is a senior grow at the farm. >> photosynthesis occurs at the two wavelengths, the red and blue. 60 and 40 nanometres. we are saying "here is the light that you really, really, really light." touch these lights. feel how cool they burn up top. hot. >> they don't generate a lot of heat. you can put them closer to the plants and stack the trace. we have 10 levels, we could probably get 15. this is a mint. taste that. tell me how you like it. >> reporter: so good. >> what is most amazing is how dark it is, and you pull it out into the light is see how green it becomes. >> reporter: warehouse growers are not the only ones turning to l.e.d.s, here researchers are testing them, to see if they can give plants a boost on short winter days. >> this opens possibilities. >> kerry mitchell is a professor of applicant physiology. >> we are showing that you can save considerable payments of electrical power using l.e.d.s. that will make it economically feasible for greenhouse growers to grow plants like the high wire tomatoes in the off season. >> researchers are studying recipes. by changing the

through photosynthesis plants make sugars that they use for energy to grow. some of those sugars are bonded together and stored creating starches, like the starch in a corn kernel, that can be used later for energy. these starches are easily broken down making them an attractive source for ethanol conversion. but some sugars are bonded differently, into long chains, like steel girders within plant cell walls. specif ically, there are three primary components of biomass -- cellulose, hemicellulose and the polymer lignin which fills the remaining spaces in the plant cell wall. plants evolved so that these materials would last a long time and be chemically difficult to break down, making the biomass conversion process challenging. nrel has created a pilot plant to test ways to improve the process of breaking down the cellulosic material and make the sugars available for fermentation. the first step in the process is pretreatment. aden: nature has really made these materials to be resistant to being broken down. so that's why we have to do some preprocessing to b