Power Green Alliance

- Solar panels
- Charge controller
- Battery
- Inverter

- Solar panels charge the battery,
- The charge controller or charge regulator insures proper charging of the

battery, - The battery provides DC voltage to the inverter,
- The inverter converts the DC voltage to normal household AC voltage.

multiplying the rated voltage by the rated amperage. The formula for wattage is

VOLTS times AMPS = WATTS. For example, a 12 volt 60 watt

solar panel measuring 20 X 44 inches has a rated voltage of 17.1 and a rated 3.5

amperage.

V x A = W 17.1 volts times 3.5 amps equals 60 watts. If an average of 6 hours of

peak sun per day is available in an area, then this solar panel can produce an

average 360 watt hours of power per day; 60w times 6 hrs = 360 watt-hours.

The intensity of sunlight varies throughout the day, therefore the term "peak sun

hours" is used to smooth out the variations. Early morning and late-in-the-day

sunlight produces less power than the mid-day sun. Cloudy days produce less

power than bright sunny days. Geographical areas are rated in average peak

sun hours per day based on yearly sun data.

Series wiring connects the positive terminal of one panel to the negative terminal

of another. The outer positive and negative terminals will produce voltage the sum

of the two panels, but the amperage remains the same as one panel. So two 12

volt/3.5 amp panels wired in series produce 24 volts at 3.5 amps. Four of these

wired in series produce 48 volts at 3.5 amps. Parallel wiring refers to connecting

positive terminals to positive terminals and negative to negative. The result is that

voltage stays the same, but amperage becomes the sum of the number of panels.

So two 12 volt/3.5 amp panels wired in parallel would produce 12 volts at 7 amps.

Four panels would produce 12 volts at 14 amps. Series/parallel wiring refers to

doing both of the above - increasing volts and amps to achieve the desired

voltage as in 24 or 48 volt systems.

- A charge controller monitors the battery's state-of-charge to ensure that

when the battery needs charge-current it gets it, and also prevents

overcharging.

- Connecting a solar panel to a battery without a controller risks damage to the

battery. Charge controllers (or charge regulators) are rated on the amount of

amperage they process from a solar array. If a controller is rated at 20 amps it

means that you can connect up to 20 amps of solar panel output current to

this one controller.

**PWM****-**The most advanced charge controllers utilize Pulse-Width-Modulation

(PWM) - which ensures the most efficient battery charging and extends the

life of the battery.

**MPPT****-**Even more advanced controllers also include Maximum Power Point

Tracking (MPPT) which maximizes the amount of current going into the battery

from the solar array by lowering the panel's output voltage, which increases

the charging amps to the battery.

**LVD****-**Many charge controllers also offer Low Voltage Disconnect (LVD) and

Battery Temperature Compensation (BTC) as an optional feature. The LVD

feature permits connecting loads to the LVD terminals which are then voltage

sensitive. If the battery voltage drops too far the loads are disconnected -

preventing potential damage to both the battery and the loads. BTC adjusts the

charge rate based on the temperature of the battery since batteries are

sensitive to temperature variations above and below about 75 F degrees.

Deep Cycle

hundreds or thousands of times. These batteries are rated in Amp Hours (ah) -

usually at 20 hours and 100 hours. Amp hours refer to the amount of current

which can be supplied by the battery over the period of hours. For example, a

350ah battery could supply 17.5 continuous amps over 20 hours or 35 continuous

amps for 10 hours.

Batteries can be wired in series and/or parallel to increase voltage and amp

hours. The battery should have sufficient amp hour capacity to supply needed

power during the longest expected period "no sun" or extremely cloudy conditions.

and availability. The most important designation is that they are

batteries. Lead-Acid batteries are available in

such as

A lead-acid battery should be sized at least 20% larger than this amount. If there

is a source of back-up power, such as a standby generator along with a battery

charger, the battery bank does not have to be sized for worst case weather

conditions. The size of the battery bank required will depend on the storage

capacity required, the maximum discharge rate, the maximum charge rate, and the

minimum temperature at which the batteries will be used.

One of the biggest mistakes made by those just starting out is not understanding

the relationship between amps and amp-hour requirements of 120 volt AC items

versus the effects on their DC low voltage batteries.

For example, say you have a 24 volt nominal system and an inverter powering a

load of 3 amps, 120VAC, which has a duty cycle of 4 hours per day. You would

have a 12 amp hour load (3A X 4 hrs=12 ah). However, in order to determine the

true drain on your batteries you have to divide your nominal battery voltage (24v)

into the voltage of the load (120v), which is 5, and then multiply this times your

120vac amp hours (5 x 12 ah). So in this case the calculation would be 60 amp

hours drained from your batteries - not the 12 ah. Another simple way is to take

the total watt-hours of your 120VAC device and divide by nominal system voltage.

