Renewable energy systems typically depend on the sun or wind for power.
When off grid systems aren’t producing – and storing – enough electricity, you have three main options:
- Buy more solar panels and higher capacity batteries
- Buy a generator and/or propane appliances
- Reduce electrical demands
As you know, the most cost-effective option is reducing your electrical load.
Here are key steps to reduce your power draw year-round.
Step 1: Reduce electrical demands:
Start by studying your power bills for the previous year:
- What is your monthly power usage?
- How does your power usage change seasonally?
- Which items use the most electricity? (If your unsure, you can use a Kill-A-Watt energy monitor or a whole home energy monitor to determine individual electrical loads.)
Switch to energy-efficient appliances:
- Upgrade old, inefficient appliances and infrastructure with Energy Star models
- Connect electronics and appliances to power strips, so you can turn them off when not in use. (This eliminates phantom loads, and can greatly decrease energy usage.)
- Make sure everyone knows when to use high energy appliances such as washing machines, dryers, electric heating, and air conditioning during peak power generation times. (This will reduce drain on the battery bank.)
- Consider running some appliances on propane, if it makes more sense.
Be wary of adding appliances:
Another critical step is making sure people in the house don’t add appliances without discussing it with an installer or each other. If you’re working with a client – or working with your family to reduce electrical demands – make sure people know how adding appliances affects the amount of solar panels and battery storage you’ll need. You can help them select energy efficient appliances, and talk about how to use them.
Step 2: Reduce reliance on traditional heating and cooling
According to the Energy Information Administration, nearly half of all household energy consumption is used to heat and cool homes. Fortunately, it’s easy to reduce that load – permanently. (http://www.eia.gov/todayinenergy/detail.cfm?id=10271U.S)
Here are some key ways to reduce HVAC energy demands:
- Change thermostat settings to as low (winter) or high (summer) as comfortable.
- Use drapes and shades to either trap heat or prevented from entering the house.
- Clean and replace air filters regularly.
- Consider adding blown in insulation to reduce heat losses and ensure a stable indoor temperature..
- If you’re building a house from the ground up, be sure to look at passive solar heating and siting options to drastically reduce your heating and cooling needs.
Finally, if you use air conditioning regularly, consider alternatives to traditional air conditioning, such as:
- Whole house fans, which pull in cool, nighttime air through open windows and expel hot air out the attic.
- Simple ventilation and cooling systems that pressurize the house to expel hot air at night.
- Compressor-less air conditioning alternatives that can reduce electrical usage by as much as 80 to 90%, without decreasing comfort.
What if you’ve already /your electrical demands – and you still don’t have enough power?
Because when a system is properly sized, everyone can live without micromanaging appliances and home comfort systems – while still avoiding paying utility bills or running out of power.
Whatever battery system you are using, be sure not to exceed 50% depth of discharge for maximum longevity. This provides additional back of her days with low electrical production. It also protects batteries from draining too deeply.
A good rule of thumb is to double the true amp hours needed for your system.
Image: Anthony Zarembski