Saturday, December 19, 2015

Why I love paying my electric utility bill

I installed the first part of my solar power system in the fall of 2009 and immediately my power bills dropped considerably. 

The chart below shows the energy flows for my property over the last several years:
Take a moment to study this chart and look at how everything interacts.  The yellow line shows how much surplus energy I export back into the grid on a monthly basis from the solar array.  Clearly, in the summer I am exporting a lot more and this more than offsets my net energy for the month.  Whenever the green net energy line goes below zero, that is when I have a credit.

This chart shows my actual bottom line monthly electric bill:
Over the years I have scaled up my solar power system and now my electric bills flatline in the summer, bottoming out to the minimum connection fee.  This year I had a surplus  from May through October and the utility gave me a credit that carried forward until it was used up.  This electric bill covers both my house, workshop, and the electricity used to charge my Chevy Volt.  So, not only am I not paying for utility energy for months at a time, I am also driving up to 37 miles a day for free on solar power.

During the summer months the energy I am exporting into the grid reduces the load on the power lines feeding my immediate neighborhood.  As neighborhoods grow, the utility often needs to upgrade the infrastructure in order to deliver power to outlying areas.  If new housing developments were all to incorporate solar roofs on their houses, this would reduce the cost of deploying and maintaining power lines to those areas.  You would think that utility companies would appreciate this benefit, but in reality they are pushing back against it because of the lost revenue.  Some utilities are even trying to punish customers with solar power with a surcharge to cover maintenance costs on their power lines.  

My solar power system, like most systems installed in the last 5 to 6 years is utility inter-tied.  This means that there is no battery bank and surplus energy is returned to the grid rather than being stored in batteries.  However, battery technology is now reaching the point where it is beginning to become relatively affordable to pull the plug on the utility altogether and simply store that surplus energy in a battery for use overnight and on cloudy days etc.  This is referred to as "grid defection".  Renewable energy pundits are suggesting that entire communities could pull the plug in the future and that utility companies will need to figure out a new business model.

Friday, December 4, 2015

Safely disposing old paint

Paint cans accumulating in my utility room
Do you have a place in your home where old partly used paint cans have accumulated?  Have you thought about how to dispose of those cans of paint safely?  Until recently there were very few options that are environmentally benign.  You can leave an opened can of latex paint out in the open until it dries out completely and then safely dispose it in the trash.  For smaller amounts of water-based paint left in the bottom of a can you can wash out the can in the sink and then put the cleaned empty can in the trash or if it is really clean - in the recycling bin.  This is not recommended for septic tanks however.  And finally, for solvent paints the only responsible option is to take them to a hazardous waste disposal facility which is tedious. 
There is now a new option offered through a nonprofit industry trade association called PaintCare that is setting up return/recycling centers where old paint can be turned in and recycled or disposed of properly.  This paint can now be collected for reuse, recycling, energy recovery, or safe disposal.  As of this writing, in December 2015 there are only eight states offering this service and you can use a map on their website to find a drop-off location near you.  These are typically hardware or paint stores or hazardous waste disposal sites.

According to their website: "The program is funded through fees on each container of architectural paint sold in states with paint stewardship programs. Budgets and fees are set on a state-by-state basis. So far these fees have been the same in each state with a program: 35 cents, 75 cents or $1.60 per container, depending on the container size."

I was very pleased to learn about this program and will be going through my collection of paint going back 15 years to decide what to recycle.

UPDATE - a few days later
drying out old paint residue
I just returned from the hardware store that participates in the program.  I took five  gallon cans with varying amounts of paint in them and the first thing the guy did in the paint department was to turn the lighter weight cans over and tap them on the bottom.  From this he was able to determine that there was a thin layer of congealed paint in the bottom that he could not use.  He told me that they are recycling the paint as useful paint and not as dried out material and that I should leave the cans open outside until the paint dries out and then just dispose of them in the trash.  Any can that is one third or more filled with liquid paint is useful to them.  

I asked him how often the paint was picked up and he said they cart off 250 gallons a WEEK!  This is just from one local Ace Hardware store in Maine.  Wow, talk about a successful program!