I have dished out a healthy share of criticism about the paths we are taking into the energy future, so perhaps it’s time I offered some paths of my own. I will outline them as simply as possible, since the data and thinking behind them could fill a book.

First we must know where we’re going.

Credible models show that by the end of this century, essentially all of the fossil fuels on earth will be consumed—oil, natural gas, and coal. Presumably, whatever fuels do remain at that point will be reserved for their highest and most valuable purposes like making crude oil into plastics and pharmaceuticals, not burning it in 15% efficient internal combustion engines.

Consider the following world model for all fossil fuels:

Source: "Olduvai Revisited 2008," The Oil Drum, by Luís de Sousa and Euan Mearns. Cumulative peak is Data sources: Jean Laherrère for natural gas, Energy Watch Group for coal and The Oil Drum for oil. [This is an exceptional study and I recommend it to my readers!]

By the end of this century then, a mere 90 years from now, we’ll need to have an infrastructure that runs exclusively on renewably generated electricity, biofuels, and possibly nuclear energy. That’s where we’re going.

Fortunately, there is more than enough available renewable energy to meet all of our needs, if we can harness it. Unfortunately, we’re starting from a point at which less than 2% of the world’s energy comes from renewables like wind, solar and geothermal.

Hydro provides about 6%, and nuclear about 6%, but for reasons too numerous to get into here, some of which my longtime readers have already heard, I don’t believe either source will increase much in the future, and both could actually decline.

Our challenge then is to make that 2% fraction grow to replace about 86% of the world’s current primary energy, in 90 years or less.

We are currently at peak oil, a short, roughly 5-year plateau which goes into terminal decline around 2012. All fossil fuel energy combined peaks around 2018, less than a decade from now.

All strategies for accommodating the fossil fuel decline require decades to have any significant effect. The now-iconic study "Peaking of World Oil Production: Impacts, Mitigation, & Risk Management" (Hirsch et al., 2005) demonstrated that it would take at least 20 years of intensive, crash-program mitigation efforts to meet the peak oil challenge gracefully. Another study, "Primary Energy Substitution Models: On the Interaction between Energy and Society," (C. Marchetti, 1977) showed that it generally takes decades to substitute one form of primary energy for another, and 100 years for a given source of energy to achieve 50% market penetration.

Therefore, we are going to have to accomplish most of the renewable energy revolution in a scenario of ever-declining fuel supply. In just 50 years, we’ll be working with about half our current energy budget. So in fact we may only have about 50 years to build most of the new renewable energy and efficiency capacity we will need to get us through the end of the century.

Another important factor is that exports will fall off much faster than total supply. (See my article on the oil export crisis from last year.) Foucher and Brown (2008) have shown that the world’s top five oil exporters could approach zero net oil exports by around 2031. Net energy importers like the US could be increasingly starved for fuel as decline sets in and accelerates, and net energy exporters could wind up shouldering much of the burden of new manufacturing. This factor means that we will have to front-load as much of our development as possible.

The final and most important factor is population. The few population models that actually take fossil fuel depletion into account assume that global population increases roughly out to the global fuel peak, and then stabilizes at that level or declines naturally while economic development promotes lower fertility rates and renewables and energy efficiency increase to fill the gap of declining fossil energy. I understand why this assumption is made—because the alternative is too ghastly to contemplate—and for the immediate purpose of this article I will go along with it. I will note however that history and scientific observation of populations suggest some sharp episodes of decline are more likely, and in my estimation we will end this century with a considerably smaller population than anyone forecasts, at some level well below today’s.

How, then, can we replace or offset through efficiency at least 40% of our current energy supply with renewables in the next 50 years, while fuel prices are rising and the global economy is flat or shrinking due to a lack of fuel?

Seven Paths to Our Energy Future

A proper model for achieving this goal would be a very large undertaking, the sort of thing that should be done by a team of experts with a budget. (Is anybody at the Department of Energy listening?) But I can identify some key pathways that are, in my estimation, no-brainers. Because the solutions going forward will be quite different for each country, I will limit my recommendations to the US.

1: Rail. Rail should be Priority 1, and should be granted the largest portion of public funding. We should begin as quickly as possible with light urban rail, and work over the next 40 years to build a comprehensive high-speed long-distance rail system.

