| |
Designing for Minimal Electrical
Energy Use
In no specific order:
- Select only select low
energy lights and appliances
- Use propane, wood, oil
or other fuels, not electricity for major heating appliances
- Install lots of extra
switches so that you can control phantom loads
without having to unplug appliances, also put less lights on each switch. Use
directed lighting where possible.
- use motion sensors and timer
switches, especially for outdoor lighting and areas where it is easy to leave
an electrical load on
- use heating systems that use
convection and don't require pumps and fans to circulate or move heat, when
they do, investigate for efficiency or if there are DC powered alternatives.
- when possible use low
voltage DC power for things such as outdoor lights, door bells
- Avoid leaving battery
chargers and motion sensors that normally on as they create phantom loads that
run continually.
- You already have equipment
that works well well with DC power. Examples of these are Camera and
Cellular phone chargers which are designed to operate from your car.
240
Volt Loads
Some inverters have this option in many case you require inverters to produce
240V single phase power. A 240V inverter or an autotransformer can
produce 240V power from 120V. Because 240V power increases system it
should but not be avoided. Deep well submersible pumps and distant or depth of well a 120V pump may
require 240V. An
autotransformer wired in a step-up
configuration can manage water pumps of up to one horsepower. To keep the
transformer off-line until required wire the well pump switch to the primary
side of the transformer. All transformers that are connected to power
continue to consume some power even when not in use.
Transformers
Other than the autotransformer mentioned above eliminate or minimize the
number of transformers within
your system if you can. Transformers are often found within equipment such as heating
systems, low voltage lighting, water softeners, etc. There are significant conversion losses as
DC low voltage power is converted from 120 AC. Transformer
conversion power loss of up to 30% is exacerbated due to the
transformer's continual power loss (phantom load) even when not active. Check with your
equipment suppliers and manufacturer to see if DC power may be used directly. It
is sometimes possible as in the example of the autotransformer above, to switch
the power supply to the transformer rather than to switch the low voltage
load (e.g. doorbell).
Grounding and Bonding
Off-grid systems have multiple items that should be well grounded and bonded:
- PV Panels
- Inverters
- Charge controller
- Generator
- AC Panel
- Wind Turbine
|