Note of the Living Deb

I just read something interesting today over at The Simple Dollar: Light Bulb Showdown: LED vs. CFL vs. Incandescent. Holly Johnson says, "they’re now available for about $8 a bulb on Amazon [$54.98 for a 6-pack of Cree 9.5-watt (60w) LED * 6 Pack * - Soft/warm White (2700k) Light Bulb]. IKEA sells its own 60W-equivalent LED light bulbs for just $5 [$4.49 for a LEDARE LED bulb E26, dimmable, globe opal], and Home Depot is reportedly running a promotion in May that will discount Philips LED light bulbs to as low as $2.50 per bulb."

(I can't find additional information on the Home Depot promotion, even though it's May tomorrow, but I do recall reading that Home Depot has some light bulbs that are subsidized by my city.)

So if you've been putting off getting these, now might be a good time financially. Also, summer is coming, so if you live somewhere hot, it might be nice to switch to some lightbulbs that don't emit heat.

I've heard mixed reviews of LEDs over the years and have started keeping track of people's favorable reviews.

In October of 2013, MMM recommended GE Energy Smart LEDs--"the first LED bulbs I found with a sufficently good "color rendering index" to make the food look tasty, and thus they finally allowed me to remove the power-hungry halogens." But his current recommendations page lists LED Waves which he reviewed in March 2012, but then updated at a later point to include those bulbs. But he likes a really focused light and I like an uncultured widely dispersed light. Why, yes, I do like overhead fixtures! (I've read that overhead fixtures are a terrible way to light up your house and instead you should have millions of spotlights in the areas where you actually like to look at things like paintings and work surfaces. Apparently I am not supposed to like to look at my whole house, like bookshelves, the inside of cabinets, or the floor I'm walking across.)

In January of 2014, Financial Ramblings liked Cree's warm white bulbs. "They immediately reach full brightness, they put out a ton of light (800 lumens/bulb), and both the color and light dispersion are fantastic. Oh, and they use marginally less electricity than an equivalent CFL (9.5W vs. 13W)."

In March 2015, Trent Hamm from The Simple Dollar liked LE's A60 E26 bulbs to replace 75-watt bulbs and Triangle's candalabra-based bulbs for ceiling fans.

In November, 2014, Miser Mom posted that she had noticed that a lot of light bulbs don't actually last as long as they're supposed to, so they don't save you money after all. Unless you save your receipts (she saves hers in an envelope in the box where she keeps her new light bulbs) and keep track of which bulbs are how old (she writes the installation date on the bulb itself when she installs it). Then you can negotiate a refund or replacement bulb.

Warning: one of the CREE reviewers on Amazon says, "Cree has stated that they will not honor their warranty for Amazon purchases, unless the seller sends you their receipt from Home Depot!"

The weird thing I want is bulbs that are equivalent to 40 watts instead of the usual 60; most of our overhead light fixtures involve two or three light bulbs.

My current plan is to see what's up at the Home Depot that is walking distance from my house tomorrow. I'm hoping to find the 40-watt equivalent Cree light bulbs.

Remember how I was comparing my spending to that of a couple of personal finance bloggers who published their spending for 2014? Well I decided to look into home energy and water costs as well.

me
* natural gas - $327
* electricity/trash/water - $2154
* total = $2482

Eco Cat Lady
* gas/electric - $1188
* water - $222
* total = $1410 (57% of what I pay)

Mr. Money Mustache
* electricity/gas/water - $1614 (65% of what I pay)

It sure looks like there is a lot of room for improvement! Of course, those two other guys do not have my same situation. They both live somewhere cold, but that just means they spend way more on heating and way less on air conditioning than I do. Eco Cat Lady has a small house like mine; Mr. Money Mustache's is bigger and holds three people. Yes, I should be able to do better as well.

But how much better? Some of my costs are fixed. I decided to find out how much.

