Electricity Handbook

IPS (Science) Group Project for Unit 3- Electricity completed at the end of school year 2006. My group members were Michael Plasmeier, Liz, Melissa, Naomi, and Tom. We had to pick appliances to put into a family home and write a training handbook for the new residents. The trouble was we had a limit of 2400 watts at one time and 90kWk a month. This made it very challenging to pick appliances to fulfill the families needs with no little amount of electricity. They can only have about $9 worth of electricity a month!!!!

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A Microsoft Word version of this work is available here: Image:Electricty Handbook.doc

Electricity Handbook for your new HFE Home!

Introduction

Welcome to your new home given to you by Homes for Everyone (HFE). We hope you enjoy your new living place. We also hope that in the future you will volunteer your time to building houses for other needy families, just like you. Please keep the generosity flowing.

Your new home has a very special electrical system. Please take a few minutes with this handbook to become familiar with the system.

Your home has a very limited supply of electricity. This is because your home is not on the power grid. Power is supplied by a special wind generator. This means you will never need to pay an electricity bill for as long as you live here. However the generator only has a limited output, which means that you must closely monitor your electricity usage. If you do not closely monitor your appliances, you will not have enough electricity to cook food and have hot water for the rest of the month. To compare with what you paid before, you have only about $9 of electricity a month to use. This is a tiny fraction of what a typical household should have. You will need to conserve energy. You can do this by turning off the lights and fan when you are out of the room, as well as the computer when you are not using it.

Hot Water System

Your new home also has a special water heating system. The hot water produced by the system heats the house in the winter and provides hot water. A large "pond" of water is located on your roof. When water is in there it will be heated without the consumption of electricity. This stretches the amount of electricity available for other uses. A transparent cover over the pond stops the water from evaporating. There is also a traditional backup water heater for cases when the sun is not strong enough.

The system works because a pump circulates the water through the system. Cold water first flows from the municipal water supply to the heating tank on the roof. There, it is warmed by the sun. The water then passes through the backup water heater which is used when the sun can not sufficiently heat the water. Then there is a switch. In the summer, the water goes to a storage tank and in the winter, the water circulates through the house to heat it. The water then is used for bathing and hand washing from the tap.

Electricity 101

This section is designed to give you a short introduction to the topics of electricity. Your new home will require you to have a basic knowledge of electricity and how it works in your home. Because of the off-the-grid nature of your home, you are responsible for keeping your electrical system up and running. There is no utility to call if something goes wrong.

Introduction to Circuits

Electricity travels only through complete circuits. Circuits are the paths which electrons follow. If the circuit breaks, the electricity can no longer go around in a circle and it stops. Electricity does not flow unless there is a circuit.

In a circuit, the electricity comes from a source. In this house, that is the batteries of the wind generator. It then flows through the wires of the house to a load, which is something that consumes electricity. After the electrons pass through loads, they return back to the source.

There are two different ways circuits can be arranged. They are called series circuits and parallel circuits. Parallel circuits are the types used in all homes including this one.

Series Circuit

A series circuit is when there’s a single path for the electrons to flow throughout the circuit. If one appliance in a series circuit is turned off, all the rest of the appliances lose power.

(diagram)

Parallel Circuit

A parallel circuit is when there are multiple paths for the electrons to take. Each load has a separate branch in the circuit. Because of the separate paths for the electrons, if one appliance is turned off the rest of the appliances can stay on. This is an advantage because if an appliance is turned off or breaks, the rest of the circuit does not lose power. However, it requires more wiring to set up.

(diagram)

Power, Current, and Voltage

There is a difference between power, current, and voltage, however they are all interrelated related.

Power: Power is the amount of electricity that something is using at an instant in time. The unit for Power is Watts. Power is equal to the current times the voltage. You need to make sure that you do not exceed 2400 Watts consumption in your house.

Current: Current is how much electricity is "flowing" through the lines. The unit for current is Amperes, often shortened to Amps. Current is equal to the wattage divided by the voltage. You must be sure not to have too much current flowing through the wires. Don’t worry; the circuit breaker will take care of that.

Voltage: Voltage is how hard the electricity is "pushing." Think of when the words "high voltage" are used. They are most often used near lots of electricity. With out voltage, there is now power. The strength of batteries is measured in voltage. (Think 9 volt batteries) Voltage is measured in Volts. More technically however, voltage is the potential difference between two points that makes electricity move. Your house will operate on 120 volts, which is the standard in the USA for AC household power. Internationally, most nations operate on 220 volts for homes.

(equation circle)

Generator and Batteries

Your new home is equipped with a wind generator to collect electricity. When the wind blows, it pushes a set of fan blades which rotates an armature inside the generator. Mounted on the edge of the generator, surrounding the armature is a magnet. When the armature rotates around the magnet, it produces DC current. That current is then fed into a battery system which stores the electricity until it is needed. The battery lets you have electricity even when there is no wind blowing.

When electricity is needed to power one of your appliances, the battery is tapped. However, the power first needs to go through an inverter. This converts the power from the DC current outputted by the battery to AC current which is the type used by your appliances.

The battery is capable of providing a maximum of 2400 Watts at on time. Over a month only 90 kWh of electricity is able to be produced with the generator. The inverter outputs 120 volts AC current at 60 Hz. This is the standard household current in the United States.