Using the above example; 3 amps x 120 volts x 4 hours = 1440 watt-hours

divided by 24 DC volts = 60 amp hours.

- An inverter is a device which changes DC power stored in a battery to

standard 120/240 VAC electricity (or 110/220). - Most solar power systems generate DC current which is stored in batteries.
- Nearly all lighting, appliances, motors, etc., are designed to use ac power, so

it takes an inverter to switch from DC to 120 VAC, 60 Hz). - In an inverter, direct current (DC) is switched back and forth to produce

alternating current (AC). Then it is transformed, filtered, stepped to get it to an

acceptable output waveform. The more processing, the cleaner and quieter

the output, but the lower the efficiency of the conversion. The goal becomes

to produce a waveform that is acceptable to all loads without sacrificing too

much power in the conversion process.

- Inverters come in two basic output designs - Sine Wave and Modified Sine

Wave. Most 120VAC devices use modified sine wave. Exceptions are

devices such as laser printers which use triacs and/or silicon controlled

rectifiers are damaged when provided mod-sine wave power. Motors and

power supplies usually run warmer and less efficiently on mod-sine wave

power. Some devices, like fans, amplifiers, and cheap fluorescent lights, give

off an audible buzz on modified sine wave power.

**M****odified sine wave inverters**make the conversion from DC to AC very

efficiently. They are relatively inexpensive, and work for most household

appliances.

**Sine wave inverters**can virtually operate anything. Your utility company

provides sine wave power, so a sine wave inverter is equal to or even better

than utility supplied power. A sine wave inverter can "clean up" utility or

generator supplied power because of its internal processing. Inverters are

made with various internal features and many permit external equipment

interface

- Common internal features are
**internal battery****chargers**which can rapidly

charge batteries when an AC source such as a generator or utility power is

connected to the inverter's INPUT terminals.

- Auto-transfer switching is also a common internal feature which enables

switching from either one AC source to another and/or from utility power to

inverter power for designated loads.

- Battery temperature compensation, internal relays to control loads, automatic

remote generator starting/stopping and many other programmable features

are available.

- Most inverters produce 120VAC, but can be equipped with a step-up
**transformer**to produce 120/240VAC. Some inverters can be series or

parallel "stacked-interfaced" to produce 120/240VAC or to increase the

available amperage.

batteries and inverters not being 100 percent efficient, and other factors. These

efficiency losses vary from component to component, and from system to system

and can be as high as 25 percent.

kWh per day. Power is defined as the rate at which work is done or energy is

consumed. The formula for average power is acquired by dividing work by the

time needed to perform work: P = W/t. Power has units of newton-meters per

second or joules per second or watts.

distribution

consisting of a central mover like a turbine that is then pushed by water or steam

to run a system of generators.

appliances there are and the amount of time they are in use. Some appliances take

a lot of energy to operate, so it will result in more use of power.

"A kilowatt-hour is the electrical energy consumed in one hour at the constant rate

of one kilowatt. The average household 8,900 kilowatt-hours of electricity each

year."

Typical Power Consumption

Air Conditioners WATTS ANNUAL kW

One ton 1,900 3,078

Three-and-one-half-ton 6,500 10,530

Five-ton 9,200 14,904

Major & General Appliances

CD Player 85 85

Clock 2 17

Clothes Dryer 2,790 900

Computers 240 1,248

Dishwasher 1,201 363

Electric Blanket 177 147

Fan (Attic) 370 291

Fan (Ceiling or Circulating) 88 43

Fan (Furnace) 500 660

Fan (Rollaway) 171 138

Fan (Window) 200 170

Fish Tank 4 35

Floor Polisher 305 15

Freezer-Upright (18 cu. ft.) 380 1450

Manual Defrost 540 1,250

Automatic Defrost 700 1,830

Hair Blow dryer 1,000 15.6

Hand Iron 1,100 60

Heat Lamp 250 13

Heating Pad 65 10

Humidifier 177 163

Jacuzzi/Spa Pump 1,300 2,100

Kiln 5,760 1,659

Lighting (Avg. Resd. Use) 1,200

Radio (Solid State) 15 18

Radio/Recorder (Solid State) 26 26

Range (with Oven) 12,200 750

Range (with self-cleaning) 12,200 775

Refrigerator-Freezer

16 cu. ft. 380 1,450

20 cu. ft. 420 1,950

Refrigerator-Freezer (frostless)

