HERE ON THE BIG ISLAND
By Kelly Moran
Could You Live Off-the-Grid?
Notice, please, the question is “Could you . . . ?”
You certainly can live where none or only some of the Big Island’s commercial services – water, electricity, telephone, television, internet – are piped into your home for a monthly fee.
And you don’t have to rough-it to live off-the-grid. You can enjoy a thoroughly up-to-date lifestyle, with all the accoutrements of a modern home, without being a customer of any commercial utility. In this and the next few blogs, I’ll tell you about the challenges and the strategies of acquiring for yourself the necessities of life here on the Big Island.
Water comes first, of course. Hawaii County has an extensive water system of wells, pumps, pipelines and meters, with high quality and modest rates. But where 40 or more inches of rain fall every year, you can reliably collect your own water from the gutters on your roof. Rain is (shall we say) especially abundant in Hilo and Puna; so even in neighborhoods, there, where County water is easily available, some homeowners choose to use catchment tanks.
- This house, though only seven miles from downtown Hilo, is entirely off the grid. The water tank – a metal frame lined with plastic – is in the foreground. The roof also has photovoltaic panels for generating electricity.
A so-called “family of four” should have at least a 10,000 gallon tank, which is generally a cylinder about twelve feet in diameter and eight feet high. Although some old redwood tanks are still in use, and are aesthetically quite pleasing, they are rarely if ever built nowadays. More common – and actually better, because they do not decompose – are tanks made of sheet metal and lined with tough plastic liners (very much like above-ground swimming pools), or tanks made of ferro-concrete (in which cement, sprayed onto a metal “rebar” frame, hardens into concrete). The latter is more expensive but will last much longer. Also, since rainwater is naturally slightly acidic, contact with the slightly alkaline concrete tends to neutralize the “ph” of stored water.
Once you have water in the tank, you still have to pipe it into the house. You’ll want some kind of filtration, because dirt and dust, or fragments of leaves, always wash down from the gutters; and though they generally settle to the bottom of the tank, little bits of stuff do sometimes get into the house’s supply line. But particulates like that are easily intercepted with simple filters which, like their smaller under-the-sink cousins, are typically replaced once or twice a year.
Getting that supply to flow inside the house’s plumbing, however, requires constant pressure in the pipes. Standard household water pressure is 40 pounds per square inch (psi). If your tank can be sited at least 40 feet higher than the highest faucet in the house, gravity will supply enough pressure. But unless your land is a steep hillside, that won’t be an easy setup. Besides, it’s much easier to site the tank close enough to the house to take the runoff from the roof.
So the force that pushes water through the plumbing typically comes from a pump and a special tank which, together, maintain constant pressure. To have that you’ll need electricity, which I’ll tell you about next time.