Solar and Wind Energy;

Our Wise and Efficient Use

Part 3

by Randy Cooper

Environmental Engineer

What’s an inverter? A charge controller? An array on a tracker? What is side-furling and electronic stall regulation? What is the difference between wiring in series versus parallel?

Good day folks. In the first two articles in this series I discussed how we can Use energy more wisely for its inherent benefits and also as the starting point in the design of solar/wind energy systems. The use of compact florescent bulbs and minimization of the heavy hitters’ energy use such as heaters (and induction motors, for further example) can drastically cut the size and cost of the solar/wind system. For those of us who pay power bills, this cuts cost.

This article will focus more on the basic hardware that our home or business solar and wind energy systems include. I hope after reading this article, alternative energy beginners and do-it-yourselfers will be knowledgeable in the terminology and the basic workings of these systems.

System Basics

The most basic system is a small 12-volt photovoltaic solar panel sitting in the sun with wires connected to something (powering a load), like a 12-volt car stereo. This will work, but there may be some problems with this. Such as, it only works during the day when the sunlight is striking the panel. There is no way to store the energy for later use at night.

So we add a battery to our system. No problem right? Well, what if the stereo doesn’t use all the power the solar panel produces each day? The rest will be stored in the battery. If overcharged, the battery will be damaged. Here is where a charge controller is used. The controller regulates the charge of the battery analogous to the regulator in a car or truck.

There are reasons why I choose to describe these systems starting basic, and adding additional parts, or terms, as the system becomes more sophisticated. I hope it is easy to follow this way and, I’m trying to demonstrate one of the really cool facts about building a solar/wind system to either power, or supplement power to, your home or business: It is completely reasonable and logical to build a little at a time. No folks, you don’t have to drop $20,000 - $40, 000 to get in this game. A small starter/expandable system can be had for $1000 - $3000 (in parts).

Folks please remember though, I’m just summarizing and giving background here. I’m leaving out many details, like fuses. Electricity can be dangerous. And it is easy to overlook that a solar panel just sitting in the sun can cause sparks and/or shocks across output terminals when working with it. Just because it isn’t making noise or doesn’t have moving parts, it is silently and steadily making electrical power.

Definitions

Now that we have a basic system it’s time to introduce some additional terms:

DC: Direct current. Automobiles are typically 12-volt DC systems. Solar panels produce DC voltage.

AC: Alternating current. Our homes are (110 ~ 120) 120-volt AC systems.

Wiring in series: A small flashlight uses two double-A (AA) batteries wired in series. Voltage is additive in series. Since AA batteries are 1.5 volts each this is a 3 volt system.

Wiring in parallel: Our household appliances are 120-volts. Standard outlets in our homes have two receptacles wired in parallel. Voltage is the same, not additive, in parallel. When we plug in two appliances into the outlet at the same time, they are both still 120-volts. Both AC and DC circuits can be wired in either series or parallel.

Inverter: Changes the solar panels DC power to AC power that typical household appliances and tools use.

Array: A group of several panels. Where 12-volt panels are wired in parallel the system remains 12-volt.

Tracker: A frame with a small motor that keeps the panels facing the sun (tracks the sun) throughout each day. Trackers maximize the efficiency of the panels as they are always facing perfectly towards the sun.

Expand Your System

Remember “build a little at a time”? Do you only want to use only DC appliances or also use your household AC ones? Add an inverter. Would you like to add panels or batteries to give your system more capacity? Add 12-volt panels in parallel to your 12-volt system, for example.

How about wind power?

Add a windmill when you can. Most people start with solar and add wind as solar is typically available daily, and wind is more supplemental. Wire it to your batteries in parallel to your solar system. Most windmills have a charge controller built in. You’ll need to verify this. High wind conditions could damage a windmill. Built into them are kind of safety devices to protect them in high winds. Some example devices are side-furling and electronic stall regulation, referring to the manner in which they protect the windmill. My mom sent me an article clipped from a current periodical highlighting Jay Leno’s home windmill.


