Sunday, July 22, 2007

Thoughts from the recent solar conference

I attended the July 9-12 Solar2007 conference in Cleveland, Ohio. This was the third ASES conference I've attended, the last one was in Orlando, FL in 2005.

I told dozens more people about my 3-D solar panel invention, and learned that many people in the industry believe that the installed cost of solar PV systems will likely drop by as much as 50% in the next ten years--the point at which solar PV reaches grid parity in a many large markets. Those cost declines are predicated on incresed production volumes of PV, which require continued favorable regional incentives for several years to come.

Two things struck me at the conference, one is PV product related and the other is transportation related.

Product: Inverter. About 15 months ago my parents were looking into options for incorporating renewables into our family farm operations. At the time we were told that there were two ways to install solar PV into a home 1) off grid w/ batteries 2) on grid w/ net metering (grid-tied). The off-grid requires batteries which boost the total system cost significantly. Of course we have long known that option 1) exits and that it makes sense if you are builing a house far from existing electrical connections. Option 2) was of more interest b/c we are already connected to the grid. One rather unsatifying result (according to the local PV installers) with grid tied, option 2) is that if the grid goes down so does the PV system, even if the sun is out. In other words a $30k investment in energy independence shuts down right when you need it most! In the end my parents tabled the idea of installing PV or wind until we learn more about existing options or the economics become more appealing (which btw our utilities recent 30% price hike seems to have moved us a big step toward). We did decide to invest in solar thermal panels to heat our hot water--we now enjoy guilt free hot showers!

The story simply illustrates that it would be very nice to have a system that lets you use a few batteries to supply PV power in case of brief emergency power outages, yet still run your meter backward ala net metering program. So I was very excited to learn that OutBack Power Systems offers a "grid-interactive" inverter which allows exactly that. Unlike most inverters which are grid tied, which means they only work if the grid works, the grid interactive inverter allows the system to pull power from either the grid or the batteries and conversly feed power to charge the batteries or if they are full, back onto the grid. Power outages in our rural area occur at least a few times a year mostly as a result of storms knocking a tree/branch into power lines--I am the one responsible for resetting blinking clocks/answering machines etc. and swear I do so once a quarter. Usually the outages are fixed within a couple hours, although even a couple minutes of outage bollix up the clocks/gadgets. I'd certainly be willing to pay a little extra for the utility and convenience of a grid-interactive system, and will lobby hard to make sure our system has this feature once we eventually decide to buy a PV system.

Finally, I've been working hard to reduce the miles I drive (more carpooling), improve my car's mileage through better maintenance (replacing the air filter helped a lot) and smarter driving (no speeding! no going 0-60 in 6.4 seconds or 60-0 in even less) and then I offset the carbon from the driving I find impossible to eliminate. I drive a sensible (although bigger than i really need) Honda Accord, and have been following the success of the Prius carefully (I even got to ride in one last fall thanks to my California friend and host). I'm also aware of the talk of plug in hybrids, which should eventually lead to all electric plug ins which will enable the post carbon transportation era.

I attended a talk on evolving transport options and learned some very interesting things from the guy who created the semi cult movie "who killed the electric car". The first thing I learned is that electric cars are more efficient...a lot more efficient. This means the cost of running electric cars is substantially less per mile. If you spend $0.15 worth of gas to drive a mile with an ICE (internal combustion engine), you could drive that same mile for ~4 cents worth of electricity. Oh yeah maintenance is a lot less with an electric car b/c you keep the moving parts to a minimum. Battery technology is advancing to the point where a car's charge should easily get you 20 miles (more if you do stop and go driving) before you need to a recharge or a backup ICE onboard (i.e. hybrid). Experts believe that 20 mile range will increase significantly in the next five to ten years. But even at a 20 mile range, most city dwellers could get to work and back or run a day's worth of errands on a single charge. The speakers explained that as battery technology improves it is also becoming less damaging for the environment. Lead-acid technology (bad) is being replaced by Nickle-metal-hydride (not as bad) and soon lithium ion (even less bad) will be the storage medium of choice. Plus the electronics for monitoring and maintaing charging and recharging of batteries is improving so that batteries are lasting longer. In fact it seems reasonable that in a short time electric vehicles could provide significant benefits to both grid stability and the electric grids ability to accomodate more renewable sources like wind and solar. Imagine what several hundred thousand (or even a million) vehicles with significant battey capacity plugged into the grid could do to help stabalize fluctuations during the day (even draw down a bit of power at times of peak demand) and then recharge primarily at night when electricity costs are lowest.

But the most interesting point of all for me was that plug in vehicles compliment solar power. The combination will allow a fully modern low carbon lifestyle for individuals. Talk about zero emissions! But also since the electric vehicles are so efficient, using your solar panels to charge your electric car saves you more money than simply turning your utility meter backwards. Using solar to charge a car means one can pay off the big investment in solar panels even faster.


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