My last City of Austin utilities bill was $129.57 for electricity, water, wastewater, trash pick-up, and other random city services. This is super low because we are in the middle of winter. Fixed costs were about $58.03. I say "about" because it's not totally black and white. This number includes:
* a tiered fixed charge of $3 for water--if we were in the first tier instead of the second, this could be less
* a trash can charge of $5.10--this is lower than for bigger trash cans, but last time I checked, we had the smallest one possible
And I am not including the 1% tax on electricity which is based on both fixed and variable expenses.

My last Texas Gas Service bill was $35.77 for natural gas (a little bigger than usual because it's winter). Of this, $20.06 was not based on usage. Again, this figure is problematic because it includes several small charges which seem to change randomly from month to month.

Still, my total annual cost just to be allowed to have these services even if I use nothing at all looks to be about $937 ($78/month). (And here is where I remind myself that it's not cheap keeping the power lines up after all our storms, dealing with tree roots growing into pipes, and driving those behemoth trash and recycling trucks all over town repeatedly.)

That fixed-cost total is 2/3 of Eco Cat Lady's total expenses and 58% of Mr. Money Mustache's. So it's not the case that my fixed costs are greater than their total costs. So that's a relief. (Unless I was in the mood to be whiny.) My original notion that there is room for improvement by adopting more of their strategies appears sound.

PV cells

The photovoltaic (PV) cell is the basic unit of solar arrays. Most are made of silicon which is made as pure as possible and then doped with boron on one side and phosphorous on the other. The boron side faces the top where the sunlight (photons) enter. It has excess electrons which are given off when the photons hit it. The phosphorous side is starving for electrons and is attached to a back layer. A wire run from the front to the back can power something.

The first PV cells were made of a slice of a single silicon crystal. This crystal cannot be cut at right angles and still preserve its important properties, so it is typically shaped like a square with the corners cut off. These cells have an efficiency of 20%. These are still the most popular and have been seen to work for 50 years. These have the highest cost per watt.

PV cells can also be made from multiple slices fused together. These are cheaper to make but are a little less efficient (13 - 16%). They can be cut at right angles and are generally rectangular. These are newer but have still been seen to work for 20 years. These cost less per watt.

Panels

PV cells are put together in rows and columns into modules (panels). Monochrystalline silicon modules are dark blue with gridlines and white diamonds (where the corners were cut off). Polychrystalline silicon modules are a brighter blue with thicker gridlines.

Modules can also be made from a thin film of either amorphous silicon with no chrystalline structure (A-Si), or Cadmium-Telluride (Cd-Te) or CIGS among other things. These are still less efficient (6-7%). These have the lowest cost per watt but require more area and much more wiring. They are flexible and see-through so they can be used for windows, awnings, and skylights. And they work better in shade than the other two types. The Cd-Te and CIGS types have no silicone which was good during the period when refining capacity was maxed out, but more capacity has since been built.

Panels are strong. All can handle 1-inch hail at 60 mph; most, golfball-sized hail at 90 mph. They are stronger than a composition shingle roof. Baseball-sized hail can take it out, though. But this can be covered by homeowner's insurance. Modules do degrade by about 1/2% efficiency per year. Maintenance is easy and involves hosing them down occasionally.

Racking

Most (90%) systems are roof-mounted and of these, 90% are flat-mounted. They are attached to rails which, in turn, are attached to the roof. For composition roofs, bolts must go through the roof into the rafters (load-bearing joists) with a lag bolt to protect against the wind. Flashing or neoprene mastic is then used to protect the roof from leaks.

Solar panels can also go on Spanish tile roofs, but it's very labor intensive (takes three times as long) and involves pulling up most of the tiles. They are easiest to install on standing-seam (metal) roofs because they can be attached directly to the seams with no roof penetration at all.

They can also be pole mounted (expensive, but you get free shade) or ground mounted (cheap, but probably doesn't work in urban settings because of shade problems and because you probably have other uses for your ground). You can put them on carports and solar awnings.

