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It’s not rocket science

March 14, 2010

It’s true that the necessary parts to have a usable solar/wind system are fairly expensive, but the skill required to make it work isn’t rocket science. In fact, it’s probably easier than auto repair. Probably more often than not, contractors will simply follow the available instructions. At worst, they might cut corners. If you do it yourself, you could probably save quite a bit of money while knowing exactly what you did and how well it was done.

Do the Research and Planning

Chances are you’re reading this blog because you want to know how renewable energy works and how you can use it. If you don’t know how to do something, you research it and find out from those who do. I didn’t know a thing about Tesla coils until a couple of years ago. Since then I’ve made a few.

Once you’ve developed a better understanding about how the parts work together and what they’re called, you can begin to plan. Here’s some good things to remember:
  • Do your homework.
  • Failure to plan is planning to fail.
  • Plan your work and work your plan.
  • Know your limits, (then reduce them).
  • Make long term plans in short term intervals.

Consider Economic Efficiency

In some instances, it might be more economically efficient for someone else to do the work. What costs more? How much is your time worth? Let’s assume the following scenario as an example:
  • You normally get paid $15 an hour.
  • You estimate it would take you ~20 hours to install your renewable energy system.
  • That would cost 20 * $15 = $300 of your time.
  • Unless someone else can do it for less than $300, you might want to do it yourself.
The above example of course doesn’t factor in intangibles. Even if you you could find someone to do it for a little less, perhaps you would still want to do it to know how it was done. Therefore the knowledge would be worth the extra hours spent as well as the peace of mind knowing it was done properly.

Consider Electrical Codes and “Qualified Personnel”

Perhaps you watched the Enphase Micro-inverter System Installation video I mentioned in my last article. Don’t let the phrases about electrical codes and “qualified personnel” scare you. Electrical codes are good to consider, but you can find and research this information on your own.

What if I miss something?

Realize that people just like you already install their own light fixtures, ceiling fans, switches, and sockets. Be honest and ask yourself if you really think anyone has studied all the electrical codes. More than likely they simply follow the instructions. Realize also that even some of the jobs done by some “professionals” could be questionable if not disturbing.

Common sense should always be used. Always turn the electricity off before servicing something electrical. By using common sense we also understand that like colored wires are usually connected together, you need larger wire for more current or power, and they shouldn’t be hanging out in the open. If there’s something you’re not sure about, ask someone or look it up.

What if I’m not “qualified personnel?”

What makes a person “qualified?” Do you think I’m qualified even though I’ve had no formal training? Does reading blogs, watching videos, and researching what you want to do, doing it, and then gaining experience make someone qualified? You must crawl before you can walk, but you won’t get anywhere if you don’t ever crawl.

Notice the video says “all work should,” not “must,” but this is all according to who? The contractors, understandably, want to get paid. They’re licensed. The reason why they need a license is because they are in the business of installing systems for other people and therefore are liable. It’s unlikely that you will sue yourself if you screw up.

Some Personal Experience with Supposed Professionals

Preparing for a Hot Tub

At some point my dad decided we would get a hot tub. The people that delivered it would connect it, but we had to supply the wire and conduit they would use to connect it to the breaker box. (We also ran the required wiring from the main breaker box and installed the dedicated external breaker box. Understandably, they would only wire it to an available box.)

Everything sounded good, but there was something fishy. They would not connect it to a GFI (ground fault interrupter) breaker in the breaker box because the hot tub already had an internal GFI circuit breaker. (Don’t we also want to protect the people outside the tub from electrocution?) When asked why, they said because a GFI breaker in a box would always trip without reason. But what they didn’t know, I researched on the web to learn about GFIs.

Learning about GFIs

A GFI is designed to detected differences in current in both the neutral and hot wires. If a GFI circuit breaker is far from the device it’s connected to, a delay in current causes the breaker to trip when it should not. However, our breaker box would be right next to the hot tub.

Had the GFI been far away, at the main breaker box, then what they claimed would probably have been true. Needless to say, when the installers went through the trouble to bypass our GFI breaker, we connected it back like it should be and haven’t had any problems since.

Hearing From a Friend

One of my best friends used to work with a general contractor. He told me about some interesting things they did and did not do. Then there’s the issues with government and insurance contractors. If you plan to find a real good contractor, you may have to do as much research to find one as you would learning to do the work yourself.

Using microinverters for solar power

March 13, 2010

If you only plan to sell the electricity you produce back to the electric company and not go off the electrical utility grid, then the microinverter may be the most elegant solution. You use a single one of these inverters with every solar panel in the system. Simply connect the solar panel to the inverter and connect the inverter to your electrical box–only two sets of connections.

What are the benefits?

If you use a microinverter, expansion is easy. You can start with a single solar panel and inverter to have a complete grid tie system. Adding to it is almost like adding a set of Christmas lights to an existing set. The plugs and sockets are different because they’re made to withstand weather.