Rail is by far the most efficient form of overland transportation we know, and moving people out of their cars and freight off the roads will yield real and immediate savings in liquid fuel consumption. Not only will this help alleviate America’s need for rapidly declining oil exports, it is a proven, fairly low-tech, sustainable and workable solution that would allow renewably generated electricity to be phased in over time with minimal disruption.

2: Rooftop Solar PV. Utility scale projects like giant solar farms in the desert and giant wind farms in the Midwest (or offshore) all face serious hurdles in siting, permitting, environmental impact, and transmission capability. Rooftop photovoltaic (PV) solar systems face no such issues and can be deployed right now, building capacity incrementally over time. PV has been proven in the field commercially for over 30 years and, speaking as a former residential and small commercial solar designer, I know that it can provide 50-100% of the needs of most small buildings.

Rooftop PV also has a capital advantage. Whereas utility-scale solar and wind projects need to secure large power purchase agreements in order to raise enormous amounts of capital that will be tied up for decades, small rooftop PV systems are purchased outright by the end-users, assisted by ratepayer-funded incentive systems. Simply getting projects done is considerably easier.

From a funding perspective, rooftop PV is arguably one of the easiest sources we can develop, and options are proliferating. Cities like Berkeley and San Jose are offering municipal bonds to finance local projects, which keeps the financing small, local, and low-risk. Third-party financing companies are springing up all over the country, making it possible for home and business owners to put solar on their roofs with no out-of-pocket expenses and pay them off at the same rates or less than they’re already paying to utilities, with nearly zero risk to all parties. End-users enjoy an additional benefit of having a known, fixed cost for their future power, even as fossil fuel prices skyrocket.

Another very important advantage is that rooftop PV is distributed, which contributes to the resiliency and robustness of the grid. In most modern neighborhoods, no grid upgrading is needed to support rooftop solar systems. More distributed power generation also means fewer points of failure: a cloud over here is compensated by clear sky one mile away. It also enables micro-islanding, which would allow most of the grid to stay up when there is an outage, instead of taking vast chunks of the country’s grid down along with it as we have seen in the recent past.

Utilities also win with rooftop PV, because it means they don’t have to spend an enormous amount of effort and money in search of enough clean, green kilowatt-hours to meet their renewable portfolio standards, nor spend it on beefing up their grids. It essentially costs utilities zero to take up energy produced this way; in fact it can be a net benefit to them because the homeowner ends up paying for the new smart meters they plan to deploy across their grids anyway (at a cost of tens of millions of dollars).

Feed-in tariffs (FiTs) that pay a premium for kilowatt-hours generated by rooftop PV have been employed with great and immediate success in Germany and Japan, to the point where both programs will be largely phased out within the first decade. Support for a national FiT in the US is still weak, but I believe it could become a reality if the public were educated about the success it has enjoyed elsewhere in the world.

3: Alternative Vehicles. Since reconfiguring our urban topology around transit and deploying light rail will take decades, we will need some transitional solutions that still allow us to get around in cars for a good many years. All-electric and plug-in hybrid electric vehicles are a two-fer: They can take advantage of growing renewable electricity supply, and they can function as a giant, distributed battery for intermittent renewable sources using vehicle-to-grid (V2G) technology. In time, V2G could provide the final link that allows renewable energy to fully displace fossil fuels.

We will need to begin building the electric vehicle charging infrastructure as quickly as possible to accommodate these new vehicles, but it needn’t be any more complicated than deploying a new row of parking meters. This I think is a good and proper use of public funding. The automakers themselves should be able to find adequate funding via the private sector, with perhaps a modicum of federal support for research to jump start next-generation development of batteries and propulsion systems.

Compressed natural gas vehicles are another transitional solution that would take advantage of domestic gas supply while cutting demand for imported crude.

Biofuels may also play a role, although I continue to be skeptical about how much they can truly achieve once net energy (EROI) and food-vs.-fuel tradeoffs are taken into account. Corn ethanol fails these tests, but to the extent that cellulosic biofuels pass them, they could take a substantial bite out of our demand for petroleum. Still, it will take a decade or more to scale it up to significant levels.

