Sunday, October 2, 2011

Fixing the Protoshield

Soldering Success

Recall from a posting or two ago - the protoshield would not clear the metal enclosure of the ethernet jack. Since then, I've been able to address and remedy the problem. This allowed me to not only salvage the SparkFun protoshield, but to improve on the initial component flaw - too-short connector tails - that kept it from being installed over top of an ethernet shield.

I was able to desolder the shorter connectors, clear the solder from the holes and install the new ones. It appears to have worked. I say "appears", because you never know how it went until you test it electrically, which is yet to come. But physically, even under a magnifying glass, it looks good. Solder flowed fine, no solder bridges, new connectors are solid. Here's how I did it - you should be able to use this process for removing and replacing any small through-hole component.

Break Off the Socket

I started by simply wiggling the black socket part of the connector back and forth until it broke off. You don't have to move it far - the metal is brittle and will break off with about 12 times of wiggling it back and forth. The little black monolith breaks off with no damage to the protoboard or the soldering holes. You can easily melt the solder enough to remove the pins.


Once the black socket is broken off, you can simply heat up the metal tail and remove it from the hole. The holes will still have the solder inside. Take the solder wick and lay it over the hole, then use the soldering iron to heat the wick. Hold the soldering iron like you are trying to poke it into the hole through the solder wick. you will see the hot solder "wicking" up into the copper braid. It doesn't take long and when you lift off the braid, the hole will be mostly empty of solder.

Finished Product

So now, the protoshield will sit properly on top of the ethernet shield without touching the ethernet jack. It's not as sexy as the new stuff I talked about previously, but it's plenty good for continuing on with the project.

Friday, September 30, 2011

"Nesting" Illustrated

How It Was:
I wanted to illustrate what I mean by "nesting" the connectors. This is not my preferred method of handling this problem, but if anyone out there has spare 10mm connectors and doesn't want to do any soldering/desoldering, it's a way to make the SparkFun protoshield work with their original ethernet shield. It's not optimal, but it works.

Here's a "tall" view of the the ethernet shield and the protoshield stacked on top of it. (By the way, the ethernet "shield" is the lower blue circuit board and the protoshield is the upper, red circuit board.) I put one pair (one 8 pin and one 6 pin) of connectors on the tails of the protoshield connectors, (It requires two pairs to be complete - I wanted to open only one pack of the parts I received.) You can see that NOW the bottom front edge of the protoboard, right under the two pushbuttons, easily clears the big metal boxed ethernet connector - by almost double the height of the ethernet connector!

You could, if you had to, nest to further heights - the bus speeds are not so fast that doing so would cause problems. Stacking shields like this works, and is a good temporary measure when you're trying to build something and need to get the idea proved out rather than worry about the details. But if you are building something that needs to last, it needs better mechanical and electrical connection - this trick just won't do for the long term. The leads can oxidize, lose spring tension, or "creep" due to heat/cold cycles.

New Arduino-format Solutions

These "shields" and the concept of stacking them are components of the "Arduino" concept.

Here's a comparison photo.

The microcontroller on the left is what I used in school - the big green PC board. The little blue PC board on the right is an Arduino. With some differences, the two microcontrollers essentially do the same stuff. Oh, except you can't program the big on in a high level language with an IDE like the Arduino. It's either machine language or a crude cross-compiler.

It's an "open microcontroller platform" intended for use by people who are not computer engineers by education, but are creative and desire to make things using a microcontroller. (but this doesn't stop computer engineers from using the platform....) There are two halves: hardware and software, to the whole, developed by brilliant professors and engineers. Their web presence is

The hardware half consists of the base CPU (Atmel 8-bit 16Mhz processor with 14 digital I/O's and 6 analog I/O's), the basic CPU shield, a USB interface for both programming and power (or an onboard power connector - the system will automatically choose between the two), an FTDI port (if you can't use the USB for some reason or have a target board for the CPU that has no other control and programming I/O), and this PCB shape that has the two 6-pin headers on one side and the two 8-pin headers on the other side. There is an off-center gap between the headers on one side intended to act as a "key" to allow only "Arduino-format" products to be plugged into an Arduino base microprocessor.

The software half is the programming environment and bootloader - all pre-programmed into the processor. You don't have to install it yourself, it comes in the EEPROM of the CPU, making it ready for immediate programming with the host-side companion software for Windows, Linux and Mac. The part that runs on the PC is called the "IDE" - Integrated Development Environment.

It makes for an amazing and complete environment right at power-up. I was able to do in 30 minutes with an Arduino what it took a week or so to do back when I was in college. All I could think when I first used an Arduino was "Why didn't they have stuff like this when I was in school?!?!?" The complete set of hardware and software gives you the ability to DO things quickly, easily and without having to worry about voltage levels or timings of signals on the I/O pins of the shields. It totally frees your mind to embrace and push the creative process.