	Solar and Wind Energy; Our Wise and Efficient Use Part 3 by Randy Cooper Environmental Engineer What’s an inverter? A charge controller? An array on a tracker? What is side-furling and electronic stall regulation? What is the difference between wiring in series versus parallel? Good day folks. In the first two articles in this series I discussed how we can Use energy more wisely for its inherent benefits and also as the starting point in the design of solar/wind energy systems. The use of compact florescent bulbs and minimization of the heavy hitters’ energy use such as heaters (and induction motors, for further example) can drastically cut the size and cost of the solar/wind system. For those of us who pay power bills, this cuts cost. This article will focus more on the basic hardware that our home or business solar and wind energy systems include. I hope after reading this article, alternative energy beginners and do-it-yourselfers will be knowledgeable in the terminology and the basic workings of these systems. System Basics The most basic system is a small 12-volt photovoltaic solar panel sitting in the sun with wires connected to something (powering a load), like a 12-volt car stereo. This will work, but there may be some problems with this. Such as, it only works during the day when the sunlight is striking the panel. There is no way to store the energy for later use at night. So we add a battery to our system. No problem right? Well, what if the stereo doesn’t use all the power the solar panel produces each day? The rest will be stored in the battery. If overcharged, the battery will be damaged. Here is where a charge controller is used. The controller regulates the charge of the battery analogous to the regulator in a car or truck. There are reasons why I choose to describe these systems starting basic, and adding additional parts, or terms, as the system becomes more sophisticated. I hope it is easy to follow this way and, I’m trying to demonstrate one of the really cool facts about building a solar/wind system to either power, or supplement power to, your home or business: It is completely reasonable and logical to build a little at a time. No folks, you don’t have to drop $20,000 - $40, 000 to get in this game. A small starter/expandable system can be had for $1000 - $3000 (in parts). Folks please remember though, I’m just summarizing and giving background here. I’m leaving out many details, like fuses. Electricity can be dangerous. And it is easy to overlook that a solar panel just sitting in the sun can cause sparks and/or shocks across output terminals when working with it. Just because it isn’t making noise or doesn’t have moving parts, it is silently and steadily making electrical power. Definitions Now that we have a basic system it’s time to introduce some additional terms: DC: Direct current. Automobiles are typically 12-volt DC systems. Solar panels produce DC voltage. AC: Alternating current. Our homes are (110 ~ 120) 120-volt AC systems. Wiring in series: A small flashlight uses two double-A (AA) batteries wired in series. Voltage is additive in series. Since AA batteries are 1.5 volts each this is a 3 volt system. Wiring in parallel: Our household appliances are 120-volts. Standard outlets in our homes have two receptacles wired in parallel. Voltage is the same, not additive, in parallel. When we plug in two appliances into the outlet at the same time, they are both still 120-volts. Both AC and DC circuits can be wired in either series or parallel. Inverter: Changes the solar panels DC power to AC power that typical household appliances and tools use. Array: A group of several panels. Where 12-volt panels are wired in parallel the system remains 12-volt. Tracker: A frame with a small motor that keeps the panels facing the sun (tracks the sun) throughout each day. Trackers maximize the efficiency of the panels as they are always facing perfectly towards the sun. Expand Your System Remember “build a little at a time”? Do you only want to use only DC appliances or also use your household AC ones? Add an inverter. Would you like to add panels or batteries to give your system more capacity? Add 12-volt panels in parallel to your 12-volt system, for example. How about wind power? Add a windmill when you can. Most people start with solar and add wind as solar is typically available daily, and wind is more supplemental. Wire it to your batteries in parallel to your solar system. Most windmills have a charge controller built in. You’ll need to verify this. High wind conditions could damage a windmill. Built into them are kind of safety devices to protect them in high winds. Some example devices are side-furling and electronic stall regulation, referring to the manner in which they protect the windmill. My mom sent me an article clipped from a current periodical highlighting Jay Leno’s home windmill.