Taking a look at the math behind Winstanley’s solar project

NEWFANE — Your article on the Winstanley Enterprises solar project [“Site near I-91 eyed for 2-megawatt solar array,” News, July 10] was very interesting and informative. I am an advocate of renewable energy sources and am glad when the public has a chance to be educated about them.

In doing so, however, it is vitally important to present the numerical data on costs and benefits in the fairest of all lights so that the public can form independent opinions.

In the article, Dan Ingold of Western Solutions is quoted as saying that, “based on 2010 data from Efficiency Vermont - the most recent data available - Brattleboro residents used about 39 kilowatt-hours of power.”

The next paragraph states that the Winstanley solar project will provide 3 million Kw-hr of power. If one looks at the data as stated in the article (and interpolates the time scales correctly), one could use simple math to project that the solar project would produce an excess of 2,999,961 Kw-hr of energy per year.

However, the data presented is misleading because of the lack of time information, and some of the data is flat incorrect.

I emailed Efficiency Vermont to get clarification on the data and was directed to the organization's website, where I learned that Ingold was referring to the entire Brattleboro residential sector and the correct usage number was a little over 39 million Kw-hr for 2010.

The 3 million Kw-hr the solar project is supposed to generate needs some clarification as well.

To compare apples to apples, I surmise the energy production rate is per year and it should have been stated that way.

The correct data tells a far different story. If the project generates the maximum 3 million Kw-hr it says it will (at the maximum rate of 2 MW), it will produce a maximum of about 7.69 percent of the energy needed for Brattleboro's residential sector based on 2010 consumption.

If the industrial sector is taken into consideration (~126 million Kw-hr usage), the solar project will produce a maximum of 1.8 percent of the energy needed for Brattleboro's combined industrial and residential sectors.

Another pertinent question that went unanswered, but that is important, is what is the target price for energy (Kw-hr) for this project without the above-market rate feed-in tariffs?

To compare the costs of producing electricity with the various technologies, we need to look carefully at the cost to consumers in a straightforward way.

Let's look at the entire story so we can make informed decisions.

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