Options for Arduino/Atmel enthusiasts are changing rapidly for the better. I've previously mentioned the Freetronics protoshield that is shorter and made to clear the ethernet connector's metal "box". This is a simple, well-designed product that will be an improvement for many of you out there who are trying to keep your protoshield projects simple and easy.

Another new product from Freetronics: an ethernet shield with built-in prototyping area AND POE.. Wow, nice. That would have let me do this project with only the Arduino Deumilanove (now the Arduino Uno) and this board.

And another beautiful way to slice it would have been to get the new Freetronics EtherTen and pair that with the protoshield short.

Warning: NEITHER of these options are going to fit in the low-cost plastic enclosure. The ethernet connector is in the "wrong place" for both of these. You would have to stick with the stock Arduino, the stock ethernet shield MAYBE the protoshield short.

DISCLAIMER: I don't know the Freetronics guys, although I understand they are good blokes and know quite a bit about the Arduino and open source hardware.

Parts From Jameco

The parts from Jameco are finally here. Sheesh - when they meant 7-10 days shipping, they were not kidding. Exactly 2 weeks from order placement to having the box on my doorstep.

The materials arrived in perfect condition. They aren't the cheapest source on the 'net for parts, but Jameco does a good job when it comes to filling orders. Every type of component in it's own bag, all in one giant sealed bag. It's painful easy to inventory your order and you can do so without opening the small bags - so you can make sure everything's in order, and if not, easily send it back. Nice!

I immediately unpacked and checked the length of the tails on the new header connectors - 15mm, just as advertised. This weekend I should be able to get time to cut off and unsolder the stock headers. The little wise voice in my head says I should order the "Protoshield Short" from Freetronics as a backup in case I destroy this one trying to get things unsoldered. I think I'll make a first attempt on only one of the pins just to make sure I can do it before I go hacking and slashing, because I know I could simply "nest" a set of spare connectors under the protoshield to clear the ethernet jack, and keep on going. It would look terrible and probably not work worth a damn as a long-term solution, but it would work well enough to continue development.

Monday, September 19, 2011

Energy Monitor Highs and Lows

The current sensor just arrived from ITeadstudio. It is exactly the same 200A model mentioned by Dave

I am all ready to go with final assembly and coding of the prototype, when an old problem I'd forgotten all about reared it's ugly head: the prototype shield sold by SparkFun will not clear the ethernet shield, also sold by SparkFun. Arrrrgggg.

What's complicating this is the fact that I happily soldered-in the header connector components without checking the length of the "tails". Surely every shield they sell will mate to any other shield, right?

Wrong. The tails on the headers for the protoshield are 10mm long. You need 15mm long tails in order for the shield to clear the big RJ45 connector that sticks up high off the board and the 10mm tails won't clear it. But the 15 mm ones will. I have no clue why I didn't get 15mm ones on the protoshield - the fully assembled ethernet shield came with 15mm ones.

So I'm ordering replacement header connectors from Jameco and using solder wick to try to remove the headers I installed without damaging the board. If I can get the old, short ones out and clear the holes, then it'll be simple to install the new ones.

By the way: the Freetronics guys are doing it right. Check out their EtherTen for an Arduino with a built-in POE capable Ethernet interface, and the cool, compatible protoshield-short. Ahhhh. It's good to see an Arduino vendor with enthusiasm and energy to think about their products!

Stay tuned - a few days to get the new headers in and try the desoldering operation. I'll post photos, success.....OR failure!

Thursday, September 1, 2011

Enphase Micro Inverters

Check out this amazing product:

It enables the build-out and operation of solar panels in the home environment using very simple, easy methods. You can expand from one-to-many panels without even having to buy the same panel, which is a serious problem for those of us who want to bild systems out a panel-at-a-time: many times panel producers will discontinue a product so they can introduce improved products. With the Enphase product, you can add that improved new panel to your solar array without problems.

Now, there are limitations and things to know about this product. So far, I've not been able to identify any way to use the product with batteries to perform a storage function for power outages, off-grid operation or overnight power supply. However, for ease of entry into generating your own home renewable energy, you can't beat the low cost, ease of use and flexibility of these modules.

More on the enphase micro-inverters later....

Did I mention Google Power Meter is dead? I mourn it's passing, but the Enphase folks provide the same kind of service to customers with their MicroInverter products, and the price is extremely reasonable, only a few dollars a year.

The High Holy Energy Conservation Season

In the US, September 1 marks the beginning of the Labor Day Holiday. While this is not a day of reverence as many holidays are, Labor Day marks the "official" end of summer and the beginning of fall. Daytime high temperatures begin to show signs of dropping off from the sweltering heat of the summertime. Nighttime temperatures drop such that people begin sleeping with their windows open and their air conditioning off. Harvesting of crops will begin in many areas, and the time of sunset in many southern locations has dropped by 1 hour at the end of the day (8:30pm local back to 7:30pm local).

