Greg's blog

There have been a lot of studies and comparisons on the savings of CO2 emissions when pv solar panels are used in place of electricity from a utility company; however, since different solar panel manufacturers use different manufactur

If you buy your car home charger through Nissan's program, you must use one of their installers.  Their minimum price with installation is around $2500, which can be excessive if you only need a little bit of electrical work done.

Another option would be to buy your own home car charger from Leviton:

http://store.leviton.com/dp/B004G6ZSZG

PG&E has a great online utility that will show you your hour-by-hour electrical consumption, directly from your smart meter.  The image below is a screenshot of the first full charge of my leaf, done around 4am after driving to work and

I did not get it in time for Christmas, but my long wait is over -- my Leaf has arrived -- in the garage, plugged in and charging up!  I've been on Nissan's waiting list since June of last year, but I have actually b

We blogged about molten-salt plants a few months ago here on greenknowe.org, and now we have some good news to go along with that. California has approved a molten-salt solar plant, and construction is expected to begin sometime late in 2011. Hopefully the cost and efficiency will play out as expected, and more of these plants will be built in the future.

By this point in the project we were running about a month behind schedule and with bad weather just around the corner, we couldnt afford any delays.  Just before our insulation was scheduled to go in, disaster struck.  Our local insulator's equipment broke down, it wasn't going to be repaired

Our home renovation project also included replacing the old flat tar and gravel roof with a new, sloped metal roof.  A sloped roof is of course much better for mounting the solar panels, and we selected a single-plane south-facing roof that faces south so that we would get good panel-placement options. 

Since we already needed to open up all of the walls in the house and take off the roof as well, this was also the perfect time to revisit the electrical system.  The house, being sixty-plus years old, still had a lot of knob-and-tube wiring, and only 60 amps of service.  Since we have been planning for some time to get an electric car (when available), that just wouldn't cut it.  Additionally, we wanted to put in enough solar panels to run the car, and that also demanded revisions to the house's electrical.

An article in inhabitat.com describes the world's first molten salt solar plant, which just went online in Italy.  The plant uses molten salt to store heat from the sun; the heat is used to produce steam to drive a turbine that generates power much in the same way a hydro-electric plant does.  Because the molten salt has such high inertial heat, the plant can generate power around the clock.

Earlier we talked about how to make your own rain barrel.  The rain barrel project was easy to do, and it was very exciting to see how quickly the barrels filled up when it rained.  Unfortunately, it was also a bit disappointing to see how quickly those sixty-five gallons of water were used up watering the yard when the rain stopped.  C