Steel racking leads to expansion issues (solar panels are framed in aluminum) and rusting. It's much better to use extruded aluminum designed for solar panels. It costs a tiny bit more at first, but then it will be trouble-free.

Conduit

The wires must go through metal (not PVC) conduit and this must be on top of your roof (not in your attic). This is to protect firefighters who might need to climb on your roof and chop through it with an axe at which time they do not want to connect with your electricity.

DC disconnect

There's a place to turn off the power.

Inverter

The inverter converts the DC current from the panels to the AC current used in your house.

This is the weakest link in the system. Therefore, make sure you get one with at least a 10-year warranty. (SMA is best. Fronius is also great and a little cheaper.) Inverters hate the sun. Therefore, it's good to install yours in the garage and terrible to install it on a south-facing wall. They can actually handle heat up to 120 degrees, but they are not good with direct sunlight. At the very least, put an awning over it.

AC disconnect

There's another place to turn off the power which our instructor called expensive and pointless. The idea is that repair people can easily find this box and turn it off, but in reality they never actually use these boxes. That's probably because grid-tied systems are designed to stop producing power in blackouts and brownouts to protect repair workers.

[It is possible to build a hybrid system with a bypass to batters to run the fridge and other critical things--not the air conditioning, but it's expensive ($1000 - 3000 just for the batteries) so it would be better to get a whole-house generator ($400 - $500 for a 4 kW generator) if you want power during blackouts.]

PV meter

The inverter actually has a meter, but it can be 5% off. Therefore, grid-tied installations also have a revenue-grade meter.

Electric panel

The system is tied to your panel. It needs two slots at the bottom (with your main/grid power at the top). If you install a solar panel system, your electrical system will have to be brought up to code. (I can tell based on various things that people laughed about in class that our 55-year-old electrical system would require a fair amount of work in this area.)

Utility Meter

Grid-tied systems are connected to your meter.

Questions

I had a few additional questions when I went in that were also answered.

What happens with the solar panels outlast the roof? Solar installers are hired to disassemble the system, then roofers can re-roof the house, then the solar installers reassemble the system. (I put in 30-year composition tiles, expected to last 23 years in Austin, 14 years ago. I want my next roof to be metal so that it is also my last roof. I should probably wait until I do that before installing solar panels.)

Can you mix and match module types, say, to put film panels in the oft-shaded areas and more efficient panels in the other areas or to add on to your system? Not really. Being in series, they need to have the same current. However, you could put them on different inverters.

Any other questions? Ask me, I might actually know the answer.

Blog entry of the day especially for my vocabulary lovers: Manly Slang from the 19th Century - "Gullyfluff. The waste—coagulated dust, crumbs, and hair—which accumulates imperceptibly in the pockets of schoolboys." I think fraeuleinchen will like most of them, such as scandal-water: "Tea; from old maids’ tea-parties being generally a focus for scandal." Raaga123 might like follow-me-lads, "Curls hanging over a lady’s shoulder." Chikuru might like hobbadehoy, "A youth who has ceased to regard himself as a boy, and is not yet regarded as a man." I think I like bully trap, "A brave man with a mild or effeminate appearance, by whom the bullies are frequently taken in."

I got my highest utility bill ever (for me) today. And I did it with:
* a high-efficiency central air conditioner
* a nice three-month AC air filter that I replace monthly
* turning the AC off all day while we go to work, even though it's 86 in the house when we get home
* never cooling the house below 75 degrees
* plenty of insulation
* solar screens on all the windows
* solar film on some windows
* curtains, blinds, and/or tin foil on most windows
* the lightest color roof shingles my roofer offered
* mostly fluorescent light bulbs
* a low-flow shower head

It was kind of boiling hot every single day, as if it were August, and we did water a million tomato plants, and I'm still working on re-growing those fallen shade trees, but still.