In other words Labor Day it's a sign that the US winter heating season will soon be upon us and we must prepare - measure, insulate, conserve and take measures to blunt the energy and cost impact of the impending winter weather. You may want to wait another couple months before installing that temporary plastic wrap on your windows to gain your cold weather insulating layer, but it's definitely time to start measuring, planning, and assembling the components you need for your home energy projects.

Ironically, the months of September through November may be the months of lowest energy usage for many of you in the temperate zones of the US. Your air conditioning stays off, you don't need heat yet, and there's enough daylight that home lighting isn't a factor. This lulls us into a false sense of energy efficiency, and we don't get our conservation projects done until it's bitterly cold outside and we've already gotten that terrible power or gas bill.

Prepare, friends. Prepare now. Start measuring now. If you have been considering buying or making energy measurement equipment, do so now and get it installed as quickly as possible. This time represents a valuable time of "baseline data" you can use as you go into the winter months to determine how well you are doing and what you can do to more effectively save energy and money during the deeply cold months of winter.

New Stuff over at OpenEnergyMonitor

The gents over at OpenEnergyMonitor have taken the power and are making a difference. If you've not checked 'em out in awhile, they've changed their gateway web page to explain all the fantastic, creative technical things they've been up to!

These guys don't mess around. Check out their goodies!

Monday, August 15, 2011

Desert Home Power Monitoring

Check out how draythomp uses Arduino to monitor power in his home in the Arizona desert, in the southwest US:

He provides some pachube-based output of his real-time power measurement...

Nanode: Strength to Strength!

With the demise of Google PowerMeter, Ken Boak's Project:Nanode brings a machine that is already being interfaced to Pachube, which can provide functionality similar to what Google PowerMeter does. Check out Ken's brainchild here

Demise of Google PowerMeter

Gaaa! Google PowerMeter is going away!

This is the thing you most fear about free services - the provider is under no obligation whatsoever to provide stability throughout perpetuity.

Which makes me wonder how long I'll be able to do THIS blog....:-(

Thursday, April 7, 2011

Credit Where Credit Is Due

When I first started working on home power monitoring, nothing existed for homeowners to understand and manage their home power consumption.

I found this home energy monitoring website, which has been around for awhile now:

His power usage display is spectacular: However, I priced out the components he used, and his Veris A/D converter runs about $1500 last time I checked. Way, way beyond the cost of the elegant Arduino.

Trystan Lea's site is where I first found Arduino and how it can be used for power measurement:
The name of this blog, "openwattmonitor", is meant to show the lineage, as the child of


"The OpenEnergyMonitor project is based on the work of two developers, Trystan Lea and Suneil, both from Wales. "This is a project to develop and build open source energy monitoring and analysis tools for energy efficiency and distributed renewable microgeneration." The project appears to have been launched in the summer of 2009."

It's all happening now, in real time. They have visualized an "energy monitoring and management framework" that encompasses both open hardware and open software in innovative ways I've seen nowhere else and mobilized an impressive force of technical ability to make it happen.

Dave's "Desert Home" blog blazes new trails in measurement of home power usage in the US, and with interfacing the output to Pachube at

Dave's writings describe how he started measuring his home energy consumption and caught his local power company overcharging him. After calling them on it, they replaced the meter and his power bill was affected very favorably.

I bought my stuff from SparkFun:

Home power monitoring is here to stay.

Assembling Arduino and Shields

There are three total PC boards for this project: the Arduino Deumilanove (now called the UNO), the ethernet shield and a protoshield that plugs into the top and holds the circuits required for measurement of the AC voltage and current waveforms. This part of the project won't need an LCD display or control panel - it will be mounted next to the main power feed for the house, in a weathertight plastic box.

Some customers have complained that the ethernet shield sits down too low on the Arduino. They must have fixed that problem, mine sits high enough to clear the USB connector on the Arduino. I'm hoping the shield will work without the need for any hardware modifications. So far, things look pretty good.

I've been considering using an Arduino "Pro" from Sparkfun: because it seems much more durable to solder the arduino and the ethernet shield together. You're certainly guaranteed the ethernet shield won't possibly touch the Arduino that way, and I like the idea of committing a lower-cost, solidly-wired Pro for the project. I'll consider swapping out the Deumilanove for the Pro after I get all the kinks worked out.

I started assembly of the protoshield tonight. First the basic components that came with the shield. Here they are simply placed on the shield, not soldered down. It won't look that bad when it's done....

The red shield will then get the components for the voltage measurement circuit. Test only those components, then assemble the current measurement circuit and test those. The prototyping area on the shield is very, very small, so I want each section to work before moving on to the next one, or it'll be a mess.

