The future as envisioned by some of the more, shall we say, avid enthusiasts of renewable energy has an energy grid dominated by small-time operators. With solar cells on every roof and wind energy at suitable locales, we won't need those big centralized power plant dinosaurs, whether they're coal, nuclear, oil, or gas. Individuals will be in greater control of their energy, and there will be less leeway for the 1% to rip off everybody else.
But it won't come out that way, for the most mundane of reasons: wire.
We all know that renewables suffer from intermittency problems. Where does your energy come from at night, when there's no wind? Advocates of renewable energy point to two independent strategies for dealing with this: energy storage and wide distribution.
Energy storage is, so far, nowhere near ready for prime time, as far as the electricity grid is concerned. We have a number of ways to store electrical energy: pumped storage, for example. We use excess electricity during the day to pump water up into a high reservoir, and then at night we reverse the process and let the water flow out, turning the pump motors into generators. This process yields between 70% and 80% efficiency — certainly good enough for our needs.
The killer problem with pumped storage is finding suitable locations. Ideally, you want a thousand-foot high cliff at the edge of a river or lake. You put the motor-generator facility at the bottom of the cliff and the water reservoir at the top of the cliff. The problem is, there aren't that many high cliffs next to rivers or lakes. They really have to be quite close (laterally) to the bottom, or you start losing energy to the friction of the water moving through long pipes. There just aren't that many good sites for pumped water storage.
There's also the prospect of batteries; one innovative idea is the use of scrapped electric car batteries for this purpose. However, again, the total capacity we can obtain in this fashion is just too low to be meaningful.
Then there's the idea of hydrogen fuel cells. We use excess electricity to hydrolyze water to make hydrogen, then run that hydrogen through fuel cells to get the electricity back. That's certainly feasible, but so far fuel cells are still too damned expensive to permit us to use them on the vast scale required for such an application.
Thus, energy storage remains inadequate to the task. I have no doubt that it will end up playing a role, but by themselves, energy storage technologies aren't hefty enough to solve the intermittency problems of solar and wind.
Which brings us to the other Great White Hope: HVDC transmission lines. Regular high-voltage transmission lines aren't efficient enough to permit us to send power any further than, oh, maybe 500 miles. We can use the highest AC voltages to wheel it up to a thousand miles, but we're losing an embarrassing percentage of that power to resistive heating.
Enter HVDC: High Voltage Direct Current. The idea here is that we can get to really high voltages (over a million volts!) using this technology, which allows us to transmit electricity greater distances with less loss to resistive heating. This will be especially important in the exploitation of wind power, because most of the best places for wind farms are pretty far from the cities that need electricity. So we build the wind farms out in the remote boonies, and ship it back to the cities using HVDC lines. Huzzah and Halleloo-whatever!
But here we get into a problem: those HVDC lines are not the kind of projects that Little Guys do. Getting all the rights of way, acquiring the large amounts of capital necessary for the installation, negotiating with the various utilities — this is a job for Big International Capitalist Corporation, not Joe's Hardware Store and Ice Cream Parlor.
We'll see the same problem with all many aspects of renewable energy. If we really do get fuel cells working right, you won't buy little 1 KW machines at your local hardware store; the big corporation that installs 100 MW fuel cells at strategic locations and sells its services to the local utility will have too many economic advantages.
Sure, much of the renewables biz is run by small time operators right now — but that's only because the business is too small to attract the attention of Daddy Warbucks. Once the New Age dawns and renewables become a big chunk of the energy economy, the big guys will move in and use economies of scale to drive all the little guys out of business.
That won't be bad — they'll be the ones making renewables cheap enough to challenge fossil fuels. Without those big companies, we might NEVER get renewables cheap enough to put Big Coal out of business.
You just can't get around dat ole' debbil economies of scale.