In other news, I’ve been appointed (pending receipt of the official notice) to my town’s Municipal Light Board, and a committee to figure out what to do with solar energy.  I’m excited for both of these posts, as I’ll learn a ton, and will have a chance to help our town be more sustainable, cost-effectively.  The solar project should be really interesting; the state solar incentive program has been tied up in a lawsuit which was just partially settled (at least the solar piece).  So, it’s time to roll.

That’s a big deal for me.  This article gives the Town Manager authorization to lease certain parcels of Town-owned land (the Ammendolia land and land around the sewage treatment plant) for 20+ years for a large-scale solar array.

There are a lot of open questions to be worked out, but it’s exciting to have the very real prospect of having a sizeable array here in town.

Here’s an article from the Concord Journal that was published before Town Meeting.  My guest commentary that appeared in the print version is not available online, alas.

• Falmouth HS (ME)
• Newton South HS (MA)
• Piscataway Township Schools (NJ)
• Deer Valley HS (AZ) (1MW!)

There are, of course, many, many more out there.

And here’s what is thought to be the first net zero energy secondary school building in the U.S. (apart from old one room schoolhouses with no heat or electricity, I presume).

Details on the economics, etc., will follow.  As far as the Town is concerned, this is largely a windfall- the school system will get free electricity from the PV system, the CSEC money is from the Sawyer Funds dedicated to sustainable energy, and CMLP should recoup their investment through lower peak demand from the grid in the summer.

I’m interested in solar energy, data analysis, and visualization, so I downloaded some data (look for e.g. the CSV button here) for August 2009-January 2010 and popped it into Tableau.  The data starts in August because the system didn’t start running reliably until mid-July.  I choose Tableau because it allows me to dig into the data in some detail quite quickly.  And it makes nice graphs.  However, it’s not perfect; it’s expensive, closed-source, and has limited ability for statistical analysis.  R is better on all of these fronts (free, open source, great stats), but at the present moment I can work much faster in Tableau.

So, here’s what I found:

First, I looked at production by month.  I expected August to have more production than December.  So far, so good:

The color of each bar is proportional to the height of the bar.  It doesn’t add any more information, so it’s kind of chart junk, but I think it accentuates the differences between months.

I was a little surprised by how low December was relative to July; to see what’s going on there (other than the days being shorter and the sun being lower in the sky), I looked at daily production:

I did the same thing with coloring here (except that I also grouped colors into 100-kWh buckets).  What’s interesting is that a good day in July resulted in over 400 kWh, while in December the best days netted 260 kWh or so.  That’s a 1.5:1 ratio, while the monthly ratios between July and December are more like 2.7:1.  The difference is clearly due to the number of bad days in each month- most days in August were good for at least 200 kWh, while there are a lot of dogs in December.  Some of these are due to cloudy conditions, while some are due to snow cover- the panels are close enough to the ground so that it takes a couple days of good sun before they melt enough snow to get going again.  It raises an interesting question of the cost/benefit of installing them a bit higher.  Without doing any analysis, I’m guessing the extra installation costs aren’t worth a few more days of mediocre production in the winter, but what do I know?

That’s all for now- the next post will show some basis analyses of this data.

Here are a few thoughts for 2010:

• I bought a few 2′ x 8′ x 2″ rigid insulation boards, which I intend to install in the crawl space underneath the room we refer to as “the cold bathroom”. The existing insulation, fiberglass batts, has largely come loose and is very ineffectual. This should be a relatively small, high-impact DIY insulation project (what’s worse than a cold tile floor in the morning?).
• Recessed lights are dodgy. We have 3 recessed lights in a cathedral ceiling. They let a lot of heat through to the roof. When it snows, you can very quickly see where these fixtures are located from outside, due to the melting pattern. We use these lights (CFLs) minimally in the winter; the ambient heat in the room just flows right through the poorly insulated fixtures. In addition to wasting energy, this also promotes ice dam formation. Something must be done!
• Massachusetts is launching a new solar incentive program. It is very complicated, but has the potential to keep solar rolling in MA- there’s more info at the mass.gov Solar Carve Out page.

Here’s what our electricity use looks like these days:

Our meter gets read every other month, but I interpolated the meter readings to estimate monthly use. January and February were high because we had our boiler replaced in January, during which we had a lot of electric heaters running (especially as the installation wasn’t so smooth). We also used electric heat in the basement (now replaced with hot water heat) and our “project room”, a poorly insulated 3-season room that we aren’t going to use much this winter. So this upcoming Jan/Feb shouldn’t be so high. Spring found us at about 17 kWh/day, and then things kicked up when it got hot and we used some A/C. I’m frankly not sure why September and October are as high as they are; I suspect it’s due to the lights in the basement getting left on too much. That will be a retrofit (more efficient lighting) and controls (auto-off when not in use) project.

As it is, our annualized use looks to be in the range of 7,000-8,600 kWh/year. The low value is based on March-present, while the high value includes all months. I suspect by the time we get to March, our trailing 12 months will be under 8,000 kWh/year. Not great, but not bad. I’ll look at how good or bad this is later.

We heat our house with the aforementioned high efficiency modulating, condensing natural gas boiler. It’s part of a FreeWatt micro-cogeneration system, but does not include the generator piece (yet).

Here’s what our usage looks like:

On first glance, the new boiler, which was installed in January, didn’t do us much good. But look at the degree days (which National Grid provides online)- January was cold! Another way to look at the data is degree days vs. therms used. Here’s a scatter plot, with each point representing one month:

It’s pretty much a straight line, with a slope of about 0.3 therms per degree day. The one outlier at 800 degree days was the one month when we had the old system (and were out of town for over a week)- looking at it this way, it does look like the new system is better! Doing the math indicates that we’d use 20% less energy at 800 degree days than we did last December. It would be nice to have more before/after data, but I’ll take it. One other interesting thing is that we used less energy last April vs. November (the two data points at ~475 degree days), even though the degree days were pretty close. That might be noise, or maybe there’s a reason. We’ll see what this December brings.

Next up: I’ll look at the inferred amount of natural gas we use for domestic hot water, figure out our (house) carbon footprint, and compare our energy use to residential benchmarks.

But there are lots of good sources for actual information about climate science on the web.  Here are my favorites:

• AGW Observer- comprehensive index to climate science papers, organized by topic.
• RealClimate Data Sources- Index to primary sources for climate data and models.
• Global Warming: Understanding the Forecast- book, video lectures, online tools.  Comprehensive.
• Index of climate science authors- A who’s who of climate scientists.

• Fat Spaniel live sites: Fat Spaniel does monitoring and reporting for renewables.
• SolRenView live sites:  Solectria makes inverters.

The Fat Spaniel sites are quite polished, but I see room for design improvements.  Specifically, I think one could integrate some information about averages into the various charts that provide a bit more context.  I’d also remove some of the distracting cartoony stuff that doesn’t add much info.

SolRenView is a lot less polished, but more or less does the job.  Plenty of room for improvement.

Both offer export capabilities.  It would be fun to pull data on say an hourly basis and generate a live map of PV output. Of course, it wouldn’t be at all comprehensive, but it would be a neat tool for raising awareness, complementary to e.g. The Open PV Project.

I would think people might like to be able to view their systems’ output on their phone.  I haven’t seen such an app yet.

I’m sure there are other public-accessible solar monitoring sites out there, but I can’t find them at the moment…