I'm thinking about adding temperature sensing to this project. It would be helpful to see how outside air temperature changes compare to energy usage.

Friday, April 1, 2011

Adding the Two Phases

Found a fellow out in Arizona who's come up with his own means for measuring his home AC power consumption:

He's employing a neat trick: "add" the two legs on the input of US 2-phase power feeds by wiring the two current transducers in series.

My original approach was to sample both legs separately, dedicating an A/D input for each leg. That would let me sample only two circuits using an Arduino Deumilanove (which has six total analog inputs...well, two-and-a-half, but that half-circuit wouldn't be useful.) While this is a precise and powerful way to do it, the phase-locked nature of the analog power waveforms allows you to "multiplex" the voltage one on top of the other by connecting one leg of each current sensor together.

The payoff is that you can use only one A/D input to measure power draw on a two-leg, two-phase US-configured power circuit. That would enable the basic Arduino Deumilanove/UNO to measure up to FIVE circuits (A0 for the voltage reference and A1-5 for the current in each circuit to be measured) instead of only TWO circuits. Excellent!

The disadvantage to this approach is that you've got to hack up your current sensor: wiring them in series like this means you ought to cut off one of the leads from the sensors and join them together. And, you can get the connection wrong.

Note to self: do more research to satisfy myself that this actually works.

Thursday, March 10, 2011

Monday, March 7, 2011

Nissan LEAF: Impressive

Three days ago, I got the opportunity to experience the Nissan LEAF 100% electric automobile – the Nissan “Drive Electric Tour” came to the NC State Farmer’s market this past weekend and I spent several hours with the car Friday, March 4th.  The Drive Electric Tour is an effort by Nissan to enable average people around the US to learn about the technology behind the car, how it works, what it’s pluses and minuses are and what it’s like to own and use such a vehicle in real-world scenarios.

Disclaimer: I have no connection at all to Nissan motor company, and I wouldn’t call myself a Nissan fanboi. But I am somewhat biased in favor of electric cars. The short 100 mile range of this car is a problem but doesn’t discourage me from considering shelling out the $32k to have one. I say this because I consider the range of the product to be a "soft" problem - something that can be solved in the future with better batteries, better automotive components, or better energy management.

I do struggle with the price of the car. But I’ve priced the components individually and you can’t build this car yourself for anywhere near $32k if you use all-new components.

This post is a quick summary - I'll follow up soon with more detail.

The Event

The Tour consists of four large glassed-in portable buildings that function like a mobile technology expo. Outside, they had one static car on display and cones set up in the parking lot outlining a course. All the buildings were connected by passageways in order to guide you through the process of being oriented to what the car is, how it works and the “extras” you get with this car vs. the average gasoline engine car.

After going through the tour, we got to drive the car. There were three of us in the car: me, my spouse, and a college student working as a guide. The guide was an intern who had been educated about the car, a college student hired by Nissan to ride and interact with prospective customers. We found out he didn’t travel with the tour, but was a student working on a Marketing degree at a local college.

The drive loop was about 2 miles and it was real-world: hilly, with stop signs, stop lights, turns, exits, on-ramps, etc.  It took us about 12 minutes to navigate the loop. When we returned, we thanked our guide and exited the car. At that point we were free to get coffee/tea at the final pavilion, look at the car on static display or make a video of our thoughts and impressions about the car.


This car is quiet – unbelievably so. It’s a surprise at how pleasant the experience is. Music and conversation inside the car happens at a level like you’re sitting in your cube talking to someone across your desk.

Performance of the car is great. There is a “Drive” mode that gives you best performance at a small cost in range. Then there is an “ECO” mode that gives you less performance but helps extend the range of the pack.

Instrumentation on the car is beautiful, very well laid out and does a great job of giving you feedback on the state of charge in the battery pack and how the car is “feeling”. You can easily tell what it will cost you in range if you run the heat or air conditioner, and you can easily tell if you are driving the car economically enough to assure you get where you are going.


I had a slight problem fitting in the driver's seat of the car (I'm 6' 1") but nothing any different from any other small vehicle. The problem is solvable if the driver’s seat had gone back another two inches. There was tons of room in the back. Hatch space was excellent.

The only negative that might surprise people is that there is no spare tire – they give you a can of fix-a-flat and that’s it.  We’ll see how that design choice plays out in the real world.


When this car gets on the road it’s not only going to change the way people drive THAT car, it’s going to change the way ANYone in a car behind it drives. Being stingy with energy is going to be a necessity with this car, so you’re going to see people driving slow with it because if you don’t drive slow, you run the risk of being stranded with the car and not being able to get to a charger. I can see wrecker companies and AAA-sponsored support services adding a generator to their trucks with a standard charging plug so they can give this car enough juice to get it to a fixed base charger.

