For existing buildings, an energy audit is a great place to start. You can do your own simple energy audit or have a professional consultant do a more thorough, technical job. Some cities, states, and utilities offer incentives for doing an energy audit on your home. Ultimately, an energy audit will tell you where inefficiencies show up and suggest ways to fix them.
Auditing and minimizing your energy usage
It makes sense to start with the simplest and cheapest; changing to more efficient light bulbs and installing some weather stripping should come before replacing all your windows. An energy-monitoring device known as a Kill A Watt can be used to measure how much electricity your various appliances and devices use. This can be an eyeopener. Try plugging your stereo into the Kill A Watt and playing with the volume to see how the power demand fluctuates when you change the volume. You may find that some of your devices even continue to draw electricity after you turn them off. Such demands are called phantom loads. Identifying and eliminating them by unplugging devices when not in use or plugging them into power strips that can be switched off can be a good first step toward conservation.
WAYS TO CONSERVE ENERGY
Heating and cooling
- Set the thermostat a couple degrees lower and wear a sweater.
- Take a swim when it’s hot.
- Improve weather stripping and insulation.
- Install a programmable thermostat.
- Build trellis or shade house to keep cool.
- Turn off lights when not in use.
- Install solar tubes for passive lighting.
- Use low-wattage task lights when possible.
Electronics and appliances
- Turn devices off when not in use.
- Use clothesline instead of dryer when weather is nice.
- Find and eliminate phantom loads so energy is not used when devices are off.
Considerations in designing a home power system
Using available resources and making the most of the energy you harness are two essential aspects of designing a home power system. You should have noted available energy resources in your site A + A. Does your site have good, consistent wind? Is the site oriented for good solar access? Is there a year-round stream on the property that could be used for microhydro? Does availability of any of these resources change at different times of year (do streams dry up, are winds seasonal, are winters overcast)? As most places do have variation by season, it is important to note that you can create hybrid systems to increase resilience and meet power needs year-round. For instance, solar and wind power make good pairings in some places because during the winter when there is little sun the winds pick up, and in the summer when the winds are relatively calm it is much sunnier.
In addition to having multiple inputs into your power system, you should design the system to maximize your use of the energy you do harness. Off-grid solar-powered systems in sunny climates may have filled their batteries by as early as 10 a.m. The rest of the energy generated by those solar panels for the rest of the day just gets wasted unless you build a system that uses all the power harnessed in order of priority. For instance, the first priority is topping off the batteries. Once that’s done, extra power could be used to fill the compressed air tank in the shop. If both the batteries and the compressed air tank are full, excess power could be used to pump water to a tank or pond high in the landscape. If there is still extra power, perhaps it could be used to run water features, fans, aerators, or some other nonessential, non–time sensitive but helpful technology. Other, more advanced ways you can research to sock away some of that surplus energy include hydrogen fuel cells, flywheels, and spring compression, although most of these require some sort of expertise to work with. Think about all the jobs that need to be done at your home and try to find ways for extra power to help make them happen.
Start small when putting in power systems but plan for growth. Many people get a very minimal system at first and use it to learn before sizing up. If they ruin their batteries somehow, at least they ruin only one or two instead of eight or twelve. If you have an idea of what your ultimate, dream power system would look like, you can design something that can grow toward that goal.
Some components are worth oversizing from the beginning. For instance, modestly oversizing the charge controller and inverter at the beginning will allow you to add more solar panels to your system and grow it over time without having to get all new equipment. You can also consider an upgrade path where old hardware is traded in or used elsewhere. Just make sure you think about it before you start and call a professional when you need help.
Jessi Bloom is an award-winning ecological landscape designer, professional horticulturalist, and certified arborist.
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