If we take the present total electricity generation in the U.S. and try to figure out how many windmills it would take to replace that, we come up with something like a bazillion windmills — but that’s not how the economy would react, Nathan Lewis says, if we had to switch away from fossil fuels:
We already know the way forward regarding “renewable” energy because we have been making these experiments for decades now. This was done by the “off grid” types beginning in the 1970s. When you disconnect from the grid, what do you do? An off-gridder has some basic decisions:
- Install solar panels, microhydro, windmills, etc. to replace the on-grid electricity that an average U.S. household would use (about 30 kWh/day.)
- Use less electricity, which means less need for solar panels, microhydro, windmills, etc.
When you do the math for a single household, it is just as ridiculous as it is for the economy as a whole. To generate 30 kWh/day, you would need about 10,000 nameplate watts of PV solar, or about eighty full-size 125 watt solar panels. That is a lot, and at $800 per panel (not to mention chargers, inverters, batteries, etc. etc.) it adds up to serious coin.
So, the typical off-gridder relies overwhelmingly on the second option, which is to use less. Many families get by very happily on 3 kWh/day (1,000 nameplate watts), and 6 kWh/day (2,000 nameplate watts) would be rather cushy. The hardcore types sometimes cut their usage down to 1 kWh/day, which is really impressive but not necessary.
They do this primarily via the technique that I refer to time and time again, which is to introduce new systems, rather than taking the existing system and trying to wring small efficiencies out of it. For example, a tweaking of an existing system would be the Prius, which gets 45 mpg instead of 35 mpg for one of the better normal-engine cars. A “new system” would be to live within walking distance of work. We saw last week that there are colossal differences between transportation energy use in various cities, not because one city is populated by self-flagellating green-living maniacs, and another is not, but because the inherent design of the city.
The off-gridders, in their efforts to live within a 3 kWh/day “budget”, will first forego the most obvious low-value electricity-consumers like electric heating, air conditioning, and water heaters. High-efficiency lighting is next, possibly followed by low-energy computers. Electric clothes dryers also get the heave-ho, along with electric stoves and ovens. Chronic energy-users like refrigerators get replaced with low-energy models, which can use as little as 20% of the electricty of the standard models but are just as cold on the inside.
The result of all this is that the off-gridder accomplishes 90% of his goal by Method 2 (using less), and only 10% by Method 1 (generating energy by alternative means.)
Note that the balance is 90%:10% and not, for the most part, 97%:3%. At some point, the additional difficulties of cutting usage still further are greater than the difficulties of just adding on a few more solar panels. The 1 kWh/day guys are the hardcore experimenters. They get by with two 125-watt solar panels, instead of eight. Most people figure: hey, just stick six more panels up there so I can have ice in my iced tea. My point is, this ratio has been the result of experimentation, and not some pre-arranged planning.
The off-grid household is a microcosm of what could be done on a city-size scale. There are certain efficiencies which can be achieved by centralizing power production, especially as regards the elimination of the need for battery banks and inverters. Instead of having a solar panel on every roof, you could have a few large-scale solar generators (on top of warehouses for example). Instead of little teeny windmills you could have huge ones, and instead of micro-hydro you can use macro-hydro. But the logic of the situation works out more or less the same: the difficulty of generating power via these means is great enough (compared to coal or natural gas) that the natural strategy would be 90% Method 2 (use less) and only 10% Method 1.
So, we already know the answer (90:10) because we already did the experiment. It’s not my opinion!
At this point, it occurs to me that the “alternative energy” system of the future is already built, because nuclear, hydro, wind and solar already account for more than 10% of electricity production.
Of course, that 10 percent of our electricity production that’s “alternative” isn’t always available when and where we need it.