In addition, microinverters give the advantage of maximum power point tracking (MPPT) for every individual panel. This means shadows or performance issues with one panel won’t affect the others. If you opt for Enphase’s microinverter, you also have the ability to get detailed day-to-day, hour-to-hour statistics for every panel! Watch the How It Works video for a video representation.

Where can I get one?

Microinverters are still somewhat new and haven’t really made it to mainstream as far as solar power is concerned. The Affordable Solar Group and EcoDirect have some pretty good prices, (but their solar panels are a bit pricey). There are many places on the web to get microinverters.

The only microinverter that is currently available is from Enphase. Another is in development from SolarBridge.

How do I connect it?

Don’t be intimidated with wiring this device. If you can install a household socket or light switch, you can install this. If you can match colors and put up Christmas lights, you can install this. The instructions alone should make it very easy to understand.

If you watch the Enphase Micro-inverter System Installation video, they make it sound simple, because it is simple. But, it does take some time. Don’t let the phrases about electrical code and “qualified personnel” scare you. I’ll discuss this in more detail in another article. Check out this New Jersey Solar Installation video for some good details.

Choosing a Solar Panel

All you really need to focus on is buying a compatible solar panel for the microinverter, (unless you’re comfortable with splicing and soldering the wires of an incompatible panel). You should be able to find a compatibility list in the support section of the company’s website. Enphase, for instance, has a download section.

Connecting the Microinverter

First you generally need your inverter in place before you connect your solar panel. Run conduit up to your roof (or your panels’ location) to a junction box. Enphase prefers you to buy an AC branch “Install Kit” for $60, but you could easily get your own parts separately. Or, you could just run the inverter wires to a box and run conduit to an inside switch which would probably be cheaper, maybe $20. From there, just run wires into your electrical box to a circuit breaker. Check out Installing Electrical Conduit Systems for more details.

Connecting a Solar Panel

The inverter and solar panel will likely have special connectors. These connectors are designed to be fool proof. But if you’re an electronic hobbyist you may want to get less expensive solar panels that aren’t on the compatibility list. If that’s the case, make sure you have the correct voltage, (you might need two panels in series or parallel). To connect a panel, just:
  1. Cut off the connectors from the solar panel and inverter (this may void the warranty)
  2. Prepare heat shrink tubing to cover your connections by placing them over the wires (available locally at Radio Shack or online)
  3. Solder positive to positive, negative to negative
  4. Cover your connections with the heat shrink tubing and shrink it

Living on DC

March 8, 2010

Most of our everyday appliances and electronic devices operate using AC (alternating current), right? … It might surprise you that most appliances we use today are using DC (direct current) rather than AC. Internally they convert the AC to DC. If you’re an electronic hobbyist, you probably already know that. If you’re using a solar system with batteries, you could save by using DC directly.

Reaping the Benefits

The benefits of running things off DC directly is that you have no conversion loss. Inverters and power supplies alike have a conversion efficiency. Most conversion efficiencies lie somewhere between 80-95%. If you can reduce the number of conversions, you will come out ahead. However, it may require you to have ten 12V batteries wired in series to obtain between 110-130 volts DC. You could use a DC-DC converter, but that would defeat the purpose.

Distinguishing What Uses AC

First you need to know what you can and can’t operate with DC. You cannot use DC on anything that has a transformer on its power input. You can use these steps as a guideline to determine what can be operated using DC, but the only way to really know is to look inside:
  1. If the appliance has a mechanical switch, turn it on unplugged.
  2. Use a multimeter to measure ohms (Ω) across the prongs of the plug.
  3. If the meter reads about 500 ohms or less, it likely uses a transformer.
Here are some things that typically require AC to operate:
  • Air conditioning and heating systems
  • General purpose fans and ceiling fans
  • Washing machines/dryers
  • Refrigerators/freezers
  • Microwave ovens
  • Garage door openers
  • Fluorescent lights with ballast transformers
  • Cell phone chargers (which are usually small wall mount transformers)
  • Anything with an AC motor

Distinguishing What Uses DC

You can use DC on anything that has a bridge rectifier on its input. A bridge rectifier is something that converts AC to DC using four diodes. If you can measure around 1 meg ohm (MΩ) or more across the prongs of the plug using a multimeter, it most likely uses a bridge rectifier. Again, the only way to really know is to look inside. Most of the following items use a bridge rectifier or can use AC or DC:
  • Any lengthwise oriented or switching power supply (doesn’t mount on the wall)
  • Computer/Laptop power supplies
  • Incandescent, CLF, and LED light bulbs or Christmas lights
  • DVD players and newer VCRs
  • Game consoles
AC wall transformers and DC switching power supplies

Replacing Wall Transformers

One of the most pesky things to deal with are those big black and inefficient wall transformers. The output of most of these are DC because they use a bridge rectifier on the output of the transformer. If you can find a switching power supply at the same DC output voltage to take it’s place, then replace it.

Insulating your home

March 7, 2010

Renewable energy is a good thing, but it won’t replace the simple concept of energy conservation and insulation. Radiant barrier is known to be the most effective insulator for your home. The bottom line is if you really want to save money, properly insulate your home and reduce your power usage. You don’t want poor insulation or running appliances fighting against your air conditioning or heating system to increase your utility bill.

