energy production

On a recent trip home to Iowa, a minor basement flood at my parents’ in-town house presented the opportunity to stay at their newly completed off-grid home out in the country. As living on a self-sufficient acreage is of course our dream, we took this as a chance for a taste of sustainable living (well, minus the homesteading aspect).

This picture shows the solar array, wind tower, propane tank, and top of the septic system. If you look in the background you’ll see the line of semis waiting to accept their load of industry-intensive corn being harvested that day. I felt it was a nice contrast between viable sustainable practices…and modern farming techniques.

In the beginning, it was all so simple. Rub two sticks together, get a fire. Stick a pipe in the ground, get some oil. Trade a cow, get a llama. Simple systems require only straightforward applications of engineering, with little need to examine precisely how individual components might interact. But as our global production system has evolved, so too has the level of complexity amongst the various components. Our society, based on ever-advancing technology of all kinds, has become a seething morass of indecipherable interactions between mind, body, finance, and resources.

What was once a world of isolated simple systems is now what we (so creatively) call a complex system. Complex systems don’t have straightforward relations between cause and effect (input and output) because there are such high numbers of interactions within the system. As such, complex systems fail in complex ways.

To determine if microhydro is viable for your homestead or community, you need to run some calculations. Using your measurements of head and flow rate from the last post on microhydro, it’s a simple matter to calculate the available power. Wikipedia has a good summary of the necessary equations.

If we define h as our head height and φ as our flow rate, we see that P = ρφgh (where P = power, ρ is mass density of water, and g is gravitational acceleration).

When exploring small-scale renewable energy sources, the most commonly considered techniques are wind and solar generators. Depending on several factors, a far better option may be small hydroelectric systems, or “microhydro”.

We learned in our discussion on ram pumps that we can use the energy of water falling from a height to pressurize tap water. Of course, that same energy can be used to drive a turbine and produce electricity, just as large projects like the Hoover Dam.

Suppose a scientist announces a newly discovered, cheap material that is capable of harnessing 95% of solar energy. Have we found the solution to Peak Oil? Not so fast!

From our earlier breakdown of energy requirements we can see we have some requirements for cooling our food for preservation (we will develop formal requirements shortly). While you should always consider alternative food preservation (smoking, canning, etc.), preserving food by cooling is extremely effective and convenient.

As mentioned before, our energy needs can be broken down according to category. From our table of electrical usage for the Peak Oil Homestead, we can extract the following:

Heating
Furnace: 300W, 8 h/day --> 4 kWh/day
Water: 4500W, 6 h/day --> 27 kWh/day

Cooling
Air conditioner: 600W, 8 h/day --> 4.8 kWh/day
Deep freezer: 600W, 12 h/day --> 7.2 kWh/day
Refrigerator: 600W, 8 h/day --> 4.8 kWh/day

Cooking
Oven: 5000W, 3 h/week --> 2.1 kWh/day

Apologies for the drop in activity -- I've been out-of-town and my internet connections did not pan out.

The other day we were looking at a house up north with a woodburning stove in the basement. Since the lot was heavily wooded, a woodburning stove was a great addition to aid in the warming of the house and transistion past Peak Oil. Unfortunately, the design of it was less than brilliant -- the stove pipe was routed from the basement to the roof outside of the house. It was such a bizarre thing to do, I could hardly imagine why they had done so. Besides the obvious loss of heat for warming the inside of the house, putting the stovepipe outside drastically increases the rate of creosote buildup. This raises the risk for chimney fires and constricts the air flow within the pipe.

For the vast majority of us working to transition to a comfortable post-Peak Oil life, our resources are seriously limited. We’re short of available time, money, land, and skills, and our windows of opportunity for acquiring all of these are rapidly shrinking. So, the more help we can get to build our future efficiently and cheaply, the better.

OtherPower has great information and products for building your own power, water, and heating systems from scratch. Done correctly, you can save quite a bit of money by building up your own systems.

Greener Shelter discusses a number of sustainable house design strategies. While they don’t have detailed plans, it might get you thinking in new directions for further research.

RobTzu called me in to an interesting thread on LATOC discussing challenges to the notion that we can't save the world from energy decline after Peak Oil. In the thread, we calculated the required cost to replace the current world power usage fully with wind energy. Here was my contribution: