If you're not taking a few seconds to look at a specification sheet to check the negative tolerance rating of the solar panels that are being installed on your roof, then your taking a major gamble on your return on investment. Some of the biggest names in the industry offer some of the poorest negative tolerance ratings on the market. A Poor Negative Tolerance Rating Can Add Years To Your Return On Investment.


Imagine buying a dozen eggs and opening the carton and only finding 10.8 eggs ?

Then imagine that you found a sticker on the carton that said that the number of eggs that are supposed to be in the carton might be off by 10%


Welcome To The World Of Negative Tolerance.

Negative tolerance used to be one of the industry's best kept secrets, and is still a subject that many solar sales people try to avoid. The negative tolerance rating of a solar panel is the amount of power that a solar panel can be "off specification", new, right out of the box.

If you bought a solar system in the last few years from that well known nationwide home improvement store that sells solar panels that are made by an oil company, then chances are you may not have faired much better than our egg purchaser because the solar panels that you bought only had a negative 9% tolerance guaranty, meaning that if you bought 200 watt solar panels from this home improvement giant, the manufacturer only guaranteed that you would receive 182 watts even though you paid for 200 watts and the solar panels were new, right out of their box.

If the same 200 watt solar panel had a 5% negative tolerance rating (which is only what Sharp and SunPower guarantees for their negative tolerance on their panels up to 235 watts), then that 200 watt panel might only produce 190 watts and would still be considered within specification by these two manufacturers.

A 3% negative tolerance might produce 194 watts. So as you can see, the lower the negative tolerance rating, the better your assurance of getting the actual power that you paid for.

At Visalia Solar Companies you will only find top name brand solar panels that offer a 3% or better negative tolerance rating which is one of the reasons why you won't find Sharp 187 through 235 watt solar panels, Sunpower 225 through 230 watt solar panels as well as brands and models offered on our website.

Before you buy a solar system from any dealer, compare their specification sheets with the specifications sheets of the solar panels that we offer and see for yourself. When it comes to price and performance, we offer only the finest ! 



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