Despite that shortcoming, if you have a predictable commute and can easily quantify how much energy you use daily and where you need to take the car, it’s going to be a huge hit. The car is spectacular. I’d love to have one. It’s better than any gasoline engine automobile of similar type.  Nissan’s got a winner on their hands and I think they are going to do pretty well with it.

Regardless of whether or not you’d ever buy one of these, go online, see if they are going to be anywhere near you with the Drive Tour and make an appointment to go drive this car. Even if you know you’re not going to get one, it’s an impressive experience – educational, fun and very satisfying.

Friday, March 4, 2011

What's In a LEAF?

Today I'll get my 1 hour turn with the Nissan LEAF. They have brought a set of the cars to the Research Triangle area (we're listed as a "second tier" area to get shipments of the cars when they are available) and today, at the North Carolina Farmer's Market, just south of downtown Raleigh, they are allowing folks who have registered for a place in line to get an hour to test drive the car. I'll take as many photos and tear apart as much of the car as I can, and I'll tell you whatever I can on this blog. Stay tuned!

Saturday, February 5, 2011

Digital Camera Surveillance with ZoneMinder

Quick side-trip to explore a usable video surveillance system:
  • A video camera with reasonably clear video
  • A PC running software to collect the video
  • Motion detection, so you don't have to go through years and years of video to get to your one event,
  • Event logging, so you can track when that motion happened and find it easily
  • A good web interface so you don't need remote software to access the server
  • The ability to post alerts out via the internet, or even send images to a remote device, like a smartphone meets all these requirements handily.  Turns out there's a delicious little virtual machine available for trying out ZoneMinder, so that you don't have to build up a full-custom machine to try it out. I had VMware Player already installed - getting the VM up and running only took about 15 minutes, and that includes the time it took to search the web to fix the VM...

Get VMware Player

Download VMware Player for free from If you have VMware Player up and running, you can then host virtual machines, try stuff out, and leave your important, fundamental desktop system configuration untouched and pristine. Nice stuff.

Get the ZoneMinder Virtual Machine

You can find this VM at There's some good initial information at the VMware page, but to download it, VMware links you to: The VM runs OK under VMware Player:

There's a problem with the file /etc/udev/rules.d/70-persistent-net.rules. It has a bug in it. It should read "eth0" at the end, not "eth1". (it is fixed already in this image) You can fix this two ways:

Easy: edit the file, change "eth1" to "eth0" at the end. Save the file, reboot the VM. 

Slightly More Manly, No Reboot:
/etc/udev/rules.d/70-persistent-net.rules contains the MAC address to eth device mappings. Delete the lines like below, noting the module name on the "# PCI device" line:

#PCI device 0x1022:0x2000 (pcnet32
SUBSYSTEM=="net", ACTION=="add"....NAME="eth1"

This removes the MAC to eth1 device mapping info - you want it to map to "eth0" so the network on the VM will start up when it boots. 

Restart udev to allow the change to take effect:

/etc/init.d/udev restart
Bounce the kernel module for the ethernet device. Use the module name from the 70-persistent-net.rules file noted above:

modprobe -r module
modprobe module

"ifconfig" should now show the eth0 interface as up and running.

A Good Webcam To Choose
The text in the notes of the ZoneMinder VM suggests trying it out with a network camera. I tried out the Linksys WVC80N. Most cool is that it's a NETWORK camera - you plug it into an ethernet and it serves up images across your network. Here's how to configure it in ZoneMinder:

The username: admin and password: admin are default for the WVC80N.  Here's what's needed to make it work:

Remote Host Name
Remote Host Path
Capture Width
Capture Height

Here's the camera control webpage under ZoneMinder:

The camera always comes up amber colored when it's in "monitor" mode. If you set it to "Modect", or motion detection, it will go green. You can see all the events I've already captured just in testing. "Modect" works great. Here's what the "event capture" web screen looks like:

To Learn More:

Getting ZoneMinder:

Some config tips for the Linksys camera. Outdated, but serves as a good pointer:

Cisco's WVC80N FAQ

Download a VM to try out ZoneMinder:

Fixing the broken VM so it will run:

Using basic webcams with ZoneMinder:

Brian Klug did a great writeup on making his ZoneMinder installation work well:

Thursday, January 20, 2011

You Gotta Measure if You're Gonna Save

Reading all the literature on "saving energy", you begin to recognize a pattern. First off, everyone with energy saving advice expects you are reading their words because your own house sucks for energy conservation, and you want some way to cut down on energy consumption and save money. And they are just the people to do it. That may, or may not be true of you if you are reading this column. (I know for a fact it's not true of me, but we aren't here to talk about me.)

