Introduction
In May, 2021, I left the Commons and moved to Living Energy Farm (LEF) in central Virginia. LEF is a 12-person intentional community, farmstead, and sustainable technology laboratory. We live on a very modest budget, use minimal fossil fuels, and produce much of our own food. Basically, we’re trying to figure out how to live in a way that—if everybody on Earth lived like us—would give everyone a decent standard of living AND stay within the planet’s carrying capacity. A sustainable future is going to involve Americans using way less electricity. According to YES! Magazine,[1]“researchers at the International Institute for Applied Systems Analysis say the minimum global energy flow required to achieve universal decent living standards could be as low as 500 watts per capita.” If you’re an average American, you use over 9,000 watts for everything from your refrigerator, to your oven, to (maybe) your house’s heating and cooling. Can you imagine living with just 500 watts of power? I hope this art project will help you imagine it. The illustrations show some of the ways we use electricity at LEF, where we generate about 220 watts per person. The Direct Drive DC Microgrid How do we get by using so little power? Of course, part of the answer is that we reduce our per capita energy use tremendously by living in community (ten adults and two children in one super-insulated house with one refrigerator, etc.); we also get energy from multiple sustainable sources, including solar thermal, wood, and biogas. But our electricity system is also pretty special. At LEF, we use a simple but very non-standard electrical system we call a “direct drive DC microgrid.” The “microgrid” part of that phrase means that our electricity comes from a series of PV panels. In January, 2022, a winter storm knocked out our neighbors’ power for ten days, but our lights never turned off. We are basically energy independent. “Direct drive” means that we wire most of our household appliances (refrigerator, water pump, etc.) directly to our panels instead of storing electricity in batteries, the way most off-grid systems do. (We do have a few batteries to charge gadgets and power lights). This saves us lots of money, since the lithium batteries most off-grid homes rely on have to be replaced on average every five years. But on the flip side, it means we only get power while the sun is shining. We have to adjust our energy use accordingly; for example, we only bake bread on sunny days. Finally, “DC” refers to the fact that our appliances run on DC, not AC, electricity. That's because PV panels produce DC electricity. Most people who take their homes off grid buy inverters to convert solar electricity to AC, but this costs a lot of money and, in low energy systems like ours, sometimes diminishes system efficiency. We save a lot of money and power by using DC power straight from our PV panels. The catch is that most U.S. appliances don’t use DC electricity; they use AC. Your washer, your fans, and your oven probably have motors specialized for AC. They are also optimized for the US 120V power grid. So a big part of what we do at LEF is develop machines that work with our power. For machines that turn—washers, mills, fans, saws—we often take off their original motors and belt them to DC-compatible motors. For machines that produce heat (ovens, hot plates), we rewire them and give them heavy-duty switches, since DC electricity is apt to arc and will burn out regular switches fast. In some cases, we build our own machines from the ground up.[2] Electricity and Food Production At LEF we grow some thirty-five crops, both for seed (our chief income source) and for our own use. We grow both staples (corn, wheat, peanuts) and vegetables and fruits (garlic, collards, persimmons), and we can, dry, and ferment a great deal of food for use in the winter. I don’t know exactly what percentage of our calories we grow ourselves, but it’s over fifty. We regularly have meals that were grown entirely on our farm: the menu might look like squash soup, sourdough bread, duck egg frittata, Lima beans, and collard greens. We use electricity at several stages of food production. We irrigate with an electric well pump. We use fans to winnow grains and legumes and to dry food and seeds. Our grain mill, which grinds cornmeal, peanut butter, and flour, is electric. And of course, we use electricity when we cook, and to refrigerate leftovers. [1] Matsue Loffleholtz, T. (2021). Energy, housing, food, water: what’s a fair share? YES! Magazine. 25 Feb. 2022. https://www.yesmagazine.org/issue/how-much-is-enough/2021/08/10/energy-housing-food-water-equity [2] As much as I’d like to see more people use direct drive DC microgrids, please don’t try building any of this stuff unless you really know what you’re doing! |