Miss Information, week of June 16, 2008

I decided to start a weekly thing called “Miss Information.” Miss Information is used often by people who want you to buy things, some times it is unintentional, other times it is not. As you can see, Miss Information looks good, sounds good, (often too good) and she can be down right convincing if you truly want to believe.  Half truths and intentional omissions are common and I believe they give good technology and or science a bad rap.

This weeks Miss Information comes from the Sam’s Club June July addition of “Source.” It has an extensive section on all things “Green,” including on page 15, a section on Solar Energy. The article starts out okay, I suppose (I am deeply suspicious of any mega retail company that suddenly becomes enthralled with the environment, but anyway…). Then in the bottom yellow box titled “Details about solar energy,” it makes two significant mistakes:

1. “If there is a power outage, you can still have electricity!” Well, sort of. If you want to spend about twice as much on your solar electric system you can have electricity when the power is out.  In a batteryless grid tied solar system (the most common type of system installed) the inverter shuts down when the power from the grid is gone.  This is to prevent utility company workers from getting electrocuted while they try to restore power.  A grid tied solar system with battery back up is about fifty percent more a batteryless grid tied system plus the extra labor to install all the batteries, extra wiring, etc. A grid independent system is several times the cost of a batteryless grid tied system.

2. “As your energy needs grow you can add more solar panels.” Again, sort of.  if you have a large enough inverter to handle the larger output from your solar array it may be possible to add more solar panels in the future.  This is almost never done by an installer because larger inverters cost more, take up more space and operate at a lower efficiency. Also, solar panels age and as they get older, their output drops. Coupling to panels together that have different output voltages will cause more current to flow in the lower voltage panel, which can damage it.

The long and the short

Solar Energy, both Photovoltaic and Solar Thermal are good choices to reduce energy use and thus expenses. They are expensive to install and payback will take several years. They do have their limitations and will not be the cure all and all for our energy problems.

Do your research and lets be careful out there.

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