Posts tagged solar

Here’s output from 5 in-town solar systems for a single day (which day is a parameter on the underlying Google spreadsheet, which I haven’t published yet). This is but a small fraction of the installations in town; these are ones that upload data to pvoutput.org. I’m working on feeds for other, bigger systems, plus New England grid (ISO-NE) demand. The latter’s relevant for assessing how well solar helps shave demand peaks.

I’m not sure if the graph below is static or will update with the spreadsheet; we’ll see-

Why do people compare the cost of electricity produced by a coal plant with that produced by solar PV? It’s like comparing the cost of ethanol, FOB the distillery, with that of a beer ordered at a bar.

Same content, sort of, but different attributes.

In case I’m not being clear: coal-powered power plants produce baseload electricity that has to be transported, sometimes quite far, to demand. Baseload electricity is relatively cheap, because there’s relatively little demand in the middle of the night, and transmission costs can be significant. Distributed solar (up to 5 MW or so) produces electricity at the right time, more or less, relative to peak demand (at least in New England, peak demand events occur on hot, sunny, summer days), and can be sited relatively close to loads, minimizing (or avoiding) transmission costs. For the case of the municipal utility that I know most about, the premium associated with local solar generation, vs. buying from the grid, amounts to between a nickel and a dime per kWh. With solar prices dropping, solar is very close to what I’ll call relative grid parity (where “relative” takes into account the solar premium).