16 cu. ft. 600 2,150

20 cu. ft. 800 2,700

Sewing Machine 75 11

Shaver (none rechargeable) 15 0.5

Sun Lamp 279 16

Swimming Pool Pump Motor 2,000 8,780

Television Cable (TV) Box 23 50

Television, Color (Tube) 286 600

Television, Color (Solid state) 175 350

Television, Screen (45") 147 329

Television, Video Games 45 100

Video Tape Rec. 175 350

Washing Machine 512 103

Water Heater 2,475 4,219

water Heater (Quick-Recovery) 4,474 4,811

Waterbed Heater 450 1,460

Well Pump 2,238 1,894

Kitchen Appliances

Broiler 1,140 85

Coffee Maker 1,200 140

Deep Fat Fryer 1,448 83

Food Blender 300 1

Food Mixer 127 2

Frying Pan 1,196 100

Hot Plate 1,200 90

Microwave Oven 1,450 190

Roaster 1,333 60

Slow/Rice Cooker 200 144

Toaster 1,146 39

Watts

specific moment. For example, 100 watts describes the amount of electricity that a

100-watt light bulb draws at any particular moment.

are a combination of the how fast the electricity is used (watts) and the length of

time it is used (hours). For example, a 100-watt light bulb, which draws 100 watts

at any one moment, uses 100 watt-hours of electricity in the course of one hour.

used by large appliances, such as refrigerators, and by households. Kilowatt-

hours are what show up on your electricity bill. One kilowatt (kW) equals 1,000

watts, and one kilowatt-hour (kWh) is one hour of using electricity at a rate of

1,000 watts. New, energy-efficient refrigerators use about 1.4 kilowatt-hours per

day, and about 500 kilowatt-hours per year.

electricity required by an entire city. One megawatt (MW) = 1,000 kilowatts =

1,000,000 watts.

gigawatt (GW) = 1,000 megawatts = 1 billion watts.

AC ApplianceHours of Daily Usage XAppliance Watts =Daily Watt Hours Used

1Microwave.5600300

2Lights (x4)640240

3Hair Dryer.75750563

4Television4100400

5Washing Machine1375375

Total Daily Watt Hrs. Used

Formula:Add Lines 1-5 >>>1,878

days of autonomy (days between charging, usually beteen 1 to 5) to determine

your Rough Battery Estimate.

Rough Battery Estimate Formula:

Total Daily Watt Hrs. Used x days of autonomy >>>5,634

size in watt hours. (This allows for 50% maximum battery

discharge in normal operation and an additional 50% in

emergency situations.) Safe Battery Size in Watt Hrs.

Formula:Rough Battery Estimate x 2 >>>11,268

Battery Size in Watt Hours by DC system voltage (i.e. 12, 24,

48 volts DC)

Safe Battery Size in Amp Hrs. Formula: Safe Battery Size in Watt Hours / System

Voltage >>>470

at the same time, and add 25%. Then roundup to the next inverter wattage size.

Properly sized inverter wattage Formula: Add Total Appliance Watts + 25% >>>2,

500

Air Conditioners for residential homes, some countries set minimum requirements

for energy efficiency. The efficiency of air conditioners is often (but not always)

rated by the

rating, the more energy efficient is the air conditioner. The SEER rating is the BTU

of cooling output during its normal annual usage divided by the total electric

energy input in watt-hour (W·h) during the same period.

SEER = BTU ÷ W·h

For example, a 5000 BTU/h air-conditioning unit, with a SEER of 10, operating for a

total of 1000 hours during an annual cooling season (i.e., 8 hours per day for 125

days) would provide an annual total cooling output of: 5000 BTU/h × 1000 h

= 5,000,000 BTU which, for a SEER of 10, would be an annual electrical energy

usage of: 5,000,000 BTU ÷ 10 = 500,000 W·h and that is equivalent

to an average power usage during the cooling season of: 500,000 W·h

÷ 1000 h = 500 W

More Solar Energy information

Millennium Planet is a wholesale distributor of an unlimited array of renewable energy components including high quality solar photovoltaic (PV) panels used in residential

and commercial applications, including off-grid, grid-tie systems, as well as portable solar systems and complete do-it-yourself kits. We're partnered with a growing list

of quality manufacturers to ensure that you get the best product for your particular application at the best price. All quality products are CE Certified and manufactured

to ISO 9001 standards.

and commercial applications, including off-grid, grid-tie systems, as well as portable solar systems and complete do-it-yourself kits. We're partnered with a growing list

of quality manufacturers to ensure that you get the best product for your particular application at the best price. All quality products are CE Certified and manufactured

to ISO 9001 standards.

- PV panels from 5 to 500 Watts
- Flexible solar panels
- Rigid solar panels
- Polycrystalline cells
- Monocrystalline cells
- Thin film panels

- AE Solar
- Evergreen Solar
- Grace Solar
- Iowa Thin Film
- Powerfilm
- Sharp
- Solartech
- Solarworld
- Sunlinq
- Suntech
- Sunwize
- Unisolar

- Solar PV Panels
- Solar generators
- Charge controllers
- Inverters
- Batteries
- Installation kits
- Mounting hardware
- Connector cables
- Portable solar chargers
- Complete solar power kits
- Lighting systems
- Water heater systems
- Automotive vents
- Attic ventilation