The advice itself isn't stupid or terrible or wrong. All of us have a "green obligation" to make sure our homes are as energy efficient as possible. But it can be short-sighted. It can be less true for you than it is for someone else. Reading these words over and over again (usually on the internet), you begin to recognize a familiar pattern of "safe" advice that sounds smart and gives the writer an air of authority, the illusion that they know what the hell they are talking about. The writer has to collect a paycheck from someone, so the writer tries to apply to as many of their readers as possible. It's advice that may or may not apply to you. The points tend to run this way:

1) Replace incandescent bulbs with CFL bulbs.
2) Change HVAC filters.
3) Caulk (in various ways, various places)
4) Turn down the thermostat on your space heat.
5) Turn down the thermostat on your water heater.
6) Put "vampire loads" on outlet strips and switch them off at night.
7) Install water saving shower heads.
8) Insulate hot water pipes.
9) Open or close crawlspace vents (as appropriate)
10) Replace outdoor floodlights with automatic sensor lights. Make those lights CFL too.

Some of the more adventurous conservation advocates will even go to the point of recommending:
11) Install a programmable thermostat.
12) Install storm windows.
13) Install storm doors.
14) Add insulation to your attic or crawlspace.

Some of these things are a hell of a lot of work. Some of these things might require hiring a professional and cost a lot of money. And some of these things just might not work worth a damn.

What Are You Saying?

Now don't get me wrong: I'm not saying "don't do these things". Do them - wholeheartedly and happily, especially if you haven't. I'll even go further and say do them without a particular dollar value of savings in mind. Why? Because all of these things generate payback. Even if you save, say, a dollar a month off your electric bill, that's a real, actual, after-tax $1.30 directly back into your pocket, every month, forever. (Well, at least until you kick the bucket, but that's another story.)

Do them if you are uncomfortable in your own home - if you freeze in the winter or burn up in the summer or if the lighting is bad or there's no airflow or if you'd just like to have a fancy thermostat. Do them if you are mad about the check you write every month and want to see some money back, even if it's a small amount. It's OK to do something if you simply WANT to.

But don't do them just because Mr. Green Advisor said to, or because you feel guilty about not being green or not saving energy. If, for you, you want to make a big impact, or save a lot of money, or really make strides and "be green", or most importantly, you are thinking about adding solar hot water, solar electric or wind power sources to your home, then keep reading.

An Exercise In Estimation

Let's estimate, using nameplate ratings, what switching over to CFL's can save you on one monthly bill.

Say you've got one of those light bars in your bathroom. It holds four incandescent "bombe" bulbs. It's the light fixture builders and interior designers pushed on all of us for the last 20 years saying "it gives the right color balance" for the morning visit to the bathroom or applying makeup.

You go out and buy a four-pack of CFL's that will nicely and attractively replace the four incandescents in your bathroom light bar. The plan is to replace four 60watt incandescents with four 14 watt CFL's. Then sit back and watch the money roll back in!

You run your bathroom light bar for two hours a day. 1 hour in the morning getting ready for work, and 1 hour at night getting ready for bed. That's approximately 60 hours per billing month on your bill.

4 x 60W = 240W - original power draw with 60W incandescents
4 x 14W = 56W - new power draw with CFL's.

You were paying:

240W instantaneous power draw, or .240KWH for each hour you use the light bar
2 hours x 30 days/month x .240KWH = 14.4 KWH power cost on each bill

If you pay 14 cents/KWH, that costs:
.14 dollar x 14.4 KWH = $2.016 per bill

The CFL's Use:

56W or .056KWH for each hour
2 hours x 30 days/month x .056KWH = 3.386KWH power cost on each bill
If you pay 14 cents/KWH, that costs:
.14 dollar x 3.386 = $0.47, or 47 cents.

You've saved:
184W instantaneous power draw, or .184KWH each hour you use the light bar
2 hours x 30 days/month x .184KWH = 11.4 KWH lowered on each bill

If you pay 14 cents/KWH, that saves you:
.14 dollar x 11.4KWH = $1.54 per bill

(and we know our calculations are good: if you just subtract the original cost from the final cost, you still get $1.54 per bill)

Reasons NOT To Use CFL's

There are subtleties to the notion of replacing your incandescent bulbs with CFL's that bear some mention.

The light output of ALL bulbs - incandescent or CFL - falls slightly - by 5-10% over the life of the bulb, and for all bulbs, there are potential changes in their electrical behavior over their life span.

CFL's also have the characteristic that they put electrical "noise" back on the power line. This can have all kinds of strange effects - for example, X10 modules won't properly control CFL's and won't consistently turn them off or on due to the electrical noise they emit. Wi-Fi network signals may be interfered with.

The light output spectrum of CFL's is different than incandescent bulbs. Some argue that the light output is of much lower quality and harder to read by. But CFL manufacturers  have responded by making devices that output light in 6000K, (daylight) 4200K (bright white) and 3500K (soft white) color temperatures.