Use Radiant Barrier

Radiant barrier is one of the best ways to reduce your heating (and cooling) bill. As the name implies, it works as a barrier to radiant heat, whether it’s outside during the summer or inside during the winter. Radiant barrier is simply two layers of aluminum foil with strands of fabric in between to support it. And it’s inexpensive! I encourage you to learn more: Sockets are culprits for air leaks

Seal the Leaks

Doors, windows, sockets, and fixtures are all likely culprits for air leaks. They are inevitably a hole in your wall if not properly insulated. If you can feel cold air coming in during the winter, it will go out during the summer. A puff of powder can visually reveal the flow of air through these holes. Check out some of the following sites for more details: You can find several types of insulation at your local hardware store, Home Depot, or Lowe’s.

Minimize Opposing Forces

People don’t generally have a heater and an air conditioner working at the same time. However, it’s easy to forget that nearly everything else produces some amount of heat that you can feel:
  • lights (incandescent, fluorescent, CLF, LED, etc.)
  • TVs, computer monitors (CRT, LCD, DLP, plasma, etc.)
  • game consoles
  • stereos
  • computers
  • Ethernet routers and switches
You’ve probably heard it before: If you’re not using it, turn it off. Also, don’t leave the refrigerator or freezer door open.

An insulated coffee mug, thermos container, and thermos

Consider the Thermos

The advantage of properly insulating your home can be seen in an ordinary thermos container. A thermos maintains the temperature of beverages or soups. Thermoses aren’t new, your parents or grandparents have probably used one.

A thermos works by maintaining a vacuum around it’s contents. Because it’s a vacuum, there is little air to conduct heat in or out. It is also coated silver to retain or reflect heat much like radiant barrier.

An insulated coffee mug works similarly, but it’s not under a vacuum. A separate atmosphere is maintained around the contents of the mug. A green house maintains it’s own atmosphere to stay warm. Atmosphere around the earth keeps it from being burned up by the sun. The less impact the outside atmosphere temperature has on your inside (home) atmosphere temperature, the better.

History Repeats Itself

These concepts of insulation, conservation, and even renewable energy aren’t new. I have a book titled Home Energy by Dan Halacy published in 1984. It’s interesting to note that 26 years later, the only things that have changed is technology. CFLs along with many other devices are much more efficient than they used to be. So, what’s our excuse?

Understanding kilowatt hours

March 3, 2010

Solar and wind systems are great, but before you buy one, it’s good to know what you’re actually getting, how much power you need, and how much you’ll save. There’s some math involved, but a few examples should make it easier to understand.

What exactly is a kilowatt hour (kWh)?

First, you need to know about kilowatt hours. A kilowatt hour is simply a thousand watt hours (Wh). A watt hour is the power of 1 watt operating for 1 hour’s time.

How many watt hours will something require?

Let’s say we wanted to calculate watt hours needed to power a 60W lightbulb for a certain amount of time:
  • 60 watts * 0.5hr (30 min) = 30 Wh (0.03 kWh)
  • 60 watts * 1 hr = 60 Wh (0.06 kWh)
  • 60 watts * 7 hrs = 420 Wh (0.42 kWh)

How many hours will something run?

Now let’s say we wanted to calculate how long we could run something at a certain wattage with 1000 Wh (1 kWh):
  • 1000 Wh / 25 watts = 40 hrs
  • 1000 Wh / 100 watts = 10 hrs
  • 1000 Wh / 4000 watts = 0.25 hr (15 min)

How many watts was something using?

Also, if something ran for 5 hours and you know how many watt hours it consumed, you can determine how many watts it was using. Generally, you may never have to calculate this:
  • 2 Wh / 5 hrs = 0.4 watts
  • 600 Wh / 5 hrs = 120 watts
  • 5000 Wh (5 kWh) / 5 hrs = 1000 watts (1 kW)

Do I need to power my whole house?

Generally people wonder how much they need to power their home. Running your house entirely on renewable energy is a good lifetime goal, not a short term goal. The best (and most practical) way is to start slow, adding as you can afford. However, unless energy consumption is simply reduced, it could be a bit pricey. One way to reduce energy consumption is to insulate your home better.

What do I need to power my house?

You probably have a good idea of how much power you need in kWhs per month from your electric bill. But what do you need to get that from solar panels or wind generators? Fortunately, if you buy a complete system (or consider it and then buy parts separately), they usually have a chart or calculator. This will shows you average monthly kWh production for a given area or wind speed. Here’s some examples: If you look at the Whisper 500’s spec. sheet, notice the curve on the bottom right. If you have an annual average wind speed of 11.25 mph, one of these generators will give you an average of 450 kWh per month. If your average monthly usage is 2000 kWh, you would need 2000 kWh / 450 kWh = 4.4 (or 5) of these units. That would cost about ~$6000 * 5 = ~$30,000 for the generators, not including the towers, wiring, and labor! However, if you shop around, you might find something better or cheaper to suit your needs.