By harnessing the power of the sun, wind or water, people all over the
world produce their own pollution-free reliable electricity. Technological
advances, government assistance, the need for reliable power, and the
growing urgency to reduce the use of fossil fuels make renewable energy
systems increasingly attractive to people around the world.
Solar technology makes it possible for home and business owners to
have dependable power from renewable sources. Mass production has
significantly reduced the price of renewable energy systems and their
components. Solar systems with battery-based backup power can ensure
reliable power even when the utility grid is down.The use of renewable
sources such as wind, water and sun increases our energy
self-sufficiency and fosters economic and national security. As more
families, individuals and businesses generate their own renewable
electricity we will reduce pollution, provide more electricity for all to use,
reduce the use of fossil fuels, and make the electricity on the grid "greener".
Deregulation has created an atmosphere of change in the United States.
We are experiencing higher electricity rates and electricity shortages.
Laws usually referred to as net metering allow solar-energy-system
owners to feed their excess generated electricity back to the utility. The
system owner receives a credit or payment for solar-generated electricity
fed into the grid. In other words, you pay only for the net electricity you
consume - the amount of electricity you take from the utility minus the
amount you generate and feed back from your solar system. With a solar
electric system, you can provide yourself with protection from the rising
prices of fuel, because your system's fuel is the sun. Additionally, state,
local and federal tax incentives and rebates make obtaining a system
more economical.
The size of a solar electric system depends on the amount of power
that is required (watts), the amount of time it is used (hours) and the
amount of energy available from the sun in a particular area (sun-hours
per day). The user has control of the first two variables, while the third
depends on the location.
Conservation
Conservation plays an important role in keeping down the cost of a
photovoltaic system. The use of energy-efficient appliances and lighting,
as well as non-electric alternatives wherever possible, can make solar
electricity a cost-competitive alternative to gasoline generators and, in
some cases, utility power.
Cooking, Heating and Cooling
Conventional electric cooking, space heating and water heating
equipment use a prohibitive amount of electricity. Electric ranges use
1500 watts or more per burner, so bottled propane or natural gas is a
popular alternative to electricity for cooking. A microwave oven has about
the same power draw, but since food cooks more quickly, the amount of
kilowatt hours used may not be large. Propane and wood are generally
better alternatives for space heating. Good passive solar design and
proper insulation can reduce the need for winter heating. Evaporative
cooling is a more reasonable load than air conditioning and in locations
with low humidity; the results are almost as good. One big plus for solar
cooling: the largest amount of solar energy is available when the need
for cooling is the greatest.
Lighting
Lighting requires the most study since many options exist in type, size,
voltage and placement. The type of lighting that is best for one system
may not be right for another. The first decision is whether your lights will
be run on low voltage direct current (DC) or conventional 110-volt
alternating current (AC). In a small home, an RV, or a boat, low voltage
DC lighting is often the best choice. DC wiring runs can be kept short,
allowing the use of fairly small gauge wire. Since an inverter is not
required, the system cost is lower. When an inverter is part of the system,
and the lights are powered directly by the battery, a home will not be
dark if the inverter fails. In addition to conventional-size medium-base
low voltage bulbs, the user can choose from a large selection of DC
fluorescent lights, which have 3 to 4 times the light output per watt of
power used compared with incandescent types. Halogen bulbs are 30%
more efficient and actually seem almost twice as bright as similar wattage
incandescent given the spectrum of light they produce. High quality
fluorescent lights are available for 12 and 24 volt systems.
In a large installation or one with many lights, the use of an inverter to
supply AC power for conventional lighting is cost-effective. AC compact
fluorescent lights will save a tremendous amount of energy. It is a good
idea to have a
DC-powered light in the room where the inverter and
batteries are in case there is a problem. AC light dimmers will only
function properly on AC power from inverters that have pure sine wave
output.
Refrigeration
Gas powered absorption refrigerators are a good choice in small systems
if bottled gas is available. Modern absorption refrigerators consume 5-10
gallons of LP gas/month. If an electric refrigerator will be used in a
standalone system, it should be a high-efficiency type. Some
high-efficiency conventional AC refrigerators use as little as 1200
watt-hours of electricity/day at a 70 degree average air temperature. A
comparably sized Sun Frost refrigerator/freezer uses half that amount of
energy and a SunDanzer refrigerator (without a freezer) uses less than
100 watt-hours per day. The higher cost of good quality DC refrigerators
is offset by savings in the number of solar modules and batteries required.
Major Appliances
Standard AC electric motors in washing machines, larger shop machinery
and tools, swamp coolers, pumps, etc. (usually 1/4 to 3/4 horsepower)
require a large inverter. Often, a 2000-watt or larger inverter will be
required. These electric motors are sometimes hard to start on inverter
power, they consume relatively large amounts of electricity, and they are
very wasteful compared to high-efficiency motors, which use 50% to 75%
less electricity. A standard washing machine uses between 300 and 500
watt-hours per load, but new front-loading models use less than 1/2 as
much power. If the appliance is used more than a few hours per week, it
is often cheaper to pay more for a high-efficiency appliance rather than
make your electrical system larger to support a low-efficiency load.
Vacuum cleaners usually consume 600 to 1,000 watts, depending on how
powerful they are, about twice what a washer uses, but most vacuum
cleaners will operate on inverters larger than 1,000 watts since they have
low-surge motors.
Small Appliances
Many small appliances such as irons, toasters and hair dryers consume
a very large amount of power when they are used but by their nature
require very short or infrequent use periods. If the system inverter and
batteries are large enough, they will be usable. Electronic equipment,
such as stereos, televisions, VCRs and computers have a fairly small
power draw. Many of these are available in low voltage DC as well as
conventional AC versions. In general, DC models use less power than
their AC counterparts
Energy Efficiency With GPL Solar
- Install a programmable thermostat
- Replace high use incandescent lamps with compact fluorescent lamps
- When replacing your dishwasher, choose an ENERGY STAR-labeled model
- When replacing your gas water heater, choose an energy efficient model
- When replacing your clothes washer, choose an ENERGY STAR-labeled model
- Insulate basement walls to R-11
- Insulate exterior walls to at least R-11
- When replacing your windows, choose a double-pane solar-control low-E argon gas wood frame window
- Have a professional seal your home's air leaks
- When replacing your gas furnace, choose an ENERGY STAR-labeled model
- When replacing your main refrigerator, choose an ENERGY STAR-labeled model
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