Before the global economic downturn, our replacement rate was about 14 million new cars and light trucks per year. We have about 250 million such vehicles now. At that rate (we’re well down from it now), it would take 18 years to replace the fleet, but we probably won’t maintain that rate while the economy shrinks and fuel prices rise. Therefore we should concentrate on a rapid, near term deployment of alternative vehicles, before it gets prohibitively expensive and difficult to do so, even if they wind up having all the sex appeal of a mass produced WWII Jeep.

Ideally, we will only have to replace a fraction of the current fleet, with the rest of the traffic having been moved to rail.

4: Efficiency. Most of the efficiency gains we can make are thermal: reducing the energy it takes to heat and cool buildings. These gains ultimately translate into less coal and natural gas demand, so they will do little to reduce our demand for oil, which must be our first priority. In the long run however, efficiency must make up for any shortfall in renewable energy production, so it must be pursued continually over many decades.

More efficient regular gasoline and diesel vehicles also belong in this category, and may reduce our dependence on oil if they are sufficiently efficient and the gains aren’t nullified by the Jevons paradox. In my view, anything under 25 MPG is simply pathetic at this point, and undeserving of any federal support. Incentives for more efficient ICE vehicles should be geared to produce the greatest possible gains in fuel economy, not the watered-down "Cash for Clunkers" bill we got, which will ensure another several years’ worth of inefficient SUV production.

5: Utility Scale Renewables. Rooftop PV may be able to fill the short-term supply gap if aggressively pursued, but in the long term we’ll need every renewable kilowatt-hour we can get. We’ll need large solar plants across the Southwest, and huge wind farms in the Midwest and offshore. Geothermal and marine power can also make major contributions in time, but they’re babies now, and will need public guarantees and funding to reach the level where they are commercially viable technologies.

6: A Beefier, Smarter Grid. In order to carry all the new renewable power, we’re going to need a bigger, more resilient, and smarter grid. The good news is that we already have most of the technologies we need in this area. All that we lack is the will and the funding to put it in place. In the same way that it took federal funding and initiative to create the interstate highway system, the grid will also probably need to be nationalized and its enhancement funded publicly in order to meet this challenge.

A key element of the new grid will be long-distance high-voltage direct current (HVDC) power lines to transmit the power from the large utility scale projects to the cities where it’s needed. This must be on the short- to medium-term agenda since it must be ready to take on real capacity within 20 years and be nearly full-blown within 40 years.

7: Keep Drilling. If we back off too much too soon from oil and gas production, it could leave us without adequate or reasonably priced fuel to accomplish this transformation, and sink the entire effort. I think we’ll need as much oil and gas (and to a lesser extent, coal) as we can possibly produce in order to pull it off. Just imagine how difficult it will be to produce a solar panel or a large wind turbine using only renewably generated electricity to mine the raw ores, crush them, transport them, smelt them down and turn them into stock, transport them again and turn them into end-products, then transport them a final time and install them. I think it’s safe to say that we have no idea how to do all that without liquid petroleum fuels.

The twilight years of hydrocarbon fuels are essentially upon us, but we’ll need them more than ever as they peak out and decline. We will have to keep drilling, and the oil business will have to be able to turn a fair profit.

At the same time, I have long maintained that after a nearly a century of commercial operation, the petroleum businesses should be able to get by on its own, without public subsidies of any kind. If that means the price of fuels goes up, then so be it. We’re going to have to start paying a fair value for those finite, rapidly disappearing resources some day, and price increases will only encourage efficiency and alternatives.

Just Do It

Turning these conceptual pathways into action will not be easy, and we may be forced into action before we have perfect clarity about where we’re going and what it’s all going to cost. Yet I have no doubt that if we move on these seven pathways as quickly as possible, we will make progress in the right direction. There will be time to fine-tune it later.

Over the long term, the economics of energy are clearly in favor of renewables. The costs of producing and burning fossil fuels can only increase, and the costs of renewable energy will fall for decades before stabilizing.

Finding the money to rebuild so much of our infrastructure will no doubt be a challenge. But if we’re willing to put a $2.5 trillion debt burden on the future to bail out the financial system, and untold trillions more to provide military protection for the oil resources that remain, perhaps it’s just a question of priorities. I have no doubt that the money would be better spent on building an energy infrastructure that will actually sustain us.

The successful pathways are the profitable pathways. Think rail, small solar PV, alt vehicles, efficiency, utility renewables, grid, and drill, baby, drill.

Until next time,

Chris

Energy and Capital