And yes, there is the concept of "embodied energy", where, if it takes much more energy to make a complicated CFL than a simple incandescent, then your net "green savings" may not have been achieved.

These are all fair criticisms of CFL's. If they bother you bad enough, or if the light output and quality are not to your liking, then don't switch to CFL's. Wait around another couple years, we'll have LED light output devices that have far, far less embodied energy, more stable wideband light output, far less deterioration over time, generate even less heat, and more importantly, use even much less more light than CFL's.

To give you a quick update on how much savings, the CFL's used in the example above draw 14W each, total 56W for the light bar. LED lamps will drop that down to 3-5W per bulb, so worst case, those LED lamps will use 20W total for the entire light bar vs. 56W for the CFL's. That's a 220W instantaneous savings for a monthly electric bill savings of $1.84. And the potential lifespan of an LED product can extend well beyond 100 years of "on time". A well engineered LED bulb could be the last bulb you ever buy in your entire lifetime for the fixture where you use it!

Not Bad, But I Expected Much More.

I hope the quick calculations have demonstrated that it is worthwhile to make changes around your home to save energy and become "more green". Good CFL's these days will last 10 years and are going for around $6/four pack, so for your $6 investment, you'll get that $1.54 back consistently on every electric bill, 12 times a year for 10 years, or 120 x $1.54 = $184 over the 10 year life of the bulb.

But even if you have a very efficient home - maybe even energy star - you're paying $150-$300/month for the various forms of power you use, and $1.54 per bill just ain't cutting it. Even the very optimistic 10 bucks per month won't even buy you and your loved one a cheeseburger meal for that night out to celebrate the savings.

So, you do some (or maybe even all - wow!) of these things. You might be more comfortable in your home, but the hoped-for percentage of savings on your electric/gas bill just doesn't materialize. You might make a dent, but nothing comparable to what you expected, and worse yet, you've spent all this money and just aren't getting the return you wanted to see - an extra $10/month just wasn't worth it.

What went wrong? Why didn't you save that "ton of money" you expected? Why didn't you make the savings predicted by the person who wrote the column?!? Where's that great payback for all the effort?

The problem is really one of first knowing what the problem is, then solving that problem. The dudes giving advice know nothing about your home or living style. No one would expect them to. But there's much art to the science of saving energy, and that's something they cannot advise you on. You have to find out for yourself.

So What's The Point?

The point of this blog isn't to sell you on the idea of doing a laundry list of changes around your home. If you live in a really crappy house in Minnesota and you're freezing yourself all winter long, you have plenty other reasons to work on your energy savings - namely so you can enjoy living in your home and not freezing your ass off. Surely you've done most of these things by now just to get control over a runaway electric or gas bill, and to be more comfortable.

The calculation above is an estimate that attempts to understand how much YOU use the light bulbs in question. You might take quick showers and spend only 30 minutes in the bathroom, or you might take long luxurious showers and spend more than that two hours daily.

The nameplate ratings of the bulbs were real - I took those right off the package, and are accurate even if they do change ever so slightly over the life of the product.

The point is that we don't even get off the dime with "being green" and saving energy without a very, very good understanding what we do and how we behave in our homes, our cars, our offices. 

And if you ARE sitting in your house in Minnesota, suffering for the six or seven months of winter every year, then you know damn well you've got to do something, and replacing four CFL's in your bathroom just isn't going to cut it.

We Buy Power After We Use It

Imagine, if you went grocery shopping, and everything you bought was in black, unlabeled boxes that you can't see, tough, measure or even weigh. You believe you are buying the right food you need, but really, you have no clue how much is in the box. You go to the checkout, scan everything, pay the bill and walk out with your new purchases. Then you get home and find out you've bought 50 lbs of dog food and you don't own a dog.

That's the way we buy power every month. When the power bill comes, most of us don't have a damn clue how much we've used or why we write the check we do.

Usually the person writing the check freaks out when they write the check, and if they are a real asshole about it, they'll blame someone in the family they know has left a light on, the fridge open or a space heater running.  The fact is, they don't really know why they are writing the check, they just know it hurts like hell and they've got to say something to somebody.

You may or may not have done the advice column things I listed at the beginning. You may be living in an apartment and have no more than, say, 10 bulbs in the whole apartment. You may be in a 5000 square foot home and replaced every damn bulb in the house and still not seeing jack for savings on your power bill.

If you are buying those black boxes every month and writing a fat check and you're pissed off and just can't take it any more, keep reading.

The Next Level: A Basic Rule of Thumb

First, I'm not saying DON'T do the advice columnist stuff. Do it, if for no other reason than to simply become more familiar with how your house is working and to get more comfortable. Use the information you can get from your five senses: if you are cold when you sit near a window, fix it, caulk it or install a storm window. If you can scald yourself in the shower or you find yourself replacing hot water heater elements, find out how to dial back your water heater or pay someone to come in and do it for you.

