Friday, June 3, 2011:  Updated July 23, 2012

Solar Panels 6 Months Later

It has been over 6 months since I installed our solar panels and we started making our own electricity. 

To recap, December was not a good month for solar energy.  The panels only made 160 kWh all month and we used 310 kWh more than we made. Just by looking at daily solar panel production for December, you can extrapolate when the winter solstice took place (TED started collecting data on December 4th). 

Even though solar panels are more efficient at making power when they are cold, having less hours of the day really hurts production. 

January more than doubled December's production with 380 kwh. February almost doubled it again and nearly zeroed out the net meter. March was the first month where production equaled consumption. Even with all the record rain fall and cloudy weather in Northern Utah, the months of April and May produced enough power to run our house for 3 months. I can't wait to see production on months where it doesn't rain every day. This unseasonably cold weather and cloudy skies hampered available solar energy but at the same time, we hardly had to turn on the air conditioner. 

The solar panels are currently producing twice the energy of what we consume. On a sunny day, they make over 3X.  

Our utility company allows us to build up a one-for-one credit with them so long as we use up that credit within 12 months of accruing it.  Under this system, the grid is effectively our battery. A non-volatile, unlimited capacity, low cost, maintenance free battery. All I pay is the $5/month fee, well worth the price in my opinion.  The electric company lets us do this because we are helping them reduce their peak demand.  You can do this too!  Solar panels are the perfect solution to preventing rolling blackouts.  

As of today, we have built up nearly 2 months worth of energy credit.

In hindsight, a 6.2 kilowatt solar system is a little too large for powering just our house's electrical needs. But when I first looked into getting solar panels, our energy consumption was much higher than it is now. An un-calculated side effect of having solar power (and a TED whole house monitoring system) is a positive lifestyle change.  Having a device that points out to you that you are being extremely wasteful will change the way you act and think forever.  

This increased awareness has indirectly reduced our energy consumption by a third.  All the while, our standard of living has remained the same or even increased. 

Now that we are making more energy than we will use in a year, I need to put it to good use before we have to give it away for free, which isn't exactly the end of the world either -- actually I would be saving the world then wouldn't I.  Here are a few ideas. 

Make some hydrogen:  
Using electricity, one can split water molecules into oxygen and hydrogen.  Storing hydrogen is tricky because it takes a lot of space and doesn't have a very high energy density.  But once you have it stored in tanks, you could then use it to power a fuel cell and generate electricity during a power outage. Or you could burn it directly for cooking or heating.  

Heat the home in the winter months:  
A deca-therm of natural gas is equivalent to 293 kWh.  Heating our home for the winter (using an electric furnace instead of natural gas) would require 16,500 kWh.  We would need a solar system nearly twice as large as what we have now just to run the furnace for the winter.  This would be a stupidly inefficient way to heat a house.  Still, if we have energy to burn, why not?  Nah. 

Charge an electric car:  
Charging an electric Chevy S-10 pickup truck after driving it 40 miles will require somewhere in the neighborhood of 9 kWh of electricity (12-14KWh with lead-acid batteries). I drive my current commuter car about 8000 miles a year. That works out to only needing 1800 kWh/year.  That would be perfectly doable with the estimated solar energy surplus and save me about $820 in gas each year. This would also knock the return on investment for the solar system down from 11 years to just over 3 years. Hmmmm. 

Power a Time Machine:  
Too cliche. By the way, a few years from now, I actually invented a time machine and went back in time to a few hours from now. Apparently, it didn't go very well and an even older version of myself had to go back in time to a few minutes ago and stop the whole event from taking place.  Time travel is tricky like that, not to mention it takes a ton of power and the stupid machine kept blowing the main breaker.
Time travel, Shmime travel, I just want a microwave oven clock that doesn't have to be reset each time the power goes out.