much carbon emission; nuclear-no mechanism in place to store radioactive waste; all biomass solutions-takes away from food production; solar power towers--they're interesting but do we really want such high temperature megaplants?

SolarCity plans on producing 1 GW of modules at the plant that they're currently building in Buffalo. Assuming 15% efficiency that's 150 MW per year. As a point of reference,-------If you shut down Indian Point 2 and 3 you need to replace 2,000 MW (or 1,800 MW if you assume 90% efficiency).

The nameplate versus actual production numbers get confusing fast---Nuclear plants have a high number because they're producing energy all the time except for maintenance/fuel rod replacement. Solar PV installations have a low number because they're not producing electricity at night, during cloudy weather, etc.  Also, solar insolation varies throughout the day, so effectively only 4-6 hours per day of "high-quality" sun is available.  (This "high-quality" number is 1000 watts per square meter per day, which is referred to as one "sun").