After four weeks of the first Wonkblog CrowdSourced, there is a consensus! Asked to explain what you view as the most promising energy source for America's economic and environmental future, you favored one answer, heavily, above the others: Low energy nuclear reactions, or cold fusion. Nine of the top ten vote-getters favored this answer. (Perhaps with an assist from the website, which urged readers to participate).

It is obvious why the possibility would be attractive: A successful LENR technology would allow practically unlimited energy production without carbon emissions or the nuclear waste that results from fission-based nuclear reactors. It's also the case that there is no such technology on the immediate horizon; researchers are far from turning cold fusion from a conceptual idea into a workable energy source.

Here's what a couple of the cold fusion enthusiasts had to say at the CrowdSourced, along with those who embraced other solutions as offering the most immediate promise for America's energy future. (Minor spelling and grammatical fixes have been made)

Writes reader Tom888:

There is little doubt that the future energy will be LENR, aka cold fusion. The field developed off the mainstream over the past years and we are at a point where commercial applications are being prepared for roll out now by several companies. This is mainly engineering and inventor driven, whereas basic science is lagging behind understanding the phenomenon. Nevertheless, the effect is indisputable now and the prospect is clean, unlimited source of thermal energy at very low cost. Today, June 03, this subject is being discussed at the EU in Brussels - questions are funding and how to move forward. In US, the company National Instruments is involves in supplying control software for LENR reactors, Siemens is looking at it, research is being done at many places (U of Missouri, NAS, SRI...). Several companies in US announced commercial LENR heaters within the coming months.
Those reactors are typically small, table top devices, overall low-tech, which can be bundled to larger units for heating, steam and electricity generation. This puts an end to CO2 problems and oil wars.

And, writes PeterRoe,

While it makes sense to continue to use existing 'renewable' energy sources such as solar, hydro and tidal power where available, all these, together with fossil fuels and nuclear will soon be obsolete. The energy source of the future is the phenomenon of cold fusion, also known as LENR etc.
Before skeptics dismiss this as fantasy, they need to do a bit of research. Several parties have recently claimed breakthroughs at kilowatt levels from cold fusion reactors including Brillouin, Defkalion Green Technologies and Leonardo Corporation (Andrea Rossi), and a number of very serious researchers are reporting positive results.
The current leader of the field seems to be Rossi, who recently had one of his devices tested by a group of independent scientists, under the auspices of a major Swedish power consortium. The test results clearly confirmed his claim that he has invented a practical cold fusion reactor. Through his agent, he is also offering to install a 1MW thermal plant free of charge to a suitable host organisation, in order to publicly demonstrate the technology in action.

Here are some leading vote-getters outside of the cold fusion crowd.

Reader JKammerer makes the case for greater efficiency as the path toward a more economically and environmentally sustainable energy future.

The single best source for energy in America is ignored by this question, as it almost always is: Increased Efficiency. Energy efficiency technology (such as cool roofs) exists today that allows Americans to significantly reduce their use of energy in their homes and businesses, but as there is no massive lobby on behalf thereof, these solutions are ignored by our legislators and the media. Reduction in demand effectively functions as an increase in supply. Reducing individual usage by increasing adoption of energy efficient technology offers shovel ready American jobs, reduced carbon footprint, money in homeowners pockets, and reduced foreclosure rates for energy efficient homes. Increasing energy efficiency of buildings is the single best energy policy America can have today. This is a win-win for everyone.

And, argues CALady, losing less power in transmission lines would be a great place to start.

Improving the efficiency of electrical transmission lines could have the most immediate impact. With 50% of electricity lost during transmission, we're wasting half of whatever source we're using to generate it.

Reader DuffWorks thinks geothermal energy is underrated.

Geothermal must be un-sexy in the extreme to get as little attention and investment as it does. But there it is, the dependable thermal gradient down into the ground. We don't have to tap the really hot stuff to generate energy, just the gradient down a few hundred feet. Come on tech guys, make it sexier.

And RonWagn urges us not to forget the promise of shale gas.

Natural gas is the revolutionary force in energy that is changing everything. It costs a small fraction of what oil and gasoline does, yet burns cleaner and allows engines to last longer. It pollutes far less than coal, and is far less expensive than nuclear, wind or solar. It is a good support for wind and solar if they are desired though, because it is not an intermittent source and can be turned off and on quickly, unlike coal and nuclear. Few people have any concept of the vast amount of natural gas that is available from many sources such as fracking, biogas, and methane hydrates, which have an estimated ten times as much as land based forms.

Have ideas of your own? It's not too late to contribute them, or to upvote those entries you find most compelling.

Meanwhile, this has been a fun experiment and we'll likely do it again. Topics we are considering include how falling energy costs might affect the economy, what the prospects are for a continued moderation in health care costs, and what policies and strategies might best improve job creation in the U.S. in the years ahead. Head to the comments section to let us know which of these you find most appealing, or to nominate your own ideas for a future CrowdSourced feature.