Circuit Breaker

The circuit breaker shuts off the power to one or more circuits if too much power is being drawn from the batteries or a short circuit occurs. The circuit breaker is located in the basement next to the battery system. Inside are a small metallic strip and an electromagnet that separate if too much current is going through them. They are like a fuse, except a circuit breaker does not need to be replaced, just flip the switch back. See http://en.wikipedia.org/wiki/Circuit_Breaker for more information

Resetting the Circuit Breaker

If you trip the circuit breaker by exceeding the maximum amount of power supported by the system follow these steps.

1. Find the reason the circuit breaker tripped. You probably added equipment that pushed the sum of all of the appliances that were on at the time over 2400 Watts.
2. Disconnect some unneeded appliances
3. Go down to the basement and find the circuit breaker.
4. Find the switch that is in the off poison. (It will be on the opposite side as all of the other switches.) Push it back to the on position.
5. Verify that all your appliances are working.

Total Power

You can only run a certain amount of electrical equipment at one time. However because an integrated ammeter located on the following devices shuts them off when you turn on another appliance, you do not need to worry about exceeding maximum power draw from the batteries.

• Water Heater
• Water Pump
• Refrigerator

The batteries from the generator can only support 2400 Watts of load. If you exceed that you will trip the circuit breaker. You can read the back of appliances to check to Wattage, or measurement of how much power the device uses.

Monthly Energy

In addition the limit on how much electrical equipment you can run at one time, you have a limited supply of total energy. This means that you can only run you appliances for a limited time each month. If you consume more than the amount of energy the generator can produce in a month, you will not have any electricity available for the rest of the month. The generator can only produce 90 kiloWatt-hours per month. You can convert that to 90,000 Watt-hours a month to make it easer to work with. This works out to about 3,000 Watt-hours a day. This is not a lot of electricity. A Watt-hour is one Watt being consumed every hour. To find how many Watts-hours you are consuming by operating an appliance, multiply the consumption in Watts by the number of hours the appliance is on.

You have now used up 450 of your 3000 daily Watt-hours. You can use the appliance chart below to find out how many watts a device consumes. Also listed are the estimated average hours the device is on per day. These are the usage limits we used when designing your home’s appliance package.

To help you further track your usage, there is an LED display next to the circuit breaker that counts the number of Watt-hours you used for that month. Remember to stay under 90,000 Watt-hours.

Appliances

Appliance	Power in Watts	Average Hours on Per day
Refrigerator w/ freezer -14c.f	226	3
This appliance was provided to store their food so it will not rot or gain harmful bacteria. (Power information from http://www.psnh.com/Residential/ReduceBill/Applianceusage.asp)
Light Duty Pump for Water Heating	150	0.5
This pump circulates the water through the system including the solar heating pond. (See the description for the system in the introduction)
Backup Water Heater	600	1
This conventional water heater turns on when the sun is not strong enough to heat the water. (See the description for the system in the introduction)
Toaster Oven	1500	0.2
This toaster oven will serve as our main source of heating food with electricity.
Living
Compact Fluorescent Lamp - Living Room	10	3
Compact Fluorescent Lamp - Living Room	10	3
Compact Fluorescent Lamp - Dining Room	10	1
Compact Fluorescent Lamp - Dining Room	10	1
Compact Fluorescent Lamp - Kitchen	10	0.75
Compact Fluorescent Lamp - Bathroom	10	0.5
Compact Fluorescent Lamp - Kid’s Room	10	0.5
Compact Fluorescent Lamp - Master Bedroom	10	1
Compact Fluorescent Lamp - Master Bedroom	10	1
The nine compact fluorescent lights use one-fourth the electricity while outputting the same amount of light. They are being used increasingly all over the world to save power (http://en.wikipedia.org/wiki/Compact_fluorescent_lamp) Lights were included for the house so that when it is dark and there is not light coming from the window lights can be turned on. Also, in some rooms one light is not enough so there needs to be more than one.
Small Fan - Living Room	100	0.75
Small Fan - Kitchen	100	0.375
Small Fan - Dining Room	100	0.5
Small Fan - Master Bedroom	100	1
Small Fan - Kid’s Bedroom	100	1
Because no air conditioning was included to battle the 90° heat, 5 fans throughout the house provide the only cooling. Because the fans will be on only half the year, the average hours on per day is only half of what the fans will be on in the spring and summer. The fans are equipped with a timer to shut off when you are asleep.
Entertainment
Radio	70	0.5
A radio in the Master Bedroom allows the parents to listen to music or talk shows in the evening when the computer is being used. In addition, the adults can hear the news and traffic in the morning before leaving for work.
Computer with TV Tuner	90	5
The computer serves multiple purposes. It will be used as a TV, our way of knowing time, and also as a regular computer to use for work and school.
20in LCD monitor	70	5
This big monitor for the computer allows television to be watched by the entire family from across the room. LCD technology is used for a smaller, thinner monitor as well as reduced electrical consumption
Printer	100	0.1
A printer is provided to print out websites, projects, or papers from the computer.
Total Power Consumption	3396
(This must remain under 2400 Watts, but not all appliances in the house are on at the same time)

House Wiring Diagram

This is a diagram of how your house is wired.

Basic Energy Spreadsheet

This is the spreadsheet I started the project on. Most of the information is now in the above handbook. What's not in the handbook is the location of our house, and the kiloWatt-hirs calculation. Basic Energy Chart (Excel Spreadsheet)