The field of research for cleaner alternatives to fossil fuels is without a doubt one of the hottest in science today. There is, of course, a good reason for that: several countries have declared climate emergencies and while declarations by themselves cannot solve a problem, research may—and does—lead to solutions. Yet not all ideas pan out as

In a recent story, Bloomberg’s Will Wade listed six failed cleaner energy ideas that never made it to commercial scale use for one reason or another. Typically these reasons come down to cost, but sometimes there are other challenges, such as regulation.

Excessive cost was what brought down ideas such as the copper-indium-gallium-selenide solar cells, for example. They were a viable alternative to silicon when silicon was expensive but when demand spurred greater production, costs came down, while the costs of CIGS cells couldn’t. That was the end of that idea.

We might be seeing something similar in batteries. Lithium-ion is the dominant technology and although alternatives are in development, so far none of these has made it beyond headlines and into commercial production. This doesn’t mean none of them will ever have the chance to take li-ion batteries on the market field. Some probably will. It will just take time.

Another green idea whose life ended prematurely because of too high costs was the idea of cellulosic biofuels. A company tried to make these from wood chips at a time when oil was trading above US$100 per barrel. Even at this level, however, the biofuel cost about US$6 per gallon to produce, which made it uncompetitive even at that price of oil.

Solar power towers are also in the past even though there are a few still functioning. Unlike the much more common solar arrays, these installations feature a central tower with a boiler on top, where the power from the panels around flows in, heats up the water and produces steam, which in turn produces electricity. This, as one would guess, is expensive. The Ivanpah solar power tower project cost US$2.2 billion for a capacity of less than 380 MW. Oil Flat, Seesaws On Demand Fears

Cost may be the most common reason why an otherwise good idea gets buried, but sometimes it’s not that. Sometimes it’s efficiency that makes a good idea impractical. This was the case with small wind turbines, mounted on rooftops like household solar installations. These turbines rotated around a vertical axis, which meant they produced less power. That meant less efficiency and it also mean higher costs—higher costs seem to be always in the picture with failed ideas.

Regulation could also be a challenge. This is what the company behind a giant flywheel energy storage project learned the hard way. Its carbon fiber cylinders, each weighing more than a ton, would rotate at a rate of 16,000 turns per minute floating on magnetic fields. They could store energy and release it to the grid on demand, but the company, Beacon, couldn’t charge different rates to different utilities because regulation doesn’t allow it. Before that changed, Beacon went under. Now, energy storage is almost all about batteries.

Bloomberg’s Wade also includes in his overview tidal power. Tidal power is technically dead. In fact, in the UK there are projects that might prove viable. The problem with tidal power is that the sea is a challenging environment for a submerged power generation system. Maintenance costs would have to be quite high, but it’s early days and we’ll have to wait and see how this works out—if it works at all.

By Mohsen Shahvar