To go beyond the "green advice columnist", to make a real and lasting impact on your energy usage and your comfort, you have got to figure out, for your particular situation, what your mix of electrical (or gas) loads are in the house, so you will know where your effort can best be put to use. You have to open the black boxes and see what's inside. To do that, you have to get a good ballpark understanding of what your usage is, then refine that ballpark understanding by measuring how much energy your house and all the appliances within are consuming.

People who make conservation their business will tell you that for an all-electric home, electrical loads are roughly distributed three ways:

1/3rd goes to HVAC
1/3rd goes to heating water
1/3rd goes to "plug loads" - anything you can plug into an outlet in the home. This includes things like the oven or dishwasher as well.

If you use gas for hot water heat, cooking or space heating, the numbers are the same on an energy basis, but may not split this way according to cost. Nevertheless, the idea holds: general understanding of what you use in energy every month.

So what? So freaking, fracking, faulking what?

If you take the average of your power bill over an entire year, and say, it's $300, then in a typical home with nothing broken and the HVAC working normally, you're spending $100 a month to heat/cool the house, $100 a month making hot water, and $100 for everything you plug into electrical outlets.

So What, is that this is a first step toward opening the black boxes. We're talking about energy here. At the point of metering, where you are getting billed, you can't see it, smell it, taste it or touch it.

Well, you can, but that wouldn't help you and it would likely kill you. So we have to go at this backward. We start with the rule of thumb, then work our way toward a better understanding, over time, of how we individually vary from this overall rule of thumb.

Along the way, we'll figure out how much energy we really can SAVE through conservation. Then we'll go further, and figure out where we can apply solar (PV or hot water) or wind energy to make an even bigger impact.

Getting Green With It All....

I live in an all-electric powered home in the southeast US. It's a relatively recently built, well designed and energy efficient home. In November 2009, we had a problem with our heat pump - it would not hold refrigerant - and it was traced to a factory defect in the "A-coil", which is the part of the heat pump that transfers heat to-or-from the interior air, being blown over the A-coil.

The local firm that installed the heat pump then replaced the A-coil. Remember, this was early November, 2009, beginning of the winter "heating season" here in the US. As a result of installing the new A-coil, the firm made mistakes that compounded themselves over the next three months. In the meantime, we had a very cold January, and the problems they caused with the heat pump developed a situation where the "emergency heat strips" were the only means of heating we had - the heat pump itself would not, well, "pump heat".

Dealing with the vendor was one bad problem, but then we got the power bill the next month for the runaway power consumption of the unit - and it was about $120 higher than normal for that time of year, even for an exceptionally cold January. The impact of the charge was significant, on top of the hundreds of dollars spent with the vendor. The sting of it all was that I had no clue the heat strips were coming on continuously until I got the bill.

Being an electrical engineer for all of my adult life, this was an unacceptable situation. Not understanding the power draw of all the circuits in my house was the key to recognizing the problem in the first place. Also realizing that with every passing day, I was losing data essential to gaining that understanding, I was willing to go out and buy something I could simply and quickly attach so I might monitor my whole-house power consumption.

With all the talk about "going green" and "reducing your carbon footprint", knowing how much energy you use in your home would be a vital, fundamental step toward saving energy, money and carbon. I expected to find at least a dozen different devices that could measure electric power draw by a home, a full range of products at all different kinds of prices.

What I found on the internet was really only two viable products: "TED 5000" (The Energy Detective) and something called "eMonitor" from Powerhouse Dynamics. The TED 5000 fit the bill for a rapid whole-house solution at about $300. Not too bad. But the eMonitor, now that was the ticket: whole house, all-circuit monitoring. It looked mature, well-made and highly capable. But to implement the eMonitor product at my home, I'd have to buy two of them, a "larger" and "smaller" version of each, to install on both breaker boxes here at the house. Total would come out to roughly $2000. And to make matters worse, when you buy the eMonitor, you send your data to them, and they keep your data in their "cloud". The initial price of the unit includes a two-year "subscription". After that, you've got to pay an annual fee to keep the power measurement goodness running.

That was enough to completely end the idea for me. I'm not interested in putting my data in your cloud and paying for it, thank you very much. I want to keep my own data so I can improve the user interface, add features when I'd like, and fine-tune the sensitivity of the unit to match the power draws of the circuits in the house.

So, the quest begins: to design, build and implement, first a whole-house power monitoring solution, then from there, move on to a whole-house power monitoring system that can track energy usage on all circuits. And to do it for well under $2000.

Follow along with me as I research the problem itself, the components needed to do the measurement, and develop a solution that takes the measurement and brings that data all the way to your computer screen, where you can look, learn, and act.