Lakis of the City of the Future Blog has read different transition reports and offers an important critique:

“For me, the most pressing and unspoken question each of these plans raise is: to what degree is it necessary, possible or desirable to rely on a massive, state, national or global-scale infrastructure build-out to save us from climate catastrophe and energy depletion? And what would such a build-out imply for the nascent but growing movement toward a more distributed, hyper-local and finely articulated economy and culture?

While the various renewable roadmap plans differ in many respects, most share a few key assumptions–assumptions that raise larger questions about what to focus on as we pursue this transition, and what our civilization will look like at the end of it.

First, each plan assumes that industrial output and travel will continue to rise over the next few decades, even as efficiency allows total energy consumption to fall.

Second, the plans call for the rapid electrification of energy demand, especially transportation. This is necessary because wind, water and solar power produce electricity, whereas cars, trucks and airplanes currently run by burning fossil fuels. The plans vary in terms of timing and degree of this part of the transition. For example the Ecofys report calls for electricity to rise from 1/5th of total energy use to 1/2 by 2050. Jacobson’s plan, by contrast, calls for a shift to 100 percent end-use electricity consumption by 2030, including for building heating and cooling.

Third, the plans all require the building of large-scale, centralized infrastructure to manage the diffuse and intermittent character of renewable energy. For their US plan, Fthenakis’ team relies heavily on a huge buildout of solar energy in the Southwestern United States, where the nation’s concentration of solar resource is the greatest.

In Fthenakis’ plan, high-voltage direct current supplies this power to the rest of the country, while compressed air in underground formations provides for storage–although less storage is required than you might think, given the time difference between the Southwest and the population centers of the East Coast (the sun is usually still shining brightly in Nevada when the lights come on for evening peak consumption in New York City). All of the technology required to implement this plan exists today and has been used in around the world.

The Jacobson plan, by contrast, relies more heavily on wind, at least for the New York State portion, which requires a buildout of more than 12,000 offshore turbines, in addition to much more onshore wind and solar. How difficult it will be to convince residents of the south shore of Long Island to accept windmills in the distance remains to be seen.

The WWF/Ecofys plan is more general, but assumes that intermittency can be dealt with through pumped hydropower (in which water generated by a hydro-electric generator is pumped upstream an stored for use when necessary), centralized hydrogen storage and grid improvements.

But if the future of renewable energy lies in large installations that share power over large areas and centralized storage, what to make of the simultaneous predictions that the future of energy is distributed — small scale, widespread and community owned?

Or, as a report from Navigant Research put it,

– “The global electric power industry is evolving from a financial and engineering model that relies on large centralized power plants owned by the utilities to one that is more diverse – both in sources of generation and ownership of the generation assets.”

In fact, the spread of renewable, distributed generation is happening so fast that utilities are now calling rooftop solar “an existential threat” to their business model, not to mention their ability to maintain the grid, according to a recent article in the New York Times.

At the heart of the companies’ complaints is the fact that the traditional utility business model works by investing in infrastructure and then recouping cost and making profit by charging customers enough to get a guaranteed return over time. But if enough solar customers are selling money back to the grid (“net metering”) then, the utilities say, there’s not enough left to pay for infrastructure maintenance and upgrades. This in turn effectively raises rates on non-solar users, encouraging even more people to put up solar panels — causing a solar “death spiral” as one executive put it in the article.

While this sounds like a tragic outcome from the perspective of the utility, those of us who support a move beyond the current centralized, corporate-dominated system will be tempted to cheer. With the increasing sophistication of microgrid technology, the potential move toward a decentralized, community-controlled energy regime seems closer than ever. Of course, as some advocates argue, there’s nothing to prevent the utilities from building their own microgrids and getting into the distributed generation business themselves.

The only catch is that while most current microgrids allow for a share of renewable energy integration, many rely on natural gas and small-scale generators for their baseload power. By generating power locally in buildings, these systems can take advantage of cogeneration, whereby waste heat from electricity is used to heat the building or district, saving significant energy.

But what happens if we want to move to an entirely renewable system? Doing so at a microgrid scale involves adding local-scale storage, usually in the form of batteries. For locations that are currently removed from a wider existing grid, renewable power with storage is already more cost-effective than fossil-fuel power in many cases.

In a place like the United States, however, the most abundant sources of energy aren’t where the people live, which seams to mean that moving to a one hundred percent renewable energy world will involve sharing power over distances and the building of some big installations–wind turbines, solar plants, compressed air storage, direct current high voltage transmission lines–to meet demand. Then the question is, can we get there without utilities–or without utilities in their current form?

As always, it seems likely that the answer will involve a complex mix of scales that incorporate everything from microgrid powered universities and villages to continent-wide distribution of renewable power. It will be interesting, to say the least, to see how it all plays out.”