Five Delayed Cleantech Innovations 2010 Still Won't Bring

It's the end of both a year and a decade, during which time the renewable energy industry has risen from the ashes of the Reagan-era cutoff of energy research funding and made rapid year-over-year advances. Despite the failure of global leaders to reach an agreement at Copenhagen, the future of clean energy technology seems assured.

Be that as it may, cleantech is often overhyped, whether by anti-coal and oil advocacy groups or by companies who hope to make a mint on unproven technology. But inflated claims are ultimately harmful to the industry -- in energy, there are no easy solutions.

So every once in a while, a reminder of the realities can be helpful. To that end, here's a list of five over-hyped areas in cleantech that won't see much development next year -- and possibly beyond. For a wider end-of-decade view, check out my colleague Kirsten Korosec's list of the top energy stories of the past ten years.

Cellulosic ethanol --The work of Mascoma, Range Fuels and other ethanol startups looks promising. Plants are expected to come online in 2010. Is cellulosic ethanol finally ready to get started?

It would be great to feel some optimism about the future of cellulosic ethanol, but that would entail ignoring the past, littered as it is with the blown targets and unfulfilled promises of ambitious startups. Grist points out that the few plants opening next year are mostly small test units. Second generation ethanol remains a field fraught with engineering problems and the realities of chemistry and physics; biomass often doesn't carry much energy to begin with, and turning it into a convenient liquid form consumes an inconvenient amount of energy. Until someone backs up their claims with reality, we should be putting more effort into bioplastics.

Solar grid-parity -- Encouraging word has come from Solyndra, a solar company that has filed for an IPO, that it thinks it's nearing "grid parity", the point at which solar power is as cheap as coal, gas or nuclear. But as with cellulosic ethanol, solar companies have made this claim many times, and any company hoping to convince investors to buy its stock will tend to be overly optimistic. Solyndra's actual numbers suggest it still faces many challenges.

A more trustworthy guide might be First Solar, the solar industry cost leader. The company has been trimming its production costs steadily, but with installation costs added in for its solar panels, it still has a way to go to reachgrid parity.

Hot rock geothermal -- Geothermal energy was beginning to look like the dark horse of renewable energy. Harvesting energy from underground is largely a matter of drilling a deep enough hole and finding a way to pump water in and let it return as steam to drive a generator. Or that's what appeared to be the case, anyway.

The most promising geothermal startup, Altarock Energy, had a rough 2009. First, the New York Times pointed out that deep drilling by geothermal companies can cause earthquakes. In September, Altarock had drilling difficulties and gave up its first site. Finally, just before Christmas, both Altarock and another Swiss project were forced to give up on drill holes. Geothermal isn't dead, but it will take longer to develop than its proponents had hoped.

A sensible plan for nuclear -- The year has been full of stories about nuclear technologies being revived (see some of our coverage here, here and here). But funding for both new research and new plants remains severely limited. Nuclear is a difficult technology to pull off, and it needs the full support and attention of the government to flourish.

While the Obama administration seems willing to reverse some of the hostility past administrations have shown toward nuclear power, it's also not providing enough support for a true resurgence -- perhaps the fault of anti-nuclear holdouts who continue to advocate against nuclear.

Carbon capture and sequestration -- This one almost goes without saying, but given the constant calm assurances from political officials that carbon capture is the future of the coal industry, it's worth pointing out again that CCS is a field of unanswered questions and difficult economic prospects. It's not just an unknown for next year; CCS may never succeed.