Steve,
I work in the electrical engineering field and have for most of my career. I work with power distribution systems for the railroad industry, I do everything from load analysis for DC emergency lighting systems to 1.2MW 3 phase power distribution. I have never purchased anything from altenergystore.com, but found this site because I was looking for a xantrex power monitor. I've been watching this thread for the past several days and it's really making the hairs on the back of my neck stand on end.
Your website mentions that the average household uses 40KWh of energy per day, and that in moderate wind conditions, the E2D can supply 25% of that power, which is 10KWh (40Kwh * 25% = 10KWh). 10KWh over 24 hours works out to a continuous output of 416.66W (10,000w / 24h = 416.66w). 416.66W works out to 30.19A at 13.8v (416.66w / 13.8v = 30.19A), the typical float voltage for a 12v deep cycle battery. Can your product produce this much power continuously in moderate wind conditions?
Your website also mentions that you can get 10KWh from each charged battery. From our calculations above, we have determined that 10KWh is about 30.19A at 13.8V over a 24 hour period. According to your website, you supply a group 27 battery with each kit. A typical group 27 AGM battery is 100Ah at a 20 hour discharge rate. This works out to 5A for 20 hours (100Ah / 20h = 5A), at 24 hours it would be 4.17A continuous (100Ah / 24h = 4.17A). This is assuming that everything is 100% efficient. For the 10KWh per battery statement on your website to be true, you would need a battery rated at 724.56Ah (30.19A * 24h = 724.56Ah). At the very least, I think that it is misleading that you don't mention this fact on your website, as a single battery that large will be quite expensive and difficult to find.
Here is a list of references if they are of any interest to you:
Ohms law:
http://en.wikipedia.org/wiki/Ohms_lawWatt's Law:
http://en.wikipedia.org/wiki/Watt%27s_lawSI Prefixes (for converting kw to w):
http://en.wikipedia.org/wiki/SI_prefixFloat and charging voltage for a typical 12v battery (AGM is included):
http://en.wikipedia.org/wiki/Lead_acid_batteryTypical Group 27 Battery Specifications:
http://www.trojanbattery.com/Products/ProductSpec.aspx?Name=27-AGMReference to Freetricity regarding KWh per day usage of a normal home and claims of producing 25% of that usage:
http://www.freetricity.com/whatcan.htmReference to Freetricity regarding 10KWh per charged battery:
http://www.freetricity.com/whatis.htmReference to Freetricity regarding the inclusion of a group 27 battery in each kit:
http://www.freetricity.com/howmuch.htmPlease feel free to check my math and my references and let me know of any errors, please include references to your